April 2014 

NASA/CR–2014-218187 

Protective Skins for Composite Airliners 

Vicki S. Johnson, Richard L. Boone, Shannon Jones, 

Vandana Pendse, and Greg Hayward 

Cessna Aircraft Company, Wichita, Kansas 
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Hampton, Virginia 23681-2199 under Contract NNC10CA36C 

 

April 2014 

NASA/CR–2014-218187 

Protective Skins for Composite Airliners 

Vicki S. Johnson, Richard L. Boone, Shannon Jones, 

Vandana Pendse, and Greg Hayward 

Cessna Aircraft Company, Wichita, Kansas 
Available from: 

NASA Center for AeroSpace Information 

7115 Standard Drive 

Hanover, MD 21076-1320 

443-757-5802 

Acknowledgments 

This work was made possible by funding from NASA’s Fundamental Aeronautics 

Program/Subsonic Fixed Wing Project through N+3 Phase 2 contract NNC10CA36C 

which was issued through a NASA Research Announcement (NRA). The FAP/SFW 

project is part of NASA’s Aeronautics Research Mission Directorate (ARMD). 

The authors would like to acknowledge and appreciate the support of the FAP/SFW. In 

particular, Dr. Mia Siochi of NASA-Langley Research Center has provided valuable and 

consistent oversight of the research project in her role as Contracting Officer’s Technical 

Representative. Melissa Merrill, Contracting Officer, of NASA-Glenn Research Center 

and William DeLong (Cessna Contracts) of Cessna Aircraft Company have ably kept the 

contract in control and moving forward smoothly. Finally Kimlan T. Pham, the Subsonic 

Fixed Wing NRA Manager, and Richard A. Wahls, Project Scientist for the FAP/SFW 

project, have provided thought-provoking questions and input during the research project. 

The use of trademarks or names of manufacturers in this report is for accurate re porting and does not constitute an 

official endorsement, either expressed or implied, of such products or manufacturers by the National Aeronautics 

and Space Administration.
Table of Contents 

 Table of Contents ......................................................................................................................i

 Table of Figures ....................................................................................................................... v

 Table of Tables .......................................................................................................................xiv

1 Introduction .............................................................................................................................. 1

2 Background .............................................................................................................................. 2

3 STAR-C2 Concept and Technical Approach ........................................................................... 4

4 Metrics ...................................................................................................................................... 9

4.1 Areal Weight .................................................................................................................. 10

4.2 Cost................................................................................................................................. 12

4.3 Thickness ........................................................................................................................ 13

4.4 Number of Layers and Unique Materials ....................................................................... 13

4.5 Visible Damage .............................................................................................................. 13

4.6 Installation and Repair ................................................................................................... 13

5 Requirements .......................................................................................................................... 14

5.1 Energy Absorption ......................................................................................................... 14

5.2 Smoothness..................................................................................................................... 18

5.2.1 Waviness ................................................................................................................. 19

5.2.2 Steps ........................................................................................................................ 19

5.2.3 Gaps ........................................................................................................................ 20

5.3 Conductivity ................................................................................................................... 20

5.3.1 Direct Effects of Lightning ..................................................................................... 21

5.3.2 IEL/HIRF ................................................................................................................ 21

5.4 Cosmetic ......................................................................................................................... 21

5.5 Heat and Moisture .......................................................................................................... 22

5.5.1 Reflectivity .............................................................................................................. 23

5.5.2 Moisture .................................................................................................................. 25

5.6 Thermal .......................................................................................................................... 25

5.7 Acoustic .......................................................................................................................... 25

5.8 Environmental Considerations ....................................................................................... 26

5.8.1 Temperature ............................................................................................................ 26

5.8.2 Fluids Susceptibility................................................................................................ 26

i
5.8.3 Salt Fog ................................................................................................................... 26

5.9 Additional Considerations .............................................................................................. 26

5.9.1 Conformability ........................................................................................................ 26

5.9.2 Reparability ............................................................................................................. 27

5.9.3 Durability ................................................................................................................ 27

6 Materials ................................................................................................................................. 27

6.1 Impact Absorbing/Spreading.......................................................................................... 28

6.2 Conductive Films ........................................................................................................... 36

6.2.1 Smoothness ............................................................................................................. 36

6.2.2 Lightning Strike ...................................................................................................... 36

6.2.3 Cosmetic ................................................................................................................. 36

6.2.4 Reflection ................................................................................................................ 36

7 First-Generation Test Articles ................................................................................................ 40

7.1 Test Articles ................................................................................................................... 40

7.1.1 Material Definition.................................................................................................. 40

7.1.2 Drawings ................................................................................................................. 43

7.1.3 Manufacturability .................................................................................................... 51

7.1.4 Base Panel Inspection ............................................................................................. 58

7.1.5 Inspection for Voids and Porosity........................................................................... 60

7.1.6 Porosity ................................................................................................................... 62

7.1.7 Base Substrate Panel Assignment to Test Article Category ................................... 67

7.2 Impact ............................................................................................................................. 67

7.2.1 Requirements .......................................................................................................... 67

7.2.2 Attaching Protective Skins to Base Panels ............................................................. 68

7.2.3 Impact Test Facility ................................................................................................ 72

7.2.4 Test Objectives........................................................................................................ 75

7.2.5 Test Results ............................................................................................................. 76

7.2.6 Data Analysis ........................................................................................................ 101

7.3 Electromagnetic Effects ............................................................................................... 110

7.3.1 Transmissivity ....................................................................................................... 110

7.3.2 Indirect Effects of Lightning ................................................................................. 122

7.3.3 Direct Effects of Lightning ................................................................................... 131

7.3.4 Electromagnetic Effects Results ........................................................................... 138

ii
7.4 Aesthetics and Smoothing ............................................................................................ 138

7.4.1 Smoothness ........................................................................................................... 139

7.4.2 Lightning Strike Panel Visual Inspection ............................................................. 154

7.4.3 Thermal Testing Results ....................................................................................... 157

7.5 Implications for Final STAR-C2 Panels ...................................................................... 161

7.5.1 Combined Test Results ......................................................................................... 161

7.5.2 Initial Thoughts on Final Material Selection ........................................................ 165

8 Second-Generation Test Articles ......................................................................................... 165

8.1 Test Article Definitions ................................................................................................ 165

8.1.1 Material Definition................................................................................................ 165

8.1.2 Drawings ............................................................................................................... 168

8.1.3 Manufacturability .................................................................................................. 175

8.1.3.1 Protective Skin Warpage during Cure ............................................................... 178

8.1.3.2 LDS-50 Fragile Material ................................................................................... 179

8.1.3.3 Integument Film Bubbles and Wrinkles............................................................ 179

8.1.4 Base Panel Inspection ........................................................................................... 179

8.2 Impact ........................................................................................................................... 184

8.2.1 Requirements ........................................................................................................ 184

8.2.2 Test Objectives...................................................................................................... 185

8.2.3 Test Articles .......................................................................................................... 185

8.2.4 Test Results ........................................................................................................... 186

8.2.5 Data Analysis ........................................................................................................ 202

8.2.5.1 NDI Analysis ..................................................................................................... 202

8.2.6 Impact Depth Analysis .......................................................................................... 204

8.2.7 Final Thoughts on Impact Testing Results ........................................................... 207

8.3 Electromagnetic Effects ............................................................................................... 207

8.3.1 Test Articles .......................................................................................................... 207

8.3.2 Transmissivity/Shielding Effectiveness (HIRF) ................................................... 207

8.3.3 Indirect Effects of Lightning ................................................................................. 218

8.3.4 Direct Effects of Lightning ................................................................................... 222

8.4 Aesthetics and Smoothing ............................................................................................ 251

8.4.1 Test Panel Assembly ............................................................................................. 252

8.4.1.1 Aesthetics and Smoothing Panels ..................................................................... 252

iii
8.4.1.2 Acoustic Panels ................................................................................................. 256

8.4.2 Aesthetic and Smoothing Test Results ................................................................. 256

8.4.2.1 Aesthetics and Smoothing Panels ..................................................................... 256

8.4.2.2 Acoustic Panels ................................................................................................. 274

8.5 Thermal Testing Results............................................................................................... 293

8.6 Acoustics ...................................................................................................................... 299

8.6.1 Test Panel Definition ............................................................................................ 299

8.6.1.1 Base Substrate Panel Definition and Actual Construction ................................ 299

8.6.1.2 Protective Skin Definition ................................................................................. 303

8.6.2 Testing................................................................................................................... 316

8.6.2.1 Test Facility ....................................................................................................... 316

8.6.2.2 Test Setup .......................................................................................................... 316

8.6.2.3 Test Procedures ................................................................................................. 322

8.6.2.4 Test Results ....................................................................................................... 322

8.6.3 Acoustics Conclusion............................................................................................ 333

9 Conclusions .......................................................................................................................... 333

10 Recommendations ................................................................................................................ 334

11 References ............................................................................................................................ 336

Appendix A - Links to Information About Materials Used ........................................................ A-1 

Appendix B - First-Generation Base Panel Inspection Results .................................................. B-1 

Appendix C - First-Generation Thermography Report ............................................................... C-1 

Appendix D - First-Generation Test Article Impact Testing Pictures ........................................ D-1 

Appendix E - First-Generation Shielding Effectiveness Test Setup Pictures .............................. E-1 

Appendix F - First-Generation Shielding Effectiveness Test Data ............................................. F-1 

Appendix G - First-Generation Indirect Effects Test Data ......................................................... G-1 

Appendix H - First Generation Direct Effects Report (DNB Report) ........................................ H-1 

Appendix I - First-Generation Direct Effects Pictures (Cessna) .................................................. I-1 

Appendix J - Second-Generation Thermography Report ............................................................. J-1 

Appendix K - Second-Generation Indirect Effects Test Data .................................................... K-1 

Appendix L - Second-Generation Direct Effects Test Data and Pictures (DNB Report) ............ L-1 

Appendix M - Acountic Test Data Uncertainty .......................................................................... M-1 

iv
Table of Figures 

Figure 1: The 2035 20-passenger advanced airliner. ..................................................................... 2

Figure 2: Conventional composite fuselage buildup. .................................................................... 5

Figure 3: Functional decomposition of conventional composite fuselage. .................................... 5

Figure 4: Potential concept for 2035 composite. ........................................................................... 6

Figure 5: Functional arrangements for primary composite structure with protective 

 skins made up of two layers. ........................................................................................... 7

Figure 6: Candidate installation concept for a STAR-C2skin. ...................................................... 8

Figure 7: Front (outside) view of composite structure after bird strike. ........................................ 8

Figure 8: Rear (inside) view of composite structure after bird strike. ........................................... 9

Figure 9: Potential weight allocation for protective skins. .......................................................... 11

Figure 10: Final protective skin weight target and range. ........................................................... 12

Figure 11: Schematic diagram of design load levels versus categories. ...................................... 15

Figure 12: Threat assessment - ground support (copied from Reference 8). ............................... 17

Figure 13: Sample threat assessment fuselage drawing. .............................................................. 17

Figure 14: Projected areas of natural laminar flow (shown in blue)............................................ 18

Figure 15: Waviness limits. ......................................................................................................... 19

Figure 16: Reference geometry for steps. .................................................................................... 20

Figure 17: Reference geometry for gaps. ..................................................................................... 20

Figure 18: Average knock downs for AGATE prepregs from different environmental 

 conditions (copied from Reference 10) ....................................................................... 23

Figure 19: Absorptivity and emissivity characteristics of surfaces and coatings 

 (copied from Reference 12). ....................................................................................... 24

Figure 20: Functional arrangement for primary composite structure. ......................................... 28

Figure 21: Compression strength as a function of density for foam and honeycomb 

 core materials. ............................................................................................................. 33

Figure 22: Required sheet thickness for honeycomb and foam core materials. .......................... 34

Figure 23: Required core thickness for varying impactor sizes. .................................................. 35

Figure 24: Functional arrangement for protective skins with three layers. ................................. 35

Figure 25: Sample drawing for the impact panels. ...................................................................... 46

Figure 26: Sample drawing for the lightning strike panels. ......................................................... 48

Figure 27: Sample drawing for aesthetics and smoothing panels. ............................................... 50

Figure 28: Material manufacturing data sought for each material used. ..................................... 52

Figure 29: Substrate panel definition. .......................................................................................... 59

Figure 30: Base substrate panel length and width measuring locations. ..................................... 60

Figure 31: Eight base substrate panels in gantry undergoing ultrasonic inspection. ................... 61

Figure 32: Ultrasonic inspection of base substrate panel 1.......................................................... 61

Figure 33: Thermographic inspection of base substrate panel 1 (1st Derv. -0.42 & 0.94 sec). ... 62

Figure 34: Ultrasonic inspection of base panel 64. ...................................................................... 62

Figure 35: Thermographic inspection of base panel 64 (1st Derv. -0.3 & Peak 

 Ampl.-Pos 2nd Derv). .................................................................................................. 62

Figure 36: Ultrasonic inspection of base panel 23. ...................................................................... 63

Figure 37: Thermography image of base panel 23. ..................................................................... 63

Figure 38: UT image for base panel 159. .................................................................................... 64

v
Figure 39: Thermographic image for base panel 159. ................................................................. 64

Figure 40: 0° and 90° photomicrography analysis (first polish) for void content of 

 base panels 159 and 23. .............................................................................................. 65

Figure 41: 0° and 90° photomicrography analysis (second polish) for void content of 

 base panels 159 and 23. .............................................................................................. 65

Figure 42: 0° and 90° photomicrography analysis (third polish) for void content of 

 base panel 159. ........................................................................................................... 66

Figure 43: Base substrate panel porosity test results. .................................................................. 66

Figure 44: Front and back visual views of impact panel with protective skin adhered 

 to substrate panel......................................................................................................... 69

Figure 45: Front and back visual views of impact panel with protective skin not 

 adhered to substrate panel. .......................................................................................... 69

Figure 46: Thermography results for protective skin adhered to substrate panel. ....................... 69

Figure 47: Thermography results for protective skin not adhered to substrate panel. ................. 70

Figure 48: Thermography result for "inner" side of substrate not adhered to substrate panel. ... 70

Figure 49: Impact test fixture test bay definition. ........................................................................ 71

Figure 50: Impact test article mounting hole definition. .............................................................. 71

Figure 51: Underneath view of test bay with panel IM-32 mounted. .......................................... 72

Figure 52: Panel IM-100 installed on drop test support fixture. .................................................. 73

Figure 53: IM-62 installed in drop test support facility. .............................................................. 73

Figure 54: Impact Tube Test Fixture (side and top view). .......................................................... 74

Figure 55: Impact test fixture. ...................................................................................................... 75

Figure 56: Top side view of IM-100 after impact. ....................................................................... 77

Figure 57: Underneath view of IM-100 with 0.5" impactor embedded. ...................................... 77

Figure 58: Before and after impact views of the front and back of IM-100. ............................... 78

Figure 59: Initial ultrasonic inspection. ....................................................................................... 78

Figure 60: Thermographic inspection of IM-100. ....................................................................... 79

Figure 61: Unidirectional fiber splitting after impact. ............................................................... 110

Figure 62: Woven outer layers stop splitting and crack growth. ............................................... 110

Figure 63: Schematic of shielding effectiveness setup. ............................................................. 111

Figure 64: Horn antenna in the big chamber. ............................................................................ 111

Figure 65: Close-up view of horn antenna in big chamber. ....................................................... 112

Figure 66: Horn antenna in the small chamber. ......................................................................... 113

Figure 67: Horn antenna in the small chamber. ......................................................................... 113

Figure 68: Mode stirrer in the small chamber. ........................................................................... 114

Figure 69: Lightning strike panel edge treatment to facilitate grounding. ................................ 114

Figure 70: Test panel with copper tape to facilitate grounding. ................................................ 115

Figure 71: "L" frame drawing and article with test panel ready for testing. ............................. 115

Figure 72: Panel LS-4 (10 pcf PU core, 1/4" thick VATRM Innegra VARTM 

 LDS 50-01 0.007 psf aluminum Integument film) with and without 

 grounding to Al frame. ............................................................................................. 116

Figure 73: Shielding effectiveness of a base substrate panel compared to an 

 Al panel and open window. ...................................................................................... 116

vi
Figure 74: Different lightning strike materials with 1/4" 10 pcf PU core with Innegra S 

 impact spreading and Integument film (LS-1 - 0.016 psf expanded Al, 

 LS-2 - 0.029 psf expanded Copper foil, LS-4 - LDS 50-01 0.007 psf Al, 

 LS-5 - Integument with integrated LSP and PSA, LS-6 – Proprietary Spray 

 material). .................................................................................................................. 117

Figure 75: Different 1/4" thick impact absorbing materials with Innegra S and Integument 

 with integrated LSP & PSA (LS-5 – 10 pcf PU core, LS-12 – 20 pcf PU core, 

 LS-19 – 3 pcf metallic honeycomb, LS-26 – 6 pcf metallic honeycomb core; and 

 LS-28 – 7.9 pcf metallic honeycomb core). ............................................................. 118

Figure 76: Comparison of two different thicknesses of polyurethane core with same 

 lightning strike protection scheme (LS-4 1/4" and LS-9 - 3/4"). ............................. 118

Figure 77: Soric cores of various thicknesses (LS-33 - Soric XF 2 mm, LS-38 - Soric XF 

 6 mm, LS-40 - Soric LRC 2 mm). ............................................................................ 119

Figure 78: Different aesthetic films with same polyurethane core (LS-4 - Integument, 

 LS-41 – 3M 5004, LS-42 – Aptiv PEEK, LS-43 – Halar ECTFE, 

 LS-44 – Kapton film). ............................................................................................... 120

Figure 79: Panels with Innegra, LDS 50-01 LSP and Integument film (LS-4 – 10 pcf 

 PU core, LS-11 – 20 pcf PU core, LS-13 – 30 pcf PU core, LS-18 – 3 pcf 

 metallic honeycomb, LS-41 – 10 pcf PU core with 3M 5004 with PSA film 

 instead of Integument). ............................................................................................. 120

Figure 80: Panels with carbon nanotube lightning strike protection (two different densities). . 121

Figure 81: Effect of Polydamp hydrophobic melamine (3/4" thick) with PEEK skin - 

 no film. ...................................................................................................................... 122

Figure 82: Shielding effectiveness for all panels plus the base panel with aluminum 

 and open as the two bounds. ..................................................................................... 122

Figure 83: Complete IEL setup (test panel is between blue foam layers at far 

 right of picture). ....................................................................................................... 123

Figure 84: IEL setup - transformer with probe. ......................................................................... 123

Figure 85: IEL setup - transformer with cable bundle termination. .......................................... 124

Figure 86: IEL setup - termination............................................................................................. 124

Figure 87: IEL setup - panel, cable bundle, and transformer. .................................................... 125

Figure 88: IEL setup - panel with bulkheads. ............................................................................ 125

Figure 89: IEL input current waveforms with characteristics of interest identified. ................. 126

Figure 90: IEL voltage waveform. ............................................................................................. 126

Figure 91: A sample of the setup for direct strike on panel LS-2. ............................................. 132

Figure 92: A sample of post strike of 100kA on panel LS-2. .................................................... 132

Figure 93: Base substrate for aesthetic and smoothing test panels showing fasteners, 

 wire bundles, and doublers. ...................................................................................... 139

Figure 94: Aesthetic and smoothing base substrate panel holder. ............................................. 140

Figure 95: Application of stack-up with pressure roller. ........................................................... 140

Figure 96: Computed maximum panel deformation. ................................................................. 149

Figure 97: Computed deformation over 0.020” doubler. ........................................................... 150

Figure 98: Computed deformation over 0.040” doubler. ........................................................... 151

vii
Figure 99: Computed deformation over 0.1875” dowel. ........................................................... 152

Figure 100: Computed deformation over 0.25” dowel. ............................................................. 153

Figure 101: Thermal performance test setup – mounting frame. ............................................... 159

Figure 102: Thermal performance test setup – oven temperature. ............................................ 159

Figure 103: Thermal performance test setup – test in progress. ................................................ 160

Figure 104: Thermal performance of polyurethane core panels. ............................................... 160

Figure 105: Picture of Carbon ALS (carbon fiber fabric with interwoven aluminum 

 lightning strike protection wire)............................................................................. 166

Figure 106: Second-generation impact and aesthetics & smoothing test article drawing. ........ 169

Figure 107: Acoustics test article drawing (only second generation). ....................................... 170

Figure 108: Second-generation lightning strike test article drawing. ........................................ 171

Figure 109: Second-generation base substrate laminate drawing. ............................................. 173

Figure 110: Acoustics base substrate panel drawing. ................................................................ 174

Figure 111: Base substrate panel impact effect for uni-directional (left) and plain 

 weave (right) outer layer. ........................................................................................ 175

Figure 112: Manufacturing Process Steps for Innegra (left) and Carbon ALS (right) panels. .. 176

Figure 113: Manufacturing process steps for metallic core panel (left) and 

 Polydamp panel (right). .......................................................................................... 177

Figure 114: Post manufacturing warpage of protective skin FIM-2. ......................................... 178

Figure 115: Post manufacturing warpage of protective skin FAC-5. ........................................ 178

Figure 116: View of back of 48” x 48” base substrate panel with overlap. .............................. 184

Figure 117: Thermographic view of 24" x 24" base substrate panel with overlap. ................... 184

Figure 118: Before and after pictures of the front of FIM-0. ..................................................... 186

Figure 119: Before and after pictures of the back of FIM-0. ..................................................... 187

Figure 120: Before thermographic images of panel FIM-0. ...................................................... 187

Figure 121: After thermographic images of panel FIM-0. ........................................................ 187

Figure 122: Before and after pictures of the front of panel FIM-1. ........................................... 188

Figure 123: Before and after pictures of the back of panel FIM-1. ........................................... 188

Figure 124: Before thermographic images of panel FIM-1. ...................................................... 189

Figure 125: After thermographic images of panel FIM-1. ........................................................ 189

Figure 126: Before and after pictures of the front of panel FIM-2. ........................................... 190

Figure 127: Before and after pictures of the back of panel FIM-2. ........................................... 190

Figure 128: Before thermographic images of panel FIM-2. ...................................................... 191

Figure 129: After thermographic images of panel FIM-2. ........................................................ 191

Figure 130: Before and after pictures of the front of panel FIM-3. ........................................... 192

Figure 131 - Before and after pictures of the back of panel FIM-3. ........................................... 192

Figure 132: Before thermographic images of FIM-3. ................................................................ 193

Figure 133: After thermographic image of FIM-3. .................................................................... 193

Figure 134: Before and after pictures of front of panel FIM-4. .................................................. 193

Figure 135: Before and after pictures of back of panel FIM-4. ................................................. 194

Figure 136: Before thermographic images of panel FIM-4. ...................................................... 194

Figure 137: After thermographic images of panel FIM-4. ........................................................ 195

Figure 138: Before and after pictures of front of panel FIM-5. ................................................. 195

Figure 139: Before and after pictures of back of panel FIM-5. ................................................. 196

Figure 140: Before thermographic image of panel FIM-5. ........................................................ 196

viii
Figure 141: After thermographic images of panel FIM-5. ........................................................ 197

Figure 142: Before and after pictures of the front of panel FIM-6. ........................................... 197

Figure 143: Before and after pictures of the back of panel FIM-6. ........................................... 198

Figure 144: Before thermographic image of panel FIM-6. ........................................................ 198

Figure 145: After thermographic image of panel FIM-6. .......................................................... 199

Figure 146: Impact depths for the 0.5" impactor. ...................................................................... 204

Figure 147: Impact depths for the 1.0" impactor. ...................................................................... 205

Figure 148: Impact depths for the 1.75" impactor. .................................................................... 205

Figure 149: FIM-1 (left) and FIM-2 (right) after impacts. ........................................................ 206

Figure 150: FIM-4 (left) and FIM-5 (right) after impacts. ........................................................ 206

Figure 151: Aluminum panel installed in the window. .............................................................. 208

Figure 152: CFC panel installed in the window. ....................................................................... 208

Figure 153: FLS-1 panel installed in the window. ..................................................................... 209

Figure 154: FLS-2 panel installed in the window. ..................................................................... 209

Figure 155: FLS-3 panel installed in the window. ..................................................................... 210

Figure 156: FLS-4 panel installed in the window. ..................................................................... 210

Figure 157: FLS-5 panel installed in the window. ..................................................................... 211

Figure 158: FLS-6 panel installed in the window. ..................................................................... 211

Figure 159: Shielding effectiveness of a base substrate panel. .................................................. 212

Figure 160: Shielding effectiveness of Panel FLS-1 with and without software filter. ............. 213

Figure 161: Shielding effectiveness of lightning strike materials with 3mm Soric core 

 with base substrate panel compared to an Al panel and open window. ................. 213

Figure 162: Shielding effectiveness of panel FLS-6 with polydamp core with base 

 substrate panel compared to an Al panel and open window. ................................. 214

Figure 163: Shielding effectiveness of lightning strike material with 3mm Soric core and 

 Polydamp core with base substrate panel compared to an Al panel and 

 open window. .......................................................................................................... 215

Figure 164: Shielding effectiveness of lightning strike material with honeycomb and 

 polyurethane core with base substrate panel compared to an Al panel and 

 open window. ........................................................................................................... 215

Figure 165: Shielding effectiveness of lightning strike material with polyurathene core 

 with base substrate panel compared to an Al panel and open window. ................. 216

Figure 166: Shielding effectiveness of all panels with base substrate panel compared to 

 an Al panel and open window. ................................................................................ 216

Figure 167: Shielding effectiveness of all panels from 700MHz to 2 GHz with base 

 substrate panel compared to an Al panel and open window. ................................. 217

Figure 168: Shielding effectiveness of new base panel CFC new compared with the 

 old base panel .......................................................................................................... 218

Figure 169: Current calibration oscillogram input waveform with 616 A. ............................... 219

Figure 170: Voltage calibration oscillogram waveform with 800 V. ........................................ 219

Figure 171: Panel FLS-1 pre strike #1 (setup). .......................................................................... 223

Figure 172: Panel FLS-1 pre strike #1 (setup). .......................................................................... 223

Figure 173: Panel FLS-1 post strike #1. .................................................................................... 224

Figure 174: Panel FLS-1 pre strike #2 (setup). .......................................................................... 224

Figure 175: Panel FLS-1 post strike #1 and #2.......................................................................... 225

ix
Figure 176: Panel FLS-1 pre strike #3. ...................................................................................... 225

Figure 177: Panel FLS-1 post strike #1, #2, and #3................................................................... 226

Figure 178: Front of panel FLS-1 post strike #1, #2, and #3. .................................................... 226

Figure 179: Back of panel FLS-1 post strike #1, #2, and #3. .................................................... 227

Figure 180: Panel FLS-2 pre strike #1 (setup). .......................................................................... 227

Figure 181: Panel FLS-2 pre strike #1 (setup). .......................................................................... 228

Figure 182: Panel FLS-2 post strike #1. .................................................................................... 228

Figure 183: Panel FLS-2 pre strike #2 (setup). .......................................................................... 229

Figure 184: Panel FLS-2 post strike #1 and #2.......................................................................... 229

Figure 185: Panel FLS-2 post strike #1 and #2.......................................................................... 230

Figure 186: Front of panel FLS-2 post strike #1 and #2. ........................................................... 230

Figure 187: Back of panel FLS-2 post strike #1 and #2. ........................................................... 231

Figure 188: Panel FLS-3 pre strike (setup). ............................................................................... 231

Figure 189: Panel FLS-3 pre strike (setup). ............................................................................... 232

Figure 190: Panel FLS-3 pre strike (setup). ............................................................................... 232

Figure 191: Panel FLS-3 pre strike (setup). ............................................................................... 233

Figure 192: Panel FLS-3 post strike #1. .................................................................................... 233

Figure 193: Panel FLS-3 post strike #1. .................................................................................... 234

Figure 194: Panel FLS-3 pre strike #2 (setup). .......................................................................... 234

Figure 195: Panel LS-3 pre strike #2 (setup). ............................................................................ 235

Figure 196: Panel FLS-3 post strike #1 and #2.......................................................................... 235

Figure 197: Panel FLS-3 post strike #1 and #2.......................................................................... 236

Figure 198: Front of panel FLS-3 post strike #1 and #2. ........................................................... 236

Figure 199: Back of panel FLS-3 post strike #1 and #2. ........................................................... 237

Figure 200: Panel FLS-4 pre strike #1 (setup). .......................................................................... 237

Figure 201: Panel FLS-4 pre strike #1 (setup). .......................................................................... 238

Figure 202: Panel FLS-4 post strike #1. .................................................................................... 238

Figure 203: Panel FLS-4 pre strike #2 (setup). .......................................................................... 239

Figure 204: Panel FLS-4 post strike #1 and #2.......................................................................... 239

Figure 205 - Front of panel FLS-4 post strike #1 and #2............................................................ 240

Figure 206: Back of panel FLS-4 post strike #1 and #2. ........................................................... 240

Figure 207: Panel FLS-5 pre strike #1(setup). ........................................................................... 241

Figure 208: Panel FLS-5 pre strike #1(setup). ........................................................................... 241

Figure 209: Panel FLS-5 post strike #1. .................................................................................... 242

Figure 210: Panel FLS-5 post strike #1. .................................................................................... 242

Figure 211: Panel FLS-5 pre strike #2 (setup). .......................................................................... 243

Figure 212: Panel FLS-5 post strike #1 and #2.......................................................................... 243

Figure 213: Front of panel FLS-5 post strike #1 and #2. ........................................................... 244

Figure 214: Back of panel FLS-5 post strike #1 and #2. ........................................................... 244

Figure 215: Panel FLS-6 pre strike #1(setup). ........................................................................... 245

Figure 216: Panel FLS-6 post strike #1. .................................................................................... 245

Figure 217: Panel FLS-6 pre strike #2 (setup). .......................................................................... 246

Figure 218: Panel FLS-6 post strike #1 and #2.......................................................................... 246

Figure 219: Front of panel FLS-6 post strike #1 and #2. ........................................................... 247

Figure 220: Back of panel FLS-6 post strike #1 and #2. ........................................................... 247

x
Figure 221: Panel FLS-6 pre strike #3 (setup). .......................................................................... 248

Figure 222: Panel FLS-6 post strike #1, #2, and #3................................................................... 248

Figure 223: Front of panel FLS-6 post strike #1, #2, and #3. .................................................... 249

Figure 224: Back of panel FLS-6 post strike #1, #2, and #3. .................................................... 249

Figure 225: Pre and post strike thermographic images of base substrate panel for FLS-6. ..... 251

Figure 226: Base substrate for aesthetic and smoothing test panels showing fasteners 

 and doublers. ........................................................................................................... 252

Figure 227: Aesthetic and smoothing base substrate panel holder. ........................................... 253

Figure 228: Aesthetic and smoothing base substrate loaded for stack-up application. ............. 254

Figure 229: Stack-up applied to base substrate.......................................................................... 254

Figure 230: Application of stack-up with pressure roller, left to right. ..................................... 255

Figure 231: Application of stack-up with pressure roller, bottom to top................................... 255

Figure 232: Panel FAS-1 front view. ......................................................................................... 256

Figure 233: Panel FAS-1 edge view. ......................................................................................... 257

Figure 234: Panel FAS-1 shaded front view. ............................................................................. 257

Figure 235: Panel FAS-2 front view. ......................................................................................... 258

Figure 236: Panel FAS-2 edge view. ......................................................................................... 258

Figure 237: Panel FAS-2 Shaded Front View. .......................................................................... 259

Figure 238: Panel FAS-3 front view. ......................................................................................... 260

Figure 239: Panel FAS-3 edge view. ......................................................................................... 260

Figure 240: Panel FAS-3 shaded front view. ............................................................................. 261

Figure 241: Panel FAS-4 front view. ......................................................................................... 262

Figure 242: Panel FAS-4 edge view. ......................................................................................... 262

Figure 243: Panel FAS-4 shaded front view. ............................................................................. 263

Figure 244: Panel FAS-5 front view. ......................................................................................... 264

Figure 245: Panel FAS-5 edge view. ......................................................................................... 264

Figure 246: Panel FAS-5 shaded front view. ............................................................................. 265

Figure 247: Panel FAS-5 tear (close-up view). ......................................................................... 266

Figure 248: Panel FAS-6 front view. ......................................................................................... 267

Figure 249: Panel FAS-6 edge view. ......................................................................................... 267

Figure 250: Panel FAS-6 shaded front view. ............................................................................. 268

Figure 251: Computed maximum panel deformation. ............................................................... 270

Figure 252: Computed deformation over 0.020” doubler. ......................................................... 272

Figure 253: Computed deformation over 0.040” doubler. ......................................................... 273

Figure 254: Panel FAC-1 front view. ........................................................................................ 274

Figure 255: Panel FAC-1 close-up view 1. ................................................................................ 275

Figure 256: Panel FAC-1 close-up view 2. ................................................................................ 276

Figure 257: Panel FAC-2 front view. ........................................................................................ 277

Figure 258: Panel FAC-2 side view. .......................................................................................... 278

Figure 259: Panel FAC-3 front view. ........................................................................................ 279

Figure 260: Panel FAC-3 close-up view 1. ................................................................................ 280

Figure 261: Panel FAC-3 close-up view 2. ................................................................................ 281

Figure 262: Panel FAC-4 front view. ........................................................................................ 282

Figure 263: Panel FAC-4 close-up view 1. ................................................................................ 283

Figure 264: Panel FAC-4 close-up view 2. ................................................................................ 284

xi
Figure 265: Panel FAC-5 front view. ........................................................................................ 285

Figure 266: Panel FAC-5 close-up view 1. ................................................................................ 286

Figure 267: Panel FAC-5 close-up view 2. ................................................................................ 287

Figure 268: Panel FAC-5 close-up view 3. ................................................................................ 288

Figure 269: Panel FAC-6 angled view....................................................................................... 289

Figure 270: Panel FAC-6 close-up view 1. ................................................................................ 290

Figure 271: Panel FAC-6 close-up view 2. ................................................................................ 291

Figure 272: Thermal performance test setup – mounting frame. ............................................... 294

Figure 273: Thermal performance test setup – oven temperature. ............................................ 295

Figure 274: Thermal performance test setup – test in progress. ................................................ 296

Figure 275: Thermal performance of panels. ............................................................................. 298

Figure 276: Base substrate panel drawing. ................................................................................ 300

Figure 277: Frame/stringer/fuselage representation drawing. ................................................... 302

Figure 278: Frame/stringer arrangement. .................................................................................. 302

Figure 279: Close-up view of frame. ......................................................................................... 303

Figure 280: Close-up view of stringer. ...................................................................................... 303

Figure 281: Protective skins definition drawing. ....................................................................... 306

Figure 282: Schematic of conventional aluminum baseline panel. ........................................... 307

Figure 283: Interior trim panel ply arrangement. ....................................................................... 308

Figure 284: Protective skin test panel configuration. ................................................................ 310

Figure 285: Overlap versus no overlap test panel configuration. .............................................. 311

Figure 286: Panel FAC-6b layout (add over-frame Nomex). .................................................... 313

Figure 287: Panel FAC-6c layout (add between-frame fiberglass). .......................................... 313

Figure 288: Panel FAC-6d Layout (Remove over-frame Nomex). ........................................... 314

Figure 289: FAC-1 installed in test window - source room....................................................... 316

Figure 290: Close-up showing rubber seal - source room. ........................................................ 317

Figure 291: FAC-9 installed in test window - source room....................................................... 317

Figure 292: FAC-6 installed in test opening - receiver room. ................................................... 318

Figure 293: Putty sealing panel to test window - receiver room. ............................................... 318

Figure 294: Trim panel installed in test window - receiver room. ............................................. 319

Figure 295: Putty sealing trim panel to test window - receiver room. ....................................... 319

Figure 296: Between frame Fiberglass installed on panel - receiver room. .............................. 320

Figure 297: Damping being applied to FAC-9 - receiver room. ................................................ 320

Figure 298: Between frame Fiberglass being applied to panel - receiver room. ....................... 321

Figure 299: Over-frame Nomex being applied to panel - receiver room. ................................. 321

Figure 300: Over-frame Fiberglass being applied to panel - receiver room. ............................. 322

Figure 301: Results from all 20 runs.......................................................................................... 323

Figure 302: Protective skin panels compared to baseline panel. ............................................... 324

Figure 303: Best Protective Skin Panels Compared – Key Frequencies. .................................. 324

Figure 304: Undamped aluminum and composite compared. ................................................... 327

Figure 305: Treatment weight effectiveness. ............................................................................. 328

Figure 306: Additional transmission loss required from FAC-1. .............................................. 329

Figure 307: Best panel with treatment options. ......................................................................... 329

Figure 308: Preferred panel FAC-6 with treatment options. ..................................................... 330

Figure 309: FAC-1 and FAC-6 with treatment options delta to baseline. ................................. 330

xii
Figure 310: Other panels with treatment. .................................................................................. 331

Figure 311: Baseline aluminum panel with treatment options. ................................................. 331

Figure 312: Repeatability of test method. .................................................................................. 332

Figure 313: Effect of composite overlap. .................................................................................. 333

xiii
Table of Figures 

Table 1 - Projected Savings of Various Technologies as a Function of Time ................................ 3

Table 2 - 2035 Final Configuration Descriptive Parameters .......................................................... 3

Table 3 - 2035 Final Configuration Performance against ............................................................... 4

Table 4 - Weights of Components Affected by Protective Skins for Phase 1 Airliners ............... 10

Table 5 - Revised Protective Skin Weight Estimates and Target ................................................. 12

Table 6 - Cost Limits for Protective Skin Layers ......................................................................... 13

Table 7 - Sample Damage Threat Assessment Table ................................................................... 16

Table 8 - Core Materials Properties Sought .................................................................................. 29

Table 9 - Core Material List.......................................................................................................... 30

Table 10 - Film Materials Properties Sought ................................................................................ 37

Table 11- Film Materials ............................................................................................................. 38

Table 12 - Energy Absorbing Materials ........................................................................................ 41

Table 13 - Impact Spreading Layer Materials .............................................................................. 41

Table 14 - Lightning Strike Protection Materials ......................................................................... 42

Table 15 - Aesthetic Layer Materials ............................................................................................ 42

Table 16 - Interface Layers Material Definition ........................................................................... 42

Table 17 - Impact Panel Material Build-up .................................................................................. 44

Table 18 - Lightning Strike Panel Material Build-up ................................................................... 47

Table 19 - Aesthetics and Smoothing Material Build-up ............................................................. 49

Table 20 - Notes for Core Materials ............................................................................................. 53

Table 21 - Notes for Non-Metallic Core ....................................................................................... 53

Table 22 - Notes for Metallic Core ............................................................................................... 53

Table 23 - Notes for Soric ............................................................................................................. 53

Table 24 - Notes for Polydamp Hydrophobic Melamine with PEEK Skin .................................. 54

Table 25 - Notes for Innegra S ...................................................................................................... 54

Table 26 - Notes for Tegris ........................................................................................................... 54

Table 27 - Notes for Carbon Epoxy .............................................................................................. 54

Table 28 - Notes for Aluminum .................................................................................................... 54

Table 29 - Notes for Integument Film with PSA .......................................................................... 55

Table 30 - Notes for 3M 5004 with PSA Aesthetic Film ............................................................. 55

Table 31 - Notes for Halar ............................................................................................................ 55

Table 32 - Notes for Aptiv PEEK with PSA................................................................................. 55

Table 33 - Notes for Kapton ......................................................................................................... 55

Table 34 - Notes for Integument with LSP and PSA .................................................................... 56

Table 35 - Notes for 0.016 psf Expanded Aluminum ................................................................... 56

Table 36 - Notes for 0.029 psf Copper ......................................................................................... 56

Table 37 - Notes for LDS 50-01 0.007 psf Aluminum ................................................................. 56

Table 38 - Notes for Proprietary Spray Material .......................................................................... 56

Table 39 - Notes for Carbon Nanotube Material .......................................................................... 56

Table 40 - Notes for VHB Double-sided Tape ............................................................................. 57

Table 41 - Notes for Aeropoxy ..................................................................................................... 57

Table 42 - Notes for AF 163 0616 Adhesive ................................................................................ 57

Table 43 - Notes for 3M 4950PC Transfer Tape .......................................................................... 57

xiv
Table 44 - Visual Representation of the Material Manufacturing Data ........................................ 58

Table 45 - PE 5 MHz UT Attenuation vs. Void Content (Optical) .............................................. 64

Table 46 - Primary Requirements for Impact ............................................................................... 68

Table 47 - Impact Test Conditions................................................................................................ 68

Table 48 - Impact Test Data Collected for Panel IM-100 ............................................................ 80

Table 49 - Description of Test Data Columns .............................................................................. 80

Table 50 - Impact Test Data.......................................................................................................... 81

Table 51 - Reformatted Impact Data .......................................................................................... 102

Table 52 - Impact Data Organized with Increasing Protective Skin Areal Density ................... 104

Table 53 - Panels That Passed All Test Conditions Sorted by Protective Skin Areal Density... 106

Table 54 - Panels with Protective Skin Areal Density Less Than 0.50 psf ................................ 107

Table 55 - Final Impact Panel Possibilities................................................................................. 109

Table 56 - Panel Details with Peak Current and Voltage ........................................................... 128

Table 57 - Indirect Effects of Lightning Test Results................................................................. 129

Table 58 - Current Waveforms Characteristics for Different Lightning Strike Materials .......... 130

Table 59 - Voltage Waveforms Characteristics for Different Lightning Strike Materials ......... 131

Table 60 - Damage and Delamination for All Panels (Post Lightning Strike) ........................... 134

Table 61 - Panels with Non-Zero Inner Delamination Due to DEL ........................................... 135

Table 62 - Lightning Strike Panels Passing DEL ....................................................................... 136

Table 63 - Visual Examination Results for Polyurethane Core Panels ...................................... 142

Table 64 - Visual Examination Results for Non-metallic Honeycomb Core Panels .................. 143

Table 65 - Visual Examination Results for Metallic Honeycomb Core Panels .......................... 144

Table 66 - Visual Examination Results for Polydamp Core Panels ........................................... 155

Table 69 - Visual Examination Results for Lightning Strike Panels with 

 Polyurethane Cores ................................................................................................... 156

Table 70 - Visual Examination Results for Lightning Strike Panels with Soric and 

 Polydamp Melamine Cores ....................................................................................... 157

Table 71 - Summary of First-Generation Test Article Thermal Performance Trends from 

 Aesthetic and Smoothing, Lightning Strike, and Baseline Panels ............................. 161

Table 72 - Lighting Strike/Impact Combined Results ................................................................ 163

Table 73 - 1/4" Thick 3 pcf Metallic Honeycomb Lightning Strike Performance ..................... 164

Table 74 - 1/4" Thick 3 pcf Metallic Honeycomb Impact Performance .................................... 164

Table 75 - Impact Materials for Second-Generation Protective Skins ....................................... 166

Table 76 - Impact Spreading Materials for Second-Generation Protective Skins ...................... 166

Table 77 - Lightning Strike Protection for Second-Generation Protective Skins ....................... 166

Table 78 - Aesthetic Layer for Second-Generation Protective Skins ......................................... 167

Table 79 - Interface Layers for Second-Generation Protective Skins ........................................ 167

Table 80 - Second-Generation Test Article Definition ............................................................... 168

Table 81 - Second-Generation 24” x 24” Base Substrate Panel Inspection ............................... 181

Table 82 - Second-Generation 48" x 48" Base Substrate Panel Inspection ................................ 183

Table 83 - Second-Generation Skins Impact Test Conditions .................................................... 185

Table 84 - Second-Generation Impact Test Articles Weights and Areal Density ...................... 186

Table 85 - Impact Test Data Collected for Panel FIM-3 ............................................................ 200

Table 86 - Description of Test Data Columns ............................................................................ 200

Table 87 - Second-Generation Skins Impact Test Data .............................................................. 201

xv
Table 88 - Reformatted Data....................................................................................................... 203

Table 89 - Realistic Impact Conditions Results Sorted in Increasing Protective Skin 

 Areal Density ............................................................................................................. 203

Table 90 - Second-Generation Lightning Strike Test Article Weights....................................... 207

Table 91 - Panel Details with Peak Current and Voltage ........................................................... 220

Table 92 - Characteristics of Current Waveforms ...................................................................... 221

Table 93 - Characteristics of Voltage Waveforms ...................................................................... 222

Table 94 - Damage and Delamination for All Panels (Post Lightning Strike) ........................... 250

Table 95 - Visual Examination Results for Aesthetic and Smoothing Panels ............................ 269

Table 96 - Visual Examination Results for Acoustic Panels ...................................................... 292

Table 97 - Summary of Thermal Performance Trends from Aesthetic and Smoothing Panels . 299

Table 98 - Acoustics Base Substrate Panel Weights .................................................................. 301

Table 99 - Protective Skin Definitions........................................................................................ 305

Table 100 - Interior Trim Panel Ply Table .................................................................................. 308

Table 101 - Notes Definitions ..................................................................................................... 309

Table 102 - Test Matrix to Compare STAR-C2 Panels to Conventional Construction .............. 310

Table 103 - Transmission Loss Material Build-Up Study Panel Definitions ............................. 312

Table 104 - Test Sequence .......................................................................................................... 315

Table 105 - Component Weights ................................................................................................ 325

Table 106 - Total Test Sample Weight and Partition Noise Metrics .......................................... 326

xvi
1

1 Introduction 

Current design of composite structures requires overdesigning to provide capacity to absorb impact 

and operate in hot, humid environments. Extrapolating progress in composites technology out three 

aircraft generations to the year 2035 results in a significant weight reduction but does not support a step 

change in weight reduction and fuel burned reduction to meet the requirements of NASA’s Fundamental 

Aeronautics Program/Subsonic Fixed Wing Project N+3 research program. 

As part of work in Phase I of the N+3 program, when pushed to find a way to get the last seven 

percent fuel burn reduction, Cessna turned the problem around and asked how to meet the structural 

requirements without overdesigning the structure. What if the primary structure is designed without any 

weight penalties (“knock downs”), and protective skins are used to meet the impact and hot, humid 

requirements? What if multiple requirements are met by one material in the protective skins? What if the 

external impact absorbing material also provides the acoustical treatment? What if the external protective 

skin can replace the thermal insulation? What if the impact damage is visible unlike many of today’s 

composite structures? What if paint is replaced by an aesthetic film, allowing both attractive decorative 

outer surfaces and smooth surfaces which facilitate natural laminar flow? Could the result be a step 

change in weight and fuel burned reduction? NASA has provided the funding for Cessna to begin to 

answer these questions through funding for this research contract (NNC10CA36C Protective Skins for 

Composite Airliners). 

The goal of this research is the development of potential concepts for protective skins which enable 

natural laminar flow and perhaps significant weight reduction in the aircraft’s primary structure. The 

primary structure carries the load. The protective skin is needed to absorb impact damage and to provide 

environmental protection. The STAR-C2

concept should be responsible for smoothing out bumps or gaps, 

providing thermal insulation, absorbing impact and acoustic energy, reflecting ultraviolet and infrared 

radiation, conducting large amounts of electrical current (for lightning strike), and providing a cosmetic or 

appealing surface. 

The outcome of this research program is proof of the feasibility of the STAR-C2concept, 

recommendations to NASA on future materials research and development by material suppliers to support 

the STAR-C2

concept, and recommendations on a potential research path to ensure that the STAR-C2

concept is capable of being applied as soon as it is ready. 

The research program was structured in two halves. During the first half of the program, the following 

activities were accomplished: defining the metrics and requirements for the protective skins; conducting 

a material search and developing the material composition for the protective skins, writing the test plans, 

conducting the tests, and analyzing the test data, and finally, using the collected test data, selecting the 

best materials for an improved set of STAR-C2protective skins. Test articles developed during the first 

half of the program are known as first-generation test articles, and test articles developed in the second 

half of the program are second-generation test articles. The second half of the program included building 

and testing the second-generation test articles, analyzing the data, and developing conclusions and 

recommendations concerning the feasibility of protective skins for composite airliners. Testing 

conducted in both halves of the program included impact, electromagnetic effects, aesthetics and 

smoothing, and thermal. Acoustic testing was also conducted for the second-generation test articles. 
2

2 Background 

Cessna Aircraft Company led the vehicle configuration development in a NASA N+3 Phase I research 

project while partnered with General Electric Aircraft Engines (prime contractor) and the Georgia 

Institute of Technology (NASA Contract NNC08CA85C). Aircraft and propulsion technologies that 

enable efficient and environmentally friendly transportation aircraft for the 2030 to 2035 time period were 

explored throughout this previous effort. A transportation system scenario and an advanced aircraft that 

satisfies all of the NASA research objectives for N+3 aircraft was developed and presented in the Phase 1 

contract report (Reference 1). 

The penultimate 2035 advanced aircraft developed during the NASA N+3 Phase 1 research project 

made use of advanced turboprop engines, an advanced composite airframe, and a vehicle shape that 

promotes natural laminar flow. While meeting all of the NASA goals at that time for reductions in 

nitrous oxide emissions (NOx), noise, and balanced field length, the configuration was short of the fuel 

burn reduction goal by nearly seven percent. In order to fully satisfy the fuel burn reduction, a novel 

protective skin concept was proposed. Table 1 shows the projected benefits of each of the technologies as 

a function of time. The protective skin (new conductive skin) shown in the 2030-2035 column of Table 1

provides an additional seven percent weight reduction. 

With the anticipated benefits of the protective skin, the final aircraft concept (see Figure 1 and Table 

2) was able to nearly meet the fuel burn reduction requirement as shown in Table 3. The technologies 

that enable this breakthrough performance and hence are relevant to NASA’s subsonic fixed wing 

research include (1) advanced turboprop engines for reduced fuel burn, (2) laminar flow for drag 

reduction, and (3) advanced composite structures and systems for a reduction in vehicle empty weight. 

Figure 1: The 2035 20-passenger advanced airliner. 
3

Table 1 - Projected Savings of Various Technologies as a Function of Time 

Table 2 - 2035 Final Configuration Descriptive Parameters 

Parameter Value

Wing Area, sq ft 203.6

Thrust per Engine, lbs 3,353

Total Fuel, lbs 1,494

Fuel Fraction 0.10

Balanced Field Length, 

ft

3,642

Empty Weight, lbs 7,636

Basic Operating 

Weight, lbs

8,325

Ramp (Gross) Weight, 

lbs

14,664

Aircraft Weight 

Groups

% of B-20 

Empty 

Weight

2010 Composite 

Aircraft - Materials 

from 2000s

2015-2020 

Composite Aircraft 

- Materials from 

2010s

2030-2035 

Composite Aircraft 

- Materials from 

2020s

Technical Approach to 2035 

Aircraft

Wing 15.60% 30.00% 35.00% 39.20%

Tail 5.16% 30.00% 35.00% 44.00%

Fuselage 24.16% 25.00% 30.00% 34.00%

Propulsion 18.98% 0.00% 0.00% 29.67% Advanced engines reduce weight & 

fuel burn

Landing Gear 5.49% 0.00% 0.00% 15.00%

Nacelle & Air 

Induction 2.71% 0.00% 0.00% 20.00%

Surface Controls 1.88% -15.00% 0.00% 15.00%

Hydraulics 1.28% -15.00% 0.00% 100%

Electrical 5.41% -35.00% 0.00% 15.00%

Avionics and 

Instruments 3.95% -35.00% 30.00% 60.00%

Avionics & instruments benefit from 

panel mount integration & 

continued breakthroughs in 

commercial electronics

Furnishings & 

Equip 10.48% -60.00% 0.00% 29.19%

Air-conditioning & 

Anti-Ice 4.06% -15.00% 0.00% 26.34%

Paint 1.12% 0.00% 0.00% 100%

Total % Savings 0 1.60% 15.47% 33.11%

Risk

Application 

of aluminum 

structure & 

system 

integration 

technology

Application of 

current composite 

& system 

integration 

technology

Improved 

Materials, EMI, 

Lightning, & Sys. 

Integration

Conductive, 

Protective, & 

Health Monitoring 

Skin

Systems, landing gear, & nacelles 

benefit from transition to electric 

systems, application of new 

materials, and optimized integration 

& installation concepts

New conductive skin reduces risk & 

supports accoustic, thermal, and 

some ice protection functions

Some functions for accoustic 

damping, thermal insullation, ice 

protection, & paint moved to wing, 

tail, and fuselage weight groups 

(New Conductive Skin)
4

Table 3 - 2035 Final Configuration Performance against 

the NASA N+3 Phase II Metrics 

Metrics

Fuel reduction compared 

to baseline B-20, %

68.9

Cert Noise: 

Cum Margin Below 

Stage 4

74 EPNdB

LTO NOx: 

Margin to CAEP/6 6000 

lb FN Req’t

77% 

margin

Field Length: 

Margin N+3 Airport 

Req’t, ft (below 4,000 ft)

358.0

The novel protective skin proposed in Phase 1 and under study for this Phase II contract effort enables 

natural laminar flow and a significant weight reduction in the aircraft’s primary structure. The protective 

skin is needed to absorb impact damage and to provide environmental protection. This skin should be 

responsible for smoothing out bumps or gaps, providing thermal insulation, absorbing impact and 

acoustic energy, reflecting ultraviolet radiation, conducting large amount of electrical current, and 

providing a cosmetic or appealing surface (STAR-C2). The STAR-C2

protective skin is not a self-healing 

skin – rather, the STAR-C2 concept should allow damage requiring repair to be visually detected, not 

hidden. 

Aircraft weight savings associated with a STAR-C2 skin can be attributed to a change in the failure 

criteria for the primary structure and a more efficient approach to the design for environmental rather than 

load bearing requirements. Traditionally, primary composite structure must support ultimate loads after 

they have been subjected to damage and a hot, wet environment. If a STAR-C2 skin can be designed to 

absorb some level of impact damage and reduce the moisture and/or temperature environment of the 

primary structure, then the primary structure need not carry additional material to maintain loads in harsh 

environments. Additional weight savings can be achieved if the STAR-C2 skin can be designed for less 

weight than the current material system that is defined by the paint system, the acoustic treatment, the 

thermal insulation, and the lightning strike protection. 

Although the motivation for STAR-C2skins was small airliners like those developed in the Phase I 

study, it is reasonable to expect the STAR-C2 skin concept to benefit composite aircraft of any size. 

Different aircraft and different portions of an aircraft would be expected to benefit differently. For 

example, portions of an aircraft that are exposed to hail damage could be expected to benefit more than 

portions that are naturally sheltered. Given the potential for the integration of active health monitoring 

and aircraft systems like ice protection in a STAR-C2 skin, all aircraft are expected to receive a 

meaningful benefit from this new concept. The concept also facilitates the integration of other 

subsystems into the surface of the aircraft structure. 

3 STAR-C2 Concept and Technical Approach 

Traditional composite structures are designed to meet requirements for flight loads, for high 

temperature conditions, for wet environments, and to withstand impact damage. The requirements for 

hot, wet, and impact add weight to the structure. Typically acoustic treatment is required on the inside of 
5

the fuselage to meet noise requirements in the cabin, and filling/fairing, lightning strike material, and 

primer/paint are required on the outside to meet the remaining requirements for composite structure as 

shown in Figure 2. 

Figure 2: Conventional composite fuselage buildup.

Another way of portraying the material buildup of a conventional composite fuselage is by examining 

the functional decomposition as shown in Figure 3. The acoustic treatment reduces the noise inside the 

cabin to acceptable levels. The composite primary structure performs the functions of loads, thermal 

resistance, moisture barrier, and impact absorption; in order to perform all of those functions, the primary 

structure must be overdesigned (i.e., heavier). The filler/fairing performs both a smoothing and cosmetic 

function, the metal mesh performs the lightning strike function, and the outer layer of paint performs the 

smoothing, cosmetic, and reflection functions. The acoustic treatment is located inside the primary 

structure while the filler/fair, metal mesh, and paint are all outside of the primary structure. 

Figure 3: Functional decomposition of conventional composite fuselage.

Primary Structure for 

Loads, Environment 

and Damage

Acoustic Foam

w/aluminum foil

Frame

Stringer Skin

Prime/Paint

Fill/Fair

Lightning Strike Acoustic

Insulation Composite 

Primary 

Structure Filler/Fair Paint Lightning 

Strike

Metal Mesh Cosmetic

Smoothing Cosmetic Thermal Smoothing Moisture

Impact

Loads

Interior Primary 

Structure External Key Reflection
6

Improvements in composites technologies (with the typical functional decomposition shown in Figure 

3) projected to be available in 2035 improved the performance of the 20-passenger airliner under study 

during Phase 1 but did not succeed in meeting NASA’s goal of 70% reduction in fuel burned. Creative 

thinking was required to find a way to reduce aircraft weight even further and to facilitate natural laminar 

flow to reduce the drag. One result of that thinking was the STAR-C2protective skins. The approach is 

to design the primary structure only for loads, move the acoustic treatment outside the primary structure, 

and combine as many functions as possible in each layer. A concept with two layers (energy absorbing 

foam and conductive skin) is shown in Figure 4. Two was thought to be the minimum number of layers 

possible; however, one material identified and tested (Polydamp Hydrophobic Melamine with metalized 

PEEK (polyether ether ketone) skin) was made up of two layers which came already attached to each 

other. One goal of this research is to determine the actual number of layers necessary to meet all of the 

requirements while also meeting the weight and cost targets. 

A functional decomposition of the two-layer concept is shown in Figure 5. The composite primary 

structure is thinner and weighs less because the only requirement is to carry the loads. The core material 

meets the requirements for impact, thermal (high temperature), and acoustic. The outermost film layer 

provides the smoothing/cosmetic function previously provided by the filling/fairing material, lightning 

strike protection, and the cosmetic/smoothing function previously provided by the filling/fairing material 

and paint. There is no layer internal to the aircraft since the core material is meeting the acoustic 

requirement. The functional requirements for a smoothing surface layer, for protection from lightning 

strike, and for protection from a specified amount of impact damage are considered critical or design 

requirements. 

Figure 4: Potential concept for 2035 composite. 

Energy 

Absorbing Foam

(Impact, Sound, 

Thermal, Space 

for wires, 

antenna’s, etc.)

Frame

Stringer

Skin

Conductive skin

(Lightning, EMI, 

Paint, 

smoothness for 

laminar flow)

Primary Structure for Loads –

Protective Skin for Environment 

and Damage
7

Figure 5: Functional arrangements for primary composite structure with 

protective skins made up of two layers. 

To be successful, the total weight of the composite primary structure, core, and film needs to be less 

than the weight of the traditional 2035 composite fuselage with all of the associated materials. The other 

element necessary for success is being easy to install and repair. Ideally the protective skins should also 

make impact damage detectable from a walk-around inspection. Figure 6 shows a potential tile plus 

overwrap concept that enables the aesthetic coating to cover impact damage tiles that are easy to remove, 

repair, and/or replace. The best approach for a STAR-C2 skin may be associated with material layers that 

provide all or part of the performance for each functional requirement. It is also recognized that the 

number of unique layers of material could vary based on the availability of materials and the assembly 

and installation process. The definition of each of these layers and the appropriate material properties for 

these layers is the goal of this research. 

Thermal Moisture 

Barrier

Impact* Composite Primary Structure

Loads Acoustic

Core Lightning 

Strike*

Film

Cosmetic

Smoothing*

*Critical or design requirement Interior Primary 

Structure External Key Reflection
8

Figure 6: Candidate installation concept for a STAR-C2 skin. 

As defined for this research, STAR-C2

is not a self-healing skin. Rather, the STAR-C2concept should 

allow damage requiring repair to be visually detected, not hidden. Visible damage after a bird strike 

when viewed from the front appears to be limited to the need to clean off the composite material as shown 

in Figure 7 while the actual damage to the hidden structure is quite significant as shown in Figure 8. 

Figure 7: Front (outside) view of composite structure after bird strike.

Conductive skin

Energy Absorbing 

Foam
9

Figure 8: Rear (inside) view of composite structure after bird strike.

Currently available materials will be used to explore the contribution of each layer of a STAR-C2

protective skin to the functional requirements, to identify candidate categories of materials, and to specify 

the properties of new materials that will lead to an optimum protective skin. The functional requirements 

for a smoothing surface layer, for protection from lightning strike, and for protection from a specified 

amount of impact damage are considered critical or design requirements. Consequently the analysis and 

test program is intended to provide insight into the best approach to satisfy these requirements with a 

STAR-C2

skin that is defined by two or more layers of material. Once an acceptable approach to these 

requirements is established, the remaining functional requirements can be used to define a set of material 

requirements that leads to the largest weight savings. The most valuable STAR-C2

skin is the one that 

satisfies many environmental protection needs, leads to an aircraft weight savings, facilitates laminar flow 

(perhaps the largest contribution to fuel burn reduction), and is easy to install and repair. 

This research program is working to accomplish the following: (1) establish the technical requirements 

for the STAR-C2 skin, (2) identify appropriate materials for this protective skin, (3) build representative 

test panels that include both structure and skin, and (4) verify through test the effectiveness of the selected 

materials at satisfying the technical requirements. The feasibility of a STAR-C2

skin will be based on the 

ability of current or future materials to satisfy both the functional protection requirements as well as some 

weight targets that enable a significant benefit to a small airliner. The outcome of this research program 

is proof of the feasibility of the STAR-C2

concept and recommendations to NASA on future materials 

research and development by material suppliers to support the STAR-C2

concept. 

4 Metrics 

A set of metrics were identified to initially set goals for the STAR-C2protective skins and then to 

compare the actual parameters achieved with the goals. The metrics include areal weight, cost, thickness, 

and thickness. Each of the metrics will be described in the following subsections. 
10

4.1 Areal Weight 

The weights associated with traditional aluminum and fuselage structures include the weight of the 

fuselage, the weight of the acoustic treatment (which is included as part of the furnishings & equipment 

weight in Cessna’s weight equations), and the weight of the paint. These estimated weights are shown in 

Table 4 for the current technology aluminum aircraft, for the 2035 composites aircraft, and for the 2035 

composites aircraft with protective skins. The weight reductions for the 2035 airplanes led to reduced 

fuel weight which led to a smaller airplane. The fuselage weight for the 2035 composites with protective 

skins includes the primary structure and the protective skins. The weight is reduced compared to the 2035 

conventional composites fuselage partly because the size of the overall aircraft has reduced and partly 

because of projected fuselage weight reductions. Similarly for the furnishings & equipment weight – the 

overall size of the aircraft is smaller and the acoustic treatment weight is eliminated. Paint for the 2035 

protective skin aircraft is completely eliminated. 

The fuselage wetted area of the current technology aluminum airplane is 1,164 ft2; the fuselage wetted 

area of the 2035 airplanes is only 962 ft2. As seen in the lower part of Table 4, the pounds per square foot 

decreases from 4.46 for the current aluminum fuselage to 3.14 pounds per square foot for the 2035 

composite protective skins fuselage.

Table 4 - Weights of Components Affected by Protective Skins for Phase 1 Airliners 

Component Current 

Technology 

Aluminum (lbs)

2035 

Conventional 

Composites 

(lbs)

2035 Composites 

with Protective 

Skins (lbs)

% Reduction 

from 2035 

Composites 

2035 

Composites 

with Protective 

Skins

Fuselage 3,512 2,359 1,988 15.7%

Furnishings & 

Equipment

1,524 1,332 1,031 22.6%

Paint 156 103 0 100%

Total 5,192 3,794 3,019 20.4%

lbs/ft24.46 3.94 3.14 20.3%

In order to meet the 70% fuel burn reduction, the weight of the 2035 composite with protective skins 

fuselage must be 1,988 lbs. The fuselage is composed of both primary structure and the protective skins. 

Separating out weight of the primary structure from weight of the skins is not feasible since the actual 

composites available in 2035 are unknown. Instead, working parametrically, it is possible to allocate 

weight between the primary structure and the skins by using percentages (i.e., 90% of the weight is 

primary structure and 10% is skins, to 70% of the weight is primary structure and 30% is skins). The line 

in Figure 9 represents the potential protective skin areal weight targets (in lbs/ft2) depending on the 

protective skins’ percentage of total fuselage weight. While providing the relationship, this approach 

does not suggest an appropriate range or target for the protective skins weight. 

Another approach for estimating a weight target is to address what will be eliminated directly by 

application of the STAR-C2skins. Current acoustic/thermal insulation on today’s aluminum aircraft 

accounts for approximately 0.40 lbs/ft2of the fuselage cockpit/cabin area (all fuselage area except the tail 

cone). Filler, primer, paint, and lightning strike material on today’s composite aircraft represents about 

0.17 lbs/ft2

on the total aircraft. The cockpit/cabin comprises about 25% of the total aircraft wetted area. 
11

Combining these weights gives a target of 0.275 lbs/ft2for the protective skins. This target does not 

include any installation hardware, and it will have to be allocated between the actual layers of skin 

developed. 

The range for weight target suggested here covers the protective skins being 5% of the total fuselage 

weight up through being 30% of the total fuselage weight. Although no formal estimates of the potential 

decrease in weight for removing the harsh environment and impact damage could be found in the 

literature, one experienced estimate was that a reduction in strength required of 40% would result in 

approximately a 10% reduction in fuselage weight, giving a protective skin weight of 0.21 lbs/ft2 which 

would indicate that 0.275 lbs/ft2is at least of the right order of magnitude. 

Figure 9: Potential weight allocation for protective skins. 

Once actual materials were considered (including adding an impact spreading shell layer to the impact 

absorbing core material), the STAR-C2

protective skins weight allocations and range was revised. The 

breakdown of weight ranges for core, shell, and film materials is shown in tabular form in Table 5, while 

the overall range and target are shown in Figure 10. The target holds at 0.275 lbs/ft2

but the range has 

been reduced from 0.140 lb/ft2 at the lower end to 0.450 lb/ft2 at the upper end, corresponding to the 

protective skins being from 7% to 27% of the total fuselage weight. 

0.000

0.100

0.200

0.300

0.400

0.500

0.600

0.700

0 5 10 15 20 25 30 35

Protective Skin Aerial Weight Target, lbs/ft^2

Protective Skin % of Fuselage Weight

Target
12

Table 5 - Revised Protective Skin Weight Estimates and Target 

Weight (lbs/ft2)

Low High

Core Material 0.040 0.200

Shell Material 0.050 0.100

Film 0.050 0.150

Total 0.140 0.450 0.275 lbs/ft2

Figure 10: Final protective skin weight target and range. 

4.2 Cost 

The cost of materials which will exist in 2035 is not known. Nor is it possible to generate credible 

estimates of what savings from aircraft performance can be allocated to the cost of skins (a “should cost” 

exercise). Additionally, the difference between obtaining sufficient materials to build test panels 

compared to buying material in quantity to cover multiple aircraft can be very large, making research cost 

targets at this early research stage of limited value. 

Because this is a fixed price contract, the cost limits for the protective skins were identified in the 

proposal for this research. They are shown in Table 6. There is no lower limit; the upper limits are based 

on Cessna’s definition of commercially available and affordable. The total cost for the skins must not 

0.000

0.100

0.200

0.300

0.400

0.500

0.600

0.700

0 5 10 15 20 25 30 35

Protective Skin Aerial Weight Target, lbs/ft^2

Protective Skin % of Fuselage Weight

Target
13

exceed $85/ft2. If layers are combined, the total cost can be redistributed to set upper limits for the 

materials actually used. 

Table 6 - Cost Limits for Protective Skin Layers 

$40/ft2for Aesthetics/Smoothing Layer

$30/ft2for EMI/Lightning Strike Layer

$5/ft2for Impact Load Distribution Layer

$10/ft2 for Impact or Energy Absorbing 

Foam

4.3 Thickness 

There is no minimum limit on thickness of the protective skins (where thickness is the distance from 

the outer surface of the primary structure to the outer surface of the protective skins). The upper limit is 

set by aerodynamic considerations. There will be some decrease in fuselage primary structure thickness 

due to the absence of the harsh environment and impact requirements. There will be some increase in 

thickness of the fuselage due to addition of the protective skins. Since the decrease in primary structure 

thickness is unknown and the increase in drag/decrease in range due to increases in aircraft skin thickness 

is not easily determined, an educated target of protective skin thickness of 0.25 inches with a maximum of 

1.0 inches thickness will be used during this research. 

4.4 Number of Layers and Unique Materials 

A key finding for this research will be the number of layers required to produce protective skins which 

meet all of the requirements. At this time, the minimum number is believed to be two layers. There is no 

maximum. In addition to the layers identified, methods to attach those layers to each other and to the 

primary structure will be required. Adhesives are a good candidate. The number of layers and the 

number of unique materials (including adhesives or other fastening materials) will strongly influence the 

cost of the skins. These two metrics will be tracked and reported on during the research. 

4.5 Visible Damage 

Impact damage which is sufficient to require repair should be visible with a visual inspection. 

Nondestructive inspection or other method could be used to determine the extent of any repair required. 

An attribute metric of yes/no will be used to track the ability of the STAR-C2

skins to show visible 

damage. 

4.6 Installation and Repair 

In order for the protective skin concept to be feasible, the skins must install in a reasonable amount of 

time and repairs must be capable of being carried out in the field, again in a reasonable amount of time. 

Trades between cost, installation process, and repair process will be useful in developing STAR-C2

concepts. For example, damage repair could take place in a local area for both the core material and the 

smoothing layer, in a local area for the core material with replacement of the entire smoothing layer, or 

with replacement of both the entire core material (or a core panel) and the entire smoothing layer. Which 

one of those repair methods is used will depend on the cost of the materials, how effective the repair is, 

and how long it takes to make the repair. 
14

5 Requirements 

The critical or design requirements for the STAR-C2

skins are energy absorption (impact), 

smoothness, and conductivity (lightning strike). Other requirements include thermal, reflectivity, 

cosmetic, acoustic, environmental considerations, and other considerations. The environmental and other 

considerations will be used to guide the selection of materials, not to define the testing required. 

Cessna has considerable experience with most of these requirements. However, there are two 

important differences between Cessna’s current view of requirements and the requirements for STAR-C2

skins. The first is the difference between current primary composite structure and primary composite 

structure protected by STAR-C2skins. Some requirements may be different (most likely lessened) 

because the skins must only protect the primary structure from the condition, not completely withstand 

the condition themselves. The second is the difference between business jets and airliners. There may be 

significant gaps between acceptable appearances on a business jet and an airliner. 

5.1 Energy Absorption 

One of the critical design requirements is the ability of the protective skin to absorb impact energy. 

Current composite structures are difficult because damage sufficient to require repair can occur but not be 

visible to the eye. Figure 11 (copied from AC20-107B2) shows the five categories of damage along with 

their associated design load levels. In the figure, BVID stands for barely visible impact damage, and VID 

stands for visible impact damage. Category 1 damage is allowable damage that may be undetected by 

scheduled or directed field inspection or allowable manufacturing defects. Category 2 damage can be 

reliably detected by scheduled or directed field inspections performed at specified intervals. Category 3 

damage should be detectable within a few flights by operations or ramp maintenance personnel without 

special skills in composite inspection. Category 4 damage is discrete source damage from a known 

incident such as rotor burst, bird strikes, tire bursts, and severe in-flight hail; flight maneuvers are limited 

when Category 4 damage has occurred. Category 5 is severe damage which might be caused by severe 

service vehicle collisions with the aircraft, anomalous flight overload conditions, abnormally hard 

landings, maintenance jacking errors, etc. 

The goal for the STAR-C2 skins is to make sure that Categories 2, 3 and 4 damage are visible to the 

flight crew during their external inspection of the aircraft. Metallic aircraft do not have Category 2 

requirements because all damage is at least Category 3 – aluminum dents easily. The STAR-C2 material 

selection process needs to address this important issue. Category 2 requirements drive the vast majority 

of impact damage sizing. To eliminate the Category 2 requirements, the STAR-C2

skins must show 

evidence of impact similar to aluminum. 

The manufacturer of a composite aircraft must go through a process to determine the impact damage 

requirements for an aircraft. First, a threat assessment matrix (such as that shown in Table 7) considers 

all possible types of damage during ground-based and flight operations. Damage tolerance categories are 

assigned for each criteria identified (some forms of damage have more than one criteria), and appropriate 

responses are described. Figure 12 (copied from Reference 3) shows a Boeing assessment of all of the 

potential ground hazards capable of impact damage for a commercial airliner. The ramp can be a busy 

and dangerous place. 

The next (and final) step is to assign impact requirements to zones of the aircraft depending on 

location of the zone and the impacts to which that zone might be subjected (see Figure 13 for a 
15

representative business jet). Impact requirements are different depending on the aircraft zone. The 

representative impact requirement for this project is 180 in-lbs with a 1-inch impactor. A three-pound 

weight dropped from a height of 60 inches generates 180 in-lbs. Terminal velocity for 1” hail represents 

13.3 in-lbs and 2” is 213 in-lbs. The requirement for 180 in-lbs was selected to represent 90-95% 

probability (less than 5-10% of occurrence). This requirement applies to the hail-ground zone on the 

aircraft (top of the aircraft). 

Figure 11: Schematic diagram of design load levels versus categories.
16

Table 7 - Sample Damage Threat Assessment Table 

Threat Operation 1 2 3 4 5 Criteria Cessna Proposed Compliamce

Small Ground X

Boeing: 48 in-lb normal to surface. 1" dia 

impactor

No visible damage. No damage growth for 3 DSG (Design Service Goal) accounted for 

Ultimate Design Allowable

Large Ground X

Boeing: Up to 1200 in-lb or defined dent 

depth. 1" dia impactor

Up to VID to be found @ scheduled maintenance. No damage growth for 3 DSG (Design 

Service Goal) accounted for Ultimate Design Allowable

Numerous Ground X

Multiple, superimposed impacts, clusters 

(large tool)

Up to VID other indicators with a high reliably detected by operations or ramp maintenance 

personnel. Limit loads, cycle in support Annual/100 hour Inspection

Ground X

Failure of structural size and degree as 

related to event 

Up to VID to be found during manufacturing or scheduled maintenance. Repaired before 

delivery or return to service 

Ground X

Energy as requiremed to achieve 

Catergory 4 damage

BVID to Severe damage and/or other indicators with a high reliably detected by operations or 

ramp maintenance personnel

Ground/ 

Flight X

Failure of structural segment, frame/ 

stiffener/ support with skin/structure

Analysis/tests shall demonstrate airframe to limit load and no detrimental damage growth in 

support of Annual/100 hour inspection. Segment defined by arrestment features

Chemical or 

Environmental

Ground/ 

Flight X

Failure of structural size and degree as 

related to event 

Analysis/tests shall demonstrate airframe will sustain limit loading and no detrimental damage 

growth in support of Annual/100 hour inspection

In-Flight Fire Flight X Summary Residual strength for "Get-Home" loads specified in the regulations

Ground Non-removable 

Structure Ground X 200 in-lb impact with simulated hail ball Ultimate design strength, no moisture intrusion and no detrimental damage growth during 3 DSG for small hail

Ground (NRS) Severe Ground X

Boeing: Up to 500 in-lb impact with 

simulated hail ball Limit loading, no detrimental damage growth in support of Annual/100 hour inspection

In-Flight Flight X

Simulated hail ball, Size and velocities 

bases on statistical data Limit loading, no detrimental damage growth in support of Annual/100 hour inspection

In-Flight Severe Flight X

Simulated hail ball up to a specific 

airspeed Residual strength for "Get-Home" loads specified in the regulations

Nominal Flight X

Approx. 50th percentile strike energy 

level

Cosmetic only. Structural repair not needed

Sealing/restoration of protection may be necessary

Dispatch Flight X

Approx. 80th to 90th percentile strike 

energy level

Visually detectable damage. Immediate Lightning Strike mtl repair. Structural repair may be 

deferred to Annual/100 hour inspection

High Energy Flight X

Strike level in accordance with zoning 

diagram

Protection of systems for lightning attachment.

Continued safe flight

Flight X

Boeing: .50 " dia spherical object @ 

tangential tire speed

Limit design strength and no detrimental damage growth in support of Annual/100 hour 

inspection

Flight X

Structure, without regard of source, 

support sudden release of pressure. Compliance is to be by analysis, supported by testing

Flight X

Structural damage from engineof rotating 

machinery failure Residual strength for "Get-Home" loads specified in the regulations

Flight X

4 lb bird at Vc @ sea level, or .85 Vc @ 

8,000 feet Bird impact test articles or components representative of design

Flight X Simulated tire burst Residual strength for "Get-Home" loads specified in the regulations

Flight X

Damage Tolerance category

Tool Drop

Flight Overload, Jacking Errors, Severe Vehicle Collisions, Loss of Parts (Causing Blunt Force)

Lightning 

Strike

Ground Operation and Maintenance 

Equipment Collisions

"Fail safety" Failure of Structural 

Segment

Runway Debris

Category 5:

Material 

Degradation

Hail

Blunt Force to Internal Structural 

Features

Rotor Burst, Threats from Rotating 

Machinery

Exploding (Main) Tires

Breaching of Pressurized FuselageSudden Decompression

Bird Strike
17

Figure 12: Threat assessment - ground support (copied from Reference 8).

Figure 13: Sample threat assessment fuselage drawing.
18

5.2 Smoothness 

The 2035 20-passenger airliner was designed for extensive natural laminar flow (see 

Figure 14). Great care was put into shaping the fuselage to bring area forward and to maintain maximum 

favorable pressure gradient. The cabin entry door was moved to the rear of the cabin out of the laminar 

flow area to avoid steps and gaps which might trip the flow and eliminate the drag reduction. The escape 

hatch was moved forward with the thought that it could potentially be covered with a film which would 

break in the unlikely event the hatch needed to be opened. 

Figure 14: Projected areas of natural laminar flow (shown in blue).

There are three primary requirements for smoothness to support natural laminar flow in addition to 

designing the airframe shape to exhibit positive pressure gradients (which was done on the 2035 20-

passenger airliner and which results in a radically different fuselage shape). The three additional 

requirements involve waviness, step heights, and gap lengths as described in Reference 4. The 

permissible sizes of waves, steps, and gaps are all a function of the Reynolds number and empirical 

relationships documented in Reference 4. Reference 5 (which is 20 years newer than Reference 4) 

confirms that shaping the aerodynamic surfaces for favorable pressure gradients does relax the allowable 

step and wave size while still maintaining natural laminar flow. The methods of Reference 5 require 

knowledge of the pressure distributions so application of the methods is not practical for comparison in 

this effort. 

For the 2035 20-passenger airliner, the cruise Mach number is 0.55 at 39,000 ft. The wing is unswept 

and has a mean aerodynamic chord of 3.81 ft (wing span is 53.39 ft and Aspect Ratio is 14). Low 

airspeed and no sweep help increase the allowable waviness, step heights, and gap lengths to maintain 

laminar flow. Each of these parameter requirements will be discussed in the following subsections. 
19

5.2.1 Waviness 

The empirical relationship for allowable waviness is: 

5.0

5.1

2

59000 cos 









 



RC

h c

 

where h and  are defined in Figure 15. RC is the Reynolds number based on chord. Λ is the wing sweep. 

The maximum allowable waviness is described as a function of wavelength  in Figure 15. Reference 4

comments that, with the modern manufacturing technologies of 1985, all aircraft studied met the waviness 

requirements except at major structural joints where one or two widely-spaced waves would be present. 

Therefore, the waviness requirement is not expected to be significant in this development work. 

Figure 15: Waviness limits. 

5.2.2 Steps

There are two potential types of steps as defined in Figure 16: rounded steps and square steps. In the 

rounded step, the radius of curvature is approximately equal to the step height, h. The equation defining 

the maximum step height to maintain laminar flow for the square step is: 

R

h





1800

and for the rounded step is: 

R

h





2700

0.000

0.010

0.020

0.030

0.040

0.050

0.060

0.070

0 2 4 6 8 10 12

Wave height, h, inches

Wave length, , inches

h

2


20

where R is the unit Reynolds number. For a square step on the 2035 airliner at cruise conditions, the 

maximum height is 0.0196 in; for the rounded step the maximum height is 0.0294 in. Work on the 

smoothing layer should include a way to round the steps rather than have them be square in order to allow 

a slightly larger step height. 

Figure 16: Reference geometry for steps.

5.2.3 Gaps 

The empirical relationship for maximum gap width (as defined in Figure 17) is: 

R

h





15,000

For the 2035 airliner at cruise conditions, the maximum gap width is 0.163 inches. There are many 

opportunities for gaps in the areas where natural laminar flow is predicted (windscreen, windows, 

emergency escape hatch, nose landing gear door). Hybrid laminar flow (perhaps by providing some 

suction in select locations) may be necessary for the windscreen and nose landing gear door since those 

cannot be covered by a film and still operated. The windows and emergency escape hatch could 

potentially be covered by a film to minimize gaps. 

Figure 17: Reference geometry for gaps. 

5.3 Conductivity 

Conductivity (lightning strike) requirements fall into two categories: direct effects of lightning (DEL) 

and Indirect Effects of Lightning (IEL) or HIRF (High-Intensity Radiated Fields). The requirements for 

these two categories will be described in the following subsections. 

h h

Square Step Rounded Step

h

Gap
21

5.3.1 Direct Effects of Lightning 

The DEL strike requirement is defined in DO-160 Section 23 (Reference 6) as swept stroke for Zone 

2A (100 k Amps). The aircraft requirement is that the aircraft be able to continue safe flight after a direct 

lightning strike (14CFR Part 25.581, 25.899, 25.981, and 25.954 from Reference 7). For structure, this 

means that the aircraft must maintain structural integrity when struck by lightning. Interpreted for 

protective skins, this requirement means that the protective skin must prevent structural damage to the 

primary structure, not that the protective skin must survive. Damage is measured by the size of the hole 

and amount of delamination on the outer and inner surfaces of the skin. DEL performance will have to be 

done outside Cessna. 

5.3.2 IEL/HIRF 

The requirement for IEL or HIRF protection (14CFR Part 25.13167) applies to electrical and 

electronic systems on the aircraft. The ability of the aircraft to meet this requirement is very dependent 

on many factors besides the skin of the aircraft. One of the primary factors is shielding. DO-160 does not 

provide requirements that decide pass/fail for shielding. Hence comparative studies are based on 

experimental data using a known material. The requirements for IEL/HIRF are to provide as much RF 

(radio frequency) shielding as carbon fiber composite (CFC) with ALS, both in low and high frequency 

ranges. This performance can be determined through a series of comparative tests performed in Cessna’s 

Electromagnetic Effects Laboratory. 

5.4 Cosmetic 

One goal for the protective skins is to eliminate the need for aircraft paint and for the polished leading 

edges which are hallmarks of Cessna business jets. Another goal is for the cosmetic layer to include 

varying colors and designs which can be even more stunning than current aircraft paint schemes. Yet 

another goal is to combine at least the smoothing and cosmetic layer; with the right material adding 

lightning strike protection could be possible. 

Like impact damage, the cosmetic requirements are a function of location, and locations which are 

visible have greater cosmetic requirements than those locations which are not easily observed (e.g., the 

wing undersides on a high wing aircraft and the side of fuselage have much more stringent cosmetic 

requirements than the top of the fuselage or wing and the bottom of most components.) There is also a 

potential difference between cosmetic expectations of business jet owners and passengers on a 

commercial airliner. The cosmetic requirements for this work will be more appropriate for a commercial 

airliner, allowing some flexibility in meeting those requirements. Finally, the smoothness requirements to 

facilitate natural laminar flow may overshadow what would otherwise be cosmetic requirements. 

The list of cosmetic requirements includes at least the following items: 

 No readily apparent rough edges 

 No readily apparent dents or bumps 

 No readily apparent cuts and scratches 

 No readily apparent blushing (haze), bleeding, blistering, and water spotting 
22

 No readily apparent shrink-down (patterns of the underlying materials are seen in the outer 

surface) 

 No peeling 

 Limited size and number of blemishes (defects from craters, dirt, and pin holes) (Reference 8) 

 Consistent and even colors where intended; no color mismatch or readily apparent mottling 

 No failure in accelerated weather resistance (Reference 9) 

 No failure in outdoor weather resistance (Reference 9) 

Typically gloss (the amount of specular reflection from the painted surface) is a requirement for paint. 

Rather than specifying a gloss level, the reflectivity requirement will be determined from a combination 

of the thermal protection requirement and visually appealing (a very subjective requirement). 

5.5 Heat and Moisture 

One of the key assumptions for viability of the STAR-C2protective skins is the ability to reduce the 

size and weight of the primary composite structure when the requirements to meet hot, wet conditions are 

eliminated. In an attempt to understand the potential magnitude of material knock downs for hot, wet 

requirements and to understand if one of the requirements is more important than the other, an analysis of 

composites data from the AGATE (Advanced General Aviation Technology Experiments) Program 

(Reference 10) was conducted. The results for the average of the unidirectional and plain weave 

composites are shown in Figure 18. In both cases, the knock down is slightly larger for wet but both wet 

and hot are around 20% knock down. The knock down for low temperatures is for load cases which do 

not drive sizing of the structure. The total knock down is just over 40% for unidirectional materials and 

just under 40% for plain weave composites. 

The hot condition is related to skin temperature which is determined primarily by reflectivity while the 

wet condition is a function of the moisture in the atmosphere. In the following subsections requirements 

for reflectivity and moisture will be identified. 
23

Figure 18: Average knock downs for AGATE prepregs from different 

environmental conditions (copied from Reference 10) 

5.5.1 Reflectivity 

The surface temperature of the skin is a function of the outer surface emissivity (ε) and outer surface 

absorptivity (α). As reported in Reference 11, the worst case condition is an airplane sitting on the ramp 

on a hot day with no wind. For a 105°F day with solar radiation intensity of 360 BTU/hr·ft2 and no wind, 

a white painted surface (ε= 0.9, α=0.35) the outer surface temperature would be 130.3°F. For the same 

conditions with polished aluminum (ε= 0.04, α=0.0.30), the outer surface temperature would be 147.3°F. 

The relationship between solar absorption and emissivity is shown in Figure 19 (copied from 

Reference 12).

0%

10%

20%

30%

40%

50%

60%

UNI-Resin Properties PW-Resin Properties

Material Degredation (Knock Down)

AGATE Prepregs - Average Knock Downs from Different Env. Conditions

-65F

Wet

180F

180FWet
24

Figure 19: Absorptivity and emissivity characteristics of surfaces and coatings (copied from Reference 12).

Current composite primary structures are designed to withstand 180°F. The upper limit requirement 

for reflectivity for the STAR-C2protective skins is to find outer coverings with the correct emissivity and 

absorptivity to match the results for a white painted surface (temperature increase of 25°F). The target 

requirement is to find a material with emissivity and absorptivity which produce a surface temperature 

15°F above ambient for this condition. 
25

5.5.2 Moisture 

While not part of the STAR-C2acronym, moisture is a consideration for the protective skins. With the 

elimination of the hot, wet requirement for the primary structure, the protective skins must serve as a 

moisture barrier. All of the skins and materials (film, shell, core, and adhesives) together must keep 

moisture out. In addition to the water absorption property of the materials, the transmission of moisture 

between gaps and seams between pieces of material must be minimized. One of the major concerns is 

knowing if and when the material has picked up moisture. 

5.6 Thermal 

The thermal requirement is strictly related to keeping the cabin comfortable. Thermal load on the 

cabin heat is composed of the electrical heat load, the solar direct heat load, the occupant heat load, the 

bleed air heat load (if present), the airframe conduction heat load, and vapor cycle cooling. Only the solar 

direct heat load and the airframe conduction load will be of interested for the STAR-C2protective skins. 

For upper to mid areas of the aircraft, the solar direct heat load is critical. For lower areas of the aircraft, 

the airframe conduction load will dominate. 

Heat conduction through the structure of a traditional aluminum aircraft follows several paths. As 

described in Reference 11, a typical upper fuselage conduction path between the frames consists of the 

following layers of materials: 1) outer skin; 2) skin damping; 3) bagged fiberglass insulation; 4) nomex 

felt; and 5) interior panel. The conductive path over the frames consists of 1) outer skin; 2) fuselage 

frame; 3) Nomex felt; and 4) interior panel. The average overall heat transfer coefficient can be found 

using the ratio of the areas for each path. 

The fuselage is divided into zones for analysis based on the types of materials in each area (e.g., 

windshield, window, door, cabin or cockpit sidewalls, etc.) and the likely heat loads (such as solar direct 

or airframe conduction). The temperature for thermal calculations when the aircraft is parked is either the 

outer fuselage skin temperature for zones with direct solar loading (from the mid-fuselage to the top of 

the aircraft) or, for zones containing the lower part of the fuselage (where airframe conduction load 

dominates), the temperature of note is the ambient air static temperature. Cessna designs primary 

structure for functionality between -67°F and +180°F.

For the STAR-C2

protective skins, the cabin headliner will be a good representation of the direct solar 

heating case and the lower cabin sidewall of the fuselage conduction case. The overall heat transfer 

coefficient for a metallic Cessna business jet similar to the 2035 Advanced Airliner is 0.1300 

BTU/hr·ft·°F (again from Reference 11) for the cabin headliner; it is 0.1344 BTU/hr·ft·°F for the lower 

cabin sidewall. The thermal requirement for the STAR-C2 protective skins is an overall heat transfer 

coefficient similar to the aluminum airplane of 0.1300 BTU/hr·ft·°F for areas exposed to direct solar 

heating and 0.1344 BTU/hr·ft·°F for areas subject just to fuselage conduction. The goal of the STAR-C2

skins will be to have the same heat transfer coefficients as an aluminum fuselage with internal insulation. 

Any area between the STAR-C2outside “shell” and the structural skin will help provide thermal 

protection. The thicker the area, the better it will protect the structural skin from solar heat. 

5.7 Acoustic 

Acoustic treatment is used inside current fuselages to reduce the noise level in the cabin. The 2035 

20-passenger airliner uses the General Electric Year 2030-2035 Ultra Quiet and Efficient Turboprop 
26

(UQETP) concept (Reference 1). Extensive effort was made to evaluate the external (community) noise 

for the Phase 1 effort. There was no NASA requirement for interior noise evaluation, and no estimated 

data was presented on interior noise. Natural laminar flow over approximately half of the fuselage should 

help reduce the interior cabin noise compared to an airliner with turbulent flow. Additionally, the 

UQETP does use “an efficient, noise-optimized propeller with advanced, low emissions turbo machinery 

and a performance- and quiet-enhancing control system (Reference 1).” Relatively low cruise speed 

(M=0.55 at 39,000 ft) results in a relatively low propeller tip speed (590 ft/sec) at cruise. The propeller 

has eight blades, a moderate 105 activity factor, and a diameter of 9.84 feet. 

Given the lack of specific information on the noise characteristics of the UQETP, the acoustic 

requirement inside the cabin is that the transmission loss (TL) should be the same (within 2 dB) or better 

than damped aluminum at frequencies below 3000 Hertz. The interior noise goal is 80-90 dBA. 

5.8 Environmental Considerations 

The applicable requirements include temperature, fluids susceptibility, and salt fog. STAR-C2skins 

will not be tested for these considerations; rather the considerations will be used to guide the selection of 

materials. These requirements will be defined in the following subsections. 

5.8.1 Temperature 

As already described in the section on thermal requirements, composite structures at Cessna are 

designed for the temperature range from -67°F to +180°F. This will be the requirement for the 

temperature operability range for the STAR-C2

protective skins. 

5.8.2 Fluids Susceptibility 

The protective skins shall tolerate the following aviation fluids with no adverse effects per DO-160G6

Section 11.0 (Category F): aviation Jet A fuel, mineral-based hydraulic fluid, phosphate ester-based 

(synthetic) Type IV hydraulic fluid, isopropyl alcohol cleaner, cleaning compound for aircraft surfaces, 

and ethylene glycol de-icing fluid. 

5.8.3 Salt Fog 

The protective skins shall withstand the DO-160G6 Section 14.0 Category S salt fog requirement. 

Category S is subject to a corrosive atmosphere in the course of normal aircraft operation. 

5.9 Additional Considerations 

These final additional considerations impact the ease of installation and repair along with how long the 

skins last. Trades will be required between reparability and durability to determine the most optimum 

skin configuration. 

5.9.1 Conformability 

The STAR-C2

protective skins (especially the outer skin) should be conformable, meaning that the 

skin assumes the shape of the surface to which it is applied without cracking or breaking and without the 
27

formation of any bubbles or wrinkles. Reference 13 suggests testing which can be conducted to 

demonstrate conformability. 

5.9.2 Reparability 

One major requirement for the STAR-C2 protective skins is that they make any meaningful damage 

visible. Once made visible, repairs to the skins should be reasonable to accomplish. Ideally, cutting out 

the damaged area, replacing it, and taking some action to smooth the skin would accomplish a repair. 

However, the outer skin may be sufficiently delicate that the most efficient repair is to remove the entire 

outer film, repair the core material, and replace the entire outer film with a new one. Cost and ease of 

installation would need to be positive characteristics of the outer skin for this to be viable. 

5.9.3 Durability 

The normal desire would be for materials which last for the life of the aircraft. However, trades will 

be necessary between appearance, degradation in performance with time, weight, cost to replace, and cost 

to repair. If the protective skins are inexpensive and relatively easy to replace, it may be most effective to 

replace them rather than to require that the cosmetic appearance stay nearly perfect. 

Additionally, previous work suggests that adhesive-backed films, applied to the flow control surfaces 

in order to maintain a smooth, protected surface for drag reduction, tend to perform poorly and are 

unsuitable for areas of high erosion such as wing and tail leading edges and nacelle inlets (Reference 13). 

Presumably, these materials would also be subject to erosion on the nose of the fuselage, an important 

consideration for these protective skins since much of the natural laminar flow benefit is achieved on the 

forward part of the fuselage. Erosion is an important consideration for the outer layer of skin. 

6 Materials 

The initial STAR-C2 protective skin concept consisted of two layers (as was shown in Figure 5 and is

repeated here in Figure 20). The core foam is expected to meet the impact, thermal, and acoustic 

requirements while the film is expected to meet the smoothing, lightning strike, cosmetic and moisture 

barrier requirements. Materials searches were conducted to find the commercially available potential 

materials which could be used to produce the protective skins. 

Databases of potential core and film materials were created from a wide-ranging Internet search. 

Little regard was given to specific design use for this initial gathering. Separate lists of characteristics 

were developed for the core and film materials. The lists of characteristics were developed based on 

every parameter imaginable which could possibly be of use or interest. The databases were populated 

using the available manufacturers’ supplied data. The following subsections will present the data 

characteristics sought and the materials identified for the core and film materials. 
28

Figure 20: Functional arrangement for primary composite structure. 

Absence of data was a major problem. Differing units of measure and test methodologies were other 

problems which made it challenging to align the data in a format to support further review. Cost was not 

available for any of the materials. The selected approach to materials selection was to use the publicly 

available data from the Internet search to down select to a smaller set of materials which were 

investigated in greater depth with manufacturers and suppliers. 

6.1 Impact Absorbing/Spreading 

As shown in Table 8, there were 42 unique characteristics sought for the core materials. The 

search resulted in 163 potential core materials (many of which were variations of the same 

material with slightly different characteristics) which are shown in 

Thermal Moisture 

Barrier

Impact* Composite Primary Structure

Loads Acoustic

Core Lightning 

Strike*

Film

Cosmetic

Smoothing*

*Critical or design requirement Interior Primary 

Structure External Key Reflection
29

Table 9. 

Table 8 - Core Materials Properties Sought 

Material Type

Manufacture

Product #

Application

MINIMUM

MAXIMUM

Length

Width

Continues

Process

T g

Open or Closed Cell

Chemical Resistant (Yes/No)

Resin Absorption

Thermal conductivity (BTU/(hr*ft*°F)

Electrical Conductivity (Siemens)

Acoustic Damping

Water absorption(lbs/ft2)

Hydroscopic (Yes/No)

Flame, Smoke, Toxicity

CTE (mean) x10-5 in/in/F 

 lbs/ft^3

Parallel

Perpendicular

Parallel

Perpendicular

Parallel(width)

Perpendicular / parallel(thick)

Parallel(width)

Perpendicular / parallel(thick)

Parallel

Perpendicular

Parallel

Perpendicular

Parallel

Perpendicular

Parallel

Perpendicular

Parallel

Perpendicular

Parallel

Perpendicular

Flexural Modulus

Compression Strength (250F)

Compression Modulus (250F)

Density Range (lbs/ft^3)

Sheet size (in)

Temperature Deg F

Compression Strength

Compression Modulus

Shear Strength

Shear Modulus

Tensile Strength

Tensile Modulus

Flexural Strength
30

Table 9 - Core Material List (1 of 3) 

Polyurethane Last-A-Foam FR-3700 Tooling

Polyurethane Last-A-Foam FR-4300 Cushion

Polyurethane Last-A-Foam FR-4500 Tooling

Polyurethane Last-A-Foam FR-6700 Structural

Polyurethane Last-A-Foam FR-7100 Tooling

Polyurethane Last-A-Foam FR-10100 Structural

Polyurethane Last-A-Foam FR-10700 Tooling

Polyurethane Last-A-Foam TR Foam Marine

Styrofoam DOW STYROFOAM RTM REFRIGERATED TRANSPORT

Styrofoam DOW STYROFOAM HD300 COLDSTORAGE

Styrofoam DOW STYROFOAM LB COMPOSITE PANELS

Styrofoam DOW STYROFOAM LT COLDSTORAGE

Styrofoam DOW STYROFOAM SP COLDSTORAGE

Polystyrene Boedeker Plastics Expanded polystyrene General Purpose Polystyrene 

(GPPS)

Polystyrene Boedeker Plastics Expanded polystyrene High Impact Polystyrene (HIPS)

Polyurethane Rigid Polyurethane Foam

Polyurethane PUR izolace s.r.o. 

Polyurethane- Fiber reinforced

Polymer Divinycell Divinycell H35 Grade Sandwich Composite 

Polymer Divinycell Divinycell H45 Grade Sandwich Composite 

Polymer Divinycell Divinycell HP60 Grade

Marine, Wind Energy, 

Transportation and Industrial 

Markets

Polymer Divinycell Divinycell HP80 Grade

Marine, Wind Energy, 

Transportation and Industrial 

Markets

Polymer Divinycell Divinycell HP100 Grade

Marine, Wind Energy, 

Transportation and Industrial 

Markets

Polymer Divinycell Divinycell HP130 Grade

Marine, Wind Energy, 

Transportation and Industrial 

Markets

Polymer Divinycell Divinycell HP160 Grade

Marine, Wind Energy, 

Transportation and Industrial 

Markets

Polymer Divinycell Divinycell HP200 Grade

Marine, Wind Energy, 

Transportation and Industrial 

Markets

Polymer Divinycell Divinycell HP250 Grade

Marine, Wind Energy, 

Transportation and Industrial 

Markets

Material Type Manufacture Product # Application
31

Table 9 - Core Material List (2 of 3) 

Polymer Divinycell Divinycell F50 Grade Aircraft Interiors

Polymer Divinycell Divinycell F90 Grade Aircraft Interiors

Polymer Divinycell Divinycell F130 Grade Aircraft Interiors

Polymer Divinycell Divinycell P60 Grade Public Transportation, 

Industrial and Wind Energy

Polymer Divinycell Divinycell P100 Grade Public Transportation, 

Industrial and Wind Energy

Polymer Divinycell Divinycell P120 Grade Public Transportation, 

Industrial and Wind Energy

Polymer Divinycell Divinycell P150 Grade Public Transportation, 

Industrial and Wind Energy

Polymer Divinycell Divinycell HT60 Grade Aerospace

Polymer Divinycell Divinycell HT80 Grade Aerospace

Polymer Divinycell Divinycell HT100 Grade Aerospace

Polymer Divinycell Divinycell HT130 Grade Aerospace

Polymer Divinycell Divinycell HCP30 Grade High Density Core for Sub-Sea 

buoyancy

Polymer Divinycell Divinycell HCP50 Grade High Density Core for Sub-Sea 

buoyancy

Polymer Divinycell Divinycell HCP70 Grade High Density Core for Sub-Sea 

buoyancy

Polymer Divinycell Divinycell HCP90 Grade High Density Core for Sub-Sea 

buoyancy

Polymer Divinycell Divinycell HCP100 Grade High Density Core for Sub-Sea 

buoyancy

Linear PVC Core Composite Thermoformable

Linear PVC Core Composite Thermoformable

X-Linked PVC Core Composite 

Structural core like marine 

hulls, decks, wind turbine 

blades

Polyethylene 

terephthalate

3A COMPOSITES CORE 

MATERIALS Airex-t92.100 windenergy,marine,industrial

Polyethylene 

terephthalate

3A COMPOSITES CORE 

MATERIALS Airex-t92.110 windenergy,marine,industrial

Polyethylene 

terephthalate

3A COMPOSITES CORE 

MATERIALS Airex-t92.130 windenergy,marine,industrial

Polyethylene 

terephthalate

3A COMPOSITES CORE 

MATERIALS Airex-t92.200 windenergy,marine,industrial

Polyethylene 

terephthalate Boedeker Plastics, Inc. Ertalyte Fuel pump components

Airex-C70 3A COMPOSITES CORE 

MATERIALS Airex-C70.4 Aerospace cockpit,fuselage

Airex-C71 3A COMPOSITES CORE 

MATERIALS Airex-C71.55

Interiors, radomes, galley 

carts, general aviation (sport 

aircraft)

Airex-R82 3A COMPOSITES CORE 

MATERIALS Airex-R82.6

Interiors, cockpit doors, 

cryogenic tanks, insulating 

panels, radomes,

Material Type Manufacture Product # Application
32

Table 9 - Core Material List (3 of 3) 

Impact damage was selected as the initial characteristic to investigate. Foam core crush strengths 

(compression) range from 36 psi on 1.7 pcf Styrofoam to 5,732 psi on 50 pcf Last-A-Foam FR 4500. 

Balsa wood 3A COMPOSITES CORE 

MATERIALS BALTEK SB 50 Aerospace

Balsa wood 3A COMPOSITES CORE 

MATERIALS BALTEK SB100 Aerospace

Balsa wood 3A COMPOSITES CORE 

MATERIALS BALTEK SB150 Aerospace

Balsa Core Composites End Grain Balsa CD 5 Marine

Balsa wood Diab products Pro Balsa LD7 light 

WEIGHT Aerospace

Honeycomb plastic Nida Core H11PP-45 windenergy,marine,industrial

Honeycomb- paper Core Composites Nomex Aircraft Interiors

Honeycomb- paper Core Composites Nomex Aircraft Interiors

Honeycomb-filled

HoneycombFibreGlass Ultracore UGF-250F-3/8 -2.5 Aerospace

HoneycombFibreGlass Ultracore UGF-256F-1/4 -4 Aerospace

Honeycomb- Metallic Core Composites Aluminium Marine Structures

Honeycomb- Metallic Core Composites Aluminium Marine Structures

Lantor Soric Lantor Composites Lantor Soric SF 2 windenergy,marine,industrial

Lantor Coremat Lantor Composites Lantor Coremat Xi windenergy,marine,industrial

Other

Innegra S Innegrity Innegra S

Police and military vests and 

helmets, composite arnor for 

aircraft and vehicles, 

aerospace structures

Tegris 

(polypropylene) Milliken & Company Tegris sheet

AntiBallistics,Transportation,Sports 

and Leisure,Watersports

Solimide Evonik industries AC530 Polymide Aerospace

Solimide Evonik industries AC550 Polymide Aerospace

Polymide GFT LLC Performa-H

IMPAXX Foam Dow IMPAXX 300 Energy 

Absorbing Foam

Variety of industries requiring 

enhanced safety features 

through energy absorbing 

coutnermeasures.

IMPAXX Foam Dow IMPAXX 700 Energy 

Absorbing Foam

Variety of industries requiring 

enhanced safety features 

through energy absorbing 

coutnermeasures.

Polydamp 

Hydrophobic 

Melamine Foam

Polymer Technologies Inc. Polydamp Hydrophobic 

Melamine foam (PHM)

HVAC and ECS ducts, 

wall/fuselage insulation in 

aircraft, mass transit, etc.

Material Type Manufacture Product # Application
33

Honeycomb crush strengths range from 95 psi on 1.5 pcf Honeycomb Nomex to 2900 psi on 12 pcf

Honeycomb Aluminum. Figure 21 clearly shows that honeycomb has greater strength at lower densities 

than foam. For a given required compression strength, a foam core would need to have approximately 

three times the density in order to match the compression strength. 

Figure 21: Compression strength as a function of density for foam and honeycomb core materials.

Compression strength is key to impact damage calculations. A core thickness prediction which meets 

the impact energy requirement can be made based on the compression modulus of the materials. The 

following assumptions were made in order to make the calculation. The load is assumed to increase 

linearly until crushing is initiated. The load is then considered to be constant until core failure. Failure is 

predicted at 50% of the core total design thickness. The requirement for impact is a standard load of 

3.0 lbs dropped from a height of 60 in yielding an impact of 180 inch-lbs. An impact diameter of 1.0 in2

was used. 

The results of the calculations are shown in Figure 22. To keep the core thickness at 0.4 in, the 

aluminum honeycomb would require 6.0 lb/ft3

density core as compared to the foam cores requiring 15-

30 lb/ft3. For this figure, the core material thickness was limited to 2.0”. The goal for the thickness 

metric set out earlier was a maximum thickness of 1.0 in and a target of 0.25 in. At total thickness of the 

core layer of 0.20” would require a 12 lb/ft3honeycomb core or between 30-35 lb/ft3foam core, with a 

possibility of up to 45 lb/ft3FR 4500 Last-A-Foam. This result allows elimination of over 50% of the 

database, including any honeycomb less than 6.0 lb/ft3 and foam under 10 lb/ft3. 

Based on these results any one of the honeycomb core materials would be a good choice for impact 

absorption ability. Honeycomb will present extra challenges compared to foam with manufacturability 

and repair. Stiffness of the honeycomb will make draping the material around complex curvatures 

0

1,000

2,000

3,000

4,000

5,000

6,000 1.5 1.7 1.9 2.1 2.5 2.8 3.0 3.8 4.0 4.5 5.0 5.4 6.0 6.3 6.4 7.0 8.0 8.1 8.8 9.0 10.0 12.0 12.5 13.1 15.0 15.6 18.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0 55.0 60.0 Compression Strength, lb/in^2

Density, lb/ft^3

FR3700

FR4300

FR4500

FR6700

FR7100

FR10100

Styrofoam

Divinycell Sand

Divinycell Aero

X-Linked PVC

H/C -Nomex

H/C Fiberglass

H/C Alum
34

difficult, and obtaining smooth seams and small gaps when joining panels together or making repairs will 

require research. Foam would be a much better solution for these issues. However, the significantly 

higher densities and thicknesses required by foam materials would quickly eliminate the lighter weight 

and increase the drag more than it is reduced by natural laminar flow. 

Figure 22: Required sheet thickness for honeycomb and foam core materials.

The core thickness calculations used an impact area of 1.0 in2. Given that the thicknesses of required 

core materials were larger than desired, a study was conducted on the effect of impact area. The 4.5 pcf 

aluminum honeycomb compression strength and modulus were used for the study; results are shown in 

Figure 23. Increasing the impact area has a large effect on the decrease in required core thickness. There 

are at least two ways to increase the impact area: 1) use a larger impactor (not practical since in actual 

use the size of objects impacting the aircraft is not controllable); or 2) put a structurally stiffer or “hard” 

shell over the core to spread the impact load over a wider area. The hard shell concept is widely used and 

can easily be seen in the helmets used by race car drivers, motorcyclists, and other numerous sporting 

activities where crash protection is critical. 

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

2.00 1.5 1.7 1.9 2.1 2.5 2.8 3.0 3.8 4.0 4.5 5.0 5.4 6.0 6.3 6.4 7.0 8.0 8.1 8.8 9.0 10.0 12.0 12.5 13.1 15.0 15.6 18.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0 55.0 60.0 Sheet Thickness, in

Density, lbs/ft^3

FR3700

FR4300

FR4500

FR6700

FR7100

FR10100

Divinycell Sand

H/C Nomex

H/C Fiberglass

H/C Alum
35

Figure 23: Required core thickness for varying impactor sizes.

The protective skin functional diagram, modified to include a shell layer, is shown in 

Figure 24. In addition to spreading the load, the shell could also potentially serve as the moisture barrier. 

With this concept, the number of layers for the protective skins would go from two to three. There is a 

possibility, although remote, that a material could be found which could meet both the shell and the film 

functions. The most likely STAR-C2

protective skin will have at least three layers. 

Figure 24: Functional arrangement for protective skins with three layers.

0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

1 0 9 8 7 6 5 4 3 2 1 0

Impact Area (in^2)

Required Core Thickness(in)

Composite 

Structure

Loads Core Lightning 

Strike*

Cosmetic

Smoothing* Shell Film Impact (spread load)*

Moisture 

Barrier

*Critical or design requirement Interior Primary 

Structure External Key

Thermal

Impact (absorb energy)*

Acoustic Reflection
36

6.2 Conductive Films 

The 32 unique characteristics sought for the film materials are shown in Table 10. While there are 

many similarities between the core and film characteristics, there are also some key differences. While 

the core materials focus on strengths, the film materials focus more on electrical conductivity and color. 

There are 44 film materials in the database as shown in Table 11. The search for these materials was 

frustrating in that there were so many options. The options for films which can be printed appear to be 

nearly unlimited. However, the options for films which can be printed, look good, withstand the flight 

environment, provide lightning protection, and provide adequate reflection to keep the primary composite 

structure skin temperature low are difficult to uncover, partly due to lack of comprehensive and consistent 

data. More work is needed with specific vendors to look for options that will work. 

6.2.1 Smoothness 

Laminar flow is a strong function of smoothness. Critical issues for the STAR-C2 skins are related to 

the joining/sectioning of the panels and around windows, doors, etc. The film materials should be thick 

enough to reduce the criticality of these joints. Having the capability to provide rounded steps is also a 

desirable property of the films. 

6.2.2 Lightning Strike 

The traditional method of protecting composite structures for lightning strike is to add a layer of 

expanded metal (usually aluminum or copper) foil. The lightest weight foils usually provide adequate 

protection over areas at least 12 in wide (Reference 14); heavier weight foils need to be applied to narrow 

strips. Expanded aluminum mesh weighing 0.016 lb/ft2provides 8-12 kA/inch of current density 

capability. For comparison, 0.028 lb/ft2copper expanded mesh provides 7 kA/inch. Solid aluminum 

0.0001 in thick provides 8 kA/in, 0.002 in thick provides 14 kA/in, 0.003 in thick provides 20 kA/in, and 

0.006 in thick provides 35 kA/in. Application of solid foil is not desirable because it is difficult to drape, 

difficult to fit over complex geometries, and difficult to bond. There is a weight penalty for traditional 

lightning protection. Expanded aluminum foil weighs about 1.6 lbs/100 ft2, interwoven aluminum wire 

about 0.024 lbs/100 ft2, solid aluminum foil about 8.5 lbs/100 ft2, aluminum thermal spray 5.75 to 8 

lbs/ft2, and silver conductive paint about 8 lbs/100 ft2. The goal for lightning strike protection for the 

STAR-C2

skins is to a material which has current density capability of 8-12 kA/in. 

6.2.3 Cosmetic 

Cosmetic concerns include the material being a reasonable overall color and being able to be colored 

in local areas by printing. Development of initial data base used screening for printing ability so materials 

which cannot be decorated by printing are not included. 

6.2.4 Reflection 

The proper reflectivity of the film material is crucial to maintaining moderate temperatures of the 

primary structure. There are very impressive window films (many made by 3M) which have 99.99% ultra 

violet (UV) rejection and 97% infrared (IR) rejection. 
37

Table 10 - Film Materials Properties Sought 

Material Type

Manufacture

Product #

Application

Density (lb/ft^3)

Low (in)

High (in)

Brittleness

Heat Deflection Temperature

Tg

Color

Chemical- resistant

Water Absorption (%, 24 hrs)

Thermal conductivity (Btu/hr/ft^2/deg F/in)

Thermal Expansion (x10-5/deg F)

HWI(in)

HAI(in)

CTE (mean) x10-5 in/in/F 

 lbs/ft^3

Puncture Resistance (ft-lb)

Initiation (lb/mil)

Propogation (lb/mil)

Strength (MAX)

Modulus

Diaelectric Strength

Dielectric Constant (ASTM D150 @60Hz)

Dielectric Constant (ASTM D150 @1M Hz)

Dissipation factor (ASTM D150 @ 60Hz)

Dissipation factor (ASTM D150 @ 1M Hz)

Volume Resistivity (W-cm)

Surface Resistivity (W-square)

Costs

Tensile (psi)

Thickness (in)

Flammability

Tear Strength
38

Table 11- Film Materials (1 of 2) 

Material Type Manufacture Product # Application

Polycarbornate LEXAN FR25A General use

Polycarbornate curbellplastics DE 1-1 gloss/gloss General use

Polycarbornate curbellplastics Polycarbo te Film PCVM 

Velvet/Matte

General use

Polyester curbellplastics SH71S mechanical and

dielectric strength

Polyester The Gund Company, Inc. Melinex Polyester Film Type 

226

electrical insulation

Questa polyester 

polyethylene terephthlate Filmquest --

electrical insulation,industries

Acrylic Polymer DOW Rhoplex EC-1791 Roof Coating

Epoxy Film 3M Super 10

Electrical Tape

Polyimide DuPont Kapton HN 

Polyimide DuPont Kapton 500HN

Polyimide DuPont Kapton 300MTB

Polyimide DuPont Kapton 500MTB

Polyimide DuPont TM Cirlex ® 900CL

Polyimide DuPont TM Cirlex ® 1200CL

Polyimide DuPont TM Cirlex ® 1500CL

Polyimide DuPont TM Cirlex ® 3000CL

Polyimide DuPont TM Cirlex ® 5000CL

Polyimide Boedeker Imidex

Thin Fluoropolymer Welch Fluorocarbon

Modified

PTFE 

(polytetrafluoroethylene)

Thin Fluoropolymer Welch Fluorocarbon PFA(perfluoroalkoxy) 

Thin Fluoropolymer Welch Fluorocarbon FEP(fluoroethylenepropylene) 

Thin Fluoropolymer Welch Fluorocarbon

ETFE(ethylenetetrafluoroethylenecopolymer)

Thin Fluoropolymer Welch Fluorocarbon(Halar®) ECTFE(ethylenechlorotrifluoroethylene)

Thin Fluoropolymer Welch Fluorocarbon PVF(polyvinyl-fluoride) 

Thin Fluoropolymer Welch Fluorocarbon(Aclar® & Clarus®) PCTFE(polychlorotrifluoroethylene)

Tempalux Westlake Plastics polyetherimide(PEI)

High temperature 

labels,Electrical insulation,Hot 

melt adhesives

Thermalux Westlake Plastics polysulfone

electronics,medical devices, 

chemical process equipment 

and automotive industries
39

Table 11 - Film Materials (2 of 2) 

Material Type Manufacture Product # Application

Tedlar(polyvinyl fluoride 

film) Dupont TTR5JAM9

gas sampling,sound-absorbing 

ceiling tiles

 Fluoropolymer film Saint-Gobain Advanced Films Norton® ECTFE

electrical tapes, cable 

insulation, printed circuits, 

capacitors

Thermoplastic 

Polyurethane Films Kerafol Keratherm – MT 102

Flexible ceramic heat 

conducting and isolating tape

Thermoplastic 

Polyurethane Films Kerafol Keratherm – MT 103 Flexible ceramic heat conducting and isolating tape

Silicone Elastomer Kerafol Keratherm White 86/30

Power supplies 

White goods 

Audio and video Components 

Engine controllers 

Power converters

Silicone Elastomer Kerafol Keratherm Green 86/37

Automotive 

Telecommunication units 

DC-DC converters 

High voltage units 

Silicone Elastomer Kerafol Keratherm Pink 86/50

Automotive 

White goods 

Engine controllers 

Audio and video Components 

LCD displays 

Power converters

Silicone Elastomer Kerafol Keratherm Red 86/81

High end thermal solutions 

Hard disc drives 

Controlling boards 

BGA applications

Silicone Elastomer Kerafol Keratherm Red 86/82 

(w/fiberglass)

High end thermal solutions 

Hard disc drives 

Controlling boards 

BGA applications

Silicone Elastomer Kerafol Keratherm Red 86/83 

(w/fiberglass)

High end thermal solutions 

Hard disc drives 

Controlling boards 

BGA applications

Silicone Elastomer Kerafol Keratherm Brown 70/50

w/fiberglass

Automotive 

White goods 

Engine controllers 

Audio and video Components 

LCD displays 

Power converters

PCE Films Kerafol Keratherm – 86/114 Flexible heat conducting and 

Isolating tape

PCE Films Kerafol Keratherm – 86/117 Flexible heat conducting and 

Isolating tape

Fluorogrip polymer 

film(ethylenechlorotrifluoroethylene)Integument Technologies, Inc. LS-1000

constructing structures that are 

susceptible to lightning strikes

FluoroGrip Optically Clear 

Film Integument Technologies, Inc. F Optically Clear (HD-FEP) Teflon

to protect standard 

polycarbonate glass used on 

equipment such as critical 

clean and etch, post-ash 

clean/photoresist strip

FluoroGrip® – E 

fluoropolymer Integument Technologies, Inc. E (ECTFE) Halar

tanks,and hoppers,pipe wraps, 

anti-graffiti, paint replacement,

splash and spill protection and 

exterior corrosion protection

of steel, concrete, fiberglass 

and other plastic structures

and equipment

FluoroGrip® – MFA Integument Technologies, Inc. TFE/perfluoromethylvinylether

tank linings,splash-and-spill 

environments,UV protection
40

7 First-Generation Test Articles 

During the program, two generations of test articles were constructed and tested. The first-generation 

test articles consisted of a wide variety of materials and thicknesses of materials. The materials were 

selected partially based on investigator familiarity and partially based on availability within the project 

timeframe. This was the first time many of these materials had been combined. Cessna standard resins 

and adhesives were used without significant consideration for the integration of the materials. The testing 

could be regarded as screening tests. The goal of the first generation of test articles was to validate 

material thoughts and provide direction on a much more focused second generation of test articles. The 

Section 7 subsections describe the first generation of test articles and the testing, with final thoughts on 

the material composition for the second generation of test articles. 

7.1 Test Articles 

The most promising materials were selected for impact spreading, impact absorbing, lightning strike 

protection, and aesthetics and smoothing. The materials are identified and described in Section 7.1.1. 

Links to manufacturer websites with information about the materials are presented in Appendix A – Links 

to Information about Materials Used. These materials were combined into 173 test articles. The test 

article composition and geometry will be presented in Section 7.1.2. 

7.1.1 Material Definition 

The materials used in the test articles are shown in the following five tables. Table 12 shows the 

energy (impact) absorbing materials used in the test articles. There are three volumetric densities of 

polyurethane core, one non-metallic honeycomb (used for aesthetics and smoothing), three volumetric 

densities of metallic honeycomb (while 9 pcf was desired, the supplier could only get 7.9 pcf in the 

timeframe available to build the panels), two different types of Soric with three thicknesses, and one 

Polydamp hydrophobic melamine foam with metalized PEEK skin. 

Table 13 shows the materials used for the impact spreading layer. The Innegra S and Tegris LM were 

of serious interest. The carbon epoxy was used to determine the performance of a known material which 

is also known to be heavy. The aluminum sheet was used for comparison because it would produce 

definite permanent damage. 
41

Table 12 - Energy Absorbing Materials 

Material Trade Name Material Composition

10 pcf polyurethane core, FR-6710 Polyurethane

20 pcf polyurethane core, FR-6720 Polyurethane

30 pcf polyurethane core, FR-3730 Polyurethane

4 pcf non-metallic (Nomex 1/8” cell)

honeycomb core

Nomex honeycomb

3 pcf metallic honeycomb core (1/4” cell, 

5052 aluminum, 0.0015” thick wall, nominally 

3.4 pcf)

Aluminum honeycomb

6 pcf metallic honeycomb core (1/4” cell, 5052 

aluminum, 0.003” thick wall, nominally 6.0 

pcf)

Aluminum honeycomb

7.9 pcf metallic honeycomb core (1/4” cell, 

5052 aluminum, 0.004” thick wall, nominally 

7.9 pcf)

Aluminum honeycomb

Soric LRC – Low Resin Content (2 and 3 mm) Polyester nonwoven with compression 

resistant hexagonal cell structure containing 

synthetic micro-spheres

Soric XF (2 and 6 mm) Polyester nonwoven with compression 

resistant hexagonal cell structure containing 

synthetic micro-spheres

Polydamp hydrophobic melamine with 

metalized PEEK skin on one side and pressure 

sensitive adhesive on the other side

Melamine foam with metalized polyether ether 

ketone thermoplastic skin on the outer facing 

side of the foam and with pressure sensitive 

adhesive on the inner facing side of the foam

Table 13 - Impact Spreading Layer Materials 

Material Trade Name Material Composition

Innegra S plain weave Polypropylene

Tegris LM plain weave Polypropylene

Carbon epoxy Besfight G30-500 3K tow 8 harness satin 

weave

Aluminum alloy sheet (0.012”) Aluminum

The lightning strike protection materials are shown in Table 14. The 0.016 psf expanded aluminum 

foil and 0.029 psf expanded copper foil are current standard lightning strike materials. The Integument 

with lightning strike protection was a premade combination of Integument film and traditional aluminum 

foil lightning strike protection. The LDS 50-01 0.007 is a new (to Cessna) very light and very fragile 

aluminum foil (it greatly resembles a gum foil wrapper). The proprietary spray and Nanocomp 

Technologies carbon nanotube materials were special materials which were included to represent newer 

technology materials. The proprietary spray material was heavy and did not perform particularly well on 

direct lightning strikes. The carbon nanotube materials did not fit within the target material cost per 

square foot. 

Table 15 describes the five aesthetic layer materials. Three of the materials (Integument, 3M 5004, 

and Aptiv PEEK) came with pressure sensitive adhesive. The 3M F9460PC transfer tape (presented in 
42

Table 16) was used for the Halar and Kapton to adhere the films to the lightning strike protection layers. 

No special treatments were requested on the adhesive side of the films to aid adhesion. 

Table 14 - Lightning Strike Protection Materials 

Material Trade Name Material Composition

0.016 psf expanded aluminum foil Aluminum

Integument with lightning strike 

protection and pressure sensitive 

adhesive

Fluorogrip polymer film (ethylenechlorotrifluoroethylene) with 0.016 psf 

expanded aluminum foil

0.029 psf expanded copper foil Copper

LDS 50-01 0.007 psf aluminum Aluminum

Proprietary Spray Material Proprietary Spray Material

Nanocomp 11 and 15 gsm carbon 

nanotube sheets

Carbon nanotubes

Table 15 - Aesthetic Layer Materials 

Material Trade Name Material Composition

Integument film with pressure sensitive 

adhesive

Fluorogrip polymer film (ethylenechlorotrifluoroethylene)

3M 5004 with pressure sensitive adhesive Fluoropolymer film with acrylic adhesive

Halar Ethylene-chlorotrifluoroethylene

Aptiv PEEK with pressure sensitive 

adhesive

Polyaryletherketone in a flexible film format

Kapton Polyimide

Table 16 - Interface Layers Material Definition 

Material Trade Name Material Composition

3M 4950 Very High Bond Double-Sided 

Foam Tape (45 mil thick)

Viscoelastic acrylic foam

Aeropoxy PR2032 and hardener PH3660 Multifunctional acrylate resin and modified 

amine mixture with diphenylolpropane 

hardener

Grade 30 film adhesive FM 73C fracture-tough modified epoxy-nitrile 

structural film

3M F9460PC transfer tape (2.0 mil thick) 3M 100MP acrylic adhesive 

The interface layers material definitions are presented in Table 16. All of the test articles had 3M 

4950 Very High Bond (VHB) double-sided foam tape on the back side of the protective skin to attach the 

protective skin to the base substrate panel. Protective backings were not removed from the 3M 4950 tape 

for most of the impact test articles so that the base substrate panels could be inspected from the top side. 

The Aeropoxy resin system was used to bond the foam cores and Soric. The Grade 30 film adhesive was 

used over the top of honeycomb to provide an adhesive surface without allowing resin to fill the cells of 

the honeycomb which would greatly increase the weight. And finally, as previously mentioned in this 

section, the 3M F9460PC transfer tape was used to adhere the Halar and Kapton aesthetic films to the 

lightning strike material. 
43

7.1.2 Drawings 

Table 17 shows the combinations of materials used in the impact panels; Figure 25 shows a sample 

drawing for the impact panels. Each panel was 24” by 24”, and all of the layers extended the full 24” by 

24.” The impact panels do not have lightning strike protection or aesthetic film; they do have the impact 

absorbing and impact spreading layers in all but one case – for panel IM-100, the material is a 

combination impact protecting/spreading layer combined. 

The combinations of materials used in the lightning strike panels is shown in Table 18, a sample 

drawing of the lightning strike panels is shown in Figure 26. The lightning strike panels contain material 

for all of the planned layers of material. The lightning strike base panels are 24” by 24” like the impact 

and aesthetics and smoothing panels. The impact absorbing, impact spreading, and lightning strike layers 

are 22” x 22” which allows the panels to fit in the opening between the two reverberation chambers used 

to measure transmissivity. The aesthetic film layer is recessed another 3⁄4” to allow grounding of the 

lightning strike layer to the aluminum frame used to mount the panels in the window. Copper tape was 

also used on the base panels to help with grounding. 

Table 19 shows the aesthetics and smoothing panels material build-up, and Figure 27 presents a 

sample drawing of the aesthetics and smoothing panels. Similar to the impact panels, all of the layers are 

24” by 24.” 
44

Table 17 - Impact Panel Material Build-up (1 of 2) 

Panel ID Base Panel Interface Impact Absorbing Foam Layer Interface Impact Spreading Layer

IM-1 7 ply carbon uni epoxy None None None None

IM-2 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1/4" thick VARTM Carbon epoxy

IM-3 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1/4" thick VARTM Innegra

IM-4 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1/4" thick adhesive 0.012" aluminum sheet

IM-5 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1/4" thick VARTM Tegris LM

IM-6 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1/2" thick VARTM Carbon epoxy

IM-7 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1/2" thick VARTM Innegra

IM-8 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1/2" thick VARTM Tegris LM

IM-9 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 3/4" thick VARTM Carbon epoxy

IM-10 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 3/4" thick VARTM Innegra

IM-11 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 3/4" thick VARTM Tegris LM

IM-12 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1" thick VARTM Carbon epoxy

IM-13 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1" thick VARTM Innegra

IM-14 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1" thick adhesive 0.012" aluminum sheet

IM-15 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1" thick VARTM Tegris LM

IM-16 7 ply carbon uni epoxy VHB Tape 20 pcf PU core, 1/4" thick VARTM Carbon epoxy

IM-17 7 ply carbon uni epoxy VHB Tape 20 pcf PU core, 1/4" thick VARTM Innegra

IM-18 7 ply carbon uni epoxy VHB Tape 20 pcf PU core, 1/4" thick adhesive 0.012" aluminum sheet

IM-19 7 ply carbon uni epoxy VHB Tape 20 pcf PU core, 1/4" thick VARTM Tegris LM

IM-20 7 ply carbon uni epoxy VHB Tape 20 pcf PU core, 1/2" thick VARTM Carbon epoxy

IM-21 7 ply carbon uni epoxy VHB Tape 20 pcf PU core, 1/2" thick VARTM Innegra

IM-22 7 ply carbon uni epoxy VHB Tape 20 pcf PU core, 1/2" thick VARTM Tegris LM

IM-23 7 ply carbon uni epoxy VHB Tape 20 pcf PU core, 3/4" thick VARTM Carbon epoxy

IM-24 7 ply carbon uni epoxy VHB Tape 20 pcf PU core, 3/4" thick VARTM Innegra

IM-25 7 ply carbon uni epoxy VHB Tape 20 pcf PU core, 3/4" thick VARTM Tegris LM

IM-26 7 ply carbon uni epoxy VHB Tape 20 pcf PU core, 1" thick VARTM Carbon epoxy

IM-27 7 ply carbon uni epoxy VHB Tape 20 pcf PU core, 1" thick VARTM Innegra

IM-28 7 ply carbon uni epoxy VHB Tape 20 pcf PU core, 1" thick adhesive 0.012" aluminum sheet

IM-29 7 ply carbon uni epoxy VHB Tape 20 pcf PU core, 1" thick VARTM Tegris LM

IM-30 7 ply carbon uni epoxy VHB Tape 30 pcf PU core, 1/4" thick VARTM Carbon epoxy

IM-31 7 ply carbon uni epoxy VHB Tape 30 pcf PU core, 1/4" thick VARTM Innegra

IM-32 7 ply carbon uni epoxy VHB Tape 30 pcf PU core, 1/4" thick adhesive 0.012" aluminum sheet

IM-33 7 ply carbon uni epoxy VHB Tape 30 pcf PU core, 1/4" thick VARTM Tegris LM

IM-34 7 ply carbon uni epoxy VHB Tape 30 pcf PU core, 1/2" thick VARTM Carbon epoxy

IM-35 7 ply carbon uni epoxy VHB Tape 30 pcf PU core, 1/2" thick VARTM Innegra

IM-36 7 ply carbon uni epoxy VHB Tape 30 pcf PU core, 1/2" thick VARTM Tegris LM

IM-37 7 ply carbon uni epoxy VHB Tape 30 pcf PU core, 3/4" thick VARTM Carbon epoxy

IM-38 7 ply carbon uni epoxy VHB Tape 30 pcf PU core, 3/4" thick VARTM Innegra

IM-39 7 ply carbon uni epoxy VHB Tape 30 pcf PU core, 3/4" thick VARTM Tegris LM

IM-40 7 ply carbon uni epoxy VHB Tape 30 pcf PU core, 1" thick VARTM Carbon epoxy

IM-41 7 ply carbon uni epoxy VHB Tape 30 pcf PU core, 1" thick VARTM Innegra

IM-42 7 ply carbon uni epoxy VHB Tape 30 pcf PU core, 1" thick adhesive 0.012" aluminum sheet

IM-43 7 ply carbon uni epoxy VHB Tape 30 pcf PU core, 1" thick VARTM Tegris LM

IM-44 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 1/4" thick adhesive Carbon epoxy

IM-45 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 1/4" thick adhesive Innegra

IM-46 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 1/4" thick adhesive 0.012" aluminum sheet

IM-47 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 1/4" thick adhesive Tegris LM

IM-48 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 1/2" thick adhesive Carbon epoxy

IM-49 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 1/2" thick adhesive Innegra

IM-50 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 1/2" thick adhesive Tegris LM
45

Table 17 – Impact Panel Material Build-up (2 of 2) 

Panel ID Base Panel Interface Impact Absorbing Foam Layer Interface Impact Spreading Layer

IM-51 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 3/4" thick adhesive Carbon epoxy

IM-52 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 3/4" thick adhesive Innegra

IM-53 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 3/4" thick adhesive Tegris LM

IM-54 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 1" thick adhesive Carbon epoxy

IM-55 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 1" thick adhesive Innegra

IM-56 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 1" thick adhesive 0.012" aluminum sheet

IM-57 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 1" thick adhesive Tegris LM

IM-58 7 ply carbon uni epoxy VHB Tape 6 pcf metallic honeycomb, 1/4" thick adhesive Carbon epoxy

IM-59 7 ply carbon uni epoxy VHB Tape 6 pcf metallic honeycomb, 1/4" thick adhesive Innegra

IM-60 7 ply carbon uni epoxy VHB Tape 6 pcf metallic honeycomb, 1/4" thick adhesive 0.012" aluminum sheet

IM-61 7 ply carbon uni epoxy VHB Tape 6 pcf metallic honeycomb, 1/4" thick adhesive Tegris LM

IM-62 7 ply carbon uni epoxy VHB Tape 6 pcf metallic honeycomb, 1/2" thick adhesive Carbon epoxy

IM-63 7 ply carbon uni epoxy VHB Tape 6 pcf metallic honeycomb, 1/2" thick adhesive Innegra

IM-64 7 ply carbon uni epoxy VHB Tape 6 pcf metallic honeycomb, 1/2" thick adhesive Tegris LM

IM-65 7 ply carbon uni epoxy VHB Tape 6 pcf metallic honeycomb, 3/4" thick adhesive Carbon epoxy

IM-66 7 ply carbon uni epoxy VHB Tape 6 pcf metallic honeycomb, 3/4" thick adhesive Innegra

IM-67 7 ply carbon uni epoxy VHB Tape 6 pcf metallic honeycomb, 3/4" thick adhesive Tegris LM

IM-68 7 ply carbon uni epoxy VHB Tape 6 pcf metallic honeycomb, 1" thick adhesive Carbon epoxy

IM-69 7 ply carbon uni epoxy VHB Tape 6 pcf metallic honeycomb, 1" thick adhesive Innegra

IM-70 7 ply carbon uni epoxy VHB Tape 6 pcf metallic honeycomb, 1" thick adhesive 0.012" aluminum sheet

IM-71 7 ply carbon uni epoxy VHB Tape 6 pcf metallic honeycomb, 1" thick adhesive Tegris LM

IM-72 7 ply carbon uni epoxy VHB Tape 9 pcf metallic honeycomb, 1/4" thick adhesive Carbon epoxy

IM-73 7 ply carbon uni epoxy VHB Tape 9 pcf metallic honeycomb, 1/4" thick adhesive Innegra

IM-74 7 ply carbon uni epoxy VHB Tape 9 pcf metallic honeycomb, 1/4" thick adhesive 0.012" aluminum sheet

IM-75 7 ply carbon uni epoxy VHB Tape 9 pcf metallic honeycomb, 1/4" thick adhesive Tegris LM

IM-76 7 ply carbon uni epoxy VHB Tape 9 pcf metallic honeycomb, 1/2" thick adhesive Carbon epoxy

IM-77 7 ply carbon uni epoxy VHB Tape 9 pcf metallic honeycomb, 1/2" thick adhesive Innegra

IM-78 7 ply carbon uni epoxy VHB Tape 9 pcf metallic honeycomb, 1/2" thick adhesive Tegris LM

IM-79 7 ply carbon uni epoxy VHB Tape 9 pcf metallic honeycomb, 3/4" thick adhesive Carbon epoxy

IM-80 7 ply carbon uni epoxy VHB Tape 9 pcf metallic honeycomb, 3/4" thick adhesive Innegra

IM-81 7 ply carbon uni epoxy VHB Tape 9 pcf metallic honeycomb, 3/4" thick adhesive Tegris LM

IM-82 7 ply carbon uni epoxy VHB Tape 9 pcf metallic honeycomb, 1" thick adhesive Carbon epoxy

IM-83 7 ply carbon uni epoxy VHB Tape 9 pcf metallic honeycomb, 1" thick adhesive Innegra

IM-84 7 ply carbon uni epoxy VHB Tape 9 pcf metallic honeycomb, 1" thick adhesive 0.012" aluminum sheet

IM-85 7 ply carbon uni epoxy VHB Tape 9 pcf metallic honeycomb, 1" thick adhesive Tegris LM

IM-86 7 ply carbon uni epoxy VHB Tape Soric LRC, 2mm thick VARTM Carbon epoxy

IM-87 7 ply carbon uni epoxy VHB Tape Soric LRC, 2mm thick VARTM Innegra

IM-88 7 ply carbon uni epoxy VHB Tape Soric LRC, 2mm thick VARTM Tegris LM

IM-89 7 ply carbon uni epoxy VHB Tape Soric LRC, 3mm thick VARTM Carbon epoxy

IM-90 7 ply carbon uni epoxy VHB Tape Soric LRC, 3mm thick VARTM Innegra

IM-91 7 ply carbon uni epoxy VHB Tape Soric LRC, 3mm thick VARTM 0.012" aluminum sheet

IM-92 7 ply carbon uni epoxy VHB Tape Soric LRC, 3mm thick VARTM Tegris LM

IM-93 7 ply carbon uni epoxy VHB Tape Soric XF, 2mm thick VARTM Carbon epoxy

IM-94 7 ply carbon uni epoxy VHB Tape Soric XF, 2mm thick VARTM Innegra

IM-95 7 ply carbon uni epoxy VHB Tape Soric XF, 2mm thick VARTM Tegris LM

IM-96 7 ply carbon uni epoxy VHB Tape Soric XF, 6mm thick VARTM Carbon epoxy

IM-97 7 ply carbon uni epoxy VHB Tape Soric XF, 6mm thick VARTM Innegra

IM-98 7 ply carbon uni epoxy VHB Tape Soric XF, 6mm thick VARTM 0.012" aluminum sheet

IM-99 7 ply carbon uni epoxy VHB Tape Soric XF, 6mm thick VARTM Tegris LM

IM-100 7 ply carbon uni epoxy VHB Tape

Polydamp Hydrophobic Melamine 

with PEEK skin (3/4" thick) None None
46

Figure 25: Sample drawing for the impact panels. 
47

Table 18 - Lightning Strike Panel Material Build-up 

Panel ID Base Panel Interface Impact Absorbing Foam Layer Interface

Impact Spreading 

Layer Interface Lightning Strike Material Interface Aesthetic Film

LS-1 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1/4" thick VARTM Innegra S VARTM 0.016 psf expanded aluminum foil none Integument film

LS-2 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1/4" thick VARTM Innegra S VARTM 0.029 expanded copper foil none Integument film

LS-4 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1/4" thick VARTM Innegra S VARTM LDS 50-01 0.007 psf aluminum none Integument film

LS-5 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1/4" thick VARTM Innegra S None Integument with integrated LSP & PSA none none

LS-6 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1/4" thick VARTM Innegra S None LORD Spray Material none Integument film

LS-7 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1/4" thick VARTM Carbon Epoxy None Integument with integrated LSP & PSA none none

LS-8 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1/4" thick VARTM Tegris LM None Integument with integrated LSP & PSA none none

LS-9 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 3/4" thick VARTM Innegra S VARTM LDS 50-01 0.007 psf aluminum none Integument film

LS-10 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 3/4" thick VARTM Innegra S None Integument with integrated LSP & PSA none none

LS-11 7 ply carbon uni epoxy VHB Tape 20 pcf PU core, 1/4" thick VARTM Innegra S VARTM LDS 50-01 0.007 psf aluminum none Integument film

LS-12 7 ply carbon uni epoxy VHB Tape 20 pcf PU core, 1/4" thick VARTM Innegra S None Integument with integrated LSP & PSA none none

LS-13 7 ply carbon uni epoxy VHB Tape 30 pcf PU core, 1/4" thick VARTM Innegra S VARTM LDS 50-01 0.007 psf aluminum none Integument film

LS-14 7 ply carbon uni epoxy VHB Tape 30 pcf PU core, 1/4" thick VARTM Innegra S None Integument with integrated LSP & PSA none none

LS-15 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 1/4" thick adhesive Innegra S VARTM 0.016 psf expanded aluminum foil none Integument film

LS-16 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 1/4" thick adhesive Innegra S VARTM 0.029 expanded copper foil none Integument film

LS-18 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 1/4" thick adhesive Innegra S VARTM LDS 50-01 0.007 psf aluminum none Integument film

LS-19 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 1/4" thick adhesive Innegra S None Integument with integrated LSP & PSA none none

LS-20 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 1/4" thick adhesive Innegra S None LORD Spray Material none Integument film

LS-21 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 1/4" thick adhesive Carbon Epoxy None Integument with integrated LSP & PSA none none

LS-22 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 1/4" thick adhesive Tegris LM None Integument with integrated LSP & PSA none none

LS-23 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 3/4" thick adhesive Innegra S VARTM LDS 50-01 0.007 psf aluminum none Integument film

LS-24 7 ply carbon uni epoxy VHB Tape 3 pcf metallic honeycomb, 3/4" thick adhesive Innegra S None Integument with integrated LSP & PSA none none

LS-25 7 ply carbon uni epoxy VHB Tape 6 pcf metallic honeycomb, 1/4" thick adhesive Innegra S VARTM LDS 50-01 0.007 psf aluminum none Integument film

LS-26 7 ply carbon uni epoxy VHB Tape 6 pcf metallic honeycomb, 1/4" thick adhesive Innegra S None Integument with integrated LSP & PSA none none

LS-27 7 ply carbon uni epoxy VHB Tape 9 pcf metallic honeycomb, 1/4" thick adhesive Innegra S VARTM LDS 50-01 0.007 psf aluminum none Integument film

LS-28 7 ply carbon uni epoxy VHB Tape 9 pcf metallic honeycomb, 1/4" thick adhesive Innegra S None Integument with integrated LSP & PSA none none

LS-29 7 ply carbon uni epoxy VHB Tape Soric XF, 2mm thick VARTM Innegra S VARTM 0.016 psf expanded aluminum foil none Integument film

LS-30 7 ply carbon uni epoxy VHB Tape Soric XF, 2mm thick VARTM Innegra S VARTM 0.029 expanded copper foil none Integument film

LS-32 7 ply carbon uni epoxy VHB Tape Soric XF, 2mm thick VARTM Innegra S VARTM LDS 50-01 0.007 psf aluminum none Integument film

LS-33 7 ply carbon uni epoxy VHB Tape Soric XF, 2mm thick VARTM Innegra S None Integument with integrated LSP & PSA none none

LS-34 7 ply carbon uni epoxy VHB Tape Soric XF, 2mm thick VARTM Innegra S None LORD Spray Material none Integument film

LS-35 7 ply carbon uni epoxy VHB Tape Soric XF, 2mm thick VARTM Carbon Epoxy None Integument with integrated LSP & PSA none none

LS-36 7 ply carbon uni epoxy VHB Tape Soric XF, 2mm thick VARTM Tegris LM None Integument with integrated LSP & PSA none none

LS-37 7 ply carbon uni epoxy VHB Tape Soric XF, 6mm thick VARTM Innegra S VARTM LDS 50-01 0.007 psf aluminum none Integument film

LS-38 7 ply carbon uni epoxy VHB Tape Soric XF, 6mm thick VARTM Innegra S None Integument with integrated LSP & PSA none none

LS-39 7 ply carbon uni epoxy VHB Tape Soric LRC, 2 mm thick VARTM Innegra S VARTM LDS 50-01 0.007 psf aluminum none Integument film

LS-40 7 ply carbon uni epoxy VHB Tape Soric LRC, 2 mm thick VARTM Innegra S None Integument with integrated LSP & PSA none none

LS-41 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1/4" thick VARTM Innegra S VARTM LDS 50-01 0.007 psf aluminum none 3M 5004

LS-42 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1/4" thick VARTM Innegra S VARTM LDS 50-01 0.007 psf aluminum adhesive Aptiv PEEK Film

LS-43 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1/4" thick VARTM Innegra S VARTM LDS 50-01 0.007 psf aluminum adhesive Halar ECTFE Film

LS-44 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1/4" thick VARTM Innegra S VARTM LDS 50-01 0.007 psf aluminum adhesive Kapton film

LS-45 7 ply carbon uni epoxy VHB Tape

Polydamp Hydrophobic Melamine with 

PEEK skin (3/4" thick) None None None None none none

LS-46 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1/4" thick VARTM Innegra S VARTM Nanocomp sheet (9-11 gsm, 1 + 1/2 layers) none Integument film

LS-47 7 ply carbon uni epoxy VHB Tape 10 pcf PU core, 1/4" thick VARTM Innegra S VARTM Nanocomp sheet (15 gsm, 1 layer) none Integument film
48

Figure 26: Sample drawing for the lightning strike panels. 
49

Table 19 - Aesthetics and Smoothing Material Build-up 

Panel 

ID Base Panel Interface Imact Absorbing Foam Layer Interface

Impact Spreading 

Layer Interface

Lightning Strike 

Material Interface Aesthetic Film

AS-1 7 ply carbon unitape epoxy VHB Tape 1/4" PU 10 pcf core VARTM Innegra None None None Integument Film with PSA

AS-2 7 ply carbon unitape epoxy VHB Tape Non-metallic honeycomb core (1/4" thick, 4 pcf) adhesive 0.012" aluminum sheet None None None Integument Film with PSA

AS-3 7 ply carbon unitape epoxy VHB Tape Metallic honeycomb core (1/4" thick, 5052, 6 pcf) adhesive 0.012" aluminum sheet None None None Integument Film with PSA

AS-4 7 ply carbon unitape epoxy VHB Tape Polydamp Hydrophobic Melamine with PEEK skin (1/2" thick) None None None None None Integument Film with PSA

AS-5 7 ply carbon unitape epoxy VHB Tape Soric XF, 2mm VARTM Innegra None None None Integument Film with PSA

AS-6 7 ply carbon unitape epoxy VHB Tape 1/4" PU 10 pcf core VARTM Innegra None None None

Integument Film with expanded aluminum foil 

& PSA

AS-7 7 ply carbon unitape epoxy VHB Tape Non-metallic honeycomb core (1/4" thick, 4 pcf) adhesive 0.012" aluminum sheet None None None

Integument Film with expanded aluminum foil 

& PSA

AS-8 7 ply carbon unitape epoxy VHB Tape Metallic honeycomb core (1/4" thick, 5052, 6 pcf) adhesive 0.012" aluminum sheet None None None

Integument Film with expanded aluminum foil 

& PSA

AS-9 7 ply carbon unitape epoxy VHB Tape Polydamp Hydrophobic Melamine with PEEK skin (1/2" thick) None None None None None

Integument Film with expanded aluminum foil 

& PSA

AS-10 7 ply carbon unitape epoxy VHB Tape Soric XF, 2mm VARTM Innegra None None None

Integument Film with expanded aluminum foil 

& PSA

AS-11 7 ply carbon unitape epoxy VHB Tape 1/4" PU 10 pcf core VARTM Innegra None None None 3M 5004 Film with PSA

AS-12 7 ply carbon unitape epoxy VHB Tape Non-metallic honeycomb core (1/4" thick, 4 pcf) adhesive 0.012" aluminum sheet None None None 3M 5004 Film with PSA

AS-13 7 ply carbon unitape epoxy VHB Tape Metallic honeycomb core (1/4" thick, 5052, 6 pcf) adhesive 0.012" aluminum sheet None None None 3M 5004 Film with PSA

AS-14 7 ply carbon unitape epoxy VHB Tape Polydamp Hydrophobic Melamine with PEEK skin (1/2" thick) None None None None None 3M 5004 Film with PSA

AS-15 7 ply carbon unitape epoxy VHB Tape Soric XF, 2mm VARTM Innegra None None None 3M 5004 Film with PSA

AS-16 7 ply carbon unitape epoxy VHB Tape 1/4" PU 10 pcf core VARTM Innegra None None adhesive Aptiv PEEK Film

AS-17 7 ply carbon unitape epoxy VHB Tape Non-metallic honeycomb core (1/4" thick, 4 pcf) adhesive 0.012" aluminum sheet None None adhesive Aptiv PEEK Film

AS-18 7 ply carbon unitape epoxy VHB Tape Metallic honeycomb core (1/4" thick, 5052, 6 pcf) adhesive 0.012" aluminum sheet None None adhesive Aptiv PEEK Film

AS-19 7 ply carbon unitape epoxy VHB Tape Polydamp Hydrophobic Melamine with PEEK skin (1/2" thick) None None None None adhesive Aptiv PEEK Film

AS-20 7 ply carbon unitape epoxy VHB Tape Soric XF, 2mm VARTM Innegra None None adhesive Aptiv PEEK Film

AS-21 7 ply carbon unitape epoxy VHB Tape 1/4" PU 10 pcf core VARTM Innegra None None adhesive Halar ECTFE Film

AS-22 7 ply carbon unitape epoxy VHB Tape Non-metallic honeycomb core (1/4" thick, 4 pcf) adhesive 0.012" aluminum sheet None None adhesive Halar ECTFE Film

AS-23 7 ply carbon unitape epoxy VHB Tape Metallic honeycomb core (1/4" thick, 5052, 6 pcf) adhesive 0.012" aluminum sheet None None adhesive Halar ECTFE Film

AS-24 7 ply carbon unitape epoxy VHB Tape Polydamp Hydrophobic Melamine with PEEK skin (1/2" thick) None None None None adhesive Halar ECTFE Film

AS-25 7 ply carbon unitape epoxy VHB Tape Soric XF, 2mm VARTM Innegra None None adhesive Halar ECTFE Film

AS-26 7 ply carbon unitape epoxy VHB Tape 1/4" PU 10 pcf core VARTM Innegra None None adhesive Kapton film

AS-27 7 ply carbon unitape epoxy VHB Tape Non-metallic honeycomb core (1/4" thick, 4 pcf) adhesive 0.012" aluminum sheet None None adhesive Kapton film

AS-28 7 ply carbon unitape epoxy VHB Tape Metallic honeycomb core (1/4" thick, 5052, 6 pcf) adhesive 0.012" aluminum sheet None None adhesive Kapton film

AS-29 7 ply carbon unitape epoxy VHB Tape Polydamp Hydrophobic Melamine with PEEK skin (1/2" thick) None None None None adhesive Kapton film

AS-30 7 ply carbon unitape epoxy VHB Tape Soric XF, 2mm VARTM Innegra None None adhesive Kapton film
50

Figure 27: Sample drawing for aesthetics and smoothing panels.
51

7.1.3 Manufacturability 

The manufacture of the panels was contracted to a supplier. A project was undertaken to capture all 

meaningful input on manufacturability of all the materials being used in the STAR-C2protective skin 

panels. This data allowed an assessment of the suitability of materials for applications to protective skins. 

Minimizing the time and bother to the supplier was a critical part of the project. 

Brainstorming the manufacturing properties required led to the topics included in Figure 28. The goal 

of the data collection process was to be very thorough without taking up a lot of the manufacturer’s time. 

The methodology used to collect the information was to go through the topics in Figure 28 for each of the 

materials shown in Tables 12 – 16 during a meeting with the two people at the supplier who had 

participated in manufacturing all of the panels. The data was collected during a meeting at the supplier’s 

facility. 

The assumption was that each of the properties for each of the materials did not have any special 

manufacturing characteristics. The goal was to discuss the exceptions rather than every property of every 

material in detail. The data collection plan was successful. A great deal of information was collected. 

The notes collected for working with each of the materials are presented in Tables 20-43. The results 

are summarized visually in Table 44Error! Reference source not found.. 
52

Figure 28: Material manufacturing data sought for each material used. 

Ease of working 

with material 

(unpacking, preparing to install)

Special storage required?

Ease of accommodating material in 

manufacturing process

Subjective 

evaluation

Any scrap from 

handling?

Any special 

considerations?

Flexibility – too much, not 

enough?

Easy to trim?

Stickiness? Sticks to the wrong 

things? Won’t stick where 

desired?

Subjective 

evaluation Lays down nicely?

Any scrap from 

the process?

Any special 

considerations?

Requires rework?

Maintains shape?

Stickiness? Sticks to the wrong 

things? Won’t stick where 

desired?

Any other 

comments?

Ease of manufacturing for complex 

curvatures?
53

Table 20 - Notes for Core Materials 

Core (10 pcf, 20

pcf, and 30 pcf)

No curvature possible

10 pcf was easy to cut, even the thicker pieces

20 pcf and 30 pcf required the band saw; the 3⁄4” and 1” bogged 

down the band saw

Had to move the 20 pcf and 30 pcf from the core cutting area 

because of dust; even cutting with a razor left a fine grit which 

required extra cleaning. Core needs its own room.

The 10 pcf core was so porous that it had to be kept covered so it 

would not get dirty

Humidity would probably be a factor – climate control storage 

would be required

Over 10 pcf the core is machinable

Didn’t like the oven – used cold bond

Table 21 - Notes for Non-Metallic Core 

4 pcf nonmetallic coreCould put in a compound, complex shape with core stabilization

Could preform

Couldn’t drill or punch – need to prepot where you want to cut or 

put a hole

Didn’t like the oven – used cold bond

Table 22 - Notes for Metallic Core 

Metallic Core (3

pcf, 6 pcf, and 

7.9 pcf

3 pcf had same problem with drilling as 4 pcf non-metallic – too 

light. Instead punched from reverse and then used holes from 

punch to guide drill bit

6 pcf and 7.9 pcf could be drilled and punched.

All thicknesses of 6 pcf were easy to work with. 

Smaller thicknesses of 7.9 pcf were easy to work with. The 3⁄4” and 

1” 7.9 pcf were a little bit difficult to work with.

Metallic cores were pretty rigid – not pliable to shape something 

out of them

Didn’t like the oven – used cold bond

Table 23 - Notes for Soric 

Soric Easy to cut/trim, easy to use, clean, didn’t leave fibers, wasn’t 

itchy.

Used a lot of resin

No difference in working with different cell sizes

Could be shaped with splicing

No stretch or give – tears at a certain point

No downsides

The big cells were fibery – soaked up a lot of resin and didn’t like 

to stick to the VHB double-sided tape
54

Table 24 - Notes for Polydamp Hydrophobic Melamine with PEEK Skin 

Polydamp 

Hydrophobic 

Melamine with 

PEEK Skin

Tore itself up – removing adhesive from backing would tear a 

bunch of foam out – extremely fragile

Not hard to stick on

Can’t bend – if bent towards backing it tears the surface aluminum 

skin; if bent towards the aluminum skin, it bends the aluminum skin

Table 25 - Notes for Innegra S 

Innegra S Everybody liked it. Mistook it for 7781 dry glass

Took resin well

Stuck down well

Had to cut it different than other materials – it would fray

Cut with scissors oversized and then trim once coated with resin

Extremely flexible

Could change the fiber direction with the resin brush once wet

Table 26 - Notes for Tegris 

Tegris LM Didn’t want to stick; wouldn’t absorb resin – resin would bead

Using a punch would cause delamination

Using a drill would fray the material

Once the resin was broken the fiber would fray

It was a pain to cut – the 2 x 2 basket weave would come apart

Not much better in resin

Couldn’t imagine making a real part out of it that would go through 

inspection successfully

Didn’t try molding – web site suggests it could be molded

Table 27 - Notes for Carbon Epoxy 

Carbon Epoxy Common place use

Flexible/bendable

Soaks up resin well

Easy to sand

Extremely sharp when dry

Extremely strong

One of the thicker and heavier materials

Lots of experience with it

Table 28 - Notes for Aluminum 

Aluminum 

(0.012” thick)

Very thin

Attaching the honeycomb to the aluminum dimpled the aluminum 

skin

Very hard to control surface quality

Used metal bond process in oven – temperature and differences in 

expansion caused major curvature of the panels
55

Table 29 - Notes for Integument Film with PSA 

Integument film 

with PSA

Pretty easy to lay down

Stuck when down – had to be careful

Won’t bend or stretch – couldn’t work around a tight curve or 

radius or shape – would need to splice

Would work well for a sidewall with a large radius

Table 30 - Notes for 3M 5004 with PSA Aesthetic Film 

3M 5004 with 

PSA

Hard to find the PSA

Stuck easily

Easier to work with than Integument

It would stretch

Could probably force around a shape better

The finish of the film is sensitive to touching; the surface quality 

can be changed by touching

Table 31 - Notes for Halar 

Halar Doesn’t like heat – low heat dimpled it

Put it in the oven at 190° for seconds to try to get it to stick – turned 

it brittle

Extremely rigid – no pliability – would crease

Would probably tear

Didn’t want to stick to anything – that could have been the transfer 

tape, but neither side wanted to stick

Scrapped quite a bit of the material trying to get it to stick and look 

nice

Spray adhesive might have worked better or a different transfer 

tape – it didn’t get a fair shake

Table 32 - Notes for Aptiv PEEK with PSA 

Aptiv with PSA Laid down easily

Thinner than Integument

Could hold one end up and slowly work down

Wouldn’t stretch

Adhesive-wise – had good PSA. Had time to work.

Once it stuck, it was down – would tear trying to get it up

Table 33 - Notes for Kapton 

Kapton Rigid like Halar – creases if you bend it

Could wrinkle like aluminum skin if you laid it down wrong

Spray adhesive might have worked better or a different transfer 

tape – it didn’t get a fair shake
56

Table 34 - Notes for Integument with LSP and PSA 

Integument with 

LSP & PSA

Really easy to lay down.

Mesh made it durable – could pull and stretch. Easy to attach.

PSA held the screen in place

Thick enough that it would stabilize what it went over

Could put on large radii. It wouldn’t bend too far.

Table 35 - Notes for 0.016 psf Expanded Aluminum 

0.016 psf 

expanded 

aluminum

Very easy to work with

Borderline being fragile – no scrap

Very easy to cut

Stuck well. At first would act like it didn’t want to stick, then laid 

down and stuck.

Table 36 - Notes for 0.029 psf Copper 

0.029 psf 

copper

Very fragile – easy to tear

Had to sandbag to cut – just cutting with a razor snagged and 

ripped

Would wrinkle on itself

Brushing resin on it would snag and bend the mesh

Copper on top of Innegra made an aesthetically pleasing panel

Bendable, pliable

Took resin; stuck good

Table 37 - Notes for LDS 50-01 0.007 psf Aluminum 

LDS 50-01 

0.007 psf 

aluminum

Extremely fragile

Came with flaws/defects; there wasn’t one perfect sheet in the pile

More challenging than copper

Very easy to tear

Had to pick up by two corners because it would not support itself

Stuck well once coated with resin and placed on the part

Laying up in prepreg might work out ok. Not good for wet layup.

Table 38 - Notes for Proprietary Spray Material 

Proprietary 

Spray Material

Laid up on panels; used air nozzle to separate spray material from 

sheet where it was sprayed

There was dry overspray – had to sand. Reminded them of a 

copper spray they use. It works best for them.

Table 39 - Notes for Carbon Nanotube Material 

Nanocomp CNT Extremely delicate – especially running with the fibers – basically 

an unsupported unidirectional material

Cut easily but if it folded over it clogged the scissors

Wetted out nicely but extra care had to be taken not to move the 

fibers around
57

Table 40 - Notes for VHB Double-sided Tape 

VHB DoubleSided Tape24” wide a challenge

If it touched to itself, it stuck

Cut well, laid down well, easy to use once they got used to it

Stretches to a point; could potentially cut the backing and get it to 

bend

Great adhesive

Table 41 - Notes for Aeropoxy 

Aeropoxy Easy to work with

Long pot life

Real slow cure at room temperature

No provisions for accelerated cure (according to the web site)

12-13 hour cure (overnight) – would still be gummy in the morning 

– couldn’t sand

Never gets hard/brittle; it will get harder

Gives enough to keep from damaging itself

Very consistent – not too thick or too thin/runny

Could have sped the process up by using the other catalyst – there 

were 2 listed

Table 42 - Notes for AF 163 0616 Adhesive 

AF 163 0616 BMS – Kaman standard

Did good on foam cores (whole sections)

For butt joints on foam, it would wick up a little

To splice with foam cores, would need to add adhesive to get a 

good bond

Easy to bond

Easy to see where it’s bonded (color)

Table 43 - Notes for 3M 4950PC Transfer Tape 

Transfer Tape Extremely hard to work with

Smaller width is easier to work with

2’ wide chunk – could cut strips and get them to lay down

The things it would stick to were really stuck

It showed on the transparent films – would ball up

Where it was put under something so that it didn’t show, it looked 

fine

Didn’t like sticking to plastics

Grabbed Innegra and aluminum

Wouldn’t stick to anything with a glassy, smooth finish

Doesn’t maintain shape; backing held it together

Don’t think you could work it around anything
58

Table 44 - Visual Representation of the Material Manufacturing Data 

Some general observations can be made from this data: 1) working with materials the manufacturer 

already had a great deal of experience was easier (e.g., carbon epoxy); 2) films with pressure sensitive 

adhesive on them were much easier to work with than films without where transfer tape had to be used to 

stick the film down; 3) Innegra was a good material with which to work; 5) the flexible lightning strike 

protection materials were especially difficult; and 6) the vast majority of these materials would not easily 

conform to a complex curvature shape. 

7.1.4 Base Panel Inspection 

The base substrate panels were built to represent the primary structure and to serve as the surface to 

which the protective skins are attached. The base panels were manufactured by Cessna. The base panels 

consist of seven plies of carbon unitape with epoxy (Material F990201) which is NCT321-G150/NAS-S12K-UNI from Newport. The panel size is 24” x 24” with gross thickness of 0.043”. The panels were 

fabricated oversize to 24” ± .25” and trimmed to size. The panel geometry and the stacking sequences of 

the layers are show in Figure 29. 
59

Figure 29: Substrate panel definition. 

The length and width of each panel were measured at the five locations per side and recorded to the 

nearest 0.05” as shown in Figure 30. Each base panel was weighed to the nearest 0.01 lb, and the weight 

was recorded. The dimensions and weights are presented in Appendix B – First-Generation Base Panel 

Inspection Results. There was a noticeable correlation between panel weight and at least one side of the 

dimensions. Panel weights varied between 1.28 lbs and 1.36 lbs. Panel areal weight was calculated based 

on panel weight and average panel length and width. Areal weights varied between 0.323 lbs/ft2and 

0.338 lbs/ft2. 
60

Figure 30: Base substrate panel length and width measuring locations. 

The base panels were received and inspected using ultrasonic or thermographic methods. Average 

ultrasonic attenuation was measured and used to assign each panel to one of the categories of test articles 

(impact, lightning strike, or aesthetics and smoothing). The following subsections will describe the 

ultrasonic/thermographic inspection, problems encountered with high levels of porosity in the panels, and 

panel assignment to a test article category. 

7.1.5 Inspection for Voids and Porosity 

All of the base substrate panels were inspected by either ultrasonic inspection or thermography or 

both. When the initial large batch of panels required inspection, Cessna’s thermography camera was 

unavailable due to upgrading. Thru-transmission ultrasonic (TTU) inspection in a gantry was conducted 

for the first large batch of panels (see Figure 31 for a view of eight of the panels in the gantry undergoing 

ultrasonic inspection). When the thermography camera returned to operation, some thermographic 

images were made to compare to the ultrasonic images, and the final panels were inspected using 

thermography. The concern was being able to determine what new damage was inflicted due to testing. 

L5

L4

L3

L2

L5

L4

L3

L2

1

TOP

LEFT

L1

W1 W2 W3 W4 W5

6”

6”

6”

6”

6” 6” 6” 6”

W1 W2 W3 W4 W5

L1
61

Figure 31: Eight base substrate panels in gantry undergoing ultrasonic inspection. 

Appendix C – First-Generation Thermography Report shows the results of all inspections of the base 

panels by either ultrasonic testing or thermography. The results are in order of base panel number. The 

appendix also shows the post-testing inspection results for the Impact and Lightning Strike panels. The 

index at the beginning of the document is for the page numbers for the base substrate panel inspection. 

Where two numbers are shown for one panel, both ultrasonic and thermographic inspections were done of 

that base panel. 

Figure 32 shows the TTU inspection of base substrate panel 1. The thermographic inspection is 

shown in Figure 33. Although the boxes on the two figures appear to be calling out different features, 

similarities can be observed between the two images. 

Figure 32: Ultrasonic inspection of base substrate panel 1. 

Accept

able 

Level 2
62

Figure 33: Thermographic inspection of base substrate panel 1 (1st Derv. -0.42 & 0.94 sec). 

Figure 34 shows the ultrasonic inspection of base substrate panel 64. For comparison, Figure 35

shows the thermographic inspection of the same panel before any modification or testing. With 

experience, a trained eye can see that the two different inspection techniques show similar features in the 

panel. The trained eyes that did the initial inspections of the base panels also conducted the final 

inspections and interpretation of results. 

Figure 34: Ultrasonic inspection of base panel 64.

 

Figure 35: Thermographic inspection of base panel 64 (1st Derv. -0.3 & Peak Ampl.-Pos 2nd Derv). 

7.1.6 Porosity 

As could be seen in Figure 33 and Figure 35, notation indicates that these panels “Fail Level 2.” The 

levels are in accordance with CSTI009 (Cessna proprietary specification: NDI – Inspection of Metal 

Adhesive Bonded, Advanced Composite, and Brazed Structures). Level 2 acceptance size limit is 

Fail 

Level 2
63

0.25 in2. Ultrasonic attenuation values recorded in the table on page 3 in Appendix C are not the worst 

areas on the panel, but an averaged value. High attenuation indicates porosity in the panel. 

Panels 23 and 159 were identified as having very high porosity and worthy of much closer inspection. 

The UT figure for Panel 23 copied from Appendix C is shown in Figure 36. The thermographic images 

are shown in Figure 37. The yellow box in the right thermography picture in Figure 37 shows the 

sectioned area, and the 0° orientation is shown with the green arrow to the lower right of the right 

thermography picture. The UT image for Panel 159 copied from Appendix C is shown in Figure 38. The 

yellow boxes in the middle thermography picture show the sectioned areas, and the green arrow below the 

middle thermography picture shows the 0° orientation. Table 45 (taken from Appendix C) shows the 

optically determined porosity, local attenuation, and averaged attenuation over the sectioned areas. These 

panels (23 and 159) were among the worst for high porosity. 

Figure 36: Ultrasonic inspection of base panel 23.

Figure 37: Thermography image of base panel 23. 
64

Figure 38: UT image for base panel 159. 

Figure 39: Thermographic image for base panel 159. 

Table 45 - PE 5 MHz UT Attenuation vs. Void Content (Optical) 

Panel ID 

pcf

Porosity 

averaged over 

~1 sq. in.

(%VC)

Local PEUT 

Attenuation 

(dB)

Average Max 

Attenuation in 

Entire Panel 

(dB)

159A 3.7 -20 -9

159B 2.9 -18 -9

23 3.9 -19 -10

The photomicrography analysis of void content for the sectioned samples is shown in Figure 40, 

Figure 41, and Figure 43 (again copied from Appendix C). The differences between the three figures are 

an increasing number of polishes: from first to second to third polish. Figure 42 contains images of only 

the two sections from Panel 159. 
65

Figure 40: 0° and 90° photomicrography analysis (first polish) for void content of base panels 159 and 23. 

Figure 41: 0° and 90° photomicrography analysis (second polish) for void content of base panels 159 and 23. 
66

Figure 42: 0° and 90° photomicrography analysis (third polish) for void content of base panel 159. 

Appendix C explains these results by saying, “Many outside studies have found a linear relation 

between attenuation, porosity and mechanical strength – if porosity voids are spherically shaped and 

uniformly distributed (e.g., in fabric). However, with UNI laminates the porosity, size, shape (often cigar 

shaped) and distribution dramatically affect void content correlation to UT attenuation – and porosity 

content to mechanical strengths as well.” 

Efforts to trace the variations in porosity to variations in materials or manufacturing processes during 

production were extensive but not conclusive. Figure 43, based on the panel inspection results, 

demonstrates that something happened between the manufacture of panels 1-31 and panels 32-106. 

Additional investigation was undertaken to determine why there was a difference. No specific root cause 

was identified. The best hypothesis (after an in-depth investigation consisting of two different team 

members visiting the manufacturing facility at two different times) was that perhaps the rolls of material 

were not sealed well and condensation took place when the material refroze after being out of the freezer. 

It is possible that the vacuum pressure and temperature were not sufficient to ‘flash off’ the water and that 

water caused porosity. 

Figure 43: Base substrate panel porosity test results.

For an actual aircraft application, this porosity may not matter. Failing Level 2 is still acceptable. The 

porosity did have an impact on the research results by causing some data resolution loss. 

All Panels

Pass Level 1

Pass Level 2

Fail Level 2

Panels 1-31

Pass Level 1

Pass Level 2

Fail Level 2

Panels 32 - 106

Pass Level 1

Pass Level 2

Fail Level 2
67

7.1.7 Base Substrate Panel Assignment to Test Article Category 

The initial attempt at assigning base substrate panels to test article category was to assign “Pass Level 

1” articles to impact testing and lightning strike if any were left, “Pass Level 2” articles to lightning strike 

articles, and “Fail Level 2” articles to aesthetics and smoothing articles. There were so few “Pass Level 

1” articles that all were assigned to impact. Because of the need to change direction of hole pattern for 

the impact panels (discovered after initial impact testing), some of the ‘Fail level 2’ panels had to be 

assigned to impact test articles. Similarly, lightning test articles wound up with a large number of “Fail 

level 2” panels. 

There were cases for both impact and lightning strike testing where the impact took place in an area of 

high porosity. The thermographic inspection result was ‘no apparent damage’ since no damage could be 

detected in a region of high porosity. Unfortunately, this left doubt about whether the protective skin 

passed the test or not. In order to not eliminate a material that might pass the requirements, the “no 

apparent damage” assessment was assumed to be “no damage” or a pass. 

7.2 Impact 

Impact testing was conducted on one bare substrate panel and 98 protective skins placed over the bare 

substrate panel. There were three impactor diameters (0.5”, 1.0”, and 1.75”) and three energy levels (50 

in-lbs, 180 in-lbs, and 250 in-lbs). An impact test facility was constructed to enable rapid testing with 

minimal variation in impacts. 

Base substrate panels were inspected with non-destructive evaluation (either ultrasonic or 

thermographic techniques) prior to and after impact testing. Data, consisting of both visual and nondestructive evaluation, was collected for analysis. The following subsections provide analysis of the data 

and draws conclusions about which materials and material combinations best meet the impact 

requirements. 

7.2.1 Requirements 

There are two primary requirements for impact damage as shown in Table 46. The critical 

requirement is that the material be able to withstand a 180 in-lb impact with no damage. Terminal 

velocity for 1” hail is 13.3 in-lbs and 2” is 213 in-lbs. The requirement for 180 in-lbs was selected to 

represent 90-95% probability (less than 5-10% of occurrence). This requirement applies to the hailground zone on the aircraft (top of the aircraft). 

Another primary requirement for impact is that damage which could require repair is visible. Current 

composite structures are difficult because damage sufficient to require repair can occur but not be visible 

to the eye. AC20-107B (Ref. 2) defines five categories of damage. Category 1 is sufficiently small 

enough to be ignored. Category 5 is so severe that it will be visible. Categories 2, 3, and 4 are in between 

and should require inspection to be sure that repair is not required. The requirement for the STAR-C2

skins relative to impact is to make all Category 2, 3, and 4 damage visible so that inspection can be 

performed. 
68

Table 46 - Primary Requirements for Impact 

Impact Energy* 180 in-lbs (5 lb weight dropped from height of 36 in)

Visible Damage Category 2, 3, & 4 (AC20-170B) damage visible to show that inspection is 

not required

*Critical Requirement

In order to expand the information obtained about the ability of the various materials to withstand 

impacts, the test matrix consists of three impact energies (50 in-lbs, 180 in-lbs, and 250 in-lbs) with three 

different impactor diameters (0.5”, 1.0”, and 1.75”) as shown in Table 47. The requirement is 1.0” at 180 

in-lbs. Realistically the protective skins do not need to pass the 180 in-lbs or 250 in-lbs for the 0.5” 

impactor or the 250 in-lbs for the 1.0” impactor. The panels should pass all energy conditions for the 

1.75” impactor.

Table 47 - Impact Test Conditions 

Impactor Diameter (in) 0.5 1.0 1.75

Impactor Weight (lbs) 5.0 5.0 5.0

50 in-lbs drop height (in) 10 10 10

180 in-lbs drop height (in) 36 36 36

250 in-lbs drop height (in) 50 50 50

Hail Energy Ref. (in-lbs) 0.83 13.3 124.9

7.2.2 Attaching Protective Skins to Base Panels 

The protective skins are all designed to be attached to the base substrate panel with double-sided tape. 

The open issue for the impact panels was whether or not the protective backing could be left on the tape 

so that the protective skin would not be attached to the substrate panel. The reason to do this is to make it 

easier to inspect the side of the substrate panel next to the protective skin. 

To provide the data necessary to make a decision, two small sample panels were provided: one with 

the protective skin stuck to the substrate and one with the backing remaining on the tape and the 

protective skin not attached to the substrate panel. Identical impacts were made on both panels. Visual 

results are shown in Figure 44 for the panel with the protective skin adhered to the substrate panel and in 

Figure 45 for the protective skin not adhered to the panel. Thermographic results are shown in Figure 46

for the protective skin adhered to the substrate panel and in Figure 47 for the protective skin not adhered 

to the substrate panel. Thermographic inspection worked well for both conditions. 
69

 

Figure 44: Front and back visual views of impact panel with protective skin adhered to substrate panel.

Figure 45: Front and back visual views of impact panel with protective skin not adhered to substrate panel. 

Figure 46: Thermography results for protective skin adhered to substrate panel. 
70

Figure 47: Thermography results for protective skin not adhered to substrate panel. 

It was much easier to visually inspect the damage on the inner surface of the substrate (next to the 

protective skin) when the protective skin was not adhered to the surface of the substrate. It was also 

possible to use thermography to inspect from the “inner” (tool side) of the substrate when the protective 

skin was not adhered to the base substrate (see Figure 48). For this reason, the supplier was asked to not 

attach the impact test articles to the substrate. Nineteen impact test articles were built before this request 

was made and comprehended. Those test articles were be used as is for this round of testing. 

Figure 48: Thermography result for "inner" side of substrate not adhered to substrate panel.
71

One other interesting thing was learned from this trial testing. The damage from the impacts ran in the 

direction of the fibers on the inner and outer layer (0° orientation as shown in Figure 29). The impact test 

fixture layout has three bays as shown in Figure 49. 

0.5" Dia Test Bay

1.0" Dia Test Bay

1.75" Dia Test Bay

Figure 49: Impact test fixture test bay definition.

There were three impacts per test bay initially. If the panel is oriented such that the inner and outer 

layers of fibers run parallel to the long direction of the test bays, the impacts interfered with each other as 

the fibers split. If the inner and outer layer of fibers run parallel to the short direction of the test bays, the 

test fixture clamps help stop the damage from running beyond the edge of the test bay. The mounting 

hole pattern was modified to include this instruction to the supplier (see Figure 50).

Figure 50: Impact test article mounting hole definition.
72

7.2.3 Impact Test Facility 

A fixture to expedite testing was designed and constructed. Each test article is impacted by three 

impactors of three different diameters at three different energy levels. Each test article is divided into 

three bays (one for each impactor) as was shown in the drawing in Figure 49. A picture of the actual bays 

of the test article support fixture are shown from underneath with a test article mounted in Figure 50. A 

side view of a test article is shown mounted on the drop test support fixture in Figure 52. The drop test 

support fixture is shown mounted in the drop test facility in Figure 53. 

Constant weight impactors with the three diameters (0.5”, 1.0”, and 1.75”) were manufactured to use 

in the test facility. The test fixture will allow three strikes at one energy level (constant height) by the 

three different impactor diameters (see Figure 54 for the drawing and Figure 55 for a picture). The 

impactors’ guide tubes have holes and pins at the three required heights. Each impactor is attached to a 

cable by an electromagnet. In preparation for testing, one impactor is placed in the tube and allowed to 

rest on the pin. The pin is removed, the electromagnet is turned off, and the impactor drops. A board (as 

shown in green in Figure 53) is placed in the test bay and is slid over the impact site as soon as the impact 

happens. The board protects the impact site from secondary impacts. 

Figure 51: Underneath view of test bay with panel IM-32 mounted. 
73

Figure 52: Panel IM-100 installed on drop test support fixture. 

Figure 53: IM-62 installed in drop test support facility. 
74

Figure 54: Impact Tube Test Fixture (side and top view). 
75

Figure 55: Impact test fixture. 

7.2.4 Test Objectives 

Two criteria (as described in the previous section on Requirements) are important for the impact tests: 

1) the amount of energy the panel is capable of absorbing; and 2) any damage which could affect ultimate 
76

strength is visible. For the purposes of the impact test, the energy threshold levels for the following five 

classes of damage will be considered: 

 Maximum energy to cause no damage to the protective skin or structure (substrate) below. 

 Maximum energy to cause visible damage to the skin but no damage to the structure below. 

 Maximum energy to cause hidden damage to the structure below. 

 Maximum energy to cause visible damage to the structure below: 

 When observed from the back (substrate) side of the test panel. 

 When observed from the front (protective skin) side of the test panel. 

These classes of damage can be related to the five FAA damage categories described in AC 20-107B 

(Reference 2) but do not align exactly. The goal of the STAR-C2protective skins will be to eliminate 

Class 3 and 4a damage. 

7.2.5 Test Results 

The 99 impact panels were tested by applying the nine impacts to each one (except for IM-100 which 

will be discussed later in this section). Pictures were taken of the front and back of each impact panel 

before and after impact testing. If features of interest were visible on the impact panel after testing, 

additional pictures of the features were taken. After impact testing was completed for each panel, 

thermographic inspection was conducted. 

Panel IM-100 was mentioned as an exception to experiencing all nine impacts. The test panel 

installed in the text fixture base was shown in Figure 52. The aftermath of testing with the 0.5” impactor 

at 180 in-lbs is shown from the top side in Figure 56 and from the underneath side in Figure 57. The 

impactor embedded in the test panel and did not bounce up. No impact was made with the 0.5” impactor 

at 250 in-lbs because it is likely that the impactor would have gone completely through the test panel and 

impacted the block of foam underneath the test fixture. 
77

Figure 56: Top side view of IM-100 after impact. 

Figure 57: Underneath view of IM-100 with 0.5" impactor embedded. 

The data which was collected from the impacts on panel IM-100 came from the front and back views 

of the panel after impact (Figure 58). For reference, the initial ultrasonic inspection of IM-100 is shown 

in Figure 59. The thermographic inspection made after impacting is shown in Figure 60. 
78

Figure 58: Before and after impact views of the front and back of IM-100.

Figure 59: Initial ultrasonic inspection. 
79

Figure 60: Thermographic inspection of IM-100.

The data was for every panel was collected in the same way that the data was collected for panel 

IM-100. The data for IM-100 is shown in Table 48. A description of the test data columns is 

presented in 

Table 49. There are nine lines of data for each test article. The first three are for the 0.5” impactor 

(shown in column 6) at 50, 180, and 250 in-lbs (shown in column 7); the next three are for the 1.0” 

impactor at the three energy levels; and the final three are for the 1.75” impactor at the three energy 

levels. The N/A’s on line 3 show that the 0.5” impactor at 250 in-lbs test was not conducted. 

Table 48 shows that IM-100 passed impact testing for 0.5” impactor at 50 in-lbs, 1.0” impactor at 50 

and 180 in-lbs, and 1.75” impactor at 50, 180, and 250 in-lbs (the set of realistic conditions suggested 

earlier). There are no cases for IM-100 where visible damage is no and base panel damage is yes (which 

would violate the need to be able to visually detect actual damage). 
80

Table 48 - Impact Test Data Collected for Panel IM-100 

Table 49 - Description of Test Data Columns 

Panel: Test article number

Impact Absorbing 

Layer:

Material used for impact absorption (including nominal 

thickness)

Impact Spreading Layer: Material used to spread impact (if present)

Protective Skin psf: Calculated protective skin areal weight in pound per square foot. 

Protective skin weight found by substrating base panel weight 

from test article weight.

Total Weight: Measured weight of the impact panel.

Visible Damage: Visible at 5 feet by untrained personnel (Category 3).

NDI Disposition: Base panel damage area measured by Thermography. A=0.000 to 

0.062 sq. in., B=0.063 to 0.25 sq. in., C=>0.25 to 0.56 sq. in., 

D=>0.56 to 1.00 sq. in., E=>1.00 sq.in. (Catecoy C, D, and E are 

failures.)

Base Panel Damage: Visible damage to base (structural panel)

Penetration (>75%): Protective skin penetration measured with depth gauge, “Y” if 

greater than 75% penetration.

All of the test article impact data collected is shown in Table 50. The thermographic inspection 

pictures can be found in Appendix C, and the supporting before and after pictures can be found in 

Appendix D – First-Generation Test Article Impact Testing Pictures. 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-100 PHM w/PEEK (3/4" T) None 0.229 2.28 0.50 50 Y A N Y

IM-100 PHM w/PEEK (3/4" T) None 0.229 2.28 0.50 180 Y E Y Y

IM-100 PHM w/PEEK (3/4" T) None 0.229 2.28 0.50 250 N/A N/A N/A N/A

IM-100 PHM w/PEEK (3/4" T) None 0.229 2.28 1.00 50 N A N N

IM-100 PHM w/PEEK (3/4" T) None 0.229 2.28 1.00 180 N A N N

IM-100 PHM w/PEEK (3/4" T) None 0.229 2.28 1.00 250 Y E Y N

IM-100 PHM w/PEEK (3/4" T) None 0.229 2.28 1.75 50 N A N N

IM-100 PHM w/PEEK (3/4" T) None 0.229 2.28 1.75 180 N A N N

IM-100 PHM w/PEEK (3/4" T) None 0.229 2.28 1.75 250 Y A N N
81

Table 50 - Impact Test Data (1 of 20) 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-1 None None 0.000 1.30 0.50 50 N D Y N/A

IM-1 None None 0.000 1.30 0.50 180 Y E Y N/A

IM-1 None None 0.000 1.30 0.50 250 Y E Y N/A

IM-1 None None 0.000 1.30 1.00 50 N C Y N/A

IM-1 None None 0.000 1.30 1.00 180 Y E Y N/A

IM-1 None None 0.000 1.30 1.00 250 Y E Y N/A

IM-1 None None 0.000 1.30 1.75 50 N C N N/A

IM-1 None None 0.000 1.30 1.75 180 Y E Y N/A

IM-1 None None 0.000 1.30 1.75 250 Y E Y N/A

IM-2 10# PU core, 1/4" T Carbon epoxy 0.536 3.49 0.50 50 Y A N N

IM-2 10# PU core, 1/4" T Carbon epoxy 0.536 3.49 0.50 180 Y E Y Y

IM-2 10# PU core, 1/4" T Carbon epoxy 0.536 3.49 0.50 250 Y E Y Y

IM-2 10# PU core, 1/4" T Carbon epoxy 0.536 3.49 1.00 50 N A N N

IM-2 10# PU core, 1/4" T Carbon epoxy 0.536 3.49 1.00 180 Y A N N

IM-2 10# PU core, 1/4" T Carbon epoxy 0.536 3.49 1.00 250 Y A N N

IM-2 10# PU core, 1/4" T Carbon epoxy 0.536 3.49 1.75 50 N A N N

IM-2 10# PU core, 1/4" T Carbon epoxy 0.536 3.49 1.75 180 N A N N

IM-2 10# PU core, 1/4" T Carbon epoxy 0.536 3.49 1.75 250 N A N N

IM-3 10# PU core, 1/4" T Innegra 0.475 3.22 0.50 50 Y A N N

IM-3 10# PU core, 1/4" T Innegra 0.475 3.22 0.50 180 Y D Y Y

IM-3 10# PU core, 1/4" T Innegra 0.475 3.22 0.50 250 Y E Y Y

IM-3 10# PU core, 1/4" T Innegra 0.475 3.22 1.00 50 Y A N N

IM-3 10# PU core, 1/4" T Innegra 0.475 3.22 1.00 180 Y A N N

IM-3 10# PU core, 1/4" T Innegra 0.475 3.22 1.00 250 Y A N N

IM-3 10# PU core, 1/4" T Innegra 0.475 3.22 1.75 50 Y A N N

IM-3 10# PU core, 1/4" T Innegra 0.475 3.22 1.75 180 Y A N N

IM-3 10# PU core, 1/4" T Innegra 0.475 3.22 1.75 250 Y A N N

IM-4 10# PU core, 1/4" T 0.012" alum 0.634 3.88 0.50 50 Y A N N

IM-4 10# PU core, 1/4" T 0.012" alum 0.634 3.88 0.50 180 Y A N Y

IM-4 10# PU core, 1/4" T 0.012" alum 0.634 3.88 0.50 250 Y E Y Y

IM-4 10# PU core, 1/4" T 0.012" alum 0.634 3.88 1.00 50 Y A N N

IM-4 10# PU core, 1/4" T 0.012" alum 0.634 3.88 1.00 180 Y A N N

IM-4 10# PU core, 1/4" T 0.012" alum 0.634 3.88 1.00 250 Y A N Y

IM-4 10# PU core, 1/4" T 0.012" alum 0.634 3.88 1.75 50 Y A N N

IM-4 10# PU core, 1/4" T 0.012" alum 0.634 3.88 1.75 180 Y A N N

IM-4 10# PU core, 1/4" T 0.012" alum 0.634 3.88 1.75 250 Y A N N

IM-5 10# PU core, 1/4" T Tegris LM 0.473 3.21 0.50 50 Y A N N

IM-5 10# PU core, 1/4" T Tegris LM 0.473 3.21 0.50 180 Y E Y Y

IM-5 10# PU core, 1/4" T Tegris LM 0.473 3.21 0.50 250 Y E Y Y

IM-5 10# PU core, 1/4" T Tegris LM 0.473 3.21 1.00 50 Y A N N

IM-5 10# PU core, 1/4" T Tegris LM 0.473 3.21 1.00 180 N A N N

IM-5 10# PU core, 1/4" T Tegris LM 0.473 3.21 1.00 250 Y A N Y

IM-5 10# PU core, 1/4" T Tegris LM 0.473 3.21 1.75 50 N A N N

IM-5 10# PU core, 1/4" T Tegris LM 0.473 3.21 1.75 180 Y A N N

IM-5 10# PU core, 1/4" T Tegris LM 0.473 3.21 1.75 250 Y A N N
82

Table 50 - Impact Test Data (2 of 20) 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-6 10# PU core, 1/2" T Carbon epoxy 0.770 4.40 0.50 50 Y A N N

IM-6 10# PU core, 1/2" T Carbon epoxy 0.770 4.40 0.50 180 Y A N Y

IM-6 10# PU core, 1/2" T Carbon epoxy 0.770 4.40 0.50 250 Y E Y Y

IM-6 10# PU core, 1/2" T Carbon epoxy 0.770 4.40 1.00 50 N A N N

IM-6 10# PU core, 1/2" T Carbon epoxy 0.770 4.40 1.00 180 Y A N N

IM-6 10# PU core, 1/2" T Carbon epoxy 0.770 4.40 1.00 250 Y A N N

IM-6 10# PU core, 1/2" T Carbon epoxy 0.770 4.40 1.75 50 N A N N

IM-6 10# PU core, 1/2" T Carbon epoxy 0.770 4.40 1.75 180 N A N N

IM-6 10# PU core, 1/2" T Carbon epoxy 0.770 4.40 1.75 250 N A N N

IM-7 10# PU core, 1/2" T Innegra 0.695 4.12 0.50 50 Y A N N

IM-7 10# PU core, 1/2" T Innegra 0.695 4.12 0.50 180 Y A N Y

IM-7 10# PU core, 1/2" T Innegra 0.695 4.12 0.50 250 Y E Y Y

IM-7 10# PU core, 1/2" T Innegra 0.695 4.12 1.00 50 Y A N N

IM-7 10# PU core, 1/2" T Innegra 0.695 4.12 1.00 180 Y A N N

IM-7 10# PU core, 1/2" T Innegra 0.695 4.12 1.00 250 Y A N Y

IM-7 10# PU core, 1/2" T Innegra 0.695 4.12 1.75 50 Y A N N

IM-7 10# PU core, 1/2" T Innegra 0.695 4.12 1.75 180 Y A N N

IM-7 10# PU core, 1/2" T Innegra 0.695 4.12 1.75 250 Y A N N

IM-8 10# PU core, 1/2" T Tegris LM 0.684 4.06 0.50 50 Y A N N

IM-8 10# PU core, 1/2" T Tegris LM 0.684 4.06 0.50 180 Y A N Y

IM-8 10# PU core, 1/2" T Tegris LM 0.684 4.06 0.50 250 Y E Y Y

IM-8 10# PU core, 1/2" T Tegris LM 0.684 4.06 1.00 50 N A N N

IM-8 10# PU core, 1/2" T Tegris LM 0.684 4.06 1.00 180 N A N N

IM-8 10# PU core, 1/2" T Tegris LM 0.684 4.06 1.00 250 Y A N N

IM-8 10# PU core, 1/2" T Tegris LM 0.684 4.06 1.75 50 N A N N

IM-8 10# PU core, 1/2" T Tegris LM 0.684 4.06 1.75 180 N A N N

IM-8 10# PU core, 1/2" T Tegris LM 0.684 4.06 1.75 250 Y A N N

IM-9 10# PU core, 3/4" T Carbon epoxy 0.948 5.15 0.50 50 Y A N N

IM-9 10# PU core, 3/4" T Carbon epoxy 0.948 5.15 0.50 180 Y A N N

IM-9 10# PU core, 3/4" T Carbon epoxy 0.948 5.15 0.50 250 Y A N Y

IM-9 10# PU core, 3/4" T Carbon epoxy 0.948 5.15 1.00 50 N A N N

IM-9 10# PU core, 3/4" T Carbon epoxy 0.948 5.15 1.00 180 Y A N N

IM-9 10# PU core, 3/4" T Carbon epoxy 0.948 5.15 1.00 250 Y A N N

IM-9 10# PU core, 3/4" T Carbon epoxy 0.948 5.15 1.75 50 N A N N

IM-9 10# PU core, 3/4" T Carbon epoxy 0.948 5.15 1.75 180 N A N N

IM-9 10# PU core, 3/4" T Carbon epoxy 0.948 5.15 1.75 250 N A N N

IM-10 10# PU core, 3/4" T Innegra 0.890 4.90 0.50 50 Y A N N

IM-10 10# PU core, 3/4" T Innegra 0.890 4.90 0.50 180 Y A N N

IM-10 10# PU core, 3/4" T Innegra 0.890 4.90 0.50 250 Y A N Y

IM-10 10# PU core, 3/4" T Innegra 0.890 4.90 1.00 50 Y A N N

IM-10 10# PU core, 3/4" T Innegra 0.890 4.90 1.00 180 Y A N N

IM-10 10# PU core, 3/4" T Innegra 0.890 4.90 1.00 250 Y A N N

IM-10 10# PU core, 3/4" T Innegra 0.890 4.90 1.75 50 Y A N N

IM-10 10# PU core, 3/4" T Innegra 0.890 4.90 1.75 180 Y A N N

IM-10 10# PU core, 3/4" T Innegra 0.890 4.90 1.75 250 Y A N N
83

Table 50 - Impact Test Data (3 of 20) 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-11 10# PU core, 3/4" T Tegris LM 0.853 4.73 0.50 50 Y A N N

IM-11 10# PU core, 3/4" T Tegris LM 0.853 4.73 0.50 180 Y A N N

IM-11 10# PU core, 3/4" T Tegris LM 0.853 4.73 0.50 250 Y A N Y

IM-11 10# PU core, 3/4" T Tegris LM 0.853 4.73 1.00 50 N A N N

IM-11 10# PU core, 3/4" T Tegris LM 0.853 4.73 1.00 180 N A N N

IM-11 10# PU core, 3/4" T Tegris LM 0.853 4.73 1.00 250 Y A N N

IM-11 10# PU core, 3/4" T Tegris LM 0.853 4.73 1.75 50 N A N N

IM-11 10# PU core, 3/4" T Tegris LM 0.853 4.73 1.75 180 N A N N

IM-11 10# PU core, 3/4" T Tegris LM 0.853 4.73 1.75 250 Y A N N

IM-12 10# PU core, 1" T Carbon epoxy 1.163 5.95 0.50 50 Y A N N

IM-12 10# PU core, 1" T Carbon epoxy 1.163 5.95 0.50 180 Y A N N

IM-12 10# PU core, 1" T Carbon epoxy 1.163 5.95 0.50 250 Y A N Y

IM-12 10# PU core, 1" T Carbon epoxy 1.163 5.95 1.00 50 N A N N

IM-12 10# PU core, 1" T Carbon epoxy 1.163 5.95 1.00 180 Y A N N

IM-12 10# PU core, 1" T Carbon epoxy 1.163 5.95 1.00 250 Y A N N

IM-12 10# PU core, 1" T Carbon epoxy 1.163 5.95 1.75 50 N A N N

IM-12 10# PU core, 1" T Carbon epoxy 1.163 5.95 1.75 180 N A N N

IM-12 10# PU core, 1" T Carbon epoxy 1.163 5.95 1.75 250 Y A N N

IM-13 10# PU core, 1" T Innegra 1.100 5.75 0.50 50 Y A N N

IM-13 10# PU core, 1" T Innegra 1.100 5.75 0.50 180 Y A N N

IM-13 10# PU core, 1" T Innegra 1.100 5.75 0.50 250 Y A N Y

IM-13 10# PU core, 1" T Innegra 1.100 5.75 1.00 50 Y A N N

IM-13 10# PU core, 1" T Innegra 1.100 5.75 1.00 180 Y A N N

IM-13 10# PU core, 1" T Innegra 1.100 5.75 1.00 250 Y A N N

IM-13 10# PU core, 1" T Innegra 1.100 5.75 1.75 50 Y A N N

IM-13 10# PU core, 1" T Innegra 1.100 5.75 1.75 180 Y A N N

IM-13 10# PU core, 1" T Innegra 1.100 5.75 1.75 250 Y A N N

IM-14 10# PU core, 1" T 0.012" alum 1.233 6.25 0.50 50 Y A N N

IM-14 10# PU core, 1" T 0.012" alum 1.233 6.25 0.50 180 Y A N N

IM-14 10# PU core, 1" T 0.012" alum 1.233 6.25 0.50 250 Y A N Y

IM-14 10# PU core, 1" T 0.012" alum 1.233 6.25 1.00 50 Y A N N

IM-14 10# PU core, 1" T 0.012" alum 1.233 6.25 1.00 180 Y A N N

IM-14 10# PU core, 1" T 0.012" alum 1.233 6.25 1.00 250 Y A N N

IM-14 10# PU core, 1" T 0.012" alum 1.233 6.25 1.75 50 Y A N N

IM-14 10# PU core, 1" T 0.012" alum 1.233 6.25 1.75 180 Y A N N

IM-14 10# PU core, 1" T 0.012" alum 1.233 6.25 1.75 250 Y A N N

IM-15 10# PU core, 1" T Tegris LM 1.095 5.70 0.50 50 Y A N N

IM-15 10# PU core, 1" T Tegris LM 1.095 5.70 0.50 180 Y A N N

IM-15 10# PU core, 1" T Tegris LM 1.095 5.70 0.50 250 Y A N Y

IM-15 10# PU core, 1" T Tegris LM 1.095 5.70 1.00 50 N A N N

IM-15 10# PU core, 1" T Tegris LM 1.095 5.70 1.00 180 N A N N

IM-15 10# PU core, 1" T Tegris LM 1.095 5.70 1.00 250 Y A N N

IM-15 10# PU core, 1" T Tegris LM 1.095 5.70 1.75 50 Y A N N

IM-15 10# PU core, 1" T Tegris LM 1.095 5.70 1.75 180 N A N N

IM-15 10# PU core, 1" T Tegris LM 1.095 5.70 1.75 250 Y A N N
84

Table 50 - Impact Test Data (4 of 20) 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-16 20# PU core, 1/4" T Carbon epoxy 0.730 4.24 0.50 50 Y A N N

IM-16 20# PU core, 1/4" T Carbon epoxy 0.730 4.24 0.50 180 Y A N N

IM-16 20# PU core, 1/4" T Carbon epoxy 0.730 4.24 0.50 250 Y A N N

IM-16 20# PU core, 1/4" T Carbon epoxy 0.730 4.24 1.00 50 N A N N

IM-16 20# PU core, 1/4" T Carbon epoxy 0.730 4.24 1.00 180 Y A N N

IM-16 20# PU core, 1/4" T Carbon epoxy 0.730 4.24 1.00 250 Y A N N

IM-16 20# PU core, 1/4" T Carbon epoxy 0.730 4.24 1.75 50 N A N N

IM-16 20# PU core, 1/4" T Carbon epoxy 0.730 4.24 1.75 180 N A N N

IM-16 20# PU core, 1/4" T Carbon epoxy 0.730 4.24 1.75 250 N A N N

IM-17 20# PU core, 1/4" T Innegra 0.670 4.02 0.50 50 Y A N N

IM-17 20# PU core, 1/4" T Innegra 0.670 4.02 0.50 180 Y A N N

IM-17 20# PU core, 1/4" T Innegra 0.670 4.02 0.50 250 Y D Y Y

IM-17 20# PU core, 1/4" T Innegra 0.670 4.02 1.00 50 N A N N

IM-17 20# PU core, 1/4" T Innegra 0.670 4.02 1.00 180 Y A N N

IM-17 20# PU core, 1/4" T Innegra 0.670 4.02 1.00 250 Y A N N

IM-17 20# PU core, 1/4" T Innegra 0.670 4.02 1.75 50 N A N N

IM-17 20# PU core, 1/4" T Innegra 0.670 4.02 1.75 180 N A N N

IM-17 20# PU core, 1/4" T Innegra 0.670 4.02 1.75 250 Y A N N

IM-18 20# PU core, 1/4" T 0.012" alum 0.814 4.58 0.50 50 Y A N N

IM-18 20# PU core, 1/4" T 0.012" alum 0.814 4.58 0.50 180 Y A N N

IM-18 20# PU core, 1/4" T 0.012" alum 0.814 4.58 0.50 250 Y A N Y

IM-18 20# PU core, 1/4" T 0.012" alum 0.814 4.58 1.00 50 Y A N N

IM-18 20# PU core, 1/4" T 0.012" alum 0.814 4.58 1.00 180 Y A N N

IM-18 20# PU core, 1/4" T 0.012" alum 0.814 4.58 1.00 250 Y A N N

IM-18 20# PU core, 1/4" T 0.012" alum 0.814 4.58 1.75 50 Y A N N

IM-18 20# PU core, 1/4" T 0.012" alum 0.814 4.58 1.75 180 Y A N N

IM-18 20# PU core, 1/4" T 0.012" alum 0.814 4.58 1.75 250 Y A N N

IM-19 20# PU core, 1/4" T Tegris LM 0.678 4.03 0.50 50 N A N N

IM-19 20# PU core, 1/4" T Tegris LM 0.678 4.03 0.50 180 Y A N N

IM-19 20# PU core, 1/4" T Tegris LM 0.678 4.03 0.50 250 Y D Y Y

IM-19 20# PU core, 1/4" T Tegris LM 0.678 4.03 1.00 50 N A N N

IM-19 20# PU core, 1/4" T Tegris LM 0.678 4.03 1.00 180 N A N N

IM-19 20# PU core, 1/4" T Tegris LM 0.678 4.03 1.00 250 Y A N N

IM-19 20# PU core, 1/4" T Tegris LM 0.678 4.03 1.75 50 N A N N

IM-19 20# PU core, 1/4" T Tegris LM 0.678 4.03 1.75 180 N A N N

IM-19 20# PU core, 1/4" T Tegris LM 0.678 4.03 1.75 250 Y A N N

IM-20 20# PU core, 1/2" T Carbon epoxy 1.133 5.85 0.50 50 Y A N N

IM-20 20# PU core, 1/2" T Carbon epoxy 1.133 5.85 0.50 180 Y A N N

IM-20 20# PU core, 1/2" T Carbon epoxy 1.133 5.85 0.50 250 Y A N N

IM-20 20# PU core, 1/2" T Carbon epoxy 1.133 5.85 1.00 50 N A N N

IM-20 20# PU core, 1/2" T Carbon epoxy 1.133 5.85 1.00 180 N A N N

IM-20 20# PU core, 1/2" T Carbon epoxy 1.133 5.85 1.00 250 Y A N N

IM-20 20# PU core, 1/2" T Carbon epoxy 1.133 5.85 1.75 50 N A N N

IM-20 20# PU core, 1/2" T Carbon epoxy 1.133 5.85 1.75 180 N A N N

IM-20 20# PU core, 1/2" T Carbon epoxy 1.133 5.85 1.75 250 Y A N N
85

Table 50 - Impact Test Data (5 of 20) 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-21 20# PU core, 1/2" T Innegra 1.065 5.60 0.50 50 Y A N N

IM-21 20# PU core, 1/2" T Innegra 1.065 5.60 0.50 180 Y A N N

IM-21 20# PU core, 1/2" T Innegra 1.065 5.60 0.50 250 Y A N N

IM-21 20# PU core, 1/2" T Innegra 1.065 5.60 1.00 50 Y A N N

IM-21 20# PU core, 1/2" T Innegra 1.065 5.60 1.00 180 Y A N N

IM-21 20# PU core, 1/2" T Innegra 1.065 5.60 1.00 250 Y A N N

IM-21 20# PU core, 1/2" T Innegra 1.065 5.60 1.75 50 N A N N

IM-21 20# PU core, 1/2" T Innegra 1.065 5.60 1.75 180 N A N N

IM-21 20# PU core, 1/2" T Innegra 1.065 5.60 1.75 250 Y A N N

IM-22 20# PU core, 1/2" T Tegris LM 1.088 5.65 0.50 50 N A N N

IM-22 20# PU core, 1/2" T Tegris LM 1.088 5.65 0.50 180 Y A N N

IM-22 20# PU core, 1/2" T Tegris LM 1.088 5.65 0.50 250 Y A N N

IM-22 20# PU core, 1/2" T Tegris LM 1.088 5.65 1.00 50 N A N N

IM-22 20# PU core, 1/2" T Tegris LM 1.088 5.65 1.00 180 N A N N

IM-22 20# PU core, 1/2" T Tegris LM 1.088 5.65 1.00 250 Y A N N

IM-22 20# PU core, 1/2" T Tegris LM 1.088 5.65 1.75 50 N A N N

IM-22 20# PU core, 1/2" T Tegris LM 1.088 5.65 1.75 180 N A N N

IM-22 20# PU core, 1/2" T Tegris LM 1.088 5.65 1.75 250 N A N N

IM-23 20# PU core, 3/4" T Carbon epoxy 1.490 7.30 0.50 50 Y A N N

IM-23 20# PU core, 3/4" T Carbon epoxy 1.490 7.30 0.50 180 Y A N N

IM-23 20# PU core, 3/4" T Carbon epoxy 1.490 7.30 0.50 250 Y A N N

IM-23 20# PU core, 3/4" T Carbon epoxy 1.490 7.30 1.00 50 N A N N

IM-23 20# PU core, 3/4" T Carbon epoxy 1.490 7.30 1.00 180 Y A N N

IM-23 20# PU core, 3/4" T Carbon epoxy 1.490 7.30 1.00 250 Y A N N

IM-23 20# PU core, 3/4" T Carbon epoxy 1.490 7.30 1.75 50 N A N N

IM-23 20# PU core, 3/4" T Carbon epoxy 1.490 7.30 1.75 180 N A N N

IM-23 20# PU core, 3/4" T Carbon epoxy 1.490 7.30 1.75 250 Y A N N

IM-24 20# PU core, 3/4" T Innegra 1.458 7.15 0.50 50 Y A N N

IM-24 20# PU core, 3/4" T Innegra 1.458 7.15 0.50 180 Y A N N

IM-24 20# PU core, 3/4" T Innegra 1.458 7.15 0.50 250 Y A N N

IM-24 20# PU core, 3/4" T Innegra 1.458 7.15 1.00 50 Y A N N

IM-24 20# PU core, 3/4" T Innegra 1.458 7.15 1.00 180 Y A N N

IM-24 20# PU core, 3/4" T Innegra 1.458 7.15 1.00 250 Y A N N

IM-24 20# PU core, 3/4" T Innegra 1.458 7.15 1.75 50 Y A N N

IM-24 20# PU core, 3/4" T Innegra 1.458 7.15 1.75 180 Y A N N

IM-24 20# PU core, 3/4" T Innegra 1.458 7.15 1.75 250 Y A N N

IM-25 20# PU core, 3/4" T Tegris LM 1.470 7.20 0.50 50 Y A N N

IM-25 20# PU core, 3/4" T Tegris LM 1.470 7.20 0.50 180 Y A N N

IM-25 20# PU core, 3/4" T Tegris LM 1.470 7.20 0.50 250 Y A N N

IM-25 20# PU core, 3/4" T Tegris LM 1.470 7.20 1.00 50 N A N N

IM-25 20# PU core, 3/4" T Tegris LM 1.470 7.20 1.00 180 N A N N

IM-25 20# PU core, 3/4" T Tegris LM 1.470 7.20 1.00 250 Y A N N

IM-25 20# PU core, 3/4" T Tegris LM 1.470 7.20 1.75 50 N A N N

IM-25 20# PU core, 3/4" T Tegris LM 1.470 7.20 1.75 180 N A N N

IM-25 20# PU core, 3/4" T Tegris LM 1.470 7.20 1.75 250 Y A N N
86

Table 50 - Impact Test Data (6 of 20) 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-26 20# PU core, 1" T Carbon epoxy 1.910 8.95 0.50 50 Y A N N

IM-26 20# PU core, 1" T Carbon epoxy 1.910 8.95 0.50 180 Y A N N

IM-26 20# PU core, 1" T Carbon epoxy 1.910 8.95 0.50 250 Y A N N

IM-26 20# PU core, 1" T Carbon epoxy 1.910 8.95 1.00 50 N A N N

IM-26 20# PU core, 1" T Carbon epoxy 1.910 8.95 1.00 180 Y A N N

IM-26 20# PU core, 1" T Carbon epoxy 1.910 8.95 1.00 250 Y A N N

IM-26 20# PU core, 1" T Carbon epoxy 1.910 8.95 1.75 50 N A N N

IM-26 20# PU core, 1" T Carbon epoxy 1.910 8.95 1.75 180 Y A N N

IM-26 20# PU core, 1" T Carbon epoxy 1.910 8.95 1.75 250 Y A N N

IM-27 20# PU core, 1" T Innegra 1.833 8.65 0.50 50 Y N N

IM-27 20# PU core, 1" T Innegra 1.833 8.65 0.50 180 Y N N

IM-27 20# PU core, 1" T Innegra 1.833 8.65 0.50 250 Y N N

IM-27 20# PU core, 1" T Innegra 1.833 8.65 1.00 50 Y N N

IM-27 20# PU core, 1" T Innegra 1.833 8.65 1.00 180 Y N N

IM-27 20# PU core, 1" T Innegra 1.833 8.65 1.00 250 Y N N

IM-27 20# PU core, 1" T Innegra 1.833 8.65 1.75 50 N N N

IM-27 20# PU core, 1" T Innegra 1.833 8.65 1.75 180 Y N N

IM-27 20# PU core, 1" T Innegra 1.833 8.65 1.75 250 Y N N

IM-28 20# PU core, 1" T 0.012" alum 2.005 9.35 0.50 50 Y A N N

IM-28 20# PU core, 1" T 0.012" alum 2.005 9.35 0.50 180 Y A N N

IM-28 20# PU core, 1" T 0.012" alum 2.005 9.35 0.50 250 Y A N N

IM-28 20# PU core, 1" T 0.012" alum 2.005 9.35 1.00 50 Y A N N

IM-28 20# PU core, 1" T 0.012" alum 2.005 9.35 1.00 180 Y A N N

IM-28 20# PU core, 1" T 0.012" alum 2.005 9.35 1.00 250 Y A N N

IM-28 20# PU core, 1" T 0.012" alum 2.005 9.35 1.75 50 Y A N N

IM-28 20# PU core, 1" T 0.012" alum 2.005 9.35 1.75 180 Y A N N

IM-28 20# PU core, 1" T 0.012" alum 2.005 9.35 1.75 250 Y A N N

IM-29 20# PU core, 1" T Tegris LM 1.928 9.05 0.50 50 Y A N N

IM-29 20# PU core, 1" T Tegris LM 1.928 9.05 0.50 180 Y A N N

IM-29 20# PU core, 1" T Tegris LM 1.928 9.05 0.50 250 Y A N N

IM-29 20# PU core, 1" T Tegris LM 1.928 9.05 1.00 50 N A N N

IM-29 20# PU core, 1" T Tegris LM 1.928 9.05 1.00 180 N A N N

IM-29 20# PU core, 1" T Tegris LM 1.928 9.05 1.00 250 Y A N N

IM-29 20# PU core, 1" T Tegris LM 1.928 9.05 1.75 50 N A N N

IM-29 20# PU core, 1" T Tegris LM 1.928 9.05 1.75 180 N A N N

IM-29 20# PU core, 1" T Tegris LM 1.928 9.05 1.75 250 Y A N N

IM-30 30# PU core, 1/4" T Carbon epoxy 0.928 5.05 0.50 50 N A N N

IM-30 30# PU core, 1/4" T Carbon epoxy 0.928 5.05 0.50 180 Y A N N

IM-30 30# PU core, 1/4" T Carbon epoxy 0.928 5.05 0.50 250 Y A N N

IM-30 30# PU core, 1/4" T Carbon epoxy 0.928 5.05 1.00 50 N A N N

IM-30 30# PU core, 1/4" T Carbon epoxy 0.928 5.05 1.00 180 Y A N N

IM-30 30# PU core, 1/4" T Carbon epoxy 0.928 5.05 1.00 250 Y A N N

IM-30 30# PU core, 1/4" T Carbon epoxy 0.928 5.05 1.75 50 N A N N

IM-30 30# PU core, 1/4" T Carbon epoxy 0.928 5.05 1.75 180 N A N N

IM-30 30# PU core, 1/4" T Carbon epoxy 0.928 5.05 1.75 250 N A N N
87

Table 50 - Impact Test Data (7 of 20) 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-31 30# PU core, 1/4" T Innegra 0.866 4.81 0.50 50 N A N N

IM-31 30# PU core, 1/4" T Innegra 0.866 4.81 0.50 180 Y A N N

IM-31 30# PU core, 1/4" T Innegra 0.866 4.81 0.50 250 Y A N N

IM-31 30# PU core, 1/4" T Innegra 0.866 4.81 1.00 50 N A N N

IM-31 30# PU core, 1/4" T Innegra 0.866 4.81 1.00 180 N A N N

IM-31 30# PU core, 1/4" T Innegra 0.866 4.81 1.00 250 Y A N N

IM-31 30# PU core, 1/4" T Innegra 0.866 4.81 1.75 50 N A N N

IM-31 30# PU core, 1/4" T Innegra 0.866 4.81 1.75 180 N A N N

IM-31 30# PU core, 1/4" T Innegra 0.866 4.81 1.75 250 N A N N

IM-32 30# PU core, 1/4" T 0.012" alum 1.003 5.35 0.50 50 Y A N N

IM-32 30# PU core, 1/4" T 0.012" alum 1.003 5.35 0.50 180 Y A N N

IM-32 30# PU core, 1/4" T 0.012" alum 1.003 5.35 0.50 250 Y A N N

IM-32 30# PU core, 1/4" T 0.012" alum 1.003 5.35 1.00 50 Y A N N

IM-32 30# PU core, 1/4" T 0.012" alum 1.003 5.35 1.00 180 Y A N N

IM-32 30# PU core, 1/4" T 0.012" alum 1.003 5.35 1.00 250 Y A N N

IM-32 30# PU core, 1/4" T 0.012" alum 1.003 5.35 1.75 50 N A N N

IM-32 30# PU core, 1/4" T 0.012" alum 1.003 5.35 1.75 180 Y A N N

IM-32 30# PU core, 1/4" T 0.012" alum 1.003 5.35 1.75 250 Y A N N

IM-33 30# PU core, 1/4" T Tegris LM 0.866 4.81 0.50 50 N A N N

IM-33 30# PU core, 1/4" T Tegris LM 0.866 4.81 0.50 180 Y A N N

IM-33 30# PU core, 1/4" T Tegris LM 0.866 4.81 0.50 250 Y A N N

IM-33 30# PU core, 1/4" T Tegris LM 0.866 4.81 1.00 50 N A N N

IM-33 30# PU core, 1/4" T Tegris LM 0.866 4.81 1.00 180 N A N N

IM-33 30# PU core, 1/4" T Tegris LM 0.866 4.81 1.00 250 N A N N

IM-33 30# PU core, 1/4" T Tegris LM 0.866 4.81 1.75 50 N A N N

IM-33 30# PU core, 1/4" T Tegris LM 0.866 4.81 1.75 180 N A N N

IM-33 30# PU core, 1/4" T Tegris LM 0.866 4.81 1.75 250 N A N N

IM-34 30# PU core, 1/2" T Carbon epoxy 1.533 7.45 0.50 50 N A N N

IM-34 30# PU core, 1/2" T Carbon epoxy 1.533 7.45 0.50 180 Y A N N

IM-34 30# PU core, 1/2" T Carbon epoxy 1.533 7.45 0.50 250 Y A N N

IM-34 30# PU core, 1/2" T Carbon epoxy 1.533 7.45 1.00 50 N A N N

IM-34 30# PU core, 1/2" T Carbon epoxy 1.533 7.45 1.00 180 N A N N

IM-34 30# PU core, 1/2" T Carbon epoxy 1.533 7.45 1.00 250 N A N N

IM-34 30# PU core, 1/2" T Carbon epoxy 1.533 7.45 1.75 50 N A N N

IM-34 30# PU core, 1/2" T Carbon epoxy 1.533 7.45 1.75 180 N A N N

IM-34 30# PU core, 1/2" T Carbon epoxy 1.533 7.45 1.75 250 N A N N

IM-35 30# PU core, 1/2" T Innegra 1.475 7.20 0.50 50 N A N N

IM-35 30# PU core, 1/2" T Innegra 1.475 7.20 0.50 180 Y A N N

IM-35 30# PU core, 1/2" T Innegra 1.475 7.20 0.50 250 Y A N N

IM-35 30# PU core, 1/2" T Innegra 1.475 7.20 1.00 50 N A N N

IM-35 30# PU core, 1/2" T Innegra 1.475 7.20 1.00 180 N A N N

IM-35 30# PU core, 1/2" T Innegra 1.475 7.20 1.00 250 Y A N N

IM-35 30# PU core, 1/2" T Innegra 1.475 7.20 1.75 50 N A N N

IM-35 30# PU core, 1/2" T Innegra 1.475 7.20 1.75 180 N A N N

IM-35 30# PU core, 1/2" T Innegra 1.475 7.20 1.75 250 N A N N
88

Table 50 - Impact Test Data (8 of 20) 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-36 30# PU core, 1/2" T Tegris LM 1.465 7.20 0.50 50 N A N N

IM-36 30# PU core, 1/2" T Tegris LM 1.465 7.20 0.50 180 Y A N N

IM-36 30# PU core, 1/2" T Tegris LM 1.465 7.20 0.50 250 Y A N N

IM-36 30# PU core, 1/2" T Tegris LM 1.465 7.20 1.00 50 N A N N

IM-36 30# PU core, 1/2" T Tegris LM 1.465 7.20 1.00 180 N A N N

IM-36 30# PU core, 1/2" T Tegris LM 1.465 7.20 1.00 250 Y A N N

IM-36 30# PU core, 1/2" T Tegris LM 1.465 7.20 1.75 50 N A N N

IM-36 30# PU core, 1/2" T Tegris LM 1.465 7.20 1.75 180 N A N N

IM-36 30# PU core, 1/2" T Tegris LM 1.465 7.20 1.75 250 N A N N

IM-37 30# PU core, 3/4" thick Carbon epoxy 2.128 9.85 0.50 50 N A N N

IM-37 30# PU core, 3/4" thick Carbon epoxy 2.128 9.85 0.50 180 Y A N N

IM-37 30# PU core, 3/4" thick Carbon epoxy 2.128 9.85 0.50 250 Y A N N

IM-37 30# PU core, 3/4" thick Carbon epoxy 2.128 9.85 1.00 50 N A N N

IM-37 30# PU core, 3/4" thick Carbon epoxy 2.128 9.85 1.00 180 N A N N

IM-37 30# PU core, 3/4" thick Carbon epoxy 2.128 9.85 1.00 250 Y A N N

IM-37 30# PU core, 3/4" thick Carbon epoxy 2.128 9.85 1.75 50 N A N N

IM-37 30# PU core, 3/4" thick Carbon epoxy 2.128 9.85 1.75 180 N A N N

IM-37 30# PU core, 3/4" thick Carbon epoxy 2.128 9.85 1.75 250 N A N N

IM-38 30# PU core, 3/4" thick Innegra 2.075 9.60 0.50 50 Y A N N

IM-38 30# PU core, 3/4" thick Innegra 2.075 9.60 0.50 180 Y A N N

IM-38 30# PU core, 3/4" thick Innegra 2.075 9.60 0.50 250 Y A N N

IM-38 30# PU core, 3/4" thick Innegra 2.075 9.60 1.00 50 N A N N

IM-38 30# PU core, 3/4" thick Innegra 2.075 9.60 1.00 180 Y A N N

IM-38 30# PU core, 3/4" thick Innegra 2.075 9.60 1.00 250 Y A N N

IM-38 30# PU core, 3/4" thick Innegra 2.075 9.60 1.75 50 N A N N

IM-38 30# PU core, 3/4" thick Innegra 2.075 9.60 1.75 180 N A N N

IM-38 30# PU core, 3/4" thick Innegra 2.075 9.60 1.75 250 Y A N N

IM-39 30# PU core, 3/4" thick Tegris LM 2.058 9.55 0.50 50 N A N N

IM-39 30# PU core, 3/4" thick Tegris LM 2.058 9.55 0.50 180 N A N N

IM-39 30# PU core, 3/4" thick Tegris LM 2.058 9.55 0.50 250 Y A N N

IM-39 30# PU core, 3/4" thick Tegris LM 2.058 9.55 1.00 50 N A N N

IM-39 30# PU core, 3/4" thick Tegris LM 2.058 9.55 1.00 180 N A N N

IM-39 30# PU core, 3/4" thick Tegris LM 2.058 9.55 1.00 250 N A N N

IM-39 30# PU core, 3/4" thick Tegris LM 2.058 9.55 1.75 50 N A N N

IM-39 30# PU core, 3/4" thick Tegris LM 2.058 9.55 1.75 180 N A N N

IM-39 30# PU core, 3/4" thick Tegris LM 2.058 9.55 1.75 250 N A N N

IM-40 30# PU core, 1" T Carbon epoxy 2.740 12.30 0.50 50 Y A N N

IM-40 30# PU core, 1" T Carbon epoxy 2.740 12.30 0.50 180 Y A N N

IM-40 30# PU core, 1" T Carbon epoxy 2.740 12.30 0.50 250 Y A N N

IM-40 30# PU core, 1" T Carbon epoxy 2.740 12.30 1.00 50 N A N N

IM-40 30# PU core, 1" T Carbon epoxy 2.740 12.30 1.00 180 Y A N N

IM-40 30# PU core, 1" T Carbon epoxy 2.740 12.30 1.00 250 Y A N N

IM-40 30# PU core, 1" T Carbon epoxy 2.740 12.30 1.75 50 N A N N

IM-40 30# PU core, 1" T Carbon epoxy 2.740 12.30 1.75 180 N A N N

IM-40 30# PU core, 1" T Carbon epoxy 2.740 12.30 1.75 250 Y A N N
89

Table 50 - Impact Test Data (9 of 20) 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-41 30# PU core, 1" T Innegra 2.658 11.95 0.50 50 Y A N N

IM-41 30# PU core, 1" T Innegra 2.658 11.95 0.50 180 Y A N N

IM-41 30# PU core, 1" T Innegra 2.658 11.95 0.50 250 Y A N N

IM-41 30# PU core, 1" T Innegra 2.658 11.95 1.00 50 Y A N N

IM-41 30# PU core, 1" T Innegra 2.658 11.95 1.00 180 Y A N N

IM-41 30# PU core, 1" T Innegra 2.658 11.95 1.00 250 Y A N N

IM-41 30# PU core, 1" T Innegra 2.658 11.95 1.75 50 N A N N

IM-41 30# PU core, 1" T Innegra 2.658 11.95 1.75 180 Y A N N

IM-41 30# PU core, 1" T Innegra 2.658 11.95 1.75 250 Y A N N

IM-43 30# PU core, 1" T Tegris LM 2.670 12.00 0.50 50 N A N N

IM-43 30# PU core, 1" T Tegris LM 2.670 12.00 0.50 180 Y A N N

IM-43 30# PU core, 1" T Tegris LM 2.670 12.00 0.50 250 Y A N N

IM-43 30# PU core, 1" T Tegris LM 2.670 12.00 1.00 50 N A N N

IM-43 30# PU core, 1" T Tegris LM 2.670 12.00 1.00 180 N A N N

IM-43 30# PU core, 1" T Tegris LM 2.670 12.00 1.00 250 Y A N N

IM-43 30# PU core, 1" T Tegris LM 2.670 12.00 1.75 50 N A N N

IM-43 30# PU core, 1" T Tegris LM 2.670 12.00 1.75 180 N A N N

IM-43 30# PU core, 1" T Tegris LM 2.670 12.00 1.75 250 N A N N

IM-44 3 pcf Al H/C, 1/4" T Carbon epoxy 0.488 3.28 0.50 50 Y A N Y

IM-44 3 pcf Al H/C, 1/4" T Carbon epoxy 0.488 3.28 0.50 180 Y E Y Y

IM-44 3 pcf Al H/C, 1/4" T Carbon epoxy 0.488 3.28 0.50 250 Y E Y Y

IM-44 3 pcf Al H/C, 1/4" T Carbon epoxy 0.488 3.28 1.00 50 N A N N

IM-44 3 pcf Al H/C, 1/4" T Carbon epoxy 0.488 3.28 1.00 180 Y A N N

IM-44 3 pcf Al H/C, 1/4" T Carbon epoxy 0.488 3.28 1.00 250 Y A N Y

IM-44 3 pcf Al H/C, 1/4" T Carbon epoxy 0.488 3.28 1.75 50 N A N N

IM-44 3 pcf Al H/C, 1/4" T Carbon epoxy 0.488 3.28 1.75 180 Y A N N

IM-44 3 pcf Al H/C, 1/4" T Carbon epoxy 0.488 3.28 1.75 250 Y A N N

IM-45 3 pcf Al H/C, 1/4" T Innegra 0.411 2.95 0.50 50 Y A N Y

IM-45 3 pcf Al H/C, 1/4" T Innegra 0.411 2.95 0.50 180 Y E N Y

IM-45 3 pcf Al H/C, 1/4" T Innegra 0.411 2.95 0.50 250 Y E Y Y

IM-45 3 pcf Al H/C, 1/4" T Innegra 0.411 2.95 1.00 50 Y A N N

IM-45 3 pcf Al H/C, 1/4" T Innegra 0.411 2.95 1.00 180 Y A N Y

IM-45 3 pcf Al H/C, 1/4" T Innegra 0.411 2.95 1.00 250 Y A N Y

IM-45 3 pcf Al H/C, 1/4" T Innegra 0.411 2.95 1.75 50 Y A N N

IM-45 3 pcf Al H/C, 1/4" T Innegra 0.411 2.95 1.75 180 Y A N N

IM-45 3 pcf Al H/C, 1/4" T Innegra 0.411 2.95 1.75 250 Y A N N
90

Table 50 - Impact Test Data (10 of 20) 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-46 3 pcf Al H/C, 1/4" T 0.012" alum 0.545 3.50 0.50 50 Y A N N

IM-46 3 pcf Al H/C, 1/4" T 0.012" alum 0.545 3.50 0.50 180 Y E Y Y

IM-46 3 pcf Al H/C, 1/4" T 0.012" alum 0.545 3.50 0.50 250 Y E Y Y

IM-46 3 pcf Al H/C, 1/4" T 0.012" alum 0.545 3.50 1.00 50 Y A N N

IM-46 3 pcf Al H/C, 1/4" T 0.012" alum 0.545 3.50 1.00 180 Y A N Y

IM-46 3 pcf Al H/C, 1/4" T 0.012" alum 0.545 3.50 1.00 250 Y A N Y

IM-46 3 pcf Al H/C, 1/4" T 0.012" alum 0.545 3.50 1.75 50 Y A N N

IM-46 3 pcf Al H/C, 1/4" T 0.012" alum 0.545 3.50 1.75 180 Y A N N

IM-46 3 pcf Al H/C, 1/4" T 0.012" alum 0.545 3.50 1.75 250 Y A N Y

IM-47 3 pcf Al H/C, 1/4" T Tegris LM 0.409 2.98 0.50 50 Y A N Y

IM-47 3 pcf Al H/C, 1/4" T Tegris LM 0.409 2.98 0.50 180 Y E Y Y

IM-47 3 pcf Al H/C, 1/4" T Tegris LM 0.409 2.98 0.50 250 Y E Y Y

IM-47 3 pcf Al H/C, 1/4" T Tegris LM 0.409 2.98 1.00 50 Y A N N

IM-47 3 pcf Al H/C, 1/4" T Tegris LM 0.409 2.98 1.00 180 Y A N N

IM-47 3 pcf Al H/C, 1/4" T Tegris LM 0.409 2.98 1.00 250 Y A N Y

IM-47 3 pcf Al H/C, 1/4" T Tegris LM 0.409 2.98 1.75 50 N A N N

IM-47 3 pcf Al H/C, 1/4" T Tegris LM 0.409 2.98 1.75 180 N A N N

IM-47 3 pcf Al H/C, 1/4" T Tegris LM 0.409 2.98 1.75 250 Y A N N

IM-48 3 pcf Al H/C, 1/2" T Carbon epoxy 0.565 3.58 0.50 50 Y A N Y

IM-48 3 pcf Al H/C, 1/2" T Carbon epoxy 0.565 3.58 0.50 180 Y E Y Y

IM-48 3 pcf Al H/C, 1/2" T Carbon epoxy 0.565 3.58 0.50 250 Y E Y Y

IM-48 3 pcf Al H/C, 1/2" T Carbon epoxy 0.565 3.58 1.00 50 N A N N

IM-48 3 pcf Al H/C, 1/2" T Carbon epoxy 0.565 3.58 1.00 180 Y A N Y

IM-48 3 pcf Al H/C, 1/2" T Carbon epoxy 0.565 3.58 1.00 250 Y A N Y

IM-48 3 pcf Al H/C, 1/2" T Carbon epoxy 0.565 3.58 1.75 50 Y A N N

IM-48 3 pcf Al H/C, 1/2" T Carbon epoxy 0.565 3.58 1.75 180 Y A N N

IM-48 3 pcf Al H/C, 1/2" T Carbon epoxy 0.565 3.58 1.75 250 Y A N N

IM-49 3 pcf Al H/C, 1/2" T Innegra 0.490 3.27 0.50 50 Y A N N

IM-49 3 pcf Al H/C, 1/2" T Innegra 0.490 3.27 0.50 180 Y E Y Y

IM-49 3 pcf Al H/C, 1/2" T Innegra 0.490 3.27 0.50 250 Y E Y Y

IM-49 3 pcf Al H/C, 1/2" T Innegra 0.490 3.27 1.00 50 Y A N N

IM-49 3 pcf Al H/C, 1/2" T Innegra 0.490 3.27 1.00 180 Y A N Y

IM-49 3 pcf Al H/C, 1/2" T Innegra 0.490 3.27 1.00 250 Y A N Y

IM-49 3 pcf Al H/C, 1/2" T Innegra 0.490 3.27 1.75 50 Y A N N

IM-49 3 pcf Al H/C, 1/2" T Innegra 0.490 3.27 1.75 180 Y A N N

IM-49 3 pcf Al H/C, 1/2" T Innegra 0.490 3.27 1.75 250 Y A N N

IM-50 3 pcf Al H/C, 1/2" T Tegris LM 0.531 3.47 0.50 50 Y A N Y

IM-50 3 pcf Al H/C, 1/2" T Tegris LM 0.531 3.47 0.50 180 Y E Y Y

IM-50 3 pcf Al H/C, 1/2" T Tegris LM 0.531 3.47 0.50 250 Y E Y Y

IM-50 3 pcf Al H/C, 1/2" T Tegris LM 0.531 3.47 1.00 50 Y A N N

IM-50 3 pcf Al H/C, 1/2" T Tegris LM 0.531 3.47 1.00 180 Y A N Y

IM-50 3 pcf Al H/C, 1/2" T Tegris LM 0.531 3.47 1.00 250 Y A N Y

IM-50 3 pcf Al H/C, 1/2" T Tegris LM 0.531 3.47 1.75 50 Y A N N

IM-50 3 pcf Al H/C, 1/2" T Tegris LM 0.531 3.47 1.75 180 Y A N N

IM-50 3 pcf Al H/C, 1/2" T Tegris LM 0.531 3.47 1.75 250 Y A N N
91

Table 50 - Impact Test Data (11 of 20) 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-51 3 pcf Al H/C, 3/4" T Carbon epoxy 0.615 3.78 0.50 50 Y A N Y

IM-51 3 pcf Al H/C, 3/4" T Carbon epoxy 0.615 3.78 0.50 180 Y E Y Y

IM-51 3 pcf Al H/C, 3/4" T Carbon epoxy 0.615 3.78 0.50 250 Y E Y Y

IM-51 3 pcf Al H/C, 3/4" T Carbon epoxy 0.615 3.78 1.00 50 N A N N

IM-51 3 pcf Al H/C, 3/4" T Carbon epoxy 0.615 3.78 1.00 180 Y A N Y

IM-51 3 pcf Al H/C, 3/4" T Carbon epoxy 0.615 3.78 1.00 250 Y A N Y

IM-51 3 pcf Al H/C, 3/4" T Carbon epoxy 0.615 3.78 1.75 50 N A N N

IM-51 3 pcf Al H/C, 3/4" T Carbon epoxy 0.615 3.78 1.75 180 Y A N N

IM-51 3 pcf Al H/C, 3/4" T Carbon epoxy 0.615 3.78 1.75 250 Y A N N

IM-52 3 pcf Al H/C, 3/4" T Innegra 0.556 3.55 0.50 50 Y A N N

IM-52 3 pcf Al H/C, 3/4" T Innegra 0.556 3.55 0.50 180 Y E Y Y

IM-52 3 pcf Al H/C, 3/4" T Innegra 0.556 3.55 0.50 250 Y E Y Y

IM-52 3 pcf Al H/C, 3/4" T Innegra 0.556 3.55 1.00 50 Y A N N

IM-52 3 pcf Al H/C, 3/4" T Innegra 0.556 3.55 1.00 180 Y A N N

IM-52 3 pcf Al H/C, 3/4" T Innegra 0.556 3.55 1.00 250 Y A N Y

IM-52 3 pcf Al H/C, 3/4" T Innegra 0.556 3.55 1.75 50 Y A N N

IM-52 3 pcf Al H/C, 3/4" T Innegra 0.556 3.55 1.75 180 Y A N N

IM-52 3 pcf Al H/C, 3/4" T Innegra 0.556 3.55 1.75 250 Y A N N

IM-53 3 pcf Al H/C, 3/4" T Tegris LM 0.578 3.65 0.50 50 Y A N N

IM-53 3 pcf Al H/C, 3/4" T Tegris LM 0.578 3.65 0.50 180 Y E Y Y

IM-53 3 pcf Al H/C, 3/4" T Tegris LM 0.578 3.65 0.50 250 Y E Y Y

IM-53 3 pcf Al H/C, 3/4" T Tegris LM 0.578 3.65 1.00 50 Y A N N

IM-53 3 pcf Al H/C, 3/4" T Tegris LM 0.578 3.65 1.00 180 Y A N N

IM-53 3 pcf Al H/C, 3/4" T Tegris LM 0.578 3.65 1.00 250 Y A N Y

IM-53 3 pcf Al H/C, 3/4" T Tegris LM 0.578 3.65 1.75 50 N A N N

IM-53 3 pcf Al H/C, 3/4" T Tegris LM 0.578 3.65 1.75 180 Y A N N

IM-53 3 pcf Al H/C, 3/4" T Tegris LM 0.578 3.65 1.75 250 Y A N N

IM-54 3 pcf Al H/C, 1" T Carbon epoxy 0.688 4.09 0.50 50 Y A N N

IM-54 3 pcf Al H/C, 1" T Carbon epoxy 0.688 4.09 0.50 180 Y C N Y

IM-54 3 pcf Al H/C, 1" T Carbon epoxy 0.688 4.09 0.50 250 Y E Y Y

IM-54 3 pcf Al H/C, 1" T Carbon epoxy 0.688 4.09 1.00 50 Y A N N

IM-54 3 pcf Al H/C, 1" T Carbon epoxy 0.688 4.09 1.00 180 Y A N N

IM-54 3 pcf Al H/C, 1" T Carbon epoxy 0.688 4.09 1.00 250 Y A N Y

IM-54 3 pcf Al H/C, 1" T Carbon epoxy 0.688 4.09 1.75 50 N A N N

IM-54 3 pcf Al H/C, 1" T Carbon epoxy 0.688 4.09 1.75 180 Y A N N

IM-54 3 pcf Al H/C, 1" T Carbon epoxy 0.688 4.09 1.75 250 Y A N N

IM-55 3 pcf Al H/C, 1" T Innegra 0.621 3.81 0.50 50 Y A N N

IM-55 3 pcf Al H/C, 1" T Innegra 0.621 3.81 0.50 180 Y A N Y

IM-55 3 pcf Al H/C, 1" T Innegra 0.621 3.81 0.50 250 Y E Y Y

IM-55 3 pcf Al H/C, 1" T Innegra 0.621 3.81 1.00 50 Y A N N

IM-55 3 pcf Al H/C, 1" T Innegra 0.621 3.81 1.00 180 Y A N N

IM-55 3 pcf Al H/C, 1" T Innegra 0.621 3.81 1.00 250 Y A N Y

IM-55 3 pcf Al H/C, 1" T Innegra 0.621 3.81 1.75 50 Y A N N

IM-55 3 pcf Al H/C, 1" T Innegra 0.621 3.81 1.75 180 Y A N N

IM-55 3 pcf Al H/C, 1" T Innegra 0.621 3.81 1.75 250 Y A N N
92

Table 50 - Impact Test Data (12 of 20) 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-56 3 pcf Al H/C, 1" T 0.012" alum 0.769 4.38 0.50 50 Y A N N

IM-56 3 pcf Al H/C, 1" T 0.012" alum 0.769 4.38 0.50 180 Y B N Y

IM-56 3 pcf Al H/C, 1" T 0.012" alum 0.769 4.38 0.50 250 Y D Y Y

IM-56 3 pcf Al H/C, 1" T 0.012" alum 0.769 4.38 1.00 50 Y A N N

IM-56 3 pcf Al H/C, 1" T 0.012" alum 0.769 4.38 1.00 180 Y A N N

IM-56 3 pcf Al H/C, 1" T 0.012" alum 0.769 4.38 1.00 250 Y A N N

IM-56 3 pcf Al H/C, 1" T 0.012" alum 0.769 4.38 1.75 50 Y A N N

IM-56 3 pcf Al H/C, 1" T 0.012" alum 0.769 4.38 1.75 180 Y A N N

IM-56 3 pcf Al H/C, 1" T 0.012" alum 0.769 4.38 1.75 250 Y A N N

IM-57 3 pcf Al H/C, 1" T Tegris LM 0.611 3.81 0.50 50 Y A N N

IM-57 3 pcf Al H/C, 1" T Tegris LM 0.611 3.81 0.50 180 Y E Y Y

IM-57 3 pcf Al H/C, 1" T Tegris LM 0.611 3.81 0.50 250 Y E Y Y

IM-57 3 pcf Al H/C, 1" T Tegris LM 0.611 3.81 1.00 50 Y A N N

IM-57 3 pcf Al H/C, 1" T Tegris LM 0.611 3.81 1.00 180 Y A N N

IM-57 3 pcf Al H/C, 1" T Tegris LM 0.611 3.81 1.00 250 Y A N Y

IM-57 3 pcf Al H/C, 1" T Tegris LM 0.611 3.81 1.75 50 N A N N

IM-57 3 pcf Al H/C, 1" T Tegris LM 0.611 3.81 1.75 180 Y A N N

IM-57 3 pcf Al H/C, 1" T Tegris LM 0.611 3.81 1.75 250 Y A N N

IM-58 6 pcf Al H/C, 1/4" T Carbon epoxy 0.541 3.49 0.50 50 Y A N N

IM-58 6 pcf Al H/C, 1/4" T Carbon epoxy 0.541 3.49 0.50 180 Y E N Y

IM-58 6 pcf Al H/C, 1/4" T Carbon epoxy 0.541 3.49 0.50 250 Y E Y Y

IM-58 6 pcf Al H/C, 1/4" T Carbon epoxy 0.541 3.49 1.00 50 N A N N

IM-58 6 pcf Al H/C, 1/4" T Carbon epoxy 0.541 3.49 1.00 180 Y A N N

IM-58 6 pcf Al H/C, 1/4" T Carbon epoxy 0.541 3.49 1.00 250 Y A N N

IM-58 6 pcf Al H/C, 1/4" T Carbon epoxy 0.541 3.49 1.75 50 N A N N

IM-58 6 pcf Al H/C, 1/4" T Carbon epoxy 0.541 3.49 1.75 180 N A N N

IM-58 6 pcf Al H/C, 1/4" T Carbon epoxy 0.541 3.49 1.75 250 Y A N N

IM-59 6 pcf Al H/C, 1/4" T Innegra 0.490 3.26 0.50 50 Y A N Y

IM-59 6 pcf Al H/C, 1/4" T Innegra 0.490 3.26 0.50 180 Y C Y Y

IM-59 6 pcf Al H/C, 1/4" T Innegra 0.490 3.26 0.50 250 Y E Y Y

IM-59 6 pcf Al H/C, 1/4" T Innegra 0.490 3.26 1.00 50 Y A N N

IM-59 6 pcf Al H/C, 1/4" T Innegra 0.490 3.26 1.00 180 Y A N Y

IM-59 6 pcf Al H/C, 1/4" T Innegra 0.490 3.26 1.00 250 Y D Y Y

IM-59 6 pcf Al H/C, 1/4" T Innegra 0.490 3.26 1.75 50 Y A N N

IM-59 6 pcf Al H/C, 1/4" T Innegra 0.490 3.26 1.75 180 Y A N N

IM-59 6 pcf Al H/C, 1/4" T Innegra 0.490 3.26 1.75 250 Y A N N

IM-60 6 pcf Al H/C, 1/4" T 0.012" alum 0.628 3.85 0.50 50 Y A N N

IM-60 6 pcf Al H/C, 1/4" T 0.012" alum 0.628 3.85 0.50 180 Y C N Y

IM-60 6 pcf Al H/C, 1/4" T 0.012" alum 0.628 3.85 0.50 250 Y E Y Y

IM-60 6 pcf Al H/C, 1/4" T 0.012" alum 0.628 3.85 1.00 50 Y A N N

IM-60 6 pcf Al H/C, 1/4" T 0.012" alum 0.628 3.85 1.00 180 Y A N Y

IM-60 6 pcf Al H/C, 1/4" T 0.012" alum 0.628 3.85 1.00 250 Y A N Y

IM-60 6 pcf Al H/C, 1/4" T 0.012" alum 0.628 3.85 1.75 50 Y A N N

IM-60 6 pcf Al H/C, 1/4" T 0.012" alum 0.628 3.85 1.75 180 Y A N N

IM-60 6 pcf Al H/C, 1/4" T 0.012" alum 0.628 3.85 1.75 250 Y A N Y
93

Table 50 - Impact Test Data (13 of 20) 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-61 6 pcf Al H/C, 1/4" T Tegris LM 0.475 3.22 0.50 50 Y A N Y

IM-61 6 pcf Al H/C, 1/4" T Tegris LM 0.475 3.22 0.50 180 Y E Y Y

IM-61 6 pcf Al H/C, 1/4" T Tegris LM 0.475 3.22 0.50 250 Y E Y Y

IM-61 6 pcf Al H/C, 1/4" T Tegris LM 0.475 3.22 1.00 50 N A N N

IM-61 6 pcf Al H/C, 1/4" T Tegris LM 0.475 3.22 1.00 180 Y A N Y

IM-61 6 pcf Al H/C, 1/4" T Tegris LM 0.475 3.22 1.00 250 Y A N Y

IM-61 6 pcf Al H/C, 1/4" T Tegris LM 0.475 3.22 1.75 50 N A N N

IM-61 6 pcf Al H/C, 1/4" T Tegris LM 0.475 3.22 1.75 180 N A N N

IM-61 6 pcf Al H/C, 1/4" T Tegris LM 0.475 3.22 1.75 250 Y A N N

IM-62 6 pcf Al H/C, 1/2" T Carbon epoxy 0.661 3.97 0.50 50 Y A N N

IM-62 6 pcf Al H/C, 1/2" T Carbon epoxy 0.661 3.97 0.50 180 Y E Y Y

IM-62 6 pcf Al H/C, 1/2" T Carbon epoxy 0.661 3.97 0.50 250 Y E Y Y

IM-62 6 pcf Al H/C, 1/2" T Carbon epoxy 0.661 3.97 1.00 50 N A N N

IM-62 6 pcf Al H/C, 1/2" T Carbon epoxy 0.661 3.97 1.00 180 Y A N N

IM-62 6 pcf Al H/C, 1/2" T Carbon epoxy 0.661 3.97 1.00 250 Y A N N

IM-62 6 pcf Al H/C, 1/2" T Carbon epoxy 0.661 3.97 1.75 50 N A N N

IM-62 6 pcf Al H/C, 1/2" T Carbon epoxy 0.661 3.97 1.75 180 Y A N N

IM-62 6 pcf Al H/C, 1/2" T Carbon epoxy 0.661 3.97 1.75 250 Y A N N

IM-63 6 pcf Al H/C, 1/2" T Innegra 0.620 3.78 0.50 50 Y A N N

IM-63 6 pcf Al H/C, 1/2" T Innegra 0.620 3.78 0.50 180 Y E Y Y

IM-63 6 pcf Al H/C, 1/2" T Innegra 0.620 3.78 0.50 250 Y E Y Y

IM-63 6 pcf Al H/C, 1/2" T Innegra 0.620 3.78 1.00 50 Y A N N

IM-63 6 pcf Al H/C, 1/2" T Innegra 0.620 3.78 1.00 180 Y A N N

IM-63 6 pcf Al H/C, 1/2" T Innegra 0.620 3.78 1.00 250 Y A N Y

IM-63 6 pcf Al H/C, 1/2" T Innegra 0.620 3.78 1.75 50 Y A N N

IM-63 6 pcf Al H/C, 1/2" T Innegra 0.620 3.78 1.75 180 Y A N N

IM-63 6 pcf Al H/C, 1/2" T Innegra 0.620 3.78 1.75 250 Y A N N

IM-64 6 pcf Al H/C, 1/2" T Tegris LM 0.610 3.78 0.50 50 Y A N N

IM-64 6 pcf Al H/C, 1/2" T Tegris LM 0.610 3.78 0.50 180 Y E N Y

IM-64 6 pcf Al H/C, 1/2" T Tegris LM 0.610 3.78 0.50 250 Y E Y Y

IM-64 6 pcf Al H/C, 1/2" T Tegris LM 0.610 3.78 1.00 50 Y A N N

IM-64 6 pcf Al H/C, 1/2" T Tegris LM 0.610 3.78 1.00 180 Y A N N

IM-64 6 pcf Al H/C, 1/2" T Tegris LM 0.610 3.78 1.00 250 Y A N Y

IM-64 6 pcf Al H/C, 1/2" T Tegris LM 0.610 3.78 1.75 50 Y A N N

IM-64 6 pcf Al H/C, 1/2" T Tegris LM 0.610 3.78 1.75 180 N A N N

IM-64 6 pcf Al H/C, 1/2" T Tegris LM 0.610 3.78 1.75 250 Y A N N

IM-65 6 pcf Al H/C, 3/4" T Carbon epoxy 0.819 4.60 0.50 50 Y A N N

IM-65 6 pcf Al H/C, 3/4" T Carbon epoxy 0.819 4.60 0.50 180 Y A N Y

IM-65 6 pcf Al H/C, 3/4" T Carbon epoxy 0.819 4.60 0.50 250 Y E Y Y

IM-65 6 pcf Al H/C, 3/4" T Carbon epoxy 0.819 4.60 1.00 50 N A N N

IM-65 6 pcf Al H/C, 3/4" T Carbon epoxy 0.819 4.60 1.00 180 Y A N N

IM-65 6 pcf Al H/C, 3/4" T Carbon epoxy 0.819 4.60 1.00 250 Y A N N

IM-65 6 pcf Al H/C, 3/4" T Carbon epoxy 0.819 4.60 1.75 50 N A N N

IM-65 6 pcf Al H/C, 3/4" T Carbon epoxy 0.819 4.60 1.75 180 Y A N N

IM-65 6 pcf Al H/C, 3/4" T Carbon epoxy 0.819 4.60 1.75 250 Y A N N
94

Table 50 - Impact Test Data (14 of 20) 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-66 6 pcf Al H/C, 3/4" T Innegra 0.749 4.34 0.50 50 Y A N N

IM-66 6 pcf Al H/C, 3/4" T Innegra 0.749 4.34 0.50 180 Y E Y Y

IM-66 6 pcf Al H/C, 3/4" T Innegra 0.749 4.34 0.50 250 Y E Y Y

IM-66 6 pcf Al H/C, 3/4" T Innegra 0.749 4.34 1.00 50 Y A N N

IM-66 6 pcf Al H/C, 3/4" T Innegra 0.749 4.34 1.00 180 Y A N N

IM-66 6 pcf Al H/C, 3/4" T Innegra 0.749 4.34 1.00 250 Y A N N

IM-66 6 pcf Al H/C, 3/4" T Innegra 0.749 4.34 1.75 50 Y A N N

IM-66 6 pcf Al H/C, 3/4" T Innegra 0.749 4.34 1.75 180 Y A N N

IM-66 6 pcf Al H/C, 3/4" T Innegra 0.749 4.34 1.75 250 Y A N N

IM-67 6 pcf Al H/C, 3/4" T Tegris LM 0.770 4.40 0.50 50 Y A N N

IM-67 6 pcf Al H/C, 3/4" T Tegris LM 0.770 4.40 0.50 180 Y E Y Y

IM-67 6 pcf Al H/C, 3/4" T Tegris LM 0.770 4.40 0.50 250 Y E Y Y

IM-67 6 pcf Al H/C, 3/4" T Tegris LM 0.770 4.40 1.00 50 Y A N N

IM-67 6 pcf Al H/C, 3/4" T Tegris LM 0.770 4.40 1.00 180 Y A N N

IM-67 6 pcf Al H/C, 3/4" T Tegris LM 0.770 4.40 1.00 250 Y A N N

IM-67 6 pcf Al H/C, 3/4" T Tegris LM 0.770 4.40 1.75 50 N A N N

IM-67 6 pcf Al H/C, 3/4" T Tegris LM 0.770 4.40 1.75 180 Y A N N

IM-67 6 pcf Al H/C, 3/4" T Tegris LM 0.770 4.40 1.75 250 Y A N N

IM-68 6 pcf Al H/C, 1" T Carbon epoxy 0.953 5.15 0.50 50 Y A N N

IM-68 6 pcf Al H/C, 1" T Carbon epoxy 0.953 5.15 0.50 180 Y C N Y

IM-68 6 pcf Al H/C, 1" T Carbon epoxy 0.953 5.15 0.50 250 Y E N Y

IM-68 6 pcf Al H/C, 1" T Carbon epoxy 0.953 5.15 1.00 50 N A N N

IM-68 6 pcf Al H/C, 1" T Carbon epoxy 0.953 5.15 1.00 180 Y A N N

IM-68 6 pcf Al H/C, 1" T Carbon epoxy 0.953 5.15 1.00 250 Y A N N

IM-68 6 pcf Al H/C, 1" T Carbon epoxy 0.953 5.15 1.75 50 N A N N

IM-68 6 pcf Al H/C, 1" T Carbon epoxy 0.953 5.15 1.75 180 Y A N N

IM-68 6 pcf Al H/C, 1" T Carbon epoxy 0.953 5.15 1.75 250 Y A N N

IM-69 6 pcf Al H/C, 1" T Innegra 0.875 4.84 0.50 50 Y A N N

IM-69 6 pcf Al H/C, 1" T Innegra 0.875 4.84 0.50 180 Y A N Y

IM-69 6 pcf Al H/C, 1" T Innegra 0.875 4.84 0.50 250 Y A N Y

IM-69 6 pcf Al H/C, 1" T Innegra 0.875 4.84 1.00 50 Y A N N

IM-69 6 pcf Al H/C, 1" T Innegra 0.875 4.84 1.00 180 Y A N N

IM-69 6 pcf Al H/C, 1" T Innegra 0.875 4.84 1.00 250 Y A N N

IM-69 6 pcf Al H/C, 1" T Innegra 0.875 4.84 1.75 50 Y A N N

IM-69 6 pcf Al H/C, 1" T Innegra 0.875 4.84 1.75 180 Y A N N

IM-69 6 pcf Al H/C, 1" T Innegra 0.875 4.84 1.75 250 Y A N N

IM-70 6 pcf Al H/C, 1" T 0.012" alum 1.033 5.45 0.50 50 Y A N N

IM-70 6 pcf Al H/C, 1" T 0.012" alum 1.033 5.45 0.50 180 Y A N Y

IM-70 6 pcf Al H/C, 1" T 0.012" alum 1.033 5.45 0.50 250 Y A N Y

IM-70 6 pcf Al H/C, 1" T 0.012" alum 1.033 5.45 1.00 50 Y A N N

IM-70 6 pcf Al H/C, 1" T 0.012" alum 1.033 5.45 1.00 180 Y A N N

IM-70 6 pcf Al H/C, 1" T 0.012" alum 1.033 5.45 1.00 250 Y A N N

IM-70 6 pcf Al H/C, 1" T 0.012" alum 1.033 5.45 1.75 50 Y A N N

IM-70 6 pcf Al H/C, 1" T 0.012" alum 1.033 5.45 1.75 180 Y A N N

IM-70 6 pcf Al H/C, 1" T 0.012" alum 1.033 5.45 1.75 250 Y A N N
95

Table 50 - Impact Test Data (15 of 20) 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-71 6 pcf Al H/C, 1" T Tegris LM 0.904 4.96 0.50 50 Y A N N

IM-71 6 pcf Al H/C, 1" T Tegris LM 0.904 4.96 0.50 180 Y A N Y

IM-71 6 pcf Al H/C, 1" T Tegris LM 0.904 4.96 0.50 250 Y E Y Y

IM-71 6 pcf Al H/C, 1" T Tegris LM 0.904 4.96 1.00 50 Y A N N

IM-71 6 pcf Al H/C, 1" T Tegris LM 0.904 4.96 1.00 180 Y A N N

IM-71 6 pcf Al H/C, 1" T Tegris LM 0.904 4.96 1.00 250 Y A N N

IM-71 6 pcf Al H/C, 1" T Tegris LM 0.904 4.96 1.75 50 Y A N N

IM-71 6 pcf Al H/C, 1" T Tegris LM 0.904 4.96 1.75 180 Y A N N

IM-71 6 pcf Al H/C, 1" T Tegris LM 0.904 4.96 1.75 250 Y A N N

IM-72 9 pcf Al H/C, 1/4" T Carbon epoxy 0.584 3.64 0.50 50 Y A N N

IM-72 9 pcf Al H/C, 1/4" T Carbon epoxy 0.584 3.64 0.50 180 Y E Y Y

IM-72 9 pcf Al H/C, 1/4" T Carbon epoxy 0.584 3.64 0.50 250 Y E Y Y

IM-72 9 pcf Al H/C, 1/4" T Carbon epoxy 0.584 3.64 1.00 50 Y A N N

IM-72 9 pcf Al H/C, 1/4" T Carbon epoxy 0.584 3.64 1.00 180 Y A N N

IM-72 9 pcf Al H/C, 1/4" T Carbon epoxy 0.584 3.64 1.00 250 Y A N Y

IM-72 9 pcf Al H/C, 1/4" T Carbon epoxy 0.584 3.64 1.75 50 Y A N N

IM-72 9 pcf Al H/C, 1/4" T Carbon epoxy 0.584 3.64 1.75 180 Y A N N

IM-72 9 pcf Al H/C, 1/4" T Carbon epoxy 0.584 3.64 1.75 250 Y A N N

IM-73 9 pcf Al H/C, 1/4" T Innegra 0.505 3.36 0.50 50 Y A N N

IM-73 9 pcf Al H/C, 1/4" T Innegra 0.505 3.36 0.50 180 Y E Y Y

IM-73 9 pcf Al H/C, 1/4" T Innegra 0.505 3.36 0.50 250 Y E Y Y

IM-73 9 pcf Al H/C, 1/4" T Innegra 0.505 3.36 1.00 50 Y A N N

IM-73 9 pcf Al H/C, 1/4" T Innegra 0.505 3.36 1.00 180 Y A N Y

IM-73 9 pcf Al H/C, 1/4" T Innegra 0.505 3.36 1.00 250 Y A N Y

IM-73 9 pcf Al H/C, 1/4" T Innegra 0.505 3.36 1.75 50 Y A N N

IM-73 9 pcf Al H/C, 1/4" T Innegra 0.505 3.36 1.75 180 Y A N N

IM-73 9 pcf Al H/C, 1/4" T Innegra 0.505 3.36 1.75 250 Y A N N

IM-74 9 pcf Al H/C, 1/4" T 0.012" alum 0.629 3.84 0.50 50 Y A N N

IM-74 9 pcf Al H/C, 1/4" T 0.012" alum 0.629 3.84 0.50 180 Y B N Y

IM-74 9 pcf Al H/C, 1/4" T 0.012" alum 0.629 3.84 0.50 250 Y E Y Y

IM-74 9 pcf Al H/C, 1/4" T 0.012" alum 0.629 3.84 1.00 50 Y A N N

IM-74 9 pcf Al H/C, 1/4" T 0.012" alum 0.629 3.84 1.00 180 Y A N Y

IM-74 9 pcf Al H/C, 1/4" T 0.012" alum 0.629 3.84 1.00 250 Y A N Y

IM-74 9 pcf Al H/C, 1/4" T 0.012" alum 0.629 3.84 1.75 50 Y A N N

IM-74 9 pcf Al H/C, 1/4" T 0.012" alum 0.629 3.84 1.75 180 Y A N N

IM-74 9 pcf Al H/C, 1/4" T 0.012" alum 0.629 3.84 1.75 250 Y A N N

IM-75 9 pcf Al H/C, 1/4" T Tegris LM 0.501 3.35 0.50 50 Y A N Y

IM-75 9 pcf Al H/C, 1/4" T Tegris LM 0.501 3.35 0.50 180 Y E Y Y

IM-75 9 pcf Al H/C, 1/4" T Tegris LM 0.501 3.35 0.50 250 Y E Y Y

IM-75 9 pcf Al H/C, 1/4" T Tegris LM 0.501 3.35 1.00 50 N A N N

IM-75 9 pcf Al H/C, 1/4" T Tegris LM 0.501 3.35 1.00 180 Y A N Y

IM-75 9 pcf Al H/C, 1/4" T Tegris LM 0.501 3.35 1.00 250 Y A N Y

IM-75 9 pcf Al H/C, 1/4" T Tegris LM 0.501 3.35 1.75 50 N A N N

IM-75 9 pcf Al H/C, 1/4" T Tegris LM 0.501 3.35 1.75 180 Y A N N

IM-75 9 pcf Al H/C, 1/4" T Tegris LM 0.501 3.35 1.75 250 Y A N N
96

Table 50 - Impact Test Data (16 of 20) 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-76 9 pcf Al H/C, 1/2" T Carbon epoxy 0.735 4.26 0.50 50 Y A N N

IM-76 9 pcf Al H/C, 1/2" T Carbon epoxy 0.735 4.26 0.50 180 Y E Y Y

IM-76 9 pcf Al H/C, 1/2" T Carbon epoxy 0.735 4.26 0.50 250 Y E Y Y

IM-76 9 pcf Al H/C, 1/2" T Carbon epoxy 0.735 4.26 1.00 50 N A N N

IM-76 9 pcf Al H/C, 1/2" T Carbon epoxy 0.735 4.26 1.00 180 Y A N N

IM-76 9 pcf Al H/C, 1/2" T Carbon epoxy 0.735 4.26 1.00 250 Y A N Y

IM-76 9 pcf Al H/C, 1/2" T Carbon epoxy 0.735 4.26 1.75 50 N A N N

IM-76 9 pcf Al H/C, 1/2" T Carbon epoxy 0.735 4.26 1.75 180 Y A N N

IM-76 9 pcf Al H/C, 1/2" T Carbon epoxy 0.735 4.26 1.75 250 Y A N N

IM-77 9 pcf Al H/C, 1/2" T Innegra 0.666 3.98 0.50 50 Y A N N

IM-77 9 pcf Al H/C, 1/2" T Innegra 0.666 3.98 0.50 180 Y C N Y

IM-77 9 pcf Al H/C, 1/2" T Innegra 0.666 3.98 0.50 250 Y E Y Y

IM-77 9 pcf Al H/C, 1/2" T Innegra 0.666 3.98 1.00 50 Y A N N

IM-77 9 pcf Al H/C, 1/2" T Innegra 0.666 3.98 1.00 180 Y A N N

IM-77 9 pcf Al H/C, 1/2" T Innegra 0.666 3.98 1.00 250 Y A N Y

IM-77 9 pcf Al H/C, 1/2" T Innegra 0.666 3.98 1.75 50 Y A N N

IM-77 9 pcf Al H/C, 1/2" T Innegra 0.666 3.98 1.75 180 Y A N N

IM-77 9 pcf Al H/C, 1/2" T Innegra 0.666 3.98 1.75 250 Y A N N

IM-78 9 pcf Al H/C, 1/2" T Tegris LM 0.645 3.91 0.50 50 Y A N N

IM-78 9 pcf Al H/C, 1/2" T Tegris LM 0.645 3.91 0.50 180 Y E Y Y

IM-78 9 pcf Al H/C, 1/2" T Tegris LM 0.645 3.91 0.50 250 Y E Y Y

IM-78 9 pcf Al H/C, 1/2" T Tegris LM 0.645 3.91 1.00 50 N A N N

IM-78 9 pcf Al H/C, 1/2" T Tegris LM 0.645 3.91 1.00 180 Y A N N

IM-78 9 pcf Al H/C, 1/2" T Tegris LM 0.645 3.91 1.00 250 Y A N Y

IM-78 9 pcf Al H/C, 1/2" T Tegris LM 0.645 3.91 1.75 50 N A N N

IM-78 9 pcf Al H/C, 1/2" T Tegris LM 0.645 3.91 1.75 180 Y A N N

IM-78 9 pcf Al H/C, 1/2" T Tegris LM 0.645 3.91 1.75 250 Y A N N

IM-79 9 pcf Al H/C, 3/4" T Carbon epoxy 0.869 4.80 0.50 50 Y A N N

IM-79 9 pcf Al H/C, 3/4" T Carbon epoxy 0.869 4.80 0.50 180 Y C N Y

IM-79 9 pcf Al H/C, 3/4" T Carbon epoxy 0.869 4.80 0.50 250 Y E Y Y

IM-79 9 pcf Al H/C, 3/4" T Carbon epoxy 0.869 4.80 1.00 50 N A N N

IM-79 9 pcf Al H/C, 3/4" T Carbon epoxy 0.869 4.80 1.00 180 Y A N N

IM-79 9 pcf Al H/C, 3/4" T Carbon epoxy 0.869 4.80 1.00 250 Y A N N

IM-79 9 pcf Al H/C, 3/4" T Carbon epoxy 0.869 4.80 1.75 50 N A N N

IM-79 9 pcf Al H/C, 3/4" T Carbon epoxy 0.869 4.80 1.75 180 Y A N N

IM-79 9 pcf Al H/C, 3/4" T Carbon epoxy 0.869 4.80 1.75 250 Y A N N

IM-80 9 pcf Al H/C, 3/4" T Innegra 0.803 4.51 0.50 50 Y A N N

IM-80 9 pcf Al H/C, 3/4" T Innegra 0.803 4.51 0.50 180 Y C N Y

IM-80 9 pcf Al H/C, 3/4" T Innegra 0.803 4.51 0.50 250 Y E Y Y

IM-80 9 pcf Al H/C, 3/4" T Innegra 0.803 4.51 1.00 50 Y A N N

IM-80 9 pcf Al H/C, 3/4" T Innegra 0.803 4.51 1.00 180 Y A N N

IM-80 9 pcf Al H/C, 3/4" T Innegra 0.803 4.51 1.00 250 Y A N N

IM-80 9 pcf Al H/C, 3/4" T Innegra 0.803 4.51 1.75 50 Y A N N

IM-80 9 pcf Al H/C, 3/4" T Innegra 0.803 4.51 1.75 180 Y A N N

IM-80 9 pcf Al H/C, 3/4" T Innegra 0.803 4.51 1.75 250 Y A N N
97

Table 50 - Impact Test Data (17 of 20) 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-81 9 pcf Al H/C, 3/4" T Tegris LM 0.810 4.56 0.50 50 Y A N N

IM-81 9 pcf Al H/C, 3/4" T Tegris LM 0.810 4.56 0.50 180 Y E Y Y

IM-81 9 pcf Al H/C, 3/4" T Tegris LM 0.810 4.56 0.50 250 Y E Y Y

IM-81 9 pcf Al H/C, 3/4" T Tegris LM 0.810 4.56 1.00 50 N A N N

IM-81 9 pcf Al H/C, 3/4" T Tegris LM 0.810 4.56 1.00 180 Y A N N

IM-81 9 pcf Al H/C, 3/4" T Tegris LM 0.810 4.56 1.00 250 Y A N N

IM-81 9 pcf Al H/C, 3/4" T Tegris LM 0.810 4.56 1.75 50 Y A N N

IM-81 9 pcf Al H/C, 3/4" T Tegris LM 0.810 4.56 1.75 180 Y A N N

IM-81 9 pcf Al H/C, 3/4" T Tegris LM 0.810 4.56 1.75 250 Y A N N

IM-82 9 pcf Al H/C, 1" T Carbon epoxy 1.040 5.50 0.50 50 Y A N N

IM-82 9 pcf Al H/C, 1" T Carbon epoxy 1.040 5.50 0.50 180 Y A N Y

IM-82 9 pcf Al H/C, 1" T Carbon epoxy 1.040 5.50 0.50 250 Y A N Y

IM-82 9 pcf Al H/C, 1" T Carbon epoxy 1.040 5.50 1.00 50 Y A N N

IM-82 9 pcf Al H/C, 1" T Carbon epoxy 1.040 5.50 1.00 180 Y A N N

IM-82 9 pcf Al H/C, 1" T Carbon epoxy 1.040 5.50 1.00 250 Y A N N

IM-82 9 pcf Al H/C, 1" T Carbon epoxy 1.040 5.50 1.75 50 Y A N N

IM-82 9 pcf Al H/C, 1" T Carbon epoxy 1.040 5.50 1.75 180 Y A N N

IM-82 9 pcf Al H/C, 1" T Carbon epoxy 1.040 5.50 1.75 250 Y A N N

IM-83 9 pcf Al H/C, 1" T Innegra 0.968 5.20 0.50 50 Y A N N

IM-83 9 pcf Al H/C, 1" T Innegra 0.968 5.20 0.50 180 Y A N Y

IM-83 9 pcf Al H/C, 1" T Innegra 0.968 5.20 0.50 250 Y A N Y

IM-83 9 pcf Al H/C, 1" T Innegra 0.968 5.20 1.00 50 Y A N N

IM-83 9 pcf Al H/C, 1" T Innegra 0.968 5.20 1.00 180 Y A N N

IM-83 9 pcf Al H/C, 1" T Innegra 0.968 5.20 1.00 250 Y A N N

IM-83 9 pcf Al H/C, 1" T Innegra 0.968 5.20 1.75 50 Y A N N

IM-83 9 pcf Al H/C, 1" T Innegra 0.968 5.20 1.75 180 Y A N N

IM-83 9 pcf Al H/C, 1" T Innegra 0.968 5.20 1.75 250 Y A N N

IM-84 9 pcf Al H/C, 1" T 0.012" alum 1.100 5.70 0.50 50 Y A N N

IM-84 9 pcf Al H/C, 1" T 0.012" alum 1.100 5.70 0.50 180 Y A N N

IM-84 9 pcf Al H/C, 1" T 0.012" alum 1.100 5.70 0.50 250 Y A N Y

IM-84 9 pcf Al H/C, 1" T 0.012" alum 1.100 5.70 1.00 50 Y A N N

IM-84 9 pcf Al H/C, 1" T 0.012" alum 1.100 5.70 1.00 180 Y A N N

IM-84 9 pcf Al H/C, 1" T 0.012" alum 1.100 5.70 1.00 250 Y A N N

IM-84 9 pcf Al H/C, 1" T 0.012" alum 1.100 5.70 1.75 50 Y A N N

IM-84 9 pcf Al H/C, 1" T 0.012" alum 1.100 5.70 1.75 180 Y A N N

IM-84 9 pcf Al H/C, 1" T 0.012" alum 1.100 5.70 1.75 250 Y A N N

IM-85 9 pcf Al H/C, 1" T Tegris LM 0.988 5.25 0.50 50 Y A N N

IM-85 9 pcf Al H/C, 1" T Tegris LM 0.988 5.25 0.50 180 Y A N Y

IM-85 9 pcf Al H/C, 1" T Tegris LM 0.988 5.25 0.50 250 Y A N Y

IM-85 9 pcf Al H/C, 1" T Tegris LM 0.988 5.25 1.00 50 N A N N

IM-85 9 pcf Al H/C, 1" T Tegris LM 0.988 5.25 1.00 180 Y A N N

IM-85 9 pcf Al H/C, 1" T Tegris LM 0.988 5.25 1.00 250 Y A N N

IM-85 9 pcf Al H/C, 1" T Tegris LM 0.988 5.25 1.75 50 Y A N N

IM-85 9 pcf Al H/C, 1" T Tegris LM 0.988 5.25 1.75 180 Y A N N

IM-85 9 pcf Al H/C, 1" T Tegris LM 0.988 5.25 1.75 250 Y A N N
98

Table 50 - Impact Test Data (18 of 20) 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-86 Soric LRC, 2mm T Carbon epoxy 0.395 2.90 0.50 50 Y A N N

IM-86 Soric LRC, 2mm T Carbon epoxy 0.395 2.90 0.50 180 Y D Y N

IM-86 Soric LRC, 2mm T Carbon epoxy 0.395 2.90 0.50 250 Y E Y Y

IM-86 Soric LRC, 2mm T Carbon epoxy 0.395 2.90 1.00 50 N A N N

IM-86 Soric LRC, 2mm T Carbon epoxy 0.395 2.90 1.00 180 Y A Y N

IM-86 Soric LRC, 2mm T Carbon epoxy 0.395 2.90 1.00 250 Y E Y N

IM-86 Soric LRC, 2mm T Carbon epoxy 0.395 2.90 1.75 50 N A N N

IM-86 Soric LRC, 2mm T Carbon epoxy 0.395 2.90 1.75 180 N A N N

IM-86 Soric LRC, 2mm T Carbon epoxy 0.395 2.90 1.75 250 N A N N

IM-87 Soric LRC, 2mm T Innegra 0.328 2.63 0.50 50 N A N N

IM-87 Soric LRC, 2mm T Innegra 0.328 2.63 0.50 180 Y E Y Y

IM-87 Soric LRC, 2mm T Innegra 0.328 2.63 0.50 250 Y E Y Y

IM-87 Soric LRC, 2mm T Innegra 0.328 2.63 1.00 50 N A N N

IM-87 Soric LRC, 2mm T Innegra 0.328 2.63 1.00 180 Y D Y N

IM-87 Soric LRC, 2mm T Innegra 0.328 2.63 1.00 250 Y E Y N

IM-87 Soric LRC, 2mm T Innegra 0.328 2.63 1.75 50 N A N N

IM-87 Soric LRC, 2mm T Innegra 0.328 2.63 1.75 180 N D Y N

IM-87 Soric LRC, 2mm T Innegra 0.328 2.63 1.75 250 N D Y N

IM-88 Soric LRC, 2mm T Tegris LM 0.311 2.55 0.50 50 Y A N N

IM-88 Soric LRC, 2mm T Tegris LM 0.311 2.55 0.50 180 Y E Y Y

IM-88 Soric LRC, 2mm T Tegris LM 0.311 2.55 0.50 250 Y E Y Y

IM-88 Soric LRC, 2mm T Tegris LM 0.311 2.55 1.00 50 N A N N

IM-88 Soric LRC, 2mm T Tegris LM 0.311 2.55 1.00 180 N E Y N

IM-88 Soric LRC, 2mm T Tegris LM 0.311 2.55 1.00 250 Y E Y N

IM-88 Soric LRC, 2mm T Tegris LM 0.311 2.55 1.75 50 N A N N

IM-88 Soric LRC, 2mm T Tegris LM 0.311 2.55 1.75 180 N A N N

IM-88 Soric LRC, 2mm T Tegris LM 0.311 2.55 1.75 250 N A N N

IM-89 Soric LRC, 3mm T Carbon epoxy 0.391 2.89 0.50 50 Y A N N

IM-89 Soric LRC, 3mm T Carbon epoxy 0.391 2.89 0.50 180 Y E Y N

IM-89 Soric LRC, 3mm T Carbon epoxy 0.391 2.89 0.50 250 Y E Y N

IM-89 Soric LRC, 3mm T Carbon epoxy 0.391 2.89 1.00 50 N A N N

IM-89 Soric LRC, 3mm T Carbon epoxy 0.391 2.89 1.00 180 Y A N N

IM-89 Soric LRC, 3mm T Carbon epoxy 0.391 2.89 1.00 250 Y E Y N

IM-89 Soric LRC, 3mm T Carbon epoxy 0.391 2.89 1.75 50 N A N N

IM-89 Soric LRC, 3mm T Carbon epoxy 0.391 2.89 1.75 180 N A N N

IM-89 Soric LRC, 3mm T Carbon epoxy 0.391 2.89 1.75 250 N A N N

IM-90 Soric LRC, 3mm T Innegra 0.310 2.58 0.50 50 N A N N

IM-90 Soric LRC, 3mm T Innegra 0.310 2.58 0.50 180 Y E N N

IM-90 Soric LRC, 3mm T Innegra 0.310 2.58 0.50 250 Y E Y Y

IM-90 Soric LRC, 3mm T Innegra 0.310 2.58 1.00 50 N A N N

IM-90 Soric LRC, 3mm T Innegra 0.310 2.58 1.00 180 Y A N N

IM-90 Soric LRC, 3mm T Innegra 0.310 2.58 1.00 250 Y E Y N

IM-90 Soric LRC, 3mm T Innegra 0.310 2.58 1.75 50 N A N N

IM-90 Soric LRC, 3mm T Innegra 0.310 2.58 1.75 180 Y A N N

IM-90 Soric LRC, 3mm T Innegra 0.310 2.58 1.75 250 Y A N N
99

Table 50 - Impact Test Data (19 of 20) 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-91 Soric LRC, 3mm T 0.012" alum 0.520 3.40 0.50 50 Y A N N

IM-91 Soric LRC, 3mm T 0.012" alum 0.520 3.40 0.50 180 Y E Y Y

IM-91 Soric LRC, 3mm T 0.012" alum 0.520 3.40 0.50 250 Y E Y Y

IM-91 Soric LRC, 3mm T 0.012" alum 0.520 3.40 1.00 50 Y A N N

IM-91 Soric LRC, 3mm T 0.012" alum 0.520 3.40 1.00 180 Y A N Y

IM-91 Soric LRC, 3mm T 0.012" alum 0.520 3.40 1.00 250 Y A N Y

IM-91 Soric LRC, 3mm T 0.012" alum 0.520 3.40 1.75 50 Y A N N

IM-91 Soric LRC, 3mm T 0.012" alum 0.520 3.40 1.75 180 Y A N N

IM-91 Soric LRC, 3mm T 0.012" alum 0.520 3.40 1.75 250 Y A N Y

IM-92 Soric LRC, 3mm T Tegris LM 0.310 2.57 0.50 50 Y A N N

IM-92 Soric LRC, 3mm T Tegris LM 0.310 2.57 0.50 180 Y E Y Y

IM-92 Soric LRC, 3mm T Tegris LM 0.310 2.57 0.50 250 Y E Y Y

IM-92 Soric LRC, 3mm T Tegris LM 0.310 2.57 1.00 50 N A N N

IM-92 Soric LRC, 3mm T Tegris LM 0.310 2.57 1.00 180 N A N N

IM-92 Soric LRC, 3mm T Tegris LM 0.310 2.57 1.00 250 Y E Y N

IM-92 Soric LRC, 3mm T Tegris LM 0.310 2.57 1.75 50 N A N N

IM-92 Soric LRC, 3mm T Tegris LM 0.310 2.57 1.75 180 N A N N

IM-92 Soric LRC, 3mm T Tegris LM 0.310 2.57 1.75 250 N A N N

IM-93 Soric XF, 2mm T Carbon epoxy 0.373 2.85 0.50 50 Y A N N

IM-93 Soric XF, 2mm T Carbon epoxy 0.373 2.85 0.50 180 Y E Y N

IM-93 Soric XF, 2mm T Carbon epoxy 0.373 2.85 0.50 250 Y E Y Y

IM-93 Soric XF, 2mm T Carbon epoxy 0.373 2.85 1.00 50 N A N N

IM-93 Soric XF, 2mm T Carbon epoxy 0.373 2.85 1.00 180 Y A N N

IM-93 Soric XF, 2mm T Carbon epoxy 0.373 2.85 1.00 250 Y E Y N

IM-93 Soric XF, 2mm T Carbon epoxy 0.373 2.85 1.75 50 N A N N

IM-93 Soric XF, 2mm T Carbon epoxy 0.373 2.85 1.75 180 N A N N

IM-93 Soric XF, 2mm T Carbon epoxy 0.373 2.85 1.75 250 N A N N

IM-94 Soric XF, 2mm T Innegra 0.296 2.52 0.50 50 N A N N

IM-94 Soric XF, 2mm T Innegra 0.296 2.52 0.50 180 Y E Y N

IM-94 Soric XF, 2mm T Innegra 0.296 2.52 0.50 250 Y E Y Y

IM-94 Soric XF, 2mm T Innegra 0.296 2.52 1.00 50 N A N N

IM-94 Soric XF, 2mm T Innegra 0.296 2.52 1.00 180 Y E Y N

IM-94 Soric XF, 2mm T Innegra 0.296 2.52 1.00 250 Y E Y N

IM-94 Soric XF, 2mm T Innegra 0.296 2.52 1.75 50 N A N N

IM-94 Soric XF, 2mm T Innegra 0.296 2.52 1.75 180 N A N N

IM-94 Soric XF, 2mm T Innegra 0.296 2.52 1.75 250 Y A N N

IM-95 Soric XF, 2mm T Tegris LM 0.328 2.63 0.50 50 N A N N

IM-95 Soric XF, 2mm T Tegris LM 0.328 2.63 0.50 180 Y E Y Y

IM-95 Soric XF, 2mm T Tegris LM 0.328 2.63 0.50 250 Y E Y Y

IM-95 Soric XF, 2mm T Tegris LM 0.328 2.63 1.00 50 N A N N

IM-95 Soric XF, 2mm T Tegris LM 0.328 2.63 1.00 180 N D Y N

IM-95 Soric XF, 2mm T Tegris LM 0.328 2.63 1.00 250 Y E Y N

IM-95 Soric XF, 2mm T Tegris LM 0.328 2.63 1.75 50 N A N N

IM-95 Soric XF, 2mm T Tegris LM 0.328 2.63 1.75 180 N D Y N

IM-95 Soric XF, 2mm T Tegris LM 0.328 2.63 1.75 250 N E Y N
100

Table 50 - Impact Test Data (20 of 20) 

Panel

Impact Absorbing 

Layer

Impact Spreading 

Layer

Protective Skin 

psf

Total Weight

Impactor Dia

IN-LBS

Visible Damage

NDI Disposition

Base Panel 

Damage

Penetration 

(>75%)

IM-96 Soric XF, 6mm T Carbon epoxy 0.423 3.03 0.50 50 Y A N N

IM-96 Soric XF, 6mm T Carbon epoxy 0.423 3.03 0.50 180 Y E Y Y

IM-96 Soric XF, 6mm T Carbon epoxy 0.423 3.03 0.50 250 Y E Y Y

IM-96 Soric XF, 6mm T Carbon epoxy 0.423 3.03 1.00 50 N A N N

IM-96 Soric XF, 6mm T Carbon epoxy 0.423 3.03 1.00 180 Y A N N

IM-96 Soric XF, 6mm T Carbon epoxy 0.423 3.03 1.00 250 Y A N Y

IM-96 Soric XF, 6mm T Carbon epoxy 0.423 3.03 1.75 50 N A N N

IM-96 Soric XF, 6mm T Carbon epoxy 0.423 3.03 1.75 180 N A N N

IM-96 Soric XF, 6mm T Carbon epoxy 0.423 3.03 1.75 250 N A N N

IM-97 Soric XF, 6mm T Innegra 0.351 2.73 0.50 50 Y A N N

IM-97 Soric XF, 6mm T Innegra 0.351 2.73 0.50 180 Y E Y Y

IM-97 Soric XF, 6mm T Innegra 0.351 2.73 0.50 250 Y E Y Y

IM-97 Soric XF, 6mm T Innegra 0.351 2.73 1.00 50 N A N N

IM-97 Soric XF, 6mm T Innegra 0.351 2.73 1.00 180 Y D Y N

IM-97 Soric XF, 6mm T Innegra 0.351 2.73 1.00 250 Y E Y N

IM-97 Soric XF, 6mm T Innegra 0.351 2.73 1.75 50 N A N N

IM-97 Soric XF, 6mm T Innegra 0.351 2.73 1.75 180 Y A N N

IM-97 Soric XF, 6mm T Innegra 0.351 2.73 1.75 250 Y A N N

IM-98 Soric XF, 6mm T 0.012" alum 0.469 3.18 0.50 50 Y A N Y

IM-98 Soric XF, 6mm T 0.012" alum 0.469 3.18 0.50 180 Y D Y Y

IM-98 Soric XF, 6mm T 0.012" alum 0.469 3.18 0.50 250 Y E Y Y

IM-98 Soric XF, 6mm T 0.012" alum 0.469 3.18 1.00 50 Y A N N

IM-98 Soric XF, 6mm T 0.012" alum 0.469 3.18 1.00 180 Y A N Y

IM-98 Soric XF, 6mm T 0.012" alum 0.469 3.18 1.00 250 Y A N Y

IM-98 Soric XF, 6mm T 0.012" alum 0.469 3.18 1.75 50 Y A N N

IM-98 Soric XF, 6mm T 0.012" alum 0.469 3.18 1.75 180 Y A N N

IM-98 Soric XF, 6mm T 0.012" alum 0.469 3.18 1.75 250 Y A N Y

IM-99 Soric XF, 6mm T Tegris LM 0.366 2.79 0.50 50 Y A N N

IM-99 Soric XF, 6mm T Tegris LM 0.366 2.79 0.50 180 Y E Y Y

IM-99 Soric XF, 6mm T Tegris LM 0.366 2.79 0.50 250 Y E Y Y

IM-99 Soric XF, 6mm T Tegris LM 0.366 2.79 1.00 50 N A N N

IM-99 Soric XF, 6mm T Tegris LM 0.366 2.79 1.00 180 N B Y N

IM-99 Soric XF, 6mm T Tegris LM 0.366 2.79 1.00 250 Y D Y N

IM-99 Soric XF, 6mm T Tegris LM 0.366 2.79 1.75 50 N A N N

IM-99 Soric XF, 6mm T Tegris LM 0.366 2.79 1.75 180 Y A N N

IM-99 Soric XF, 6mm T Tegris LM 0.366 2.79 1.75 250 Y A N N

IM-100 PHM w/PEEK (3/4" T) None 0.229 2.28 0.50 50 Y A N Y

IM-100 PHM w/PEEK (3/4" T) None 0.229 2.28 0.50 180 Y E Y Y

IM-100 PHM w/PEEK (3/4" T) None 0.229 2.28 0.50 250 N/A N/A N/A N/A

IM-100 PHM w/PEEK (3/4" T) None 0.229 2.28 1.00 50 N A N N

IM-100 PHM w/PEEK (3/4" T) None 0.229 2.28 1.00 180 N A N N

IM-100 PHM w/PEEK (3/4" T) None 0.229 2.28 1.00 250 Y E Y N

IM-100 PHM w/PEEK (3/4" T) None 0.229 2.28 1.75 50 N A N N

IM-100 PHM w/PEEK (3/4" T) None 0.229 2.28 1.75 180 N A N N

IM-100 PHM w/PEEK (3/4" T) None 0.229 2.28 1.75 250 Y A N N
101

7.2.6 Data Analysis 

In order to start to make sense out of the data, the raw data in Table 50 was reorganized to have one 

line per impact panel with only the protective skin areal weight and the NDI rating for each impactor and 

each energy level as shown in Table 51. The “A”, “B”, “C”, “D”, and “E” NDI ratings were converted to 

numerical values “0”, “1”, “2”, “3”, and “4” where 0 corresponds to A (no damage) and 4 corresponds to 

E (maximum damage). The NDI ratings have been color coded to help visually inspect the data. The 

average NDI rating (sum of each NDI rating for a panel divided by 9) is also shown. An average NDI 

rating of 0 means that the panel passed all impact cases; similarly, an average NDI rating of 4 means the 

panel failed all impact cases. The average does not provide any insight into which impact conditions 

were failed for non-zero average NDI ratings. 

The data in Table 51 was further reorganized by sorting by protective skin areal weight (protective 

skin psf) as shown in Table 52. Examining the areal weights illustrates the process variation in 

manufacturing the protective skins. In some cases (e.g., IM-90 and IM-92 with 3 mm Soric LRC) the 

protective skins weigh exactly the same whether they have the Tegris LM or Innegra impact spreading 

layer. In other cases (e.g., IM-94 and IM-95) the protective skin weight varies from 0.296 psf to 0.328 

psf for Innegra and Tegris LM, respectively. The variation is due to difficulty in fully wetting the Soric 

and in fully wetting the Tegris. The resin application process was done by hand using a brush. 

The lowest areal weight is the base substrate panel (IM-01) with a protective skin psf of 0 since there 

is no protective skin. Next lightest is panel IM-100 (the Polydamp hydrophobic melamine with metalized 

PEEK skin) with a protective skin areal weight of 0.229 psf. The Polydamp material is 3⁄4” thick with 

most of the thickness being the melamine material which is a very low density and fragile foam. The 

Polydamp material does not impress as suitable for an external aircraft application. 

The required areal weight range for the protective skin impact absorbing and impact spreading layers 

was 0.09 – 0.40 psf from the metrics development work. Only 12 of the impact panels have protective 

skin areal weights less than 0.4 psf; extending the range to 0.5 psf adds another 10 panels. 

Table 52 shows that many of the lighter impact test panels do not pass all test conditions (seen with 

NDI values great than “2” in the table). All of the panels which did pass all of the impact conditions are 

shown in Table 53. The lightest panel that meets all of the requirements is IM-16 which is made of 20 lb 

polyurethane core with a carbon epoxy spreading layer; it has a protective skin areal weight of 0.730 psf 

(significantly greater than the desired upper limit of 0.5 psf). Most of the weights are above 1.0 and many 

are above 2.0 psf. 
102

Table 51 - Reformatted Impact Data (1 of 2) 

Panel ID Impact Absorbing Layer

Impact Spreading 

Layer

Protective 

Skin psf

50 in-lbs180 in-lbs250 in-lbs50 in-lbs180 in-lbs250 in-lbs50 in-lbs180 in-lbs250 in-lbs

Avg. NDI

IM-01 None None 0.000 3 4 4 2 4 4 2 4 4 3.444

IM-02 10# PU core, 1/4" T Carbon epoxy 0.536 0 4 4 0 0 0 0 0 0 0.889

IM-03 10# PU core, 1/4" T Innegra 0.475 0 3 4 0 0 0 0 0 0 0.778

IM-04 10# PU core, 1/4" T 0.012" alum 0.634 0 0 4 0 0 0 0 0 0 0.444

IM-05 10# PU core, 1/4" T Tegris LM 0.473 0 4 4 0 0 0 0 0 0 0.889

IM-06 10# PU core, 1/2" T Carbon epoxy 0.770 0 0 4 0 0 0 0 0 0 0.444

IM-07 10# PU core, 1/2" T Innegra 0.695 0 0 4 0 0 0 0 0 0 0.444

IM-08 10# PU core, 1/2" T Tegris LM 0.684 0 0 4 0 0 0 0 0 0 0.444

IM-09 10# PU core, 3/4" T Carbon epoxy 0.948 0 0 0 0 0 0 0 0 0 0.000

IM-10 10# PU core, 3/4" T Innegra 0.890 0 0 0 0 0 0 0 0 0 0.000

IM-11 10# PU core, 3/4" T Tegris LM 0.853 0 0 0 0 0 0 0 0 0 0.000

IM-12 10# PU core, 1" T Carbon epoxy 1.163 0 0 0 0 0 0 0 0 0 0.000

IM-13 10# PU core, 1" T Innegra 1.100 0 0 0 0 0 0 0 0 0 0.000

IM-14 10# PU core, 1" T 0.012" alum 1.233 0 0 0 0 0 0 0 0 0 0.000

IM-15 10# PU core, 1" T Tegris LM 1.095 0 0 0 0 0 0 0 0 0 0.000

IM-16 20# PU core, 1/4" T Carbon epoxy 0.730 0 0 0 0 0 0 0 0 0 0.000

IM-17 20# PU core, 1/4" T Innegra 0.670 0 0 3 0 0 0 0 0 0 0.333

IM-18 20# PU core, 1/4" T 0.012" alum 0.814 0 0 0 0 0 0 0 0 0 0.000

IM-19 20# PU core, 1/4" T Tegris LM 0.678 0 0 3 0 0 0 0 0 0 0.333

IM-20 20# PU core, 1/2" T Carbon epoxy 1.133 0 0 0 0 0 0 0 0 0 0.000

IM-21 20# PU core, 1/2" T Innegra 1.065 0 0 0 0 0 0 0 0 0 0.000

IM-22 20# PU core, 1/2" T Tegris LM 1.088 0 0 0 0 0 0 0 0 0 0.000

IM-23 20# PU core, 3/4" T Carbon epoxy 1.490 0 0 0 0 0 0 0 0 0 0.000

IM-24 20# PU core, 3/4" T Innegra 1.458 0 0 0 0 0 0 0 0 0 0.000

IM-25 20# PU core, 3/4" T Tegris LM 1.470 0 0 0 0 0 0 0 0 0 0.000

IM-26 20# PU core, 1" T Carbon epoxy 1.910 0 0 0 0 0 0 0 0 0 0.000

IM-27 20# PU core, 1" T Innegra 1.833 0 0 0 0 0 0 0 0 0 0.000

IM-28 20# PU core, 1" T 0.012" alum 2.005 0 0 0 0 0 0 0 0 0 0.000

IM-29 20# PU core, 1" T Tegris LM 1.928 0 0 0 0 0 0 0 0 0 0.000

IM-30 30# PU core, 1/4" T Carbon epoxy 0.928 0 0 0 0 0 0 0 0 0 0.000

IM-31 30# PU core, 1/4" T Innegra 0.866 0 0 0 0 0 0 0 0 0 0.000

IM-32 30# PU core, 1/4" T 0.012" alum 1.003 0 0 0 0 0 0 0 0 0 0.000

IM-32 30# PU core, 1/4" T 0.012" alum 1.003 0 0 0 0 0 0 0 0 0 0.000

IM-33 30# PU core, 1/4" T Tegris LM 0.866 0 0 0 0 0 0 0 0 0 0.000

IM-34 30# PU core, 1/2" T Carbon epoxy 1.533 0 0 0 0 0 0 0 0 0 0.000

IM-35 30# PU core, 1/2" T Innegra 1.475 0 0 0 0 0 0 0 0 0 0.000

IM-36 30# PU core, 1/2" T Tegris LM 1.465 0 0 0 0 0 0 0 0 0 0.000

IM-37 30# PU core, 3/4" thick Carbon epoxy 2.128 0 0 0 0 0 0 0 0 0 0.000

IM-38 30# PU core, 3/4" thick Innegra 2.075 0 0 0 0 0 0 0 0 0 0.000

IM-39 30# PU core, 3/4" thick Tegris LM 2.058 0 0 0 0 0 0 0 0 0 0.000

IM-40 30# PU core, 1" T Carbon epoxy 2.740 0 0 0 0 0 0 0 0 0 0.000

IM-41 30# PU core, 1" T Innegra 2.658 0 0 0 0 0 0 0 0 0 0.000

IM-43 30# PU core, 1" T Tegris LM 2.670 0 0 0 0 0 0 0 0 0 0.000

IM-44 3 pcf Al H/C, 1/4" T Carbon epoxy 0.488 0 4 4 0 0 0 0 0 0 0.889

IM-45 3 pcf Al H/C, 1/4" T Innegra 0.411 0 4 4 0 0 0 0 0 0 0.889

IM-46 3 pcf Al H/C, 1/4" T 0.012" alum 0.545 0 4 4 0 0 0 0 0 0 0.889

IM-47 3 pcf Al H/C, 1/4" T Tegris LM 0.409 0 4 4 0 0 0 0 0 0 0.889

IM-48 3 pcf Al H/C, 1/4" T Carbon epoxy 0.565 0 4 4 0 0 0 0 0 0 0.889

IM-49 3 pcf Al H/C, 1/2" T Innegra 0.490 0 4 4 0 0 0 0 0 0 0.889

.5" Impacter 1.0" Impacter 1.75" Impacter
103

Table 51 - Reformatted Impact Data (2 of 2) 

Panel ID Impact Absorbing Layer

Impact Spreading 

Layer

Protective 

Skin psf

50 in-lbs180 in-lbs250 in-lbs50 in-lbs180 in-lbs250 in-lbs50 in-lbs180 in-lbs250 in-lbs

Avg. NDI

IM-50 3 pcf Al H/C, 1/2" T Tegris LM 0.531 0 4 4 0 0 0 0 0 0 0.889

IM-51 3 pcf Al H/C, 3/4" T Carbon epoxy 0.615 0 4 4 0 0 0 0 0 0 0.889

IM-52 3 pcf Al H/C, 3/4" T Innegra 0.556 0 4 4 0 0 0 0 0 0 0.889

IM-53 3 pcf Al H/C, 3/4" T Tegris LM 0.578 0 4 4 0 0 0 0 0 0 0.889

IM-54 3 pcf Al H/C, 1" T Carbon epoxy 0.688 0 3 4 0 0 0 0 0 0 0.778

IM-55 3 pcf Al H/C, 1" T Innegra 0.621 0 0 4 0 0 0 0 0 0 0.444

IM-56 3 pcf Al H/C, 1" T 0.012" alum 0.769 0 1 3 0 0 0 0 0 0 0.444

IM-57 3 pcf Al H/C, 1" T Tegris LM 0.611 0 4 4 0 0 0 0 0 0 0.889

IM-58 6 pcf Al H/C, 1/4" T Carbon epoxy 0.541 0 4 4 0 0 0 0 0 0 0.889

IM-59 6 pcf Al H/C, 1/4" T Innegra 0.490 0 2 4 0 0 3 0 0 0 1.000

IM-60 6 pcf Al H/C, 1/4" T 0.012" alum 0.628 0 2 4 0 0 0 0 0 0 0.667

IM-61 6 pcf Al H/C, 1/4" T Tegris LM 0.475 0 4 4 0 0 0 0 0 0 0.889

IM-62 6 pcf Al H/C, 1/2" T Carbon epoxy 0.661 0 4 4 0 0 0 0 0 0 0.889

IM-63 6 pcf Al H/C, 1/2" T Innegra 0.620 0 4 4 0 0 0 0 0 0 0.889

IM-64 6 pcf Al H/C, 1/2" T Tegris LM 0.610 0 4 4 0 0 0 0 0 0 0.889

IM-65 6 pcf Al H/C, 3/4" T Carbon epoxy 0.819 0 0 4 0 0 0 0 0 0 0.444

IM-66 6 pcf Al H/C, 3/4" T Innegra 0.749 0 4 4 0 0 0 0 0 0 0.889

IM-67 6 pcf Al H/C, 3/4" T Tegris LM 0.770 0 4 4 0 0 0 0 0 0 0.889

IM-68 6 pcf Al H/C, 1" T Carbon epoxy 0.953 0 2 4 0 0 0 0 0 0 0.667

IM-69 6 pcf Al H/C, 1" T Innegra 0.875 0 0 0 0 0 0 0 0 0 0.000

IM-70 6 pcf Al H/C, 1" T 0.012" alum 1.033 0 0 0 0 0 0 0 0 0 0.000

IM-71 6 pcf Al H/C, 1" T Tegris LM 0.904 0 0 4 0 0 0 0 0 0 0.444

IM-72 9 pcf Al H/C, 1/4" T Carbon epoxy 0.584 0 4 4 0 0 0 0 0 0 0.889

IM-73 9 pcf Al H/C, 1/4" T Innegra 0.505 0 4 4 0 0 0 0 0 0 0.889

IM-74 9 pcf Al H/C, 1/4" T 0.012" alum 0.629 0 1 4 0 0 0 0 0 0 0.556

IM-75 9 pcf Al H/C, 1/4" T Tegris LM 0.501 0 4 4 0 0 0 0 0 0 0.889

IM-76 9 pcf Al H/C, 1/2" T Carbon epoxy 0.735 0 4 4 0 0 0 0 0 0 0.889

IM-77 9 pcf Al H/C, 1/2" T Innegra 0.666 0 2 4 0 0 0 0 0 0 0.667

IM-78 9 pcf Al H/C, 1/2" T Tegris LM 0.645 0 4 4 0 0 0 0 0 0 0.889

IM-79 9 pcf Al H/C, 3/4" T Carbon epoxy 0.869 0 2 4 0 0 0 0 0 0 0.667

IM-80 9 pcf Al H/C, 3/4" T Innegra 0.803 0 2 4 0 0 0 0 0 0 0.667

IM-81 9 pcf Al H/C, 3/4" T Tegris LM 0.810 0 4 4 0 0 0 0 0 0 0.889

IM-82 9 pcf Al H/C, 1" T Carbon epoxy 1.040 0 0 0 0 0 0 0 0 0 0.000

IM-83 9 pcf Al H/C, 1" T Innegra 0.968 0 0 0 0 0 0 0 0 0 0.000

IM-84 9 pcf Al H/C, 1" T 0.012" alum 1.100 0 0 0 0 0 0 0 0 0 0.000

IM-85 9 pcf Al H/C, 1" T Tegris LM 0.988 0 0 0 0 0 0 0 0 0 0.000

IM-86 Soric LRC, 2mm T Carbon epoxy 0.395 0 3 4 0 0 4 0 0 0 1.222

IM-87 Soric LRC, 2mm T Innegra 0.328 0 4 4 0 3 4 0 3 3 2.333

IM-88 Soric LRC, 2mm T Tegris LM 0.311 0 4 4 0 4 4 0 0 0 1.778

IM-89 Soric LRC, 3mm T Carbon epoxy 0.391 0 4 4 0 0 4 0 0 0 1.333

IM-90 Soric LRC, 3mm T Innegra 0.310 0 4 4 0 0 4 0 0 0 1.333

IM-91 Soric LRC, 3mm T 0.012" alum 0.520 0 4 4 0 0 0 0 0 0 0.889

IM-92 Soric LRC, 3mm T Tegris LM 0.310 0 4 4 0 0 4 0 0 0 1.333

IM-93 Soric XF, 2mm T Carbon epoxy 0.373 0 4 4 0 0 4 0 0 0 1.333

IM-94 Soric XF, 2mm T Innegra 0.296 0 4 4 0 4 4 0 0 0 1.778

IM-95 Soric XF, 2mm T Tegris LM 0.328 0 4 4 0 3 4 0 3 4 2.444

IM-96 Soric XF, 6mm T Carbon epoxy 0.423 0 4 4 0 0 0 0 0 0 0.889

IM-97 Soric XF, 6mm T Innegra 0.351 0 4 4 0 3 4 0 0 0 1.667

IM-98 Soric XF, 6mm T 0.012" alum 0.469 0 3 4 0 0 0 0 0 0 0.778

IM-99 Soric XF, 6mm T Tegris LM 0.366 0 4 4 0 1 3 0 0 0 1.333

IM-100 PHM w/PEEK (3/4" T) None 0.229 0 4 N/A 0 0 4 0 0 0 1.333

.5" Impacter 1.0" Impacter 1.75" Impacter
104

Table 52 - Impact Data Organized with Increasing Protective Skin Areal Density (1 of 2) 

Panel ID Impact Absorbing Layer

Impact Spreading 

Layer

Protective 

Skin psf

50 in-lbs180 in-lbs250 in-lbs50 in-lbs180 in-lbs250 in-lbs50 in-lbs180 in-lbs250 in-lbs

Avg. NDI

IM-01 None None 0.000 3 4 4 2 4 4 2 4 4 3.444

IM-100 PHM w/PEEK (3/4" T) None 0.229 0 4 N/A 0 0 4 0 0 0 1.333

IM-94 Soric XF, 2mm T Innegra 0.296 0 4 4 0 4 4 0 0 0 1.778

IM-92 Soric LRC, 3mm T Tegris LM 0.310 0 4 4 0 0 4 0 0 0 1.333

IM-90 Soric LRC, 3mm T Innegra 0.310 0 4 4 0 0 4 0 0 0 1.333

IM-88 Soric LRC, 2mm T Tegris LM 0.311 0 4 4 0 4 4 0 0 0 1.778

IM-87 Soric LRC, 2mm T Innegra 0.328 0 4 4 0 3 4 0 3 3 2.333

IM-95 Soric XF, 2mm T Tegris LM 0.328 0 4 4 0 3 4 0 3 4 2.444

IM-97 Soric XF, 6mm T Innegra 0.351 0 4 4 0 3 4 0 0 0 1.667

IM-99 Soric XF, 6mm T Tegris LM 0.366 0 4 4 0 1 3 0 0 0 1.333

IM-93 Soric XF, 2mm T Carbon epoxy 0.373 0 4 4 0 0 4 0 0 0 1.333

IM-89 Soric LRC, 3mm T Carbon epoxy 0.391 0 4 4 0 0 4 0 0 0 1.333

IM-86 Soric LRC, 2mm T Carbon epoxy 0.395 0 3 4 0 0 4 0 0 0 1.222

IM-47 3 pcf Al H/C, 1/4" T Tegris LM 0.409 0 4 4 0 0 0 0 0 0 0.889

IM-45 3 pcf Al H/C, 1/4" T Innegra 0.411 0 4 4 0 0 0 0 0 0 0.889

IM-96 Soric XF, 6mm T Carbon epoxy 0.423 0 4 4 0 0 0 0 0 0 0.889

IM-98 Soric XF, 6mm T 0.012" alum 0.469 0 3 4 0 0 0 0 0 0 0.778

IM-05 10# PU core, 1/4" T Tegris LM 0.473 0 4 4 0 0 0 0 0 0 0.889

IM-03 10# PU core, 1/4" T Innegra 0.475 0 3 4 0 0 0 0 0 0 0.778

IM-61 6 pcf Al H/C, 1/4" T Tegris LM 0.475 0 4 4 0 0 0 0 0 0 0.889

IM-44 3 pcf Al H/C, 1/4" T Carbon epoxy 0.488 0 4 4 0 0 0 0 0 0 0.889

IM-59 6 pcf Al H/C, 1/4" T Innegra 0.490 0 2 4 0 0 3 0 0 0 1.000

IM-49 3 pcf Al H/C, 1/2" T Innegra 0.490 0 4 4 0 0 0 0 0 0 0.889

IM-75 9 pcf Al H/C, 1/4" T Tegris LM 0.501 0 4 4 0 0 0 0 0 0 0.889

IM-73 9 pcf Al H/C, 1/4" T Innegra 0.505 0 4 4 0 0 0 0 0 0 0.889

IM-91 Soric LRC, 3mm T 0.012" alum 0.520 0 4 4 0 0 0 0 0 0 0.889

IM-50 3 pcf Al H/C, 1/2" T Tegris LM 0.531 0 4 4 0 0 0 0 0 0 0.889

IM-02 10# PU core, 1/4" T Carbon epoxy 0.536 0 4 4 0 0 0 0 0 0 0.889

IM-58 6 pcf Al H/C, 1/4" T Carbon epoxy 0.541 0 4 4 0 0 0 0 0 0 0.889

IM-46 3 pcf Al H/C, 1/4" T 0.012" alum 0.545 0 4 4 0 0 0 0 0 0 0.889

IM-52 3 pcf Al H/C, 3/4" T Innegra 0.556 0 4 4 0 0 0 0 0 0 0.889

IM-48 3 pcf Al H/C, 1/4" T Carbon epoxy 0.565 0 4 4 0 0 0 0 0 0 0.889

IM-53 3 pcf Al H/C, 3/4" T Tegris LM 0.578 0 4 4 0 0 0 0 0 0 0.889

IM-72 9 pcf Al H/C, 1/4" T Carbon epoxy 0.584 0 4 4 0 0 0 0 0 0 0.889

IM-64 6 pcf Al H/C, 1/2" T Tegris LM 0.610 0 4 4 0 0 0 0 0 0 0.889

IM-57 3 pcf Al H/C, 1" T Tegris LM 0.611 0 4 4 0 0 0 0 0 0 0.889

IM-51 3 pcf Al H/C, 3/4" T Carbon epoxy 0.615 0 4 4 0 0 0 0 0 0 0.889

IM-63 6 pcf Al H/C, 1/2" T Innegra 0.620 0 4 4 0 0 0 0 0 0 0.889

IM-55 3 pcf Al H/C, 1" T Innegra 0.621 0 0 4 0 0 0 0 0 0 0.444

IM-60 6 pcf Al H/C, 1/4" T 0.012" alum 0.628 0 2 4 0 0 0 0 0 0 0.667

IM-74 9 pcf Al H/C, 1/4" T 0.012" alum 0.629 0 1 4 0 0 0 0 0 0 0.556

IM-04 10# PU core, 1/4" T 0.012" alum 0.634 0 0 4 0 0 0 0 0 0 0.444

IM-78 9 pcf Al H/C, 1/2" T Tegris LM 0.645 0 4 4 0 0 0 0 0 0 0.889

IM-62 6 pcf Al H/C, 1/2" T Carbon epoxy 0.661 0 4 4 0 0 0 0 0 0 0.889

IM-77 9 pcf Al H/C, 1/2" T Innegra 0.666 0 2 4 0 0 0 0 0 0 0.667

IM-17 20# PU core, 1/4" T Innegra 0.670 0 0 3 0 0 0 0 0 0 0.333

IM-19 20# PU core, 1/4" T Tegris LM 0.678 0 0 3 0 0 0 0 0 0 0.333

IM-08 10# PU core, 1/2" T Tegris LM 0.684 0 0 4 0 0 0 0 0 0 0.444

IM-54 3 pcf Al H/C, 1" T Carbon epoxy 0.688 0 3 4 0 0 0 0 0 0 0.778

.5" Impacter 1.0" Impacter 1.75" Impacter
105

Figure 52 - Impact Data Organized with Increasing Protective Skin Areal Density (2 of 2) 

Panel ID Impact Absorbing Layer

Impact Spreading 

Layer

Protective 

Skin psf

50 in-lbs180 in-lbs250 in-lbs50 in-lbs180 in-lbs250 in-lbs50 in-lbs180 in-lbs250 in-lbs

Avg. NDI

IM-07 10# PU core, 1/2" T Innegra 0.695 0 0 4 0 0 0 0 0 0 0.444

IM-16 20# PU core, 1/4" T Carbon epoxy 0.730 0 0 0 0 0 0 0 0 0 0.000

IM-76 9 pcf Al H/C, 1/2" T Carbon epoxy 0.735 0 4 4 0 0 0 0 0 0 0.889

IM-66 6 pcf Al H/C, 3/4" T Innegra 0.749 0 4 4 0 0 0 0 0 0 0.889

IM-56 3 pcf Al H/C, 1" T 0.012" alum 0.769 0 1 3 0 0 0 0 0 0 0.444

IM-06 10# PU core, 1/2" T Carbon epoxy 0.770 0 0 4 0 0 0 0 0 0 0.444

IM-67 6 pcf Al H/C, 3/4" T Tegris LM 0.770 0 4 4 0 0 0 0 0 0 0.889

IM-80 9 pcf Al H/C, 3/4" T Innegra 0.803 0 2 4 0 0 0 0 0 0 0.667

IM-81 9 pcf Al H/C, 3/4" T Tegris LM 0.810 0 4 4 0 0 0 0 0 0 0.889

IM-18 20# PU core, 1/4" T 0.012" alum 0.814 0 0 0 0 0 0 0 0 0 0.000

IM-65 6 pcf Al H/C, 3/4" T Carbon epoxy 0.819 0 0 4 0 0 0 0 0 0 0.444

IM-11 10# PU core, 3/4" T Tegris LM 0.853 0 0 0 0 0 0 0 0 0 0.000

IM-31 30# PU core, 1/4" T Innegra 0.866 0 0 0 0 0 0 0 0 0 0.000

IM-33 30# PU core, 1/4" T Tegris LM 0.866 0 0 0 0 0 0 0 0 0 0.000

IM-79 9 pcf Al H/C, 3/4" T Carbon epoxy 0.869 0 2 4 0 0 0 0 0 0 0.667

IM-69 6 pcf Al H/C, 1" T Innegra 0.875 0 0 0 0 0 0 0 0 0 0.000

IM-10 10# PU core, 3/4" T Innegra 0.890 0 0 0 0 0 0 0 0 0 0.000

IM-71 6 pcf Al H/C, 1" T Tegris LM 0.904 0 0 4 0 0 0 0 0 0 0.444

IM-30 30# PU core, 1/4" T Carbon epoxy 0.928 0 0 0 0 0 0 0 0 0 0.000

IM-09 10# PU core, 3/4" T Carbon epoxy 0.948 0 0 0 0 0 0 0 0 0 0.000

IM-68 6 pcf Al H/C, 1" T Carbon epoxy 0.953 0 2 4 0 0 0 0 0 0 0.667

IM-83 9 pcf Al H/C, 1" T Innegra 0.968 0 0 0 0 0 0 0 0 0 0.000

IM-85 9 pcf Al H/C, 1" T Tegris LM 0.988 0 0 0 0 0 0 0 0 0 0.000

IM-32 30# PU core 0.012" alum 1.003 0 0 0 0 0 0 0 0 0 0.000

IM-32 30# PU core, 1/4" T 0.012" alum 1.003 0 0 0 0 0 0 0 0 0 0.000

IM-70 6 pcf Al H/C, 1" T 0.012" alum 1.033 0 0 0 0 0 0 0 0 0 0.000

IM-82 9 pcf Al H/C, 1" T Carbon epoxy 1.040 0 0 0 0 0 0 0 0 0 0.000

IM-21 20# PU core, 1/2" T Innegra 1.065 0 0 0 0 0 0 0 0 0 0.000

IM-22 20# PU core, 1/2" T Tegris LM 1.088 0 0 0 0 0 0 0 0 0 0.000

IM-15 10# PU core, 1" T Tegris LM 1.095 0 0 0 0 0 0 0 0 0 0.000

IM-13 10# PU core, 1" T Innegra 1.100 0 0 0 0 0 0 0 0 0 0.000

IM-84 9 pcf Al H/C, 1" T 0.012" alum 1.100 0 0 0 0 0 0 0 0 0 0.000

IM-20 20# PU core, 1/2" T Carbon epoxy 1.133 0 0 0 0 0 0 0 0 0 0.000

IM-12 10# PU core, 1" T Carbon epoxy 1.163 0 0 0 0 0 0 0 0 0 0.000

IM-14 10# PU core, 1" T 0.012" alum 1.233 0 0 0 0 0 0 0 0 0 0.000

IM-24 20# PU core, 3/4" T Innegra 1.458 0 0 0 0 0 0 0 0 0 0.000

IM-36 30# PU core, 1/2" T Tegris LM 1.465 0 0 0 0 0 0 0 0 0 0.000

IM-25 20# PU core, 3/4" T Tegris LM 1.470 0 0 0 0 0 0 0 0 0 0.000

IM-35 30# PU core, 1/2" T Innegra 1.475 0 0 0 0 0 0 0 0 0 0.000

IM-23 20# PU core, 3/4" T Carbon epoxy 1.490 0 0 0 0 0 0 0 0 0 0.000

IM-34 30# PU core, 1/2" T Carbon epoxy 1.533 0 0 0 0 0 0 0 0 0 0.000

IM-27 20# PU core, 1" T Innegra 1.833 0 0 0 0 0 0 0 0 0 0.000

IM-26 20# PU core, 1" T Carbon epoxy 1.910 0 0 0 0 0 0 0 0 0 0.000

IM-29 20# PU core, 1" T Tegris LM 1.928 0 0 0 0 0 0 0 0 0 0.000

IM-28 20# PU core, 1" T 0.012" alum 2.005 0 0 0 0 0 0 0 0 0 0.000

IM-39 30# PU core, 3/4" thick Tegris LM 2.058 0 0 0 0 0 0 0 0 0 0.000

IM-38 30# PU core, 3/4" thick Innegra 2.075 0 0 0 0 0 0 0 0 0 0.000

IM-37 30# PU core, 3/4" thick Carbon epoxy 2.128 0 0 0 0 0 0 0 0 0 0.000

IM-41 30# PU core, 1" T Innegra 2.658 0 0 0 0 0 0 0 0 0 0.000

IM-43 30# PU core, 1" T Tegris LM 2.670 0 0 0 0 0 0 0 0 0 0.000

IM-40 30# PU core, 1" T Carbon epoxy 2.740 0 0 0 0 0 0 0 0 0 0.000

.5" Impacter 1.0" Impacter 1.75" Impacter
106

Table 53 - Panels That Passed All Test Conditions Sorted by Protective Skin Areal Density 

As was mentioned in Section 7.2.1 – Impact Requirements, a realistic pass condition for the panels is 

to pass the 0.5” impactor at 50 in-lbs, the 1.0” impactor at 50 and 180 in-lbs, and to pass the 1.75” 

impactor at all energy levels. Table 54 shows only those impact conditions in the columns under each 

impactor diameter. Panels are sorted by areal weight, and only panels with areal weights less than 0.5 psf 

are shown. There are 16 panels which pass the realistic requirements; only six fail. Unfortunately, those 

six are some of the lightest protective skins. After IM-100, IM-92 and IM-90 at 0.31 psf are the next two 

panels to meet the requirements. They both use the Soric LRC (Low Resin Content) 3 mm impact 

absorbing layer with Tegris LM and Innegra S, respectively, for the impact spreading layer. 

Panel ID Impact Absorbing Layer

Impact Spreading 

Layer

Protective 

Skin psf

50 in-lbs180 in-lbs250 in-lbs50 in-lbs180 in-lbs250 in-lbs50 in-lbs180 in-lbs250 in-lbs

Avg. NDI

IM-16 20# PU core, 1/4" T Carbon epoxy 0.730 0 0 0 0 0 0 0 0 0 0.000

IM-18 20# PU core, 1/4" T 0.012" alum 0.814 0 0 0 0 0 0 0 0 0 0.000

IM-11 10# PU core, 3/4" T Tegris LM 0.853 0 0 0 0 0 0 0 0 0 0.000

IM-31 30# PU core, 1/4" T Innegra 0.866 0 0 0 0 0 0 0 0 0 0.000

IM-33 30# PU core, 1/4" T Tegris LM 0.866 0 0 0 0 0 0 0 0 0 0.000

IM-69 6 pcf Al H/C, 1" T Innegra 0.875 0 0 0 0 0 0 0 0 0 0.000

IM-10 10# PU core, 3/4" T Innegra 0.890 0 0 0 0 0 0 0 0 0 0.000

IM-30 30# PU core, 1/4" T Carbon epoxy 0.928 0 0 0 0 0 0 0 0 0 0.000

IM-09 10# PU core, 3/4" T Carbon epoxy 0.948 0 0 0 0 0 0 0 0 0 0.000

IM-83 9 pcf Al H/C, 1" T Innegra 0.968 0 0 0 0 0 0 0 0 0 0.000

IM-85 9 pcf Al H/C, 1" T Tegris LM 0.988 0 0 0 0 0 0 0 0 0 0.000

IM-32 30# PU core 0.012" alum 1.003 0 0 0 0 0 0 0 0 0 0.000

IM-32 30# PU core, 1/4" T 0.012" alum 1.003 0 0 0 0 0 0 0 0 0 0.000

IM-70 6 pcf Al H/C, 1" T 0.012" alum 1.033 0 0 0 0 0 0 0 0 0 0.000

IM-82 9 pcf Al H/C, 1" T Carbon epoxy 1.040 0 0 0 0 0 0 0 0 0 0.000

IM-21 20# PU core, 1/2" T Innegra 1.065 0 0 0 0 0 0 0 0 0 0.000

IM-22 20# PU core, 1/2" T Tegris LM 1.088 0 0 0 0 0 0 0 0 0 0.000

IM-15 10# PU core, 1" T Tegris LM 1.095 0 0 0 0 0 0 0 0 0 0.000

IM-13 10# PU core, 1" T Innegra 1.100 0 0 0 0 0 0 0 0 0 0.000

IM-84 9 pcf Al H/C, 1" T 0.012" alum 1.100 0 0 0 0 0 0 0 0 0 0.000

IM-20 20# PU core, 1/2" T Carbon epoxy 1.133 0 0 0 0 0 0 0 0 0 0.000

IM-12 10# PU core, 1" T Carbon epoxy 1.163 0 0 0 0 0 0 0 0 0 0.000

IM-14 10# PU core, 1" T 0.012" alum 1.233 0 0 0 0 0 0 0 0 0 0.000

IM-24 20# PU core, 3/4" T Innegra 1.458 0 0 0 0 0 0 0 0 0 0.000

IM-36 30# PU core, 1/2" T Tegris LM 1.465 0 0 0 0 0 0 0 0 0 0.000

IM-25 20# PU core, 3/4" T Tegris LM 1.470 0 0 0 0 0 0 0 0 0 0.000

IM-35 30# PU core, 1/2" T Innegra 1.475 0 0 0 0 0 0 0 0 0 0.000

IM-23 20# PU core, 3/4" T Carbon epoxy 1.490 0 0 0 0 0 0 0 0 0 0.000

IM-34 30# PU core, 1/2" T Carbon epoxy 1.533 0 0 0 0 0 0 0 0 0 0.000

IM-27 20# PU core, 1" T Innegra 1.833 0 0 0 0 0 0 0 0 0 0.000

IM-26 20# PU core, 1" T Carbon epoxy 1.910 0 0 0 0 0 0 0 0 0 0.000

IM-29 20# PU core, 1" T Tegris LM 1.928 0 0 0 0 0 0 0 0 0 0.000

IM-28 20# PU core, 1" T 0.012" alum 2.005 0 0 0 0 0 0 0 0 0 0.000

IM-39 30# PU core, 3/4" thick Tegris LM 2.058 0 0 0 0 0 0 0 0 0 0.000

IM-38 30# PU core, 3/4" thick Innegra 2.075 0 0 0 0 0 0 0 0 0 0.000

IM-37 30# PU core, 3/4" thick Carbon epoxy 2.128 0 0 0 0 0 0 0 0 0 0.000

IM-41 30# PU core, 1" T Innegra 2.658 0 0 0 0 0 0 0 0 0 0.000

IM-43 30# PU core, 1" T Tegris LM 2.670 0 0 0 0 0 0 0 0 0 0.000

IM-40 30# PU core, 1" T Carbon epoxy 2.740 0 0 0 0 0 0 0 0 0 0.000

.5" Impacter 1.0" Impacter 1.75" Impacter
107

Table 54 - Panels with Protective Skin Areal Density Less Than 0.50 psf 

Examining the raw data in Table 50 (the visible damage and base panel damage columns) for those 

panels which failed shows that the panels highlighted in mauve in Table 54 never had base panel damage 

with no visible damage. The panels highlighted in red did have a case or cases of base panel damage with 

no visible damage – in addition to not meeting the impact requirements, these panels also fail the visible 

damage requirement. Examination of the remainder of the panels shows that no other panels fail to meet 

the visible damage requirement. 

The value of carbon epoxy as an impact spreading layer is evident from examining 

Table 54. Both the Soric XF and LRC 2 mm impact absorbing layer failed with Innegra and Tegris LM 

(with one exception), but both passed with carbon epoxy as the impact spreading layer. The carbon 

epoxy layer is heavier but could possibly be worth the weight in order to reduce the thickness of the 

impact absorbing layer. A decision to use carbon epoxy cannot be made based on impact alone, however, 

because the lightning strike protection due to corrosion issues would have to be copper or brass in order to 

be compatible – both of those options would be heavier than available aluminum options. 

The 16 panels remaining in Table 54 which passed all of the realistic test conditions are all 

potential candidates for the next phase of protective skin development. They are called out in 

.5" 

Impacter

Panel Absorbing Layer Absorb T Spreading Layer psf 50 50 180 50 180 250

IM-1 None 0.000 None 0.000 3 2 4 2 4 4

IM-100 PHM w/PEEK 0.750 None 0.229 0 0 0 0 0 0

IM-94 Soric XF 0.079 Innegra 0.296 0 0 4 0 0 0

IM-92 Soric LRC 0.118 Tegris LM 0.310 0 0 0 0 0 0

IM-90 Soric LRC 0.118 Innegra 0.310 0 0 0 0 0 0

IM-88 Soric LRC 0.079 Tegris LM 0.311 0 0 4 0 0 0

IM-87 Soric LRC 0.079 Innegra 0.328 0 0 3 0 3 3

IM-95 Soric XF 0.079 Tegris LM 0.328 0 0 3 0 3 4

IM-97 Soric XF 0.236 Innegra 0.351 0 0 3 0 0 0

IM-99 Soric XF 0.236 Tegris LM 0.366 0 0 1 0 0 0

IM-93 Soric XF 0.079 Carbon epoxy 0.373 0 0 0 0 0 0

IM-89 Soric LRC 0.118 Carbon epoxy 0.391 0 0 0 0 0 0

IM-86 Soric LRC 0.079 Carbon epoxy 0.395 0 0 0 0 0 0

IM-47 3 pcf Al H/C 0.250 Tegris LM 0.409 0 0 0 0 0 0

IM-45 3 pcf Al H/C 0.250 Innegra 0.411 0 0 0 0 0 0

IM-96 Soric XF 0.236 Carbon epoxy 0.423 0 0 0 0 0 0

IM-98 Soric XF 0.236 0.012" alum 0.469 0 0 0 0 0 0

IM-5 10# PU core 0.250 Tegris LM 0.473 0 0 0 0 0 0

IM-3 10# PU core 0.250 Innegra 0.475 0 0 0 0 0 0

IM-61 6 pcf Al H/C 0.250 Tegris LM 0.475 0 0 0 0 0 0

IM-44 3 pcf Al H/C 0.250 Carbon epoxy 0.488 0 0 0 0 0 0

IM-59 6 pcf Al H/C 0.250 Innegra 0.490 0 0 0 0 0 0

IM-49 3 pcf Al H/C 0.500 Innegra 0.490 0 0 0 0 0 0

1.0" Impacter 1.75" Impacter KEY

Failed 1.0" at 180 in-lbs

Failed 1.0" at 180 in-lbs

and damage was not visible
108

Table 55. The Soric LRC 3 mm is still in play with both Tegris LM and Innegra. Soric XF 6mm is 

only an option with carbon epoxy or aluminum (which was included in the test matrix to compare 

impacts). Eliminating the panels with carbon epoxy and aluminum leaves 10 potential candidates. There 

are several 1⁄4” thick 3 pcf metallic honeycomb and 10 lb polyurethane core options with both Tegris and 

Innegra. There are even some 1⁄4” thick 6 pcf metallic honeycomb options and one 1⁄2” thick 3 pcf metallic 

honeycomb options with areal weights less than 0.5 psf. 

A major finding from this testing was that thicker materials are not required. The test matrix 

included 1⁄4”, 1⁄2”, 3⁄4”, and 1” thicknesses of the metallic honeycombs and polyurethane cores. Being able 

to use thinner skins which fulfill the requirements is excellent news from a drag perspective. The other 

surprise is that heavier honeycomb and core densities are not required. While two panels with 6 pcf 

metallic honeycomb appear in the final panel possibilities, the 3 pcf metallic honeycomb panels are also 

there and have a lower areal weight (0.490 psf compared to 0.411 psf with Innegra). 

As mentioned in Section 7.2.2 – Attaching the Protective Skins to Base Panels, the base panels were 

observed to split in the direction of the top and bottom plies of the uni-directional material (see Figure 

61). This necessitated ensuring the base panels were oriented with the top and bottom plies running 

across the test bays instead of in the long direction of the bays. The uni-directional material was chosen 

because representative of what might be primary structure in 2035 – it is strong and production could be 

automated. Year 2012 structures, which often have to deal with impact damage, replace the most outer 

and inner uni-directional plies with woven materials. The woven material cross fibers act like a stop to 

minimize crack growth (see Figure 62).

In order to obtain the best impact data possible during the next phase of testing, the base substrate 

panels will be constructed with five layers of uni-directional fibers between two outer layers of woven 

material. This should eliminate the need to worry about orientation of the base substrate panel in the test 

fixture and produce more accurate and accurately measureable results. 
109

Table 55 - Final Impact Panel Possibilities 

Panel ID Impact Absorbing 

Foam Layer Interface Impact Spreading Layer psf

IM-100

Polydamp 

Hydrophobic 

Melamine with PEEK 

skin (3/4" thick)

None None 0.229

IM-92 Soric LRC, 3mm thick Aeropoxy Tegris LM 0.310

IM-90 Soric LRC, 3mm thick Aeropoxy Innegra 0.310

IM-99 SORIC XF, 6 mm thick Aeropoxy Tegris LM 0.366

IM-93 Soric XF, 2mm thick Aeropoxy Carbon epoxy 0.373

IM-89 Soric LRC, 3mm thick Aeropoxy Carbon epoxy 0.391

IM-86 Soric LRC, 2mm thick Aeropoxy Carbon epoxy 0.395

IM-47

3 pcf metallic 

honeycomb, 

1/4" thick

Grade 30 

adhesive Tegris LM 0.409

IM-45

3 pcf metallic 

honeycomb, 

1/4" thick

Grade 30 

adhesive Innegra 0.411

IM-96 Soric XF, 6mm thick Aeropoxy Carbon epoxy 0.423

IM-98 Soric XF, 6mm thick Aeropoxy 0.012" aluminum 

sheet 0.469

IM-5 10# PU core, 1/4" 

thick (FR-6710) Aeropoxy Tegris LM 0.473

IM-3 10# PU core, 1/4" 

thick (FR-6710) Aeropoxy Innegra 0.475

IM-61

6 pcf metallic 

honeycomb, 

1/4" thick

Grade 30 

adhesive Tegris LM 0.475

IM-44

3 pcf metallic 

honeycomb, 

1/4" thick

Grade 30 

adhesive Carbon epoxy 0.488

IM-49

3 pcf metallic 

honeycomb, 

1/2" thick

Grade 30 

adhesive Innegra 0.490

IM-59

6 pcf metallic 

honeycomb, 

1/4" thick

Grade 30 

adhesive Innegra 0.490
110

Figure 61: Unidirectional fiber splitting after impact. 

Figure 62: Woven outer layers stop splitting and crack growth. 

7.3 Electromagnetic Effects 

With the requirements from 5.3.1, three sets of testing were done with the lighting strike panels: 

1) shielding effectiveness (HIRF or High Intensity Radiated Fields); 2) indirect effects of lightning (IEL); 

and 3) direct effects of lightning (DEL). (Visual inspection of the lightning strike panels was also 

conducted before DEL testing – that will be reported on in the next section on Aesthetics and Smoothing.) 

Shielding effectiveness and indirect effects of lightning testing were conducted at Cessna Aircraft 

Company; the direct effects’ testing was conducted at DNB Engineering in Fullerton, California. The 

electromagnetic effects test results are shown in detail in Appendix F – First-Generation Shielding 

Effectiveness Test Data, Appendix G – First-Generation Indirect Effects Test Data, Appendix H – FirstGeneration Direct Effects (DNB) Report, and Appendix I – First-Generation Direct Effects Pictures 

(Cessna). Results will be summarized in the following subsections. 

7.3.1 Transmissivity 

A schematic of the test setup for transmissivity testing is shown in Figure 63. The aperture is where 

the panel is placed. Figure 64 through Figure 68 shows pictures of the transmissivity testing setup. More 
111

detailed pictures along with pictures of all of the test articles mounted in the chamber may be found in 

Appendix E – First-Generation Shielding Effectiveness Test Setup Pictures. 

Figure 63: Schematic of shielding effectiveness setup. 

Figure 64: Horn antenna in the big chamber. 
112

Figure 65: Close-up view of horn antenna in big chamber. 
113

Figure 66: Horn antenna in the small chamber. 

Figure 67: Horn antenna in the small chamber. 
114

Figure 68: Mode stirrer in the small chamber. 

The aperture opening is 22” x 22” so the lightning strike test panels were designed to have 22” x 22” 

impact absorbing and spreading layers along with lightning strike materials (see Figure 69). The outer 

one inch of the base substrate panel was bare; in preparation for testing, copper tape with conducting 

adhesive 3⁄4” wide was applied to the edge of the protective skin and 2” tape was wrapped around the bare 

base substrate panel as shown in Figure 70. One key to transmissivity testing is a good ground between 

the edge of the panel and the window of the test chamber aperture. The edges of the test articles were 

designed to leave the lightning strike protection material uncovered by the aesthetic film by leaving the 

outer 0.75” edge of the lightning strike material bare as shown in Figure 69. 

Figure 69: Lightning strike panel edge treatment to facilitate grounding. 
115

Figure 70: Test panel with copper tape to facilitate grounding.

In order to ground the test articles to the chamber wall, an innovative “L” frame as shown in the left 

side of Figure 71 was designed and fabricated at Cessna. The inner piece of the “L” frame has an inner 

edge which comes into contact with the test panel; the outer piece of the “L” frame has an outer edge 

which comes into contact with the chamber wall. The “L” frame is innovative in that it can be adjusted to 

accommodate all of the thicknesses of the test articles. 

 

Figure 71: "L" frame drawing and article with test panel ready for testing.

Figure 72 shows a 10dB difference in the raw data of power received by the top hat antenna inside the 

shielded reverberation chamber for the lightning strike panel LS-4 with and without the grounding of the 

lightning strike material on the core to the Al frame. LS-4 used resin to attach the lightning strike 

material. The resin prevented grounding and caused a decrease in shielding effectiveness. In order to 

achieve grounding it was necessary to lightly sand the resin around the outer 3⁄4” of the panels. The 

grounded result in Figure 72 shows that the sanding was effective. This also provides a validation of the 

“sealing” method used for the leakage current. 
116

Figure 72: Panel LS-4 (10 pcf PU core, 1/4" thick VATRM Innegra VARTM LDS 50-01 

0.007 psf aluminum Integument film) with and without grounding to Al frame. 

Figure 73 shows the comparison between the open window, the Al panel, and the base substrate panel. 

There is a difference of 25 dB from 700 MHz to 6 GHz (the frequency range of interest) between the Al 

and base substrate panel. Addition of the protective skins is necessary to produce shielding effectiveness 

results closer to aluminum. Shielding effectiveness testing of the panels gives an insight into materials to 

be chosen to get close to the shielding effectiveness of aluminum. 

Figure 73: Shielding effectiveness of a base substrate panel compared to an Al panel and open window. 

The effects of different lightning strike materials are shown in Figure 74. All of the panels have 1⁄4” 

thick 10 pcf polyurethane core with an Innegra S impact spreading layer and Integument film. The 
117

differences shown are within the noise level of the data. The shielding level is much closer to that of 

aluminum than the open hole. 

Figure 74: Different lightning strike materials with 1/4" 10 pcf PU core with Innegra S impact spreading and 

Integument film (LS-1 - 0.016 psf expanded Al, LS-2 - 0.029 psf expanded Copper foil, LS-4 - LDS 50-01 0.007 psf 

Al, LS-5 - Integument with integrated LSP and PSA, LS-6 – Proprietary Spray material). 

The effect of varying impact absorbing material is shown in Figure 75. All of the materials are 1⁄4” 

thick and have Innegra S impact absorbing layer and Integument film with integrated lightning strike 

protection (LSP) and pressure sensitive adhesive (PSA). There are no significant differences in shielding 

for any of the impact absorbing materials. Again the shielding levels are close to that of aluminum. 

Figure 76 shows the difference in shielding for two different thicknesses of 10 pcf polyurethane core 

material. Both panels have Innegra S impact spreading layer, LDS 50-01 LSP, and Integument film. 

There is a noticeable difference in shielding levels with the 3⁄4” thick providing more shielding than the 

1⁄4”-thick core. This is as expected since the shielding is primarily a function of material thickness. The 

3⁄4” core does provide shielding close to the same level as aluminum. 

10

2 103 104 105

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

Frequency(MHz) Received Pwr + Abs(Insertion loss of Chamber) (dBm)

Al Open

LS-1

LS-2

LS-4

LS-5

LS-6
118

Figure 75: Different 1/4" thick impact absorbing materials with Innegra S and Integument with integrated LSP & 

PSA (LS-5 – 10 pcf PU core, LS-12 – 20 pcf PU core, LS-19 – 3 pcf metallic honeycomb, LS-26 – 6 pcf metallic 

honeycomb core; and LS-28 – 7.9 pcf metallic honeycomb core). 

Figure 76: Comparison of two different thicknesses of polyurethane core with same 

lightning strike protection scheme (LS-4 1/4" and LS-9 - 3/4"). 

Figure 77 shows the effect of Soric thickness on shielding. No lighting strike panels were built with 3 

mm Soric LRC. As would be anticipated because of the extremely small differences in thickness, there is 

no quantifiable difference in shielding for the various thicknesses. 

10

2 103 104 105

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

Frequency(MHz) Received Pwr + Abs(Insertion loss of Chamber) (dBm)

Al Open

LS-5

LS-12

LS-19

LS-26

LS-28

10

2 103 104 105

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10 Al Open

LS-4

LS-9
119

Figure 77: Soric cores of various thicknesses (LS-33 - Soric XF 2 mm, 

LS-38 - Soric XF 6 mm, LS-40 - Soric LRC 2 mm). 

The effect of aesthetic films on shielding is shown in Figure 78. All of the panels have 1⁄4” thick 10 

pcf polyurethane core for impact absorbing, Innegra S for the impact spreading layer, and LDS 50-01 for 

the lightning strike layer. There appears to be a potentially significant difference between LS-4 

(Integument film) and LS-41 (3M-5004) which is surprising since they have the same chemical 

composition. The Integument film is twice as thick (4 mils as opposed to 2 mils for the 3M 5004). For 

the rest of the materials, there does not appear to be any significant difference. 

To investigate, a comparison of panels with Innegra S, LDS 50-01 LSP, and Integument film is shown 

in Figure 79. All of the panels have different impact absorbing layers; all layers are 1⁄4” thick. LS-41 

(same as LS-4 except for 3M 5004 film instead of Integument) is shown for comparison. LS-4 and LS-18 

(3 pcf metallic honeycomb instead of 10 pcf PU core) have almost identical shielding results. There were 

no significant differences shown for various impact absorbing layers in Figure 75. The most likely 

explanation is that the grounding for LS-4 and LS-18 was not good (the grounding issue with LS-4 was 

shown earlier in Figure 72), and the most likely conclusion for aesthetic films is that there is no real effect 

on shielding by varying aesthetic films. 

10

2 103 104 105

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

Frequency(MHz) Received Pwr + Abs(Insertion loss of Chamber) (dBm)

Al Open

LS-33

LS-38

LS-40
120

Figure 78: Different aesthetic films with same polyurethane core (LS-4 - Integument, LS-41 – 3M 5004, 

LS-42 – Aptiv PEEK, LS-43 – Halar ECTFE, LS-44 – Kapton film). 

Figure 79: Panels with Innegra, LDS 50-01 LSP and Integument film (LS-4 – 10 pcf PU core, 

LS-11 – 20 pcf PU core, LS-13 – 30 pcf PU core, LS-18 – 3 pcf metallic honeycomb, 

LS-41 – 10 pcf PU core with 3M 5004 with PSA film instead of Integument). 

The shielding effectiveness of the two carbon nanotube panels is presented in Figure 80. Both panels 

have 1⁄4” thick 10 pcf polyurethane core, Innegra S impact spreading layer, and Integument film aesthetic 

layer. The difference in thicknesses of the carbon nanotube sheets is 9-11 gsm (one and then 1 1⁄2 layers 

10

2 103 104 105

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

Frequency(MHz) Received Pwr + Abs(Insertion loss of Chamber) (dBm)

Al Open

LS-4

LS-41

LS-42

LS-43

LS-44
121

on LS-46) and one layer of 15-18 gsm on LS-47. There is no perceptible difference between the two 

panels. 

Figure 80: Panels with carbon nanotube lightning strike protection (two different densities). 

The shielding effectiveness for Polydamp hydrophobic melamine with metalized PEEK skin is shown 

in Figure 81. The panel has no film and no other layers of materials except the base substrate panel. The 

Polydamp does an excellent job of shielding, coming very close to that of the aluminum panel and 

significantly beating the plain base substrate panel which was shown in Figure 73. 

The shielding effectiveness for all panels (including the base panel) is overlaid on Figure 82. None of 

the panels are more effective than aluminum. In the outer areas of the region of interest (700 MHz to 1 

GHz and 4 GHz to 6 GHz) the base panel is in the middle of the coverage areas of all panels. In the 

region 1 GHz to 4 GHz, all of the test panels provide more shielding than the base panel. 

10

2 103 104 105

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

Frequency(MHz) Received Pwr + Abs(Insertion loss of Chamber) (dBm)

Al Open

LS-46

LS-47
122

Figure 81: Effect of Polydamp hydrophobic melamine (3/4" thick) with PEEK skin - no film. 

Figure 82: Shielding effectiveness for all panels plus the base panel 

 with aluminum and open as the two bounds. 

7.3.2 Indirect Effects of Lightning 

The panels were evaluated for possible effects of indirect effects of lightning coupling factors into a 

known “standard” wire bundle, based on Section 22 of RTCA DO-160G for open circuit voltage (Voc) 

and closed circuit current (Isc) for a standard cable bundle using waveforms 1 and 2. 

The overall test setup for IEL testing is shown in Figure 83 through Figure 88. Figure 83 shows the 

complete setup with labels on the various components. Figure 84 through Figure 88 show more detailed 

views of each of the areas. 

10

2 103 104 105

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

Frequency(MHz) Received Pwr + Abs(Insertion loss of Chamber) (dBm)

Al Open

LS-45

10

2 103 104 105

-90

-80

-70

-60

-50

-40

-30

-20

-10

0

10

Frequency (MHz) Received Pwr + abs(Insertion loss of Chamber)(dBm)

All Panels

Al Open CFConly Panel data
123

Figure 83: Complete IEL setup (test panel is between blue foam layers at far right of picture). 

Figure 84: IEL setup - transformer with probe. 

10kV power supply

Waveform 1-2 generator Oscilloscope

Injection core

Voltage probe

Signal Generator

Current probe

Panel
124

Figure 85: IEL setup - transformer with cable bundle termination. 

Figure 86: IEL setup - termination. 
125

Figure 87: IEL setup - panel, cable bundle, and transformer. 

Figure 88: IEL setup - panel with bulkheads. 
126

Current waveform 1 and voltage waveform 2 were injected on the cable bundles using an induction 

current transformer. All the waveforms were tested to current level 3 with a peak equal to 608 A (Figure 

89), and with the impedance of the panels the voltage (Figure 90) was tested to 1.1kV - 1.2kV. 

Figure 89: IEL input current waveforms with characteristics of interest identified.

Figure 90: IEL voltage waveform. 

T2 (Time to 

50% max)

Time to 10% 

max

T1 

(Time 

to 

max)
127

Table 56 shows results for different lightning strike protection materials for maximum peak current, 

maximum peak voltage and resistance between the bulkheads. These measurements were used to attempt 

to make a relative comparison of the important waveform parameters between the various materials. 

Table 57 shows some of the panels as compared to Al panel (433A, 0.97mΩ). These panels chosen were a 

representative of the lightning strike protection material. Table 58 for current and Table 59 for voltage 

were obtained by digitizing measured signals of closed circuit current and open circuit voltage on the 

cable bundle. Peak voltage varied from 16V – 19V for all materials except for three outliers (carbon 

nanotube and the Polydamp Hydrophobic Melamine with metalized PEEK skin), and peak current varied 

from 433A - 362A for all of the materials except for three outliers (carbon nanotube and the Polydamp 

Hydrophobic Melamine with metalized PEEK skin). 
128

Table 56 - Panel Details with Peak Current and Voltage (1 of 2) 

Panel 

ID Lightning Strike Material Current(A)

Voltage

(V)

Resistance 

(m Ω)

Al Al 433 18 0.97

CFC None 358 15 41.4

LS-01 0.016 psf expanded aluminum foil 424.5 18 5.9

LS-02 0.029 expanded copper foil 424.5 17.5 8.6

LS-04 LDS 50-01 0.007 psf aluminum 416 17 17.1

LS-05 Integument with integrated LSP 425 18 12.8

LS-06 Proprietary Spray Material 370.5 15.5 20.2

LS-07 Integument with integrated LSP 425 18 7.9

LS-08 Integument with integrated LSP 420.5 18 11.2

LS-09 LDS 50-01 0.007 psf aluminum 408 16.5 18.5

LS-10 Integument with integrated LSP 429 18 6.9

LS-11 LDS 50-01 0.007 psf aluminum 420.5 18 21.1

LS-12 Integument with integrated LSP 425 18.5 7.7

LS-13 LDS 50-01 0.007 psf aluminum 425 17.5 9.8

LS-14 Integument with integrated LSP 420.5 18 7.9

LS-15 0.016 psf expanded aluminum foil 429 18 35.6

LS-16 0.029 expanded copper foil 429 17 8.3

LS-18 LDS 50-01 0.007 psf aluminum 425 18 22.6

LS-19 Integument with integrated LSP 425 17 8.1

LS-20 Proprietary Spray Material 370.5 15.5 37.5

LS-21 Integument with integrated LSP 424.5 17.5 6.4

LS-22 Integument with integrated LSP 425 19 15

LS-23 LDS 50-01 0.007 psf aluminum 416.5 17 13.5

LS-24 Integument with integrated LSP 424.5 18 8.4

LS-25 LDS 50-01 0.007 psf aluminum 416 17.5 14

LS-26 Integument with integrated LSP 424.5 17 6.7

LS-27 LDS 50-01 0.007 psf aluminum 425 18 11.4

LS-28 Integument with integrated LSP 416.5 17 11.2

LS-29 0.016 psf expanded aluminum foil 433 18 12.8

LS-30 0.029 expanded copper foil 425 17 12.3

LS-32 LDS 50-01 0.007 psf aluminum 424.5 18 11.7

LS-33 Integument with integrated LSP 408 16.5 20.4

LS-34 Proprietary Spray Material 362 15 19.3

LS-35 Integument with integrated LSP 429 17 9.2

LS-36 Integument with integrated LSP 425 17.5 8.3

LS-37 LDS 50-01 0.007 psf aluminum 408 17.5 13.6
129

Table 56 - Panel Details with Peak Current and Voltage (2 of 2) 

Panel 

ID Lightning Strike Material Current(A)

Voltage

(V)

Resistance 

(m Ω)

LS-38 Integument with integrated LSP 424.5 17 6.9

LS-39 LDS 50-01 0.007 psf aluminum 425 17.5 10.2

LS-40 Integument with integrated LSP 380 16 21

LS-41 LDS 50-01 0.007 psf aluminum 412 18 14.6

LS-42 LDS 50-01 0.007 psf aluminum 425 18 6.6

LS-43 LDS 50-01 0.007 psf aluminum 425 18 7.4

LS-44 LDS 50-01 0.007 psf aluminum 412 17.5 13.2

LS-45 Polydamp Hydrophobic Melamine with 

metallized PEEK skin 25.5 45.5 43.4

LS-46 Nanocomp sheet (carbon nanotube) 279 12 42.76

LS-47 Nanocomp sheet (carbon nanotube) 302 13 41.8

Table 57 - Indirect Effects of Lightning Test Results 

Lightning strike 

Protection Material

Average 

Current

(A)

Average 

Voltage

(V)

Average 

Resistance 

(mΩ)

Current 

range

(A)

Voltage 

range

(V)

Resistance 

range (mΩ)

Al Panel 433 18 0.97 433 18 0.97

0.016 psf 

expanded 

aluminum foil

429 18 18 424.5-

433 18 5.9 - 35.6

0.029 expanded 

copper foil 320 13 7

424.7-

429 17-17.5 8.3-12.3

Integument with 

integrated LSP 397 17 10 380-429 16-19 6.7-21

LDS 50-01 0.007 

psf aluminum 386 16 12 408-425 16.5-18 6.6-21.1

LDS 50-01 0.007 

psf aluminum 421 18 20 416-425 17-18 11.7-22.6

Proprietary Spray 

Material 368 15 26 362-370.5 15-15.5 19.3-37.5

Nanocomp sheet 291 13 42 279-302 12-13 41.8-42.76

None (base panel) 358 15 41.4 358 15 41.4

Polydamp 

Hydrophobic 

Melamine with 

metallized PEEK 

skin

26 46 43 26 46 43
130

Table 58 - Current Waveforms Characteristics for Different Lightning Strike Materials 

Panel

Lightning 

protection 

material

Time 

for 

10% 

(μs)

Amplitude 

at 10%

(A)

Rati

o

Time 

at 

max 

(μs)

Max 

peak 

(A)

Tim

e at 

50% 

(μs)

Amplitude 

50%

(A)

Rati

o

Al Al 0.00 40.00 9 5.77 431

46.5

5 228.89 53

CFC None 0.04 35.42 10 4.25 354

15.6

9 192.62 54

LS-20 Proprietary

Spray Material 0.48 36.88 10 4.79 368 14.91

194.01 52

LS-29

0.016 psf 

expanded 

aluminum foil

0.66 42.63 10 6.60 426 42.7

7

222.94 52

LS-2

0.029 

expanded 

copper foil

0.62 42.27 10 6.24 422 40.3

9

224.84 53

LS-33

Integument 

with integrated 

LSP & PSA

0.60 39.15 10 5.99 391 20.6

2

213.75 54

LS-39

LDS 50-01 

0.007 psf 

aluminum

0.88 42.41 10 8.80 424 42.7

4

220.17 51

LS-43

LDS 50-01 

0.007 psf 

aluminum 0.71 34.51 10 7.07 345

44.7

1 187.36 54

LS-47

Nanocomp 

sheet (15 gsm, 

1 layer)

0.33 30.05 10 3.35 300 9.09 158.66 52
131

Table 59 - Voltage Waveforms Characteristics for Different Lightning Strike Materials 

Panel

Lightning 

protection 

material

Time 

for 

10% 

(μs)

Amplitude 

at 10%

(V)

Ratio

Time 

at max 

(μs)

Max 

peak 

(V)

Time 

at 

50% 

(μs)

Amplitude 

50%

(V)

Ratio

Al Al

0.00 1.68 10 9.59 17 44.95 9.54 54

CFC None

0.00 1.55 11 2.50 14 15.26 7.71 53

LS-20

Proprietary 

Spray

Material 0.49 1.52 10 4.93 15 16.22 8.08 53

LS-29

0.016 psf 

expanded 

aluminum 

foil 0.70 1.76 10 6.96 17 41.49 9.68 54

LS-2

0.029 

expanded 

copper foil 0.74 1.79 10 7.38 17 45.70 9.14 51

LS-33

Integumen

t with 

integrated 

LSP & 

PSA 0.65 1.61 10 6.47 16 21.46 8.66 53

LS-39

LDS 50-01 

0.007 psf 

aluminum 0.78 1.74 10 7.80 17 41.23 9.41 54

LS-43

LDS 40-

03(N) 

0.0016 psf 

nickel 

coated 

copper 0.56 2.12 10 5.59 21 42.05 11.45 54

LS-47

Nanocomp 

sheet (15 

gsm, 1 

layer) 0.37 1.25 10 3.72 12 9.51 6.78 54

7.3.3 Direct Effects of Lightning 

The composite panels were struck using current component D (ARP 5412A (Reference 15) with an 

amplitude of 100 kA on the protective skin side of the composite panel. The panels were tested according 

to applicable sections of SAE ARP5416 (Reference 16). In addition, a metal rod and “fuse” wire were 

installed under the panels to simulate a system (cable bundle, hydraulic line, etc) routed under the skin to 

determine effects. This configuration was used on all panels. Testing was conducted at DNB Engineering 

in Fullerton, California. Figure 91 and Figure 92 show a sample of pretest setup and post strike of LS–2. 
132

Figure 91: A sample of the setup for direct strike on panel LS-2.

Figure 92: A sample of post strike of 100kA on panel LS-2.

Cu

Trip wire

Fuse wire

Conducting 

plate

Non conducting 
133

Test results for all panels are shown in Table 60. The shaded rows in Table 60 are for the second 

strike at 200kAmps for three panels. The convention for damage on the panel’s inner hole is a hole in the 

base substrate panel, and outer hole is a hole in the outer layers of the protective skin. Inner delamination 

(debond and delamination seen in the base substrate panel) and outer delamination (debond seen in the 

protective skin) were measured with thermography and tap test respectively. Tap tests were done to get 

an approximate measurement of debond in the core location. The inner delamination number presented is 

the equivalent diameter of a circle with the area found from the thermography inspection. 
134

Table 60 - Damage and Delamination for All Panels (Post Lightning Strike) 

*no apparent damage with direct strike in area of porosity 

Current

(k A)

LS01 1 0 0.00* 0 1.19 1.8 100

LS02 1 0 0.00* 0 0.46 3.6 100

LS04 1 0 0.00* 0 0 7.5 100

LS05 1 0 0.00* 0 0.41 2 100

LS06 1 0 0.00* 0 0.2 3.3 100

LS07 1 0 0.00* 0 0 2.9 100

LS08 1 0 0.00* 0 0.82 4.3 100

LS09 1 0 0.00* 0 0 7.1 100

LS10 1 0 0.00* 0 0.82 1.3 100

LS11 1 0 0.00* 0 0 1.7 100

LS12 1 0 0.00* 0 0.3 2.8 100

LS13 1 0 0.00* 0 0 0 100

LS14 1 0 0.00* 0 0 4 100

LS15 1 0 0.00* 0 1.18 7.7 100

LS16 1 0 0.00* 0 1.96 6 100

LS18 1 0 0.00* 0 0 6 100

LS19 1 0 0.00* 0 2.03 7.1 100

LS20 1 0 2.47 0 2.65 9.6 100

LS21 1 0 0.00* 0 0.78 2 100

LS22 1 0 0.00* 0 3.32 3 100

LS23 1 0 0.00* 0 0 9 100

LS24 1 0 0 0 1.6 5.5 100

LS25 1 0 0 0 0.55 7 100

LS26 1 0 0.00* 0 1.56

ALS not 

bonded 

properly 100

LS27 1 0 0.00* 0 0 5.2 100

LS28 1 0 0.00* 0 0.81 4.8 100

LS29 1 0 0 0 0.84 6 100

LS30 1 0 0.78 0 0.45 4.2 100

LS32 1 0 0.00* 0 0.3 7 100

LS33 1 0 0.00* 0 1.37 3.7 100

LS34 1 0 0.00* 0 0.4 3.2 100

LS34 2 0 0.00* 0 0.4 9.2 200

LS35 1 0 0.00* 0 0.1 4.3 100

LS36 1 0 1.67 0 1.85 6 100

LS37 1 0 0.00* 0 0.2 9 100

LS38 1 0 0.84 0 1.99 4.2 100

LS39 1 0 0.00* 0 0 8.5 100

LS39 2 0 0.00* 0 0 13.5 200

LS40 1 0 2.02 0 0.27 3.4 100

LS40 2 0 1.92 0 0.38 9.4 200

LS41 1 0 0.00* 0 0 8.9 100

LS42 1 0 0 0 0 3.9 100

LS43 1 0 0.00* 0 0 6.7 100

LS44 1 0 0.70* 0 0 3.7 100

LS45 1 0 0 0 0.86 10.5 100

LS46 1 0 1.68 0 9 20 100

LS47 1 0 1.67 0 9 20 100

Outer 

Delamination 

(in)

Panel 

number Strike

Inner 

Hole 

(in)

Inner 

Delamination 

(in)

Inner 

damage 

(in)

Outer 

Hole 

(in)
135

The requirement to pass direct effects of lightning testing is to have no inner hole and no inner 

delamination (no hole or delamination in the base substrate panel). There is no requirement on outer 

holes or delamination; the protective skin can be completely gone after a lightning strike. Table 61 shows 

debond in the carbon fiber composite (laminate) at the back of the core for eight panels; the other 36 did 

not have evidence of damage. The effect of base substrate panel porosity does appear here in a negative 

way. There were 34 lightning strike panels where no apparent damage was found, but the direct strike 

occurred in an area of high porosity, making it impossible to determine if there was actual damage or not. 

The conservative approach is to assume no damage and keep those materials in consideration for the final 

set of STAR-C2

panels. 

Table 61 - Panels with Non-Zero Inner Delamination Due to DEL 

Table 62 isolates only those eight panels that have been identified as having inner delamination based 

on thermography report. Inspection through thermography shows panel LS-20 with honeycomb core had 

the maximum inner delamination of all the panels. LS-46 and LS-47, the carbon nanotube panels, also 

had significant base substrate panel delamination (not surprising given the violence of what appeared to 

happen during the lightning strike). Somewhat surprising was panel LS-40. It was struck a second time 

with 200 k Amps because it appeared to do very well the first time. Thermography showed that it had 

base substrate panel delamination from both the 100 and the 200kAmp strikes.

LS20 100 1 2.47 2.65 9.6

3 pcf metallic 

honeycomb, 

1/4" thick

LORD Spray 

Material

LS30 100 1 0.78 0.45 4.2

Soric XF, 2mm 

thick

0.029 

expanded 

copper foil

LS36 100 1 1.67 1.85 6

Soric XF, 2mm 

thick

LDS 40-03(N) 

0.0016 psf 

nickel coated 

copper

LS38 100 1 0.84 1.99 4.2

Soric XF, 6mm 

thick

Integument 

with integrated 

LSP

LS40 100 1 2.02 0.27 3.4

Soric LRC, 2 

mm thick

Integument 

with integrated 

LSP

LS40 200 2 1.92 0.38 9.4

Soric LRC, 2 

mm thick

Integument 

with integrated 

LSP

LS44 100 1 0.7 0 3.7

10# PU core, 

1/4" thick

LDS 40-03(N) 

0.0016 psf 

nickel coated 

copper with 

Kapton film 

LS46 100 1 1.68 9 20

10# PU core, 

1/4" thick

Nanocomp 

sheet

LS47 100 1 1.67 9 20

10# PU core, 

1/4" thick

Nanocomp 

sheet

Lightning 

Strike 

Material

Current 

(k Amps)

Panel 

number Strike

Inner 

Delamination

Outer 

Hole

Outer 

Delamination

Impact 

Absorbing 

Foam Layer
136

Table 62 - Lightning Strike Panels Passing DEL (1 of 2) 

Panel ID

Base Panel Interface Impact Absorbing 

Foam Layer Interface Impact Spreading Layer Interface Lightning Strike Material Interface Aesthetic Film psf

LS-45 7 ply carbon uni epoxy 3M 4950 Polydamp Hydrophobic 

Melamine with 

None None None None none none

0.220

LS-32 7 ply carbon uni epoxy 3M 4950 Soric XF, 2mm thick Aeropoxy Innegra S Aeropoxy LDS 50-01 0.007 psf aluminum none

Integument film 

w/PSA 0.354

LS-33 7 ply carbon uni epoxy 3M 4950 Soric XF, 2mm 

thick Aeropoxy Innegra S None Integument with integrated LSP & PSA none none

0.381

LS-29 7 ply carbon uni epoxy 3M 4950 Soric XF, 2mm 

thick Aeropoxy Innegra S Aeropoxy 0.016 psf expanded aluminum foil none

Integument film 

w/PSA 0.387

LS-37 7 ply carbon uni epoxy 3M 4950 Soric XF, 6mm 

thick Aeropoxy Innegra S Aeropoxy LDS 50-01 0.007 psf aluminum none

Integument film 

w/PSA 0.393

LS-39 7 ply carbon uni epoxy 3M 4950 Soric LRC, 2 mm thick Aeropoxy Innegra S Aeropoxy LDS 50-01 0.007 psf aluminum none

Integument film 

w/PSA 0.399

LS-34 7 ply carbon uni epoxy 3M 4950 Soric XF, 2mm thick Aeropoxy Innegra S None LORD Spray Material none Integument film w/PSA 0.440

LS-35 7 ply carbon uni epoxy 3M 4950 Soric XF, 2mm thick Aeropoxy Carbon Epoxy None Integument with integrated LSP & PSA none none0.446

LS-22 7 ply carbon uni epoxy 3M 4950 3 pcf metallic honeycomb, 1/4" 

thick

Grade 30 

adhesive Tegris LM None Integument with integrated LSP & PSA none none0.464

LS-18 7 ply carbon uni epoxy 3M 4950 3 pcf metallic honeycomb, 1/4" 

thick

Grade 30 

adhesive Innegra S Aeropoxy LDS 50-01 0.007 psf aluminum none

Integument film 

w/PSA 0.470

LS-15 7 ply carbon uni epoxy 3M 4950 3 pcf metallic 

honeycomb, 1/4" 

thick

Grade 30 

adhesive Innegra S Aeropoxy 0.016 psf expanded aluminum foil none

Integument film 

w/PSA 0.488

LS-42 7 ply carbon uni epoxy 3M 4950 10# PU core, 1/4" 

thick Aeropoxy Innegra S Aeropoxy LDS 50-01 0.007 psf aluminum none

Aptiv PEEK Film 

w/PSA 0.488

LS-16 7 ply carbon uni epoxy 3M 4950 3 pcf metallic 

honeycomb, 1/4" 

thick

Grade 30 

adhesive Innegra S Aeropoxy 0.029 expanded copper foil none

Integument film 

w/PSA 0.494

LS-19 7 ply carbon uni epoxy 3M 4950 3 pcf metallic 

honeycomb, 1/4" 

thick

Grade 30 

adhesive Innegra S None Integument with integrated LSP & PSA none none 0.500
137

Table 62 - Lightning Strike Panels Passing DEL (2 of 2) 

Panel ID

Base Panel Interface Impact Absorbing 

Foam Layer Interface Impact Spreading Layer Interface Lightning Strike Material Interface Aesthetic Film psf

LS-41 7 ply carbon uni epoxy 3M 4950 10# PU core, 1/4" thick Aeropoxy Innegra S Aeropoxy LDS 50-01 0.007 psf aluminum none 3M 50040.506

LS-43 7 ply carbon uni epoxy 3M 4950 10# PU core, 1/4" thick Aeropoxy Innegra S Aeropoxy LDS 50-01 0.007 psf aluminum

3M 

F9460PC

Halar ECTFE 

Film 0.506

LS-4 7 ply carbon uni epoxy 3M 4950 10# PU core, 1/4" 

thick Aeropoxy Innegra S Aeropoxy LDS 50-01 0.007 psf aluminum none

Integument film 

w/PSA 0.530

LS-26 7 ply carbon uni epoxy 3M 4950 6 pcf metallic 

honeycomb, 1/4" 

thick

Grade 30 

adhesive Innegra S None Integument with integrated LSP & PSA none none0.542

LS-28 7 ply carbon uni epoxy 3M 4950 7.9 pcf metallic honeycomb, 1/4" 

thick

Grade 30 

adhesive Innegra S None Integument with integrated LSP & PSA none none0.542

LS-21 7 ply carbon uni epoxy 3M 4950 3 pcf metallic honeycomb, 1/4" 

thick

Grade 30 

adhesive Carbon Epoxy None Integument with integrated LSP & PSA none none0.548

LS-25 7 ply carbon uni epoxy 3M 4950 6 pcf metallic honeycomb, 1/4" 

thick

Grade 30 

adhesive Innegra S Aeropoxy LDS 50-01 0.007 psf aluminum none

Integument film 

w/PSA 0.548

LS-27 7 ply carbon uni epoxy 3M 4950 7.9 pcf metallic honeycomb, 1/4" 

thick

Grade 30 

adhesive Innegra S Aeropoxy LDS 50-01 0.007 psf aluminum none

Integument film 

w/PSA 0.554

LS-5 7 ply carbon uni epoxy 3M 4950 10# PU core, 1/4" 

thick (FR-6710) Aeropoxy Innegra S None Integument with integrated LSP & PSA none none0.565

LS-2 7 ply carbon uni epoxy 3M 4950 10# PU core, 1/4" thick (FR-6710) Aeropoxy Innegra S Aeropoxy 0.029 expanded copper foil none

Integument film 

w/PSA 0.568

LS-1 7 ply carbon uni epoxy 3M 4950 10# PU core, 1/4" 

thick (FR-6710) Aeropoxy Innegra S Aeropoxy 0.016 psf expanded aluminum foil none

Integument film 

w/PSA 0.571

LS-23 7 ply carbon uni epoxy 3M 4950 3 pcf metallic honeycomb, 3/4" 

thick

Grade 30 

adhesive Innegra S Aeropoxy LDS 50-01 0.007 psf aluminum none

Integument film 

w/PSA 0.598

LS-7 7 ply carbon uni epoxy 3M 4950 10# PU core, 1/4" thick (FR-6710) Aeropoxy Carbon Epoxy None Integument with integrated LSP & PSA none none0.601

LS-8 7 ply carbon uni epoxy 3M 4950 10# PU core, 1/4" thick (FR-6710) Aeropoxy Tegris LM None Integument with integrated LSP & PSA none none0.607

LS-6 7 ply carbon uni epoxy 3M 4950 10# PU core, 1/4" 

thick (FR-6710) Aeropoxy Innegra S None LORD Spray Material none Integument film w/PSA 0.619

LS-24 7 ply carbon uni epoxy 3M 4950 3 pcf metallic honeycomb, 3/4" 

thick

Grade 30 

adhesive Innegra S None Integument with integrated LSP & PSA none none0.625

LS-12 7 ply carbon uni epoxy 3M 4950 20# PU core, 1/4" thick (FR-6720) Aeropoxy Innegra S None Integument with integrated LSP & PSA none none0.735

LS-11 7 ply carbon uni epoxy 3M 4950 20# PU core, 1/4" 

thick (FR-6720) Aeropoxy Innegra S Aeropoxy LDS 50-01 0.007 psf aluminum none

Integument film 

w/PSA 0.738

LS-9 7 ply carbon uni epoxy 3M 4950 10# PU core, 3/4" thick (FR-6710) Aeropoxy Innegra S Aeropoxy LDS 50-01 0.007 psf aluminum none

Integument film 

w/PSA 0.935

LS-10 7 ply carbon uni epoxy 3M 4950 10# PU core, 3/4" thick (FR-6710) Aeropoxy Innegra S None Integument with integrated LSP & PSA none none0.940

LS-14 7 ply carbon uni epoxy 3M 4950 30# PU core, 1/4" 

thick (FR-6720) Aeropoxy Innegra S None Integument with integrated LSP & PSA none none 0.940

LS-13 7 ply carbon uni epoxy 3M 4950 30# PU core, 1/4" 

thick (FR-6720) Aeropoxy Innegra S Aeropoxy LDS 50-01 0.007 psf aluminum none

Integument film 

w/PSA 0.964
138

7.3.4 Electromagnetic Effects Results 

Three different electromagnetic effects tests were conducted: 1) transmissivity; 2) indirect effects of 

lighting; and 3) direct effects of lightning. None of the panels failed transmissivity. None were as good 

as plain aluminum but all were much better than the base substrate panel with no extra protection. 

Material thickness was the only property that seemed to have any effect on shielding (transmissivity). 

The IEL testing failed to produce any conclusive results. The carbon nanotube and Polydamp 

hydrophobic melamine were identified as having current and voltage results different than the other 

panels and different than aluminum. Even with that, no conclusions could be drawn. IEL is very 

configuration sensitive; screening tests are of limited value. 

The DEL testing did provide useful data. Eight of the panels failed direct strike testing. The 

remaining panels are shown in Table 62; the panels are sorted by areal weight. Unlike the impact panels, 

these panels have all layers of material and represent the total weight of the protective skin. The first 

page of Table 62 is all of the lightning strike panels with areal weights of 0.500 psf or less (14 panels). 

At the top of the list is the Polydamp hydrophobic melamine with metalized PEEK skin with an areal 

weight of 0.220 psf which is less than the target of 0.275 psf. The other panels are all over the target but 

these 14 are all at or under the upper boundary. Five of the panels which failed were under the upper 

boundary of 0.5 psf; three were over by a small amount (0.512, 0.521, and 0.530 psf). 

The Soric had mixed results. All of the Soric panels had areal weights less than 0.5 psf. Five of the 

panels with Soric XF 2 mm passed lightning strike; two of the panels with Soric XF 2 mm failed lightning 

strike. The panels which failed had a combination of Innegra and Tegris; the panels which passed had a 

combination of Innegra and carbon epoxy. Integument with integrated LSP and PSA failed as often as it 

passed on the 2 mm Soric XF. One Soric XF 6 mm panel passed and one failed; the difference was LDS 

50-01 LSP with Integument film on the panel that passed and Integument film with integrated LSP and 

PSA on the panel that failed. One Soric LRC 2mm panel passed and one failed. The one that passed had 

Innegra with LDS 50-01 and Integument film. The panel that failed had Innegra with Integument with 

integrated LSP and PSA. There were no lightning strike panels with the 3mm Soric LRC. 

All but one of the other panels which failed all had areal weights greater than 0.5 psf. The exception 

was panel LS-44 which was 1⁄4” thick 10 pcf polyurethane core with Innegra, LDS 50-01 LSP, and 

Kapton. Another of the panels which failed had 3 pcf 1⁄4” thick metallic honeycomb with LORD spray 

material and Integument film. 

In general, Soric may be a good material, Innegra did extremely well, the LDS 50-01 did well and was 

light, and the Integument film with PSA did a respectable job. These results, when combined with the 

impact results and the aesthetics and smoothing results, will provide guidance on the final materials and 

panel matrix for the second generation of STAR-C2

protective skins. 

7.4 Aesthetics and Smoothing 

There were three primary areas of aesthetics and smoothing tests: 1) visual inspection of the 30 

aesthetics and smoothing (AS-1 to AS-30) test articles after installing each protective skin over a base 

substrate panel containing multiple geometric features; 2) visual inspection of the lightning strike panels; 

and 3) thermal testing. The testing and test results will be described in the following subsections. 
139

7.4.1 Smoothness 

The material combinations used for impact energy absorption, impact energy spreading, lightning 

strike protection and aesthetics and smoothing as listed in Table 19 were combined into single piece 

stack-ups prior to being applied to the modified base substrate panels (drawing shown in Figure 93). 

These material stack-ups each included a layer of 3M 4950 VHB tape, which was used to attach the stackups to the base substrates. A special fixture was constructed (Figure 94) and a pressure roller was used to 

consistently attach the protective skin panels to the base substrate panels (Figure 95). 

Figure 93: Base substrate for aesthetic and smoothing test panels showing fasteners, wire bundles, and doublers. 
140

Figure 94: Aesthetic and smoothing base substrate panel holder.

Figure 95: Application of stack-up with pressure roller. 

The test plan for the aesthetic and smoothing test panels originally called for ATOS white light scans 

of the outer surface of the completed panels to assess any surface deviations that resulted from the 

underlying geometric features on the modified base substrates. During and after the application of the 

material stack-ups, it was noted that the stiffness of most of the stack-ups was significantly higher than 

the base substrate panels. As a result, after application, for most panels, the stack-ups produced 

significant deformation of the base substrate and the geometric features were not uniquely translated to 

the outer aesthetic layer. Therefore, the ATOS white light scan data would have been of limited 

usefulness, because much of the deformation at the surface was also impacted by the deformation of the 

underlying structure. In order to gain some useful data with which to analyze the effectiveness of the 
141

stack-ups for aesthetics and smoothing, notes from visual examinations of the panels were recorded, a 

number of physical measurements of the panels were taken, and photographs of the panels were captured. 

As data was collected, it became clear that the performance trends were largely influenced by the 

combinations of impact absorbing layer materials and energy absorbing material layers, rather than by the 

aesthetic and smoothing layer. As a result, the results presented will tend to be grouped by the impact 

spreading and energy absorbing layers first, with aesthetic and smoothing films secondary. The end result 

of this is that the panel identification numbers are out of sequence, because the test matrix was arranged 

with the aesthetic and smoothing layer materials as the primary variable and the others secondary. 

The visual indications that were recorded consisted of whether or not the various fasteners were visible 

at the outer layer, whether the dowel rods were visible, either from local deformation or a global 

perspective, and whether the 0.020” and 0.040” aluminum doublers were visible at the surface. The 

summary from the visual examinations are presented in Tables 63 through 67. As can be seen in the 

tables, none of the combinations investigated completely covered the surface geometry deviations, 

without some translation to the surface. For the stiffer combinations, the dowels on the surface created 

global deformations of the stack-ups that resulted in the materials not contacting the base panel between 

them. Most of the panels did fairly well hiding the flush and smaller size protruding fasteners, with only 

a few showing the largest -6 protruding head fasteners at the outer surface. 

From a purely cosmetic standpoint, there was little difference between the polyurethane, metallic 

honeycomb and non-metallic honeycomb panels, as can be seen in Tables 63, 64, and 65. Table 66 shows 

that the Polydamp hydrophobic melamine cores did not perform very well in hiding the doublers or 

fasteners when tested at 1⁄2” thick, but at 3⁄4” thick, they hid both the fasteners and doublers quite well. 

The Polydamp core also performed differently than all of the other cores with respect to the dowels, in 

that it compressed over the dowel and was conformal enough that it did attach to the base substrate panel 

between them, although this did cause some wrinkling at the outer surface and the dowels could be seen 

as a local deformation at the outer surface of the panel as well. Finally, Table 67 shows that the Soric 

core based panels did not perform well in their ability to hide any of the surface geometric features on the 

base substrates. 
142

Table 63 - Visual Examination Results for Polyurethane Core Panels 

Panel ID: AS-1 AS-6 AS-11 AS-16 AS-21 AS-26

Core Material: FR6710 1/4" FR6710 1/4" FR6710 1/4" FR6710 1/4" FR6710 1/4" FR6710 1/4"

Impact Spreading 

Layer:

Innegra Innegra Innegra Innegra Innegra Innegra

Aesthetic Layer: Integument Integument with 

ALS

3M 5004 Aptiv PEEK Halar Kapton

-4 Protruding Not Visible Not Visible Not Visible Not Visible Not Visible Not Visible

-5 Protruding Not Visible Not Visible Not Visible Not Visible Not Visible Not Visible

-6 Protruding Not Visible Not Visible Not Visible Not Visible Not Visible Visible

-4 Flush Not Visible Not Visible Not Visible Not Visible Not Visible Not Visible

-5 Flush Not visible Not visible Not visible Not Visible Not visible Not visible

0.1875" Dowel Globally Visible Globally Visible Globally Visible Globally Visible Globally Visible Globally Visible

0.25" Dowel Globally Visible Globally Visible Globally Visible Globally Visible Globally Visible Globally Visible

0.020" Al 

Doubler

Not Visible Not Visible Not Visible Not Visible Not Visible Not Visible

0.040" Al 

Doubler

Not Visible Not Visible Not Visible Not Visible Not Visible Not Visible
143

Table 64 - Visual Examination Results for Non-metallic Honeycomb Core Panels 

Panel ID: AS-2 AS-7 AS-12 AS-17 AS-22 AS-27

Core Material: 4 PCF Nomex 

1/2"

4 PCF Nomex 

1/2"

4 PCF Nomex 

1/2"

4 PCF Nomex 

1/2"

4 PCF Nomex 

1/2"

4 PCF Nomex 

1/2"

Impact Spreading 

Layer:

0.012" 

aluminum

0.012" 

aluminum

0.012" 

aluminum

0.012" 

aluminum

0.012" 

aluminum

0.012" 

aluminum

Aesthetic Layer: Integument Integument with 

ALS

3M 5004 Aptiv PEEK Halar Kapton

-4 Protruding Not Visible Not Visible Not Visible Not Visible Not Visible Not Visible

-5 Protruding Not Visible Not Visible Not Visible Not Visible Not Visible Not Visible

-6 Protruding Not Visible Not Visible Not Visible Not Visible Not Visible Visible

-4 Flush Not Visible Not Visible Not Visible Not Visible Not Visible Not Visible

-5 Flush Not Visible Not Visible Not Visible Not Visible Not Visible Not Visible

0.1875" Dowel Globally Visible Globally Visible Globally Visible Globally Visible Globally Visible Globally Visible

0.25" Dowel Globally Visible Globally Visible Globally Visible Globally Visible Globally Visible Globally Visible

0.020" Al Doubler Not Visible Not Visible Not Visible Not Visible Not Visible Not Visible

0.040" Al Doubler Not Visible Not Visible Not Visible Not Visible Not Visible Not Visible
144

Table 65 - Visual Examination Results for Metallic Honeycomb Core Panels 

Panel ID: AS-3 AS-8 AS-13 AS-18 AS-23 AS-28

Core Material: 6 PCF Metallic 

1/4"

6 PCF Metallic 

1/4"

6 PCF Metallic 

1/4"

6 PCF Metallic 

1/4"

6 PCF Metallic 

1/4"

6 PCF Metallic 

1/4"

Impact Spreading 

Layer:

0.012" 

aluminum

0.012" 

aluminum

0.012" 

aluminum

0.012" 

aluminum

0.012" 

aluminum

0.012" 

aluminum

Aesthetic Layer: Integument Integument with 

ALS

3M 5004 Aptiv PEEK Halar Kapton

-4 Protruding Not Visible Not Visible Not Visible Not Visible Not Visible Not Visible

-5 Protruding Not Visible Not Visible Not Visible Not Visible Visible Not Visible

-6 Protruding Not Visible Not Visible Not Visible Not Visible Visible Not Visible

-4 Flush Not Visible Not Visible Not Visible Not Visible Not Visible Not Visible

-5 Flush Not Visible Not Visible Not Visible Not Visible Not Visible Not Visible

0.1875" Dowel Globally Visible Globally Visible Globally Visible Globally Visible Globally Visible Globally Visible

0.25" Dowel Globally Visible Globally Visible Globally Visible Globally Visible Globally Visible Globally Visible

0.020" Al Doubler Not Visible Not Visible Not Visible Not Visible Not Visible Not Visible

0.040" Al Doubler Not Visible Not Visible Not Visible Not Visible Not Visible Not Visible
145

Table 66 - Visual Examination Results for Polydamp Core Panels 

Panel ID: AS-9 AS-14 AS-19 AS-29 AS-4 AS-24

Core Material: Polydamp 1/2" Polydamp 1/2" Polydamp 1/2" Polydamp 1/2" Polydamp 3/4" Polydamp 3/4"

Impact Spreading 

Layer:

None None None None None None

Aesthetic Layer: Integument with 

ALS

3M 5004 Aptiv PEEK Kapton Integument Halar

-4 Protruding Not Visible Visible Not Visible Not Visible Not Visible Not Visible

-5 Protruding Not Visible Visible Not Visible Not Visible Not Visible Not Visible

-6 Protruding Not Visible Not Visible Visible Not Visible Not Visible Not Visible

-4 Flush Not Visible Not Visible Not Visible Not Visible Not Visible Not Visible

-5 Flush Not Visible Not Visible Not Visible Not Visible Not Visible Not Visible

0.1875" Dowel Individually 

Visible

Individually 

Visible

Individually 

Visible

Individually 

Visible

Individually 

Visible

Individually 

Visible

0.25" Dowel Individually 

Visible

Individually 

Visible

Individually 

Visible

Individually 

Visible

Individually 

Visible

Individually 

Visible

0.020" Al Doubler Not Visible Not Visible Visible Not Visible Not Visible Not Visible

0.040" Al Doubler Not Visible Visible Visible Visible Not Visible Not Visible
146

Table 67 - Visual Examination Results for Soric Core Panels 

Panel ID: AS-5 AS-10 AS-15 AS-20 AS-25 AS-30

Core Material: Soric XF 2mm Soric XF 2mm Soric XF 2mm Soric XF 2mm Soric XF 2mm Soric XF 2mm

Impact Spreading 

Layer:

Innegra Innegra Innegra Innegra Innegra Innegra

Aesthetic Layer: Integument Integument with 

ALS

3M 5004 Aptiv PEEK Halar Kapton

-4 Protruding Visible Visible Visible Visible Visible Visible

-5 Protruding Visible Visible Visible Visible Visible Visible

-6 Protruding Visible Visible Visible Visible Visible Visible

-4 Flush Visible Not Visible Visible Visible Not Visible Not Visible

-5 Flush Visible Not Visible Visible Visible Not Visible Not Visible

0.1875" Dowel Globally Visible Globally Visible Globally Visible Globally Visible Globally Visible Globally Visible

0.25" Dowel Globally Visible Globally Visible Globally Visible Globally Visible Globally Visible Globally Visible

0.020" Al Doubler Visible Visible Visible Visible Visible Visible

0.040" Al Doubler Visible Visible Visible Visible Visible Visible
147

In order to further characterize these panels, physical measurements were taken for the following 

parameters: 

 Panel deformation 

 Panel thickness over the 0.020” thick doubler 

 Panel thickness over the 0.040” thick doubler 

 Panel thickness over the 0.1875” dowel 

 Panel thickness over the 0.25” dowel 

The overall panel deformation was measured by placing the panels on a flat table with the outer layer 

face down. The maximum height of the backside of the panel was measured along the bottom edge of the 

panel, and its height and location from the left edge were recorded. For characterization and data 

analysis, the nominal panel thickness was subtracted from the recorded value, to arrive at a computed 

value for the distance between the table and the outer layer of the panel. This value was compared across 

the various panel combinations and is shown in Figure 96. 

The panel thicknesses over the two dowels and two doublers were all measured with a digital caliper. 

For reporting purposes, the nominal thickness of the panel was subtracted from the recorded value, as was 

the thickness of the particular item at each location. The resulting values were used in the comparisons of 

the different panel configurations as shown in Figure 96 through Figure 100. 

As can be seen in Figure 96, the largest panel deformations are related to the non-metallic honeycomb 

core. The deflections for the metallic honeycomb, polyurethane, and Soric cores are not significantly 

different, implying that the stiffness of those panels is similar and lower than the stiffness of the nonmetallic honeycomb cores. The Polydamp cores are the least stiff of the stack-ups and therefore have the 

lowest amount of overall panel deformation. Further of note is that the results are relatively insensitive to 

the aesthetic layer used, with the energy absorbing and impact spreading layer combinations being the 

major dependant variable in the panels. 

Similarly, Figure 97 and Figure 98 show the results for the 0.020” and 0.040” aluminum doublers, 

respectively. For the most part, the panels show small increases over the doublers, although it is noted 

that no allowance was made mathematically for the paste adhesive bonding thickness used to bond the 

doublers to the base panels. The few negative thickness values associated with some of the Polydamp 

panels are indicative of the compressibility of the melamine foam over the surface deviations. The 

relatively large data scatter associated with the Polydamp samples is attributed to the difficulty of 

measuring a soft compressible foam core with a caliper. 

Finally, Figure 99 and Figure 100 show the results of the 0.1875” and 0.25” diameter dowels that were 

used to mimic potential wire bundle configurations on the outer surface of the structure. As was seen 

earlier in the visual examination results, the global deformation of the outer surfaces of the more stiff 

panels shows fairly consistent results for the metallic honeycomb, non-metallic honeycomb, polyurethane 

and Soric cores, with substantially different results for the Polydamp compares to all of the others. 

Similar to the aluminum doublers, the negative values for the Polydamp-based panels are representative 

of the compressibility of the melamine foam over these surface deviations. For the most part, the other 

cores showed relatively small deviations over the 0.1875” dowels, with the exception of the stiffest panels 
148

based on the non-metallic honeycomb cores. For those panels, the increase deformation is likely 

representative of the fact that the panels were not in direct contact with the 0.1875” dowels after being 

pushed further away by the 0.25” dowel offset. Figure 100 shows additional negative deformation values 

for other cores than the Polydamp, which may be attributable to local core crushing over this feature, 

which was the tallest out-of-plane feature that existed on the panels. 
149

Figure 96: Computed maximum panel deformation.

Core Material

Aesthetic Layer

Panel ID

Soric XF 2mm

Polydamp 3/4"Polydamp 1/2"

FR6710 1/4"

6 PCF Metallic 1/4"

4 PCF Nomex 1/2"

Kapton

Integument with ALS

Integument

Halar

Aptiv PEEK

3M 5004

Integument

Halar

Kapton

Integument with ALS

Aptiv PEEK

3M 5004

Kapton

Integument with ALS

Integument

Halar

Aptiv PEEK

3M 5004

Kapton

Integument with ALS

Integument

Halar

Aptiv PEEK

3M 5004

Kapton

Integument with ALS

Integument

Halar

Aptiv PEEK

3M 5004

AS-30AS-10

AS-5

AS-25AS-20AS-15

AS-4

AS-24AS-29

AS-9

AS-19AS-14AS-26

AS-6AS-1

AS-21AS-16AS-11AS-28

AS-8AS-3

AS-23AS-18AS-13AS-27

AS-7AS-2

AS-22AS-17AS-12

0.6

0.5

0.4

0.3

0.2

0.1

0.0

Panel Deflections (inches)
150

Figure 97: Computed deformation over 0.020” doubler. 

Core Material

Aesthetic Layer

Panel ID

Soric XF 2mm

Polydamp 3/4"Polydamp 1/2"

FR6710 1/4"

6 PCF Metallic 1/4"

4 PCF Nomex 1/2"

Kapton

Integument with ALS

Integument

Halar

Aptiv PEEK

3M 5004

Integument

Halar

Kapton

Integument with ALS

Aptiv PEEK

3M 5004

Kapton

Integument with ALS

Integument

Halar

Aptiv PEEK

3M 5004

Kapton

Integument with ALS

Integument

Halar

Aptiv PEEK

3M 5004

Kapton

Integument with ALS

Integument

Halar

Aptiv PEEK

3M 5004

AS-30AS-10

AS-5

AS-25AS-20AS-15

AS-4

AS-24AS-29

AS-9

AS-19AS-14AS-26

AS-6AS-1

AS-21AS-16AS-11AS-28

AS-8AS-3

AS-23AS-18AS-13AS-27

AS-7AS-2

AS-22AS-17AS-12

0.05

0.04

0.03

0.02

0.01

0.00

-0.01

-0.02

-0.03

0.020" Doubler Deformation (inches)
151

Figure 98: Computed deformation over 0.040” doubler. 

Core Material

Aesthetic Layer

Panel ID

Soric XF 2mm

Polydamp 3/4"Polydamp 1/2"

FR6710 1/4"

6 PCF Metallic 1/4"

4 PCF Nomex 1/2"

Kapton

Integument with ALS

Integument

Halar

Aptiv PEEK

3M 5004

Integument

Halar

Kapton

Integument with ALS

Aptiv PEEK

3M 5004

Kapton

Integument with ALS

Integument

Halar

Aptiv PEEK

3M 5004

Kapton

Integument with ALS

Integument

Halar

Aptiv PEEK

3M 5004

Kapton

Integument with ALS

Integument

Halar

Aptiv PEEK

3M 5004

AS-30AS-10

AS-5

AS-25AS-20AS-15

AS-4

AS-24AS-29

AS-9

AS-19AS-14AS-26

AS-6AS-1

AS-21AS-16AS-11AS-28

AS-8AS-3

AS-23AS-18AS-13AS-27

AS-7AS-2

AS-22AS-17AS-12

0.05

0.04

0.03

0.02

0.01

0.00

-0.01

-0.02

-0.03

0.040" Doubler Deformation (inches)
152

Figure 99: Computed deformation over 0.1875” dowel. 

Core Material

Aesthetic Layer

Panel ID

Soric XF 2mm

Polydamp 3/4"Polydamp 1/2"

FR6710 1/4"

6 PCF Metallic 1/4"

4 PCF Nomex 1/2"

Kapton

Integument with ALS

Integument

Halar

Aptiv PEEK

3M 5004

Integument

Halar

Kapton

Integument with ALS

Aptiv PEEK

3M 5004

Kapton

Integument with ALS

Integument

Halar

Aptiv PEEK

3M 5004

Kapton

Integument with ALS

Integument

Halar

Aptiv PEEK

3M 5004

Kapton

Integument with ALS

Integument

Halar

Aptiv PEEK

3M 5004

AS-30AS-10

AS-5

AS-25AS-20AS-15

AS-4

AS-24AS-29

AS-9

AS-19AS-14AS-26

AS-6AS-1

AS-21AS-16AS-11AS-28

AS-8AS-3

AS-23AS-18AS-13AS-27

AS-7AS-2

AS-22AS-17AS-12

0.10

0.05

0.00

-0.05

-0.10

-0.15

-0.20

0.1875" Dowel Deformation (inches)
153

Figure 100: Computed deformation over 0.25” dowel.

Core Material

Aesthetic Layer

Panel ID

Soric XF 2mm

Polydamp 3/4"Polydamp 1/2"

FR6710 1/4"

6 PCF Metallic 1/4"

4 PCF Nomex 1/2"

Kapton

Integument with ALS

Integument

Halar

Aptiv PEEK

3M 5004

Integument

Halar

Kapton

Integument with ALS

Aptiv PEEK

3M 5004

Kapton

Integument with ALS

Integument

Halar

Aptiv PEEK

3M 5004

Kapton

Integument with ALS

Integument

Halar

Aptiv PEEK

3M 5004

Kapton

Integument with ALS

Integument

Halar

Aptiv PEEK

3M 5004

AS-30AS-10

AS-5

AS-25AS-20AS-15

AS-4

AS-24AS-29

AS-9

AS-19AS-14AS-26

AS-6AS-1

AS-21AS-16AS-11AS-28

AS-8AS-3

AS-23AS-18AS-13AS-27

AS-7AS-2

AS-22AS-17AS-12

0.05

0.00

-0.05

-0.10

-0.15

-0.20

-0.25

0.25" Dowel Deformation (inches)
154

7.4.2 Lightning Strike Panel Visual Inspection 

The panels fabricated for the direct and indirect effects of lightning testing were visually examined for 

outer layer surface anomalies prior to being subjected to their associated lighting strike tests. The results 

of these examinations are captured in Error! Not a valid bookmark self-reference. through Table 70. 

For the metallic honeycomb cores, the core was first stabilized with film adhesive prior to placing the 

outer layers over it. For several of the panels, the film stabilized side of the core was incorrectly placed 

against the foam VHB tape rather than the impact spreading layer. These panels are identified with an 

asterisk in the Core/Impact Spreading column of Error! Not a valid bookmark self-reference.. In 

general, the metallic honeycomb-based panels shown in Error! Not a valid bookmark self-reference.

had relatively smooth outer surfaces that were free of bubbles and wrinkles. The two lighter densities 

(3.4 pcf and 6 pcf) exhibited the core pattern at the outer surface, regardless of the impact spreading layer, 

lightning strike layer, and aesthetic layer materials that were used. The highest density core (7.9 pcf) was 

not found to show the core pattern at the surface. 

The results of the polyurethane based core panels are shown in Table 69. For the most part, these 

panels were not as smooth as those built with metallic honeycomb core. There were a number of panels 

that exhibited bubbles and wrinkles. Several of these panels used materials that were not used in the 

panels with metallic honeycomb cores, specifically, the Halar and Kapton aesthetic layer materials. 

These materials were not supplied with pressure sensitive adhesives already applied so a layer a transfer 

tape was applied to them during the material manufacture. Most of the bubbles and wrinkles seen in these 

panels were a result of the transfer tape application, but nonetheless were significant in the visual 

aesthetic evaluation. Overall, the polyurethane cores are smooth on the outer surface, and while there was 

no overall honeycomb core-type features projected to the surface, there were several panels with a wavy 

or wrinkled outer surface as well as several that showed the fabric weave pattern of the Innegra impact 

spreading layer on the outer surface. 

Finally, Table 70 shows the results of the lightning strike panels built with Soric core as well as the 

panel built with the Polydamp hydrophobic melamine core. Overall the Soric core panels exhibited 

smooth outer surface layers that were free of bubbles and wrinkles. Visual indication showed that the 

impact spreading layer fabric weave patterns as well as the Soric core cell patterns were visible at the 

outer surface. Whether this is a visual or physical phenomenon is hard to determine, but based on other 

investigations on the aesthetic and smoothing panels, it is believed to be a visual phenomenon related to 

transparent films. The Polydamp-based panel did not contain bubbles, but was wrinkled on the outer 

surface due to the nature of the material. The aesthetics and smoothing panels with Polydamp had similar 

surface anomalies, but they were not as prevalent in those panels because of the presence of the additional 

aesthetic layer materials providing additional support to the outermost surfaces. 
155

Table 68 - Visual Examination Results for Lightning Strike Panels with Metallic Honeycomb 

Cores 

Panel 

ID

Core 

Material

Impact 

Spreading 

Layer

Lightning 

Strike 

Layer

Aesthetic 

Layer

Smoothness Bubbles Wrinkles Core / 

Impact 

Spreading

LS213.4 PCF 

Metallic 

1/4"

Carbon 

Epoxy

Integument 

with ALS

Integument 

with ALS

Smooth No No Core*

LS153.4 PCF 

Metallic 

1/4"

Innegra 0.016 psf 

Al

Integument Smooth No No Core*

LS163.4 PCF 

Metallic 

1/4"

Innegra 0.029 psf 

Cu

Integument Smooth No No Core*

LS193.4 PCF 

Metallic 

1/4"

Innegra Integument 

with ALS

Integument 

with ALS

Smooth No No Core*

LS183.4 PCF 

Metallic 

1/4"

Innegra LDS 50-01 Integument Smooth No No Core

LS203.4 PCF 

Metallic 

1/4"

Innegra LORD 

Spray

Integument Smooth No No Core

LS223.4 PCF 

Metallic 

1/4"

Tegris Integument 

with ALS

Integument 

with ALS

Smooth No No Core*

LS243.4 PCF 

Metallic 

3/4"

Innegra Integument 

with ALS

Integument 

with ALS

Smooth No No Core*

LS233.4 PCF 

Metallic 

3/4"

Innegra LDS 50-01 Integument Smooth No No Core

LS266 PCF 

Metallic 

1/4"

Innegra Integument 

with ALS

Integument 

with ALS

Smooth No No Core*

LS256 PCF 

Metallic 

1/4"

Innegra LDS 50-01 Integument Smooth No No Core

LS287.9 PCF 

Metallic 

1/4"

Innegra Integument 

with ALS

Integument 

with ALS

Smooth No No No

LS277.9 PCF 

Metallic 

1/4"

Innegra LDS 50-01 Integument Smooth No No No
156

Table 69 - Visual Examination Results for Lightning Strike Panels with Polyurethane Cores 

Panel 

ID

Core 

Material

Impact 

Spreading 

Layer

Lightning 

Strike 

Layer

Aesthetic 

Layer

Smoothness Bubbles Wrinkles Core / 

Impact 

Spreading

LS-7 FR6710 

1/4"

Carbon 

Epoxy

Integument 

with ALS

Integument 

with ALS

Smooth No No Fabric 

Weave

LS-1 FR6710 

1/4"

Innegra 0.016 psf 

Al

Integument Smooth No No No

LS-2 FR6710 

1/4"

Innegra 0.029 psf 

Cu

Integument Smooth No No No

LS-5 FR6710 

1/4"

Innegra Integument 

with ALS

Integument 

with ALS

Smooth No No No

LS41FR6710 

1/4"

Innegra LDS 50-01 3M 5004 Smooth No No No

LS42FR6710 

1/4"

Innegra LDS 50-01 Aptiv 

PEEK

Smooth No No No

LS43FR6710 

1/4"

Innegra LDS 50-01 Halar Ripples, 

patches

Yes No No

LS-4 FR6710 

1/4"

Innegra LDS 50-01 Integument Smooth No No No

LS44FR6710 

1/4"

Innegra LDS 50-01 Kapton Bubbles Yes No No

LS-6 FR6710 

1/4"

Innegra Proprietary 

Spray

Integument Smooth No No No

LS46FR6710 

1/4"

Innegra Nanocomp 

10 gsm

Integument Not 

Smooth

No No Fabric 

Weave

LS47FR6710 

1/4"

Innegra Nanocomp 

15 gsm

Integument Not 

Smooth

No No Fabric 

Weave

LS-8 FR6710 

1/4"

Tegris Integument 

with ALS

Integument 

with ALS

Smooth No No No

LS10FR6710 

3/4"

Innegra Integument 

with ALS

Integument 

with ALS

Smooth No No No

LS-9 FR6710 

3/4"

Innegra LDS 50-01 Integument Smooth No No No

LS12FR6720 

1/4"

Innegra Integument 

with ALS

Integument 

with ALS

Smooth No No Fabric 

Weave

LS11FR6720 

1/4"

Innegra LDS 50-01 Integument Smooth No No No

LS14FR3730 

1/4"

Innegra Integument 

with ALS

Integument 

with ALS

Wrinkled No No Fabric 

Weave

LS13FR3730 

1/4"

Innegra LDS 50-01 Integument Not 

Smooth

No Yes Fabric 

Weave
157

Table 70 - Visual Examination Results for Lightning Strike Panels with Soric and Polydamp 

Melamine Cores 

Panel 

ID

Core 

Material

Impact 

Spreading 

Layer

Lightning 

Strike 

Layer

Aesthetic 

Layer

Smoothness Bubbles Wrinkles Core / 

Impact 

Spreading

LS40Soric 

LRC 2 

mm

Innegra Integument 

with ALS

Integument 

with ALS

Smooth No No Core / 

Fabric

LS39Soric 

LRC 2 

mm

Innegra LDS 50-01 Integument Smooth No Yes Core / 

Fabric

LS35Soric XF 

2 mm

Carbon 

Epoxy

Integument 

with ALS

Integument 

with ALS

Smooth No No Core / 

Fabric

LS29Soric XF 

2 mm

Innegra 0.016 psf 

Al

Integument Smooth No No Core / 

Fabric

LS30Soric XF 

2 mm

Innegra 0.029 psf 

Cu

Integument Smooth No No Core / 

Fabric

LS33Soric XF 

2 mm

Innegra Integument 

with ALS

Integument 

with ALS

Smooth No No Core / 

Fabric

LS32Soric XF 

2 mm

Innegra LDS 50-01 Integument Smooth No No Core / 

Fabric

LS34Soric XF 

2 mm

Innegra LORD 

Spray

Integument Smooth No No Core / 

Fabric

LS36Soric XF 

2 mm

Tegris Integument 

with ALS

Integument 

with ALS

Smooth No No Core / 

Fabric

LS37Soric XF 

6 mm

Innegra LDS 50-01 Integument Smooth No No Core / 

Fabric

LS38Soric XF 

6 mm

Innegra Integument 

with ALS

Integument 

with ALS

Smooth No No Core / 

Fabric

LS45Polydamp 

3/4"

None None None Not 

Smooth

No No Wrinkles

7.4.3 Thermal Testing Results 

Thermal analysis testing was performed on the aesthetic and smoothing panels in order to characterize 

how the material stack-ups would perform as thermal insulation. In order to support this testing, a test 

fixture was fabricated and mounted in the door opening of a Blue M convection laboratory oven. The test 

fixture was mounted into the opening through the use of several rare earth magnets and was sealed against 

the internal frames of the oven to prevent air leaks. An opening allowed for the panels to be mounted into 

the fixture through the use of a ring doubler and toggle clamps. A surface thermocouple was placed on 

the back surface of the mounted test panel, and the temperature rise over time was recorded. Additional 

thermocouples were mounted to aluminum plates and placed adjacent to the oven and in the oven, so that 

ambient and oven air temperatures could be recorded respectively. The test setup is shown in Figure 101

through Figure 103. 

Prior to running a test, the oven was pre-heated to 160°F with a cover plate over the fixture opening. 

Once stabilized, a test panel was loaded into the fixture, and the digital data recorder for the 
158

thermocouples was started. Once the back-side temperatures of the panels stabilized, the recording was 

stopped and the process was repeated with the next panel. Throughout all of the thermal testing of the 

panels, the oven temperature remained within ±5° of the 160°F set point, and the ambient room 

temperature was fairly consistent. 

While testing the aesthetics and smoothing panels, the overwhelming dependant variables in thermal 

performance were found to be the combination of impact spreading layer and energy absorbing layer. In 

order to understand some of the other material combinations that were not represented in the aesthetics 

and smoothing panel matrix, several lightning strike panel combinations were also tested for thermal 

performance. 

Figure 104 shows a sample graphical plot of the data generated for the polyurethane core panels. 

Similar data was generated from the remainder of the aesthetics and smoothing panels. The steady state 

temperatures varied along with the rate at which the maximum temperature was reached. The data 

gathered shows that the thermal performance was not sensitive to the outer aesthetic and smoothing layer, 

again showing the energy absorbing and impact spreading layers to be the larger contributing factors to a 

panel’s performance. Due to the structure of the panels fabricated for this effort, it was not possible to 

separate the contribution of the energy absorbing core from the impact spreading layer, but it is theorized 

that most of the differences in the thermal performance from one series of panels to the next was due to 

the energy absorbing core more than the impact spreading layers. 

Table 71 summarizes the data for all panels tested. The unmodified base substrate showed a 

maximum temperature of 125.4°F. The best performing cores were the 3⁄4” Polydamp melamine foam 

with a maximum temperature of 90.7°F, followed by the 1⁄2” thick Polydamp melamine foam with a 

maximum temperature of 95.5°F. The third best performing material of those tested was the 1⁄2” thick 

non-metallic honeycomb material with a maximum of 97.7°F. The worst performing materials in the 

thermal test were the 1⁄4” thick metallic honeycomb-based panels and the Soric XF 2mm thick cores, all 

which had temperatures over 115°F. 
159

Figure 101: Thermal performance test setup – mounting frame.

Figure 102: Thermal performance test setup – oven temperature. 
160

Figure 103: Thermal performance test setup – test in progress.

Figure 104: Thermal performance of polyurethane core panels. 

7 0

8 0

9 0

100

110

120

0:00:00 0:07:12 0:14:24 0:21:36 0:28:48 0:36:00 0:43:12

Backside Panel Temperature (°F)

Time (h:mm:ss)

Polyurethane Core

A S-1

A S-6

A S-1 1

A S-1 6

A S-2 1

A S-2 6
161

Table 71 - Summary of First-Generation Test Article Thermal Performance Trends 

from Aesthetic and Smoothing, Lightning Strike, and Baseline Panels 

Panel ID Core Type Max. Temp. 

(°F)

Average Baseline Panel 125.4

Average Soric XF, 2mm thick 115

Average Metallic Honeycomb, 6 pcf, 1⁄4” thick 110.5

Average Polyurethane, 10 pcf, 1⁄4” thick 101.1

Average Non-Metallic Honeycomb, 4 pcf, 1⁄2” 

thick

97.7

Average Polydamp, 1⁄2” thick 95.5

Average Polydamp, 3⁄4” thick 90.7

LS-11 Polyurethane, 20 pcf, 1⁄4” thick 108.7

LS-13 Polyurethane, 30 pcf, 1⁄4” thick 109.8

LS-18 Metallic Honeycomb, 3 pcf, 1⁄4” thick 115.3

LS-27 Metallic Honeycomb, 9 pcf, 1⁄4” thick 116.8

LS-37 Soric XF, 6 mm thick 100.6

7.5 Implications for Final STAR-C2Panels 

7.5.1 Combined Test Results 

Impact and direct effects of lightning testing identified panels which passed the testing requirements. 

The combined impact/lightning strike test results (using the lightning strike panels) are shown in Table 

72. The impact panels did not have the lightning strike protection (LSP) or the aesthetic film. The next 

phase of testing will confirm or refute the hypothesis that the LSP and aesthetic film will not contribute 

significantly to the panel’s ability to meet the impact requirements. 

Panels which passed both tests are shown in Table 72 with no shading. Panels which failed lightning 

strike have grey shading and lines through the text. Panels which failed impact testing are shown with 

mauve highlighting. Panels which failed both lightning strike and impact are shown with rotating grey 

and mauve cells with lined out text. 

The only panel to pass both impact and DEL and meet the areal weight target was the Polydamp 

hydrophobic melamine foam. It also performed best in thermal testing. However, the compressibility of 

the foam makes it a very poor candidate for surviving actual flight conditions. The Soric did not survive 

impact testing and in some cases DEL. Thinking back to the impact test results (Table 54), Soric LRC 

3 mm passed the impact tests; there was not a lightning strike panel made with this material so it should 

be carried forward. 

Five of the six other panels to pass both tests were 3 pcf metallic honeycomb 1⁄4” thick with Innegra S 

in four cases and Tegris LM in the fifth case, with various lightning strike protection materials, and with 
162

Integument film. The sixth panel was 10 pcf Polyurethane core 1⁄4” thick with Innegra, LDS 50-01 LSP, 

and Aptiv PEEK film. 

The 1⁄4” thick 3 pcf metallic honeycomb is an interesting material. As seen in Table 73, all but one of 

the panels passed lightning strike tests. The panels are at the upper range of the desired areal weight 

boundary. Table 74 shows the impact performance of the 3 pcf honeycomb. Both panels passed the 

necessary 0.5” 50 in-lbs condition and all 1.0” and 1.75” conditions. This would imply there is 

potentially some excess ability to absorb impact successfully and leads to a question if the metallic 

honeycomb could be thinner? The downsides of the metallic honeycomb are that it didn’t do well in 

thermal tests and required adhesive on the interface to prevent the core from showing through and to keep 

the honeycomb cells from filling with resin. The adhesive adds weight, but honeycomb cells full of resin 

would add even more weight. 
163

Table 72 - Lighting Strike/Impact Combined Results 

Panel ID Impact Absorbing 

Foam Layer Interface Impact Spreading Layer Interface Lightning Strike Material Interface Aesthetic Film psf

LS-45

Polydamp 

Hyrdrophobic 

Melamine with 

PEEK skin (3/4" 

None None None None none none 0.220

LS-32 Soric XF, 2 mm 

thick Aeropoxy Innegra S Aeropoxy LDS 50-01 0.007 psf aluminum none

Integument film 

w/PSA 0.354

LS-33 Soric XF, 2 mm 

thick Aeropoxy Innegra S None Integument with integrated LSP & PSA none none 0.381

LS-36 Soric XF, 2 mm 

thick Aeropoxy Tegris LM None Integument with integrated LSP & PSA none none 0.381

LS-29 Soric XF, 2 mm 

thick Aeropoxy Innegra S Aeropoxy 0.016 psf expanded aluminum foil none

Integument film 

w/PSA 0.387

LS-30 Soric XF, 2 mm 

thick Aeropoxy Innegra S Aeropoxy 0.029 expanded copper foil none

Integument film 

w/PSA 0.387

LS-37 Soric XF, 6 mm 

thick Aeropoxy Innegra S Aeropoxy LDS 50-01 0.007 psf aluminum none

Integument film 

w/PSA 0.393

LS-39 Soric LRC, 2 mm 

thick Aeropoxy Innegra S Aeropoxy LDS 50-01 0.007 psf aluminum none

Integument film 

w/PSA 0.399

LS-40 Soric LRC, 2 mm 

thick Aeropoxy Innegra S None Integument with integrated LSP & PSA none none 0.408

LS-38 Soric XF, 6 mm 

thick Aeropoxy Innegra S None Integument with integrated LSP & PSA none none 0.423

LS-34 Soric XF, 2 mm 

thick Aeropoxy Innegra S None LORD Spray Material none Integument film w/PSA 0.440

LS-35 Soric XF, 2 mm 

thick Aeropoxy Carbon Epoxy None Integument with integrated LSP & PSA none none 0.446

LS-22

3 pcf metallic 

honeycomb, 1/4" 

thck

Grade 30 

adhesive Tegris LM None Integument with integrated LSP & PSA none none 0.464

LS-18

3 pcf metallic 

honeycomb, 1/4" 

thck

Grade 30 

adhesive Innegra S Aeropoxy LDS 50-01 0.007 psf aluminum none

Integument film 

w/PSA 0.470

LS-15

3 pcf metallic 

honeycomb, 1/4" 

thck

Grade 30 

adhesive Innegra S Aeropoxy 0.016 psf expanded aluminum foil none

Integument film 

w/PSA 0.488

LS-42 10 pcf PU core, 

1/4" thick

Grade 30 

adhesive Innegra S Aeropoxy LDS 50-01 0.007 psf aluminum adhesive Aptiv PEEK Film w/PSA 0.488

LS-16

3 pcf metallic 

honeycomb, 1/4" 

thck

Grade 30 

adhesive Innegra S Aeropoxy 0.029 expanded copper foil none

Integument film 

w/PSA 0.494

LS-44 10 pcf PU core, 

1/4" thick Aeropoxy Innegra S Aeropoxy LDS 50-01 0.007 psf aluminum adhesive Kapton film 0.494

LS-19

3 pcf metallic 

honeycomb, 1/4" 

thck

Grade 30 

adhesive Innegra S None Integument with integrated LSP & PSA none none 0.500

Key
164

Table 73 - 1/4" Thick 3 pcf Metallic Honeycomb Lightning Strike Performance

Table 74 - 1/4" Thick 3 pcf Metallic Honeycomb Impact Performance 
165

7.5.2 Initial Thoughts on Final Material Selection 

The analysis of the test data for the first-generation protective skins suggests the following materials 

as good candidates for the final set of STAR-C2 protective skins: 

 Polydamp hydrophobic melamine with metalized PEEK skin with a layer of Innegra, LSP, and 

film 

 Soric LRC 3 mm, 3 pcf metallic core (perhaps less than 1⁄4” thick), and 10 pcf polyurethane core 

(again perhaps less than 1⁄4” thick) for the impact absorbing materials 

 Innegra (similar results to Tegris but easier to work with) and carbon epoxy (too heavy but 

excellent results) for impact spreading materials 

 LDS 50-01 0.007 psf aluminum for lightning strike protection (it gave good results and was very 

light) 

 Integument with PSA and 3M 5004 with PSA with opaque same color for aesthetic film 

The actual determination of the test panel matrix for the final set of STAR-C2 protective skins was 

made in the next phase of this research program. 

8 Second-Generation Test Articles 

Using lessons learned from the first generation of test articles, a second (and final for this effort) 

generation of test articles was defined. Similar to the first generation of test articles, the second 

generation was tested for impact, electromagnetic effects, aesthetics and smoothing, and thermal. In 

addition, acoustic testing was done to see how effective the STAR-C2test articles were at absorbing 

acoustic energy. Section 8 will describe the test articles, the manufacturing challenges and lessons 

learned, and the test results. 

8.1 Test Article Definitions 

8.1.1 Material Definition 

The materials used to perform the impact and acoustic energy absorption function are shown in Table 

75. These materials are, except for the Polydamp hydrophobic melamine, identical to the materials used 

in the first-generation test panels. The Polydamp hydrophobic melamine had pressure sensitive adhesive 

on both sides of the foam for the second-generation skin. Replacing the metalized peek skin with Innegra 

and LDS 50-01 provided both an impact spreading layer and lightning protection. 
166

Table 75 - Impact Materials for Second-Generation Protective Skins 

Material Trade Name Material Composition

10 pcf polyurethane core, FR-6710 Polyurethane

3 pcf metallic honeycomb core (1/4” cell, 5052 

aluminum, 0.0015” thick wall, nominally 3.1

pcf/ft3)

Aluminum honeycomb

Soric LRC – Low Resin Content (3 mm) Polyester nonwoven with compression 

resistant hexagonal cell structure containing 

synthetic micro-spheres

Polydamp hydrophobic melamine with 

pressure sensitive adhesive on both sides

Melamine foam

The impact spreading materials used for the second-generation protective skins are shown in Table 76. 

The Innegra S plain weave fabric was identical to that used for the first-generation skins. The carbon 

fiber plain weave fabric was also the same fabric, but this time it included aluminum wire woven in the 

fabric to provide lightning protection (see Figure 105).

Table 76 - Impact Spreading Materials for Second-Generation Protective Skins 

Material Trade Name Material Composition

Innegra S plain weave fabric Polypropylene

Standard modulus carbon fiber plain weave 

fabric

Besfight G30-500 3K tow 8 harness satin 

weave

Figure 105: Picture of Carbon ALS (carbon fiber fabric with interwoven aluminum lightning strike protection wire) 

Table 77 lists the lightning strike materials used on the second generation of panels. LDS 50-01 was 

used on the first generation. The ALS system interwoven in the carbon fiber plain weave fabric is new to 

the project. The goal of this material is to include two functions (impact spreading and lightning strike 

protection) in one material which can be easily integrated into the protective skin build-up. Previous 

testing at Cessna of the Carbon ALS fabric has been very successful. 

Table 77 - Lightning Strike Protection for Second-Generation Protective Skins 

Material Trade Name Material Composition

LDS 50-01 0.007 psf aluminum Aluminum

20 gsm nominal interwoven aluminum wire

(ALS)

Aluminum wire woven in carbon fiber plain 

weave fabric
167

Only one aesthetic layer was used for the second-generation protective skins – Integument – as shown 

in Table 78. The Integument and 3M 5004 fluoropolymer films were chemically very similar and both 

provided good results on the first-generation protective skins. One lesson learned from the tests was that 

effective evaluation of aesthetics requires materials of similar color and transparency. Integument had 

sufficient quantities of opaque white film to cover all of the second-generation test articles immediately 

available. The 3M 5004 was not available in opaque white in a timely manner. The Integument film had 

a shiny side and a matte side. The pressure sensitive adhesive was applied to the matte side so that the 

shiny side was visible (similar to shiny aircraft paint). 

Table 78 - Aesthetic Layer for Second-Generation Protective Skins 

Material Trade Name Material Composition

Integument film with pressure sensitive 

adhesive

Fluorogrip polymer film (ethylenechlorotrifluoroethylene)

The interface layers for the second-generation protective skins are shown in Table 79. The 3M 4950 

VHB double-sided foam tape and the Grade 30 film adhesive are the same as used for the first-generation 

skins. The Aeropoxy PR2032 and hardener PH3660 were replaced by Epon Epoxy (9504 Resin and 9554 

Hardener). The 3M F9460PC transfer tape was eliminated completely from the second-generation 

protective skins since it was hard to handle and difficult to make look good. 

Table 79 - Interface Layers for Second-Generation Protective Skins 

Material Trade Name Material Composition

3M 4950 Very High Bond (VHB) DoubleSided Foam Tape (45 mil thick)Viscoelastic acrylic foam

Epon Epoxy (9504 Resin and 9554 Hardener) Multifunctional acrylate resin and modified 

amine mixture with diphenylolpropane 

hardener

Grade 30 film adhesive FM 73C fracture-tough modified epoxy-nitrile 

structural film

The materials listed above were combined into the six test articles shown in Table 80. For the 

second-generation test articles, all test articles were complete protective skins (i.e., had all layers of 

materials). 
168

Table 80 - Second-Generation Test Article Definition 

Panel 

pcf

Interface Impact 

Absorbing

Interface Impact 

Spreading

Interface Lightning 

Strike

Aesthetic 

Film

FXX-1 3M 4950 3 mm Soric 

LRC

Epon 

Epoxy

Innegra Epon 

Epoxy

LDS 50-

01

Integument 

Film with 

PSA

FXX-2 3M 4950 3 mm Soric 

LRC

Epon 

Epoxy

Carbon 

ALS

None None Integument 

Film with 

PSA

FXX-3 3M 4950 1⁄4” 3 pcf

metallic 

honeycomb

Grade 30 

Adhesive

Innegra Epon 

Epoxy

LDS 50-

01

Integument 

Film with 

PSA

FXX-4 3M 4950 1⁄4” 10 pcf

PU Core

Epon 

Epoxy

Innegra Epon 

Epoxy

LDS 50-

01

Integument 

Film with 

PSA

FXX-5 3M 4950 1⁄4” 10 pcf

PU Core

Epon 

Epoxy

Carbon 

ALS

None None Integument 

Film with 

PSA

FXX-6 PSA Polydamp 

(1/2”)

PSA Innegra Epon 

Epoxy

LDS 50-

01

Integument 

Film with 

PSA

8.1.2 Drawings 

The drawing for the second-generation impact and aesthetics and smoothing test articles is shown in 

Figure 106. Like the first-generation panels, these are 24 inches x 24 inches. This time both sets of 

panels have the impact absorbing, impact spreading, lightning strike, and aesthetic film on all panels. The 

acoustics test articles (shown in Figure 107) are identical to the second-generation impact and aesthetics 

and smoothing test articles except for size – the acoustics test articles are 48 inches x 48 inches for 

compatibility with acoustic test facilities. 

The lightning strike test articles are shown in Figure 108. Like the first-generation articles, the impact 

absorbing/spreading layers are inset one inch from the panel edge so that the panels will fit in the 

transmissivity chamber. The aesthetic film is inset another 0.75 inches from the edges of the impact 

layers to leave room for grounding in the “L” frame (which was shown in Figure 71). 
169

Figure 106: Second-generation impact and aesthetics & smoothing test article drawing. 
170

Figure 107: Acoustics test article drawing (only second generation). 
171

Figure 108: Second-generation lightning strike test article drawing.
172

The first-generation base substrate laminates were seven plies of carbon uni-directional tape with 

epoxy to support automated manufacturing which might be appropriate in 2030-2035. As mentioned in 

Section 7.2.6, when impacted the laminates tended to split in the direction of the outer layers of unidirectional tape. To prevent splitting, the second-generation base panels were constructed with five plies 

of carbon uni-directional tape and an outer layer of woven material on each side of the panel as shown in 

Figure 109 for the 24 inch by 24 inch panels. The base substrate panel drawing for the acoustic panels is 

shown in Figure 110; the only difference between it and the other panels is size (48 inches by 48 inches). 

The woven material successfully acts as a stop to minimize crack growth (see Figure 111). 
173

Figure 109: Second-generation base substrate laminate drawing. 
174

Figure 110: Acoustics base substrate panel drawing. 
175

 

Figure 111: Base substrate panel impact effect for uni-directional (left) and plain weave (right) outer layer. 

8.1.3 Manufacturability 

This was the second time through working with these materials but the supplier building the panels 

changed and different manufacturing methods were used, so there were still lessons learned from building 

the protective skins. 

The steps to manufacture the panels are shown on the left side of Figure 112 for the panels made with 

Soric or Polyurethane core and Innegra (FXX-1 and FXX-4). The right side of Figure 112 shows the 

steps to manufacture the panels made with Soric or Polyurethane core and Carbon ALS (FXX-2 and 

FXX-5). (The FXX designation is used because the panels could be FIM or impact, FLS or lightning 

strike, FAS or aesthetics & smoothing, and FAC or acoustic. The same processes were used to make all 

of the panels.) The process steps for the Soric and Innegra are identical except for the extra step of 

adding the layer of LDS 50-01 for the Innegra panels; Carbon ALS has the lightning protection already 

included in the material. 

The left side of Figure 113 shows the process of manufacturing the panel with metallic honeycomb 

while the right side of the figure shows the process of manufacturing the panel with the Polydamp 

Hydrophobic Melamine. The process to combine Innegra and LDS 50-01 is identical. The metallic 

honeycomb requires the addition of adhesive (which adds weight) to keep the resin from filling the 

honeycomb and adding a lot of weight during the second VARTM process. Applying the Integument 

film to the LDS 50-01 is the same for both articles. The metallic honeycomb uses the double-sided tape 

to attach the honeycomb to the base substrate panel. The Polydamp Hydrophobic Melamine has pressure 

sensitive adhesive on both sides so does not require the double-sided tape, reducing weight but perhaps 

also reducing the amount of impact resistance. 
176

Layup LDS 50-01 on tool

Place Innegra on top of LDS 50-01

Place Soric or Polyurethane Core on top of Innegra Bag, pull vacuum, add 

Epon Resin System

Heat to 250°F and wait for cure

Peel backing off Integument film PSA and 

stick down to LDS 50-01

Peel backing off one side 

of the 3M 4950 and 

attach double-sided tape 

to the back of the Soric or Polyurethane Core 

For all but impact and 

aesthetics & smoothing 

panels, peel backing off 

other side of 3M 4950 

double-sided tape and 

stick protective skin 

down to base substrate panel.

Layup Carbon ALS on tool

Place Soric or Polyurethane Core on top of Carbon ALS

Bag, pull vacuum, add 

Epon Resin System

Heat to 250°F and wait for cure

Peel backing off Integument film PSA and 

stick down to LDS 50-01

Peel backing off one side 

of the 3M 4950 and 

attach double-sided tape 

to the back of the Soric or Polyurethane Core 

For all but impact and 

aesthetics & smoothing 

panels, peel backing off 

other side of 3M 4950 

double-sided tape and 

stick protective skin 

down to base substrate panel.

Panels FXX-1 & FXX-4 Panels FXX-2 & FXX-5

Figure 112: Manufacturing Process Steps for Innegra (left) and Carbon ALS (right) panels. 
177

Layup LDS 50-01 on tool

Place Innegra on top of LDS 50-01

Apply film adhesive to 

pre-cured Innegra skin 

and assemble honeycomb

Bag, pull vacuum, add 

Epon Resin System

Heat to 250°F and wait for cure

Peel backing off Integument film PSA and 

stick down to LDS 50-01

Peel backing off one side 

of the 3M 4950 and 

attach double-sided tape to the back of the 

metallic honeycomb 

For all but impact and 

aesthetics & smoothing 

panels, peel backing off 

other side of 3M 4950 

double-sided tape and 

stick protective skin 

down to base substrate panel.

Panel FXX-3

Bag, pull vacuum, add 

Epon Resin System

Heat to 250°F and wait for cure

Layup LDS 50-01 on tool

Place Innegra on top of LDS 50-01

Peal PSA backing off one 

side of the Polydamp 

panel and attach to the Inegra skin.

Bag, pull vacuum, add 

Epon Resin System

Heat to 250°F and wait for cure

For all but impact and 

aesthetics & smoothing 

panels, peel backing off 

other side of Polydamp 

and stick protective skin 

down to base substrate panel.

Panel FXX-6

Peel backing off Integument film PSA and 

stick down to LDS 50-01

Figure 113: Manufacturing process steps for metallic core panel (left) and Polydamp panel (right). 

There were three main challenges in the manufacturing process: 1) protective skin warpage during 

cure for the Soric and Polyurethane Core panels; 2) LDS 50-01 manufacturing flaws and fragility; and 

3) difficulty putting down the Integument film smoothly and without bubbles or wrinkles. Each of these 

challenges will be described in the following subsections. 
178

8.1.3.1 Protective Skin Warpage during Cure 

The protective skin original cure temperature was 250°F. Protective skins FXX-2 and FXX-5 (Soric 

with carbon ALS and polyurethane core with carbon ALS) – all of the panels with carbon ALS – warped 

badly during the cure process (see Figure 114 and Figure 115). The warpage was bad enough that the 

protective skins broke during trying to flatten them out to attach to the base substrate panels. 

Figure 114: Post manufacturing warpage of protective skin FIM-2.

Figure 115: Post manufacturing warpage of protective skin FAC-5.

The warpage happened in the first four steps of the process for FXX-2 and FXX-5; it did not happen in 

the same equivalent five steps for FXX-1 and FXX-4. All of the materials were the same, including the 

resin system for the VARTM process, except Innegra and LDS 50-01 versus Carbon ALS. The panels 

made with Carbon ALS are the ones that warped. Both Innegra and carbon fibers have negative 

coefficients of thermal expansion by themselves (refs. 17 and 18, respectively). Aluminum has a positive 

coefficient of thermal expansion (ref. 19). Perhaps the expansion of the greater surface area of the LDS 

50-01 in contact with the Innegra and resin helped offset the shrinkage of the Innegra, causing less 

warpage than the carbon with only a small amount of aluminum wires in contact with the carbon and 

resin. 
179

Reducing the cure temperature to 125°F, while extending the cure time, reduced the warpage to a 

workable level. Even better would be a resin that develops full strength characteristics with a room 

temperature cure. 

8.1.3.2 LDS-50 Fragile Material 

The LDS 50-01 material from Lightning Diversion Systems is extremely fragile. Supplied in 24 inch 

by 26 inch sheets, almost every sheet contains some flaw. A few of the flaws were large enough to 

require scrapping the sheet. The fragility and flaws were frustrating for protective skin manufacturing, 

but did not seem to harm the lightning strike protection performance. The manufacturer noted that the 

material is handled in the plant and then sent to an outside company for further processing. That leads to 

some flaw(s) in the material. Scaling up to sizes more representative of full-scale aircraft could be a 

challenge. 

8.1.3.3 Integument Film Bubbles and Wrinkles 

The manufacturer of the second-generation protective skins had a very difficult time getting the 

Integument film down without bubbles and/or wrinkles in the film. The problem was especially bad for 

the larger acoustic test articles. Integument was contacted and provided a set of work instructions along 

with some advice on getting the film down wrinkle/bubble free. The techniques being used by the 

manufacturer were very similar to what Integument recommended. There is certainly some art and a 

learning curve to success with visually appealing application of the film. 

8.1.4 Base Panel Inspection 

The second-generation base substrate panels were inspected using the same methods employed 

for the first-generation panels. Each panel was weighed and measurements. Measurements were 

made in accordance with Figure 30. The 24” x 24” panel weights and measurements are shown 

in Table 81 while 
180

Table 82 shows the weights and measurements for the 48” x 48” base substrate panels for the 

acoustics test articles. 

The tables contain some panels with the notation “No OL” next to the panel number. This notation 

was necessary because many of the panels were made with overlaps (rather than butt splices) where 

necessary. Even though the material size was large enough to accommodate no overlaps, the panel 

supplier “helped” by including significant regularly spaced overlaps (see Figure 116 for a visual picture 

and Figure 117 for a thermographic inspection image). The overlapping material caused added base 

laminate weight and put obstructions in the testing area of interest. There was some porosity in the 

overlaps as can be seen in Appendix J – Second-Generation Thermography Report. These panels with 

overlaps were used for the lightning strike (the target for the direct strike testing was aimed for the empty 

space between the legs of the “X”) and aesthetics and smoothing panels. The impact panels were all 

panels without overlap. The acoustics panels had both. In order to ensure that there was no impact of the 

overlap on transmission loss, two panels with the same configuration except for overlap were run. There 

was no difference. 

The tables also contain two panels that have a “red tg” notation by the panel number. The autoclave 

heating ramp rate for those two panels was less than the specified rate. The panels were both noticeably 

heavier than the other similar panels. One possible explanation is that the slower heating rate did not 

flash off the liquid resin as fast, leaving more resin present. These red tg panels were not used for testing. 

After accounting for the no overlap panels and the “red tg” panels, the differences in measurements 

(especially for the 24” x 24” panels) are very small. The differences in weights from panel to panel are 

also very small with distinct differences between the overlap and no overlap panels. 
181

Table 81 - Second-Generation 24” x 24” Base Substrate Panel Inspection (1 of 2) 

0.01 lbs

Panel Number Bare Panel Weight L1 L2 L3 L4 L5 Avg Std Dev W1 W2 W3 W4 W5 Avg Std Dev

18170 1.50 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18169 1.50 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18168 1.52 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18163 1.50 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18162 1.48 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18161 1.50 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18160 1.50 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18164 1.48 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18167 1.50 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18157 1.50 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18166 1.48 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18155 1.50 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18189 1.50 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18186 1.50 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18165 1.49 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18141 1.50 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18172 1.50 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18158 1.50 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18171 1.50 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18187 1.50 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

0.05 in
182

Table 81 - Second-Generation 24” x 24” Base Substrate Panel Inspection (2 of 2) 

0.01 lbs

Panel Number Bare Panel Weight L1 L2 L3 L4 L5 Avg Std Dev W1 W2 W3 W4 W5 Avg Std Dev

18156 1.50 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18188 1.48 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18830(No OL) 1.46 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18829 (No OL) 1.46 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18831(No OL) 1.45 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18154(red tg) 1.70 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18159 1.48 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.00 24.00 0.00

18201(No OL) 1.44

18200(No OL) 1.44

18202(No OL) already attached

18129(No OL) 1.44

0.05 in
183

Table 82 - Second-Generation 48" x 48" Base Substrate Panel Inspection 

0.01 lbs

Panel Number Bare Panel Weight L1 L2 L3 L4 L5 Avg Std Dev W1 W2 W3 W4 W5 Avg Std Dev

18191 5.94 48.05 48.05 48.10 48.05 48.05 48.06 0.02 48.05 48.05 48.05 48.05 48.05 48.05 0.00

18190 5.94 48.05 48.05 48.05 48.05 48.05 48.05 0.00 48.05 48.05 48.05 48.05 48.05 48.05 0.00

18195 5.94 48.00 48.00 48.00 48.00 48.00 48.00 0.00 48.00 48.00 48.00 48.00 48.00 48.00 0.00

18193 5.95 48.05 48.05 48.00 48.00 48.00 48.02 0.02 48.05 48.00 48.00 48.00 48.00 48.01 0.02

18129 (No OL) 5.82 48.00 48.00 48.00 48.00 48.00 48.00 0.00 48.05 48.05 48.00 48.05 48.05 48.04 0.02

18192 (No OL) 5.8 48.05 48.05 48.05 48.05 48.05 48.05 0.00 48.00 48.00 48.00 48.00 48.00 48.00 0.00

18194 (No OL) 5.82 48.05 48.00 48.00 48.00 48.05 48.02 0.02 48.00 48.00 48.00 48.00 48.00 48.00 0.00

18173 (red tg) 6.04 48.00 48.00 48.00 48.00 48.00 48.00 0.00 48.00 48.00 48.00 48.00 48.00 48.00 0.00

19953 (No OL) 5.80

19554 5.80

0.05 in
184

Figure 116: View of back of 48” x 48” base substrate panel with overlap. 

 

Figure 117: Thermographic view of 24" x 24" base substrate panel with overlap. 

8.2 Impact 

Impact tests very similar to those conducted on the first generation of protective skins were conducted 

on the second generation of skins. The impact test fixture designed for the first-generation skins (see 

Figure 55) was used to conduct impact tests on the second generation of test articles. The test 

requirements, test objectives, and test results will be described in the following subsections. 

8.2.1 Requirements 

The primary requirements for impact remain the same (see Table 46). The critical requirement is that 

the material withstands a 180 in-lb impact with no damage to the base substrate panel. This 180 in-lb 

energy is obtained by dropping a five pound weight from a height of 36 inches. The other primary 
185

requirement is that the damage which could require repair (Categories 3 and 4 from Reference 2) is 

visible. 

In order to expand the information obtained about the ability of the various materials to withstand 

impacts, the test matrix consists of three impact energies (150 in-lbs, 180 in-lbs, and 210 in-lbs) with 

three different impactor diameters (0.5”, 1.0”, and 1.75”) as shown in Table 83. The requirement is 1.0” 

at 180 in-lbs. The first-generation skins were tested at 50 in-lbs, 180 in-lbs, and 250 in-lbs. Because 

there was reasonable certainty that these second-generation protective skins would pass the primary 

requirement, the range of impact energies around that primary requirement was reduced (from 50 to 250 

in lbs to 150 to 210 in lbs) to see with how much margin each panel passed. 

Table 83 - Second-Generation Skins Impact Test Conditions 

Impactor Diameter (in) 0.5 1.0 1.75

Impactor Weight (lbs) 5.0 5.0 5.0

150 in-lbs drop height (in) 30 30 30

180 in-lbs drop height (in) 36 36 36

210 in-lbs drop height (in) 42 42 42

Hail Energy Ref. (in-lbs) 0.83 13.3 124.9

8.2.2 Test Objectives 

The test objectives were described in terms of five categories of damage in Section 7.2.4. The goal 

remains to eliminate categories 3 and 4a damage: 

 3. Maximum energy to cause hidden damage to the structure below. 

 4. Maximum energy to cause visible damage to the structure below: 

 a. When observed from the back (substrate) side of the test panel. 

8.2.3 Test Articles 

The second-generation impact test articles were constructed with the materials which were defined in 

Table 76. The measured and calculated weights of the test article components and the resulting areal 

density of the test articles are shown in Table 84. In the case of test article FIM-4, the protective skin 

weight (without backing paper) had to be inferred from the total panel weight and the base substrate panel 

weight because the protective skins was accidentally attached to the base substrate panel. This also 

complicated thermographic inspection. 
186

Table 84 - Second-Generation Impact Test Articles Weights and Areal Density 

8.2.4 Test Results 

The six second-generation impact panels and one bare substrate panel were tested by applying the nine 

impacts to each one. Pictures were taken of the front and back of each impact panel before and after 

impact testing. If features of interest were visible on the impact panel after testing, additional pictures of 

the features were taken. After impact testing was completed for each panel, thermographic inspection 

was conducted. The full thermography report is presented in Appendix J. Pictures of the panels before 

and after impact and thermographic images before and after impact are shown in Figure 118 through 

Figure 145. For each impact article, four pictures are shown: 1) before and after impact of the front of 

the panel; 2) before and after impact of the back of the panel; 3) before impact thermographic images; and 

4) after impact thermographic images. Images are shown for panel FIM-0 (bare base substrate panel with 

no protective skin) in Figure 118 through Figure 121. Panel FIM-1 images are shown in Figure 122

through Figure 125. Panel FIM-2 images are shown in Figure 126 through Figure 129. Figure 130

through Figure 133 are the pictures and images from FIM-3. Figure 134 through Figure 137 are the 

pictures and images from FIM-4. The pictures and images for FIM-5 are shown in Figure 138 through 

Figure 141. Figure 142 through Figure 145 show the pictures and images from FIM-6.

Figure 118: Before and after pictures of the front of FIM-0.

Test Article No. Panel No.

Protective Skin 

Weight, lb (with 

backing paper)

Base 

Substrate 

Panel 

Weight, lb

Total Panel 

Weight, lb

Areal Density of 

Protective Skin, lb/ft^2

FIM-0 18129 0 1.44 1.44 0.000

FIM-1 18831 2.58 1.45 4.03 0.645

FIM-2 18829 2.2 1.45 3.65 0.550

FIM-3 18200 1.82 1.44 3.26 0.455

FIM-4* 18202 2.62 1.44 4.06 0.655

FIM-5 18201 2.42 1.44 3.86 0.605

FIM-6 18830 0.98 1.46 2.44 0.245

* Protective skin attached to bare panel before weighing
187

Figure 119: Before and after pictures of the back of FIM-0.

Figure 120: Before thermographic images of panel FIM-0.

Figure 121: After thermographic images of panel FIM-0.
188

Figure 122: Before and after pictures of the front of panel FIM-1.

Figure 123: Before and after pictures of the back of panel FIM-1.
189

Figure 124: Before thermographic images of panel FIM-1.

Figure 125: After thermographic images of panel FIM-1.
190

Figure 126: Before and after pictures of the front of panel FIM-2.

Figure 127: Before and after pictures of the back of panel FIM-2.
191

Figure 128: Before thermographic images of panel FIM-2.

Figure 129: After thermographic images of panel FIM-2.
192

Figure 130: Before and after pictures of the front of panel FIM-3.

Figure 131 - Before and after pictures of the back of panel FIM-3.
193

Figure 132: Before thermographic images of FIM-3.

Figure 133: After thermographic image of FIM-3.

Figure 134: Before and after pictures of front of panel FIM-4.
194

Figure 135: Before and after pictures of back of panel FIM-4.

Figure 136: Before thermographic images of panel FIM-4.
195

Figure 137: After thermographic images of panel FIM-4.

Figure 138: Before and after pictures of front of panel FIM-5.
196

Figure 139: Before and after pictures of back of panel FIM-5.

Figure 140: Before thermographic image of panel FIM-5.
197

Figure 141: After thermographic images of panel FIM-5.

Figure 142: Before and after pictures of the front of panel FIM-6.
198

Figure 143: Before and after pictures of the back of panel FIM-6.

Figure 144: Before thermographic image of panel FIM-6.
199

Figure 145: After thermographic image of panel FIM-6.

The data which was collected from the impacts on panel FIM-3 came from the front and back views of 

the panel after impact as shown in Figure 130 and Figure 131. For reference, the pre-impact 

thermographic inspection image of FIM-3 is shown in Figure 132. The thermographic inspection made 

after impacting is shown in Figure 133. 

The data was collected for panel FIM-3 in the same way that the data was collected for every panel. 

The data for FIM-3 is shown in Table 85. A description of the test data columns is presented in Table 86. 

There are nine lines of data for each test article. The first three are for the 0.5” impactor (shown in 

column 2) at 50, 180, and 250 in-lbs (shown in column 3); the next three are for the 1.0” impactor at the 

three energy levels; and the final three are for the 1.75” impactor at the three energy levels. 

Table 85 shows that FIM-3 passed impact testing for 0.5” impactor at 150 and 180 in-lbs, 1.0” 

impactor at 150, 180, and 210 in-lbs, and 1.75” impactor at 150, 180, and 210 in-lbs. There are no cases 

for FIM-3 where visible damage is no and base panel damage is yes (which would violate the need to be 

able to visually detect actual damage). In fact, all cases tested have visible damage. 
200

Table 85 - Impact Test Data Collected for Panel FIM-3 

Panel

FIMpactor DiaIN-LBSVisible DamageNDI Measurement (IN

2

) NDI 

DispositionBase Panel DamagePenetration (IN)

Comments

FIM-3 0.50 150 Y 0 A N 0.21

Big diamond shaped 

impacts

FIM-3 0.50 180 Y 0.2 B N 0.275

Big diamond shaped 

impacts

FIM-3 0.50 210 Y 0.7 D Y 0.28

Big diamond shaped 

impacts

FIM-3 1.00 150 Y 0 A N 0.117

Big diamond shaped 

impacts

FIM-3 1.00 180 Y 0 A N 0.116

Big diamond shaped 

impacts

FIM-3 1.00 210 Y 0 A N 0.121

Big diamond shaped 

impacts

FIM-3 1.75 150 Y 0 A N 0.101

Big diamond shaped 

impacts

FIM-3 1.75 180 Y 0 A N 0.104

Big diamond shaped 

impacts

FIM-3 1.75 210 Y 0 A N 0.115

Big diamond shaped 

impacts

Table 86 - Description of Test Data Columns 

Impactor Diameter 

(inches):

Size of the impactor (0.5, 1.0, 1.75).

Force Applied (in-lbs): The amount of force applied (150, 180, 210).

Visible damage: Visible at 5 feet by untrained personnel (Category 3).

NDI Disposition: Base panel damage area measured by Thermography. 

A=0.000 to 0.062 sq. in., B=0.063 to 0.25 sq. in., C=>0.25 to 

0.56 sq. in., D=>0.56 to 1.00 sq. in., E=>1.00 sq.in. (Catecoy 

C, D, and E are failures.)

Base Panel Damage: Visible damage to base (structural) panel.

Penetration (in): Protective skin penetration measured with depth gauge.

Table 87 contains all of the data for all of the test articles. Table 87 shows that all of the impacts were 

visible on the protective skin; no test articles were eliminated from consideration because the protective 

skin hid damage. 
201

Table 87 - Second-Generation Skins Impact Test Data (1 of 2) 

Panel

FIMpactor Dia

IN-LBS

Visible Damage

NDI 

Measurement 

(IN

2

)

NDI Disposition

Base Panel 

Damage

Penetration (IN)

Comments

FIM-0 0.50 150 Y 1.3 E Y 0.276

FIM-0 0.50 180 Y 1.5 E Y 0.301

FIM-0 0.50 210 Y 2.3 E Y 0.253

FIM-0 1.00 150 Y 2 E Y 0.158

FIM-0 1.00 180 Y 2.5 E Y 0.25

FIM-0 1.00 210 Y 2.5 E Y 0.267

FIM-0 1.75 150 Y 1.4 E Y 0.005 Did not break completely through to back side

FIM-0 1.75 180 Y 1.7 E Y 0.017 Did not break completely through to back side

FIM-0 1.75 210 Y 2.6 E Y 0.015 Did not break completely through to back side

FIM-1 0.50 150 Y 0.61 D Y 0.046

FIM-1 0.50 180 Y 0.61 D Y 0.079

FIM-1 0.50 210 Y 0.74 D Y 0.081

FIM-1 1.00 150 Y 0 A N 0.03

FIM-1 1.00 180 Y 0.61 D Y 0.032

FIM-1 1.00 210 Y 0.38 C N 0.034

FIM-1 1.75 150 Y 0 A N 0.021

FIM-1 1.75 180 Y 0.61 D Y 0.015

FIM-1 1.75 210 Y 0.38 C N 0.017

FIM-2 0.50 150 Y 0.35 C N 0.109

FIM-2 0.50 180 Y 0.48 C N 0.14

FIM-2 0.50 210 Y 1.68 E Y 0.161

FIM-2 1.00 150 Y 0 A N 0.059

FIM-2 1.00 180 Y 0.15 B N 0.073

FIM-2 1.00 210 Y 0.56 C N 0.077

FIM-2 1.75 150 Y 0 A N 0.019

FIM-2 1.75 180 Y 0.12 B N 0.018

FIM-2 1.75 210 Y 0.12 B N 0.02

FIM-3 0.50 150 Y 0 A N 0.21 Big diamond shaped impacts

FIM-3 0.50 180 Y 0.2 B N 0.275 Big diamond shaped impacts

FIM-3 0.50 210 Y 0.7 D Y 0.28 Big diamond shaped impacts

FIM-3 1.00 150 Y 0 A N 0.117 Big diamond shaped impacts

FIM-3 1.00 180 Y 0 A N 0.116 Big diamond shaped impacts

FIM-3 1.00 210 Y 0 A N 0.121 Big diamond shaped impacts

FIM-3 1.75 150 Y 0 A N 0.101 Big diamond shaped impacts

FIM-3 1.75 180 Y 0 A N 0.104 Big diamond shaped impacts

FIM-3 1.75 210 Y 0 A N 0.115 Big diamond shaped impacts
202

Table 87 - Second-Generation Skins Impact Test Data (2 of 2) 

8.2.5 Data Analysis 

8.2.5.1 NDI Analysis 

In order to start to make sense out of the data, the raw data in Table 87 was reorganized to have one 

line per impact panel with only the protective skin areal weight and the NDI rating for each impactor and 

each energy level as shown in Table 88. The “A”, “B”, “C”, “D”, and “E” NDI ratings were converted to 

numerical values “0”, “1”, “2”, “3”, and “4” where 0 corresponds to A (no damage) and 4 corresponds to 

E (maximum damage). The NDI ratings have been color coded to help visually inspect the data. An NDI 

rating of 0 (A), 1 (B), or 2 (C) was deemed to be passing. The average NDI rating (sum of each NDI 

Panel

FIMpactor Dia

IN-LBS

Visible Damage

NDI Measurement 

(IN

2

)

NDI Disposition

Base Panel 

Damage

Penetration (IN)

Comments

FIM-4 0.50 150 Y 0.07 B N 0.128

FIM-4 0.50 180 Y 0.38 C N 0.14

FIM-4 0.50 210 Y 0 A N 0.16

FIM-4 1.00 150 Y 0 A N 0.056

FIM-4 1.00 180 Y 0 A N 0.056

FIM-4 1.00 210 Y 0 A N 0.067

FIM-4 1.75 150 Y 0 A N 0.043

FIM-4 1.75 180 Y 0 A N 0.045

FIM-4 1.75 210 Y 0 A N 0.054

FIM-5 0.50 150 Y 0.24 B N 0.14

FIM-5 0.50 180 Y 1.26 E Y 0.177

FIM-5 0.50 210 Y 2.8 E Y 0.303

FIM-5 1.00 150 Y 0 A N 0.138

FIM-5 1.00 180 Y 0 A N 0.134

FIM-5 1.00 210 Y 0 A N 0.136

FIM-5 1.75 150 Y 0 A N 0.031

FIM-5 1.75 180 Y 0 A N 0.088

FIM-5 1.75 210 Y 0 A N 0.095

FIM-6 0.50 150 Y 0.28 C N 0.07 Could feel but not see back side damage

FIM-6 0.50 180 Y 0.27 C N 0.15 Could feel but not see back side damage

FIM-6 0.50 210 Y 1.44 E Y 0.201

FIM-6 1.00 150 Y 0.27 C N 0.025 Could feel but not see back side damage

FIM-6 1.00 180 Y 0.24 B N 0.034 Could feel but not see back side damage

FIM-6 1.00 210 Y 0.27 C N 0.047 Could feel but not see back side damage

FIM-6 1.75 150 Y 0.18 B N 0.018

FIM-6 1.75 180 Y 0.32 C N 0.035

FIM-6 1.75 210 Y 0.32 C N 0.035
203

rating for a panel divided by 9) is also shown. An average NDI rating of 0 means that the panel passed all 

impact cases; similarly, an average NDI rating of 4 means the panel failed all impact cases. The average 

does not provide any insight into which impact conditions were failed for non-zero average NDI ratings. 

Table 88 - Reformatted Data 

None of the test articles shown in Table 88 successfully resisted all of the impact conditions (with a 2 

or less NDI rating). This is probably not surprising for two reasons: 1) the minimum impact was raised 

to 150 in-lbs from 50 in-lbs; and 2) the second-generation test articles used the data from the firstgeneration articles to minimize the amount of material in the test articles (these were expected to be “on 

the edge”). 

As was mentioned in Section 2.0 Requirements, a realistic pass condition for the panels is to pass the 

0.5” impactor at 150 in-lbs, the 1.0” impactor at 150 and 180 in-lbs, and to pass the 1.75” impactor at all 

energy levels. Table 89 shows only those impact conditions in the columns under each impactor 

diameter. All but panel FIM-0 (with no protective skin) and FIM-1 pass all of the realistic conditions 

Table 89 - Realistic Impact Conditions Results Sorted in Increasing Protective Skin Areal 

Density 

The panels are sorted by areal density in Table 89. The lowest areal density is the base 

substrate panel (FIM-0) with a protective skin psf of 0 since there is no protective skin. Next 

lightest is panel FIM-6 (the Polydamp hydrophobic) with a protective skin areal density of 0.245 

psf which is significantly below the target. FIM-3 is close to the upper bound of the weight 

target. Panels FIM-4 and FIM-5 are the two polyurethane panels – they are very heavy, with 

areal densities over 0.6 psf. 

FIM-1 (with 3 mm Soric LRC for impact absorbing and Innegra for impact spreading) is very 

heavy (0.645 psf) and failed the impact test at both the set impact condition (180 in-lbs with a 

1.0” impactor) and at the other realistic impact conditions. The manufacturing process used true 

VARTM (Vacuum Assisted Resin Transfer Molding). Both the Soric and Innegra were difficult 

to get fully wetted with the wet layup technique used for the first-generation test articles. This 

Panel Absorbing 

Layer Absorb T Spreading Layer psf 150 180 210 150 180 210 150 180 210 Average

FIM-0 None 0.000 None 0.000 4 4 4 4 4 4 4 4 4 4.000

FIM-6 Polydamp 0.500 Innegra 0.245 2 2 4 2 1 2 1 2 2 2.000

FIM-3 3# honeycomb 0.250 Innegra 0.455 0 1 3 0 0 0 0 0 0 0.444

FIM-2 3 mm Soric LRC 0.118 Carbon ALS 0.550 2 2 4 0 1 2 0 1 1 1.444

FIM-5 10# PU core 0.250 Carbon ALS 0.605 1 4 4 0 0 0 0 0 0 1.000

FIM-1 3 mm Soric LRC 0.118 Innegra 0.645 3 3 3 0 3 2 0 3 2 2.111

FIM-4 10# PU core 0.250 Innegra 0.655 1 3 0 0 0 0 0 0 0 0.444

.5" Impactor 1.0" Impactor 1.75" Impactor

Panel Absorbing 

Layer Absorb T Spreading Layer psf 150 150 180 150 180 210 Average

FIM-0 None 0.000 None 0.000 4 4 4 4 4 4 4.000

FIM-6 Polydamp 0.500 Innegra 0.245 2 2 1 1 2 2 2.000

FIM-3 3# honeycomb 0.250 Innegra 0.455 0 0 0 0 0 0 0.444

FIM-2 3 mm Soric LRC 0.118 Carbon ALS 0.550 2 0 1 0 1 1 1.444

FIM-5 10# PU core 0.250 Carbon ALS 0.605 1 0 0 0 0 0 1.000

FIM-1 3 mm Soric LRC 0.118 Innegra 0.645 3 0 3 0 3 2 2.111

FIM-4 10# PU core 0.250 Innegra 0.655 1 0 0 0 0 0 0.444

.5" Impactor 1.0" Impactor 1.75" Impactor
204

panel is considerably heavier than the first-generation panels, suggesting that the VARTM 

process was more effective in getting resin into the Soric and Innegra. Perhaps that more solid 

resin resulted in a more brittle test article, as suggested by significant delamination with both the 

1.0” and 1.75” impactors at 180 in-lbs. 

Panel FIM-2 differs from Panel FIM-1 only in the Carbon ALS rather than Innegra as the 

impact spreading layer. Carbon ALS was not used in the first-generation test articles, but 

Carbon (without the aluminum lightning strike protection wires) was used. The Carbon wetted 

very well using the wet layup technique on the first-generation test articles. FIM-2 with Carbon 

ALS was not as heavy as FIM-1 with Innegra. The pattern of delamination is similar but at a 

reduced and acceptable level (1 or up to 0.25 sq. in.), suggesting that perhaps less of the “brittle” 

resin reduced the impact damage. 

8.2.6 Impact Depth Analysis 

The actual impact depths were measured for these panels. The measured depths are shown in the 

seventh column (Penetration (in)) in Table 87. Figure 146 contains the penetration depths for all panels 

with the 0.5” impactor, Figure 147 contains the depths for the 1.0” impactor, and Figure 148 for the 1.75” 

impactor. Not unexpectedly, the impact depths tend to be greatest for the 0.5” impactor and least for the 

1.75” impactor. 

150 160 170 180 190 200 210

0.30

0.25

0.20

0.15

0.10

0.05

Impact Energy, in-lbs

Depth, in

FIM-0

FIM-1

FIM-2

FIM-3

FIM-4

FIM-5

FIM-6

No._0.50

Panel

Impact Depths for 0.5 in Impactor

Figure 146: Impact depths for the 0.5" impactor. 
205

150 160 170 180 190 200 210

0.30

0.25

0.20

0.15

0.10

0.05

0.00

Impact Energy, in-lbs

Depth, in

FIM-0

FIM-1

FIM-2

FIM-3

FIM-4

FIM-5

FIM-6

No._1.00

Panel

Impact Depths for 1.0 in Impactor

Figure 147: Impact depths for the 1.0" impactor. 

150 160 170 180 190 200 210

0.12

0.10

0.08

0.06

0.04

0.02

0.00

Impact Energy, in-lbs

Depth, in

FIM-0

FIM-1

FIM-2

FIM-3

FIM-4

FIM-5

FIM-6

No._1.75

Panel

Impact Depths for 1.75 in Impactor

Figure 148: Impact depths for the 1.75" impactor. 

Of interest about these graphs are the differences in impact depths between FIM-1 and FIM-2 and 

FIM-4 and FIM-5 where the difference in materials is Innegra and LDS 50-01 or Carbon ALS. In all 

cases, the carbon ALS panels have a greater impact depth. For the 1.75” impactor where the depths are 

fairly small anyway, the actual differences between FIM-1 and FIM-2 are almost the same. Otherwise, 

the Carbon ALS panels have a noticeably greater impact depth (especially for the polyurethane core of 
206

panels FIM-4 and FIM-5). This is consistent with the visual observations as seen in Figure 149 and 

Figure 150. 

Figure 149: FIM-1 (left) and FIM-2 (right) after impacts. 

Figure 150: FIM-4 (left) and FIM-5 (right) after impacts. 

Also of interesting note is that the Innegra panels (FIM-1 and FIM-4) are heavier than the Carbon ALS 

panels (FIM-2 and FIM-5) as was shown in Table 87. Carbon ALS is heavier than Innegra. However, the 

Carbon ALS has lightning protection included while the Innegra has LDS 50-01 added. While the LDS 

50-01 has an areal density of only 0.07 psf, it is possible that the vacant spaces in the LDS 50-01 also 

harbor resin and increase the weight. 
207

8.2.7 Final Thoughts on Impact Testing Results 

Impact testing, consisting of three impactor diameters and three energy levels, was conducted on six 

second-generation panels along with one base substrate panel. Before and after impact pictures were 

taken and thermographic inspection was performed on each panel. All of the panels except FIM-1 passed. 

The Polydamp Hydrophobic test article had acceptable amounts of delamination at all impact energies of 

interest and was below the weight target. The thinner material with an impact spreading layer worked 

very well. 

8.3 Electromagnetic Effects 

The purpose of this testing is to evaluate the second generation of STAR-C2

protective skin test panels 

for shielding effectiveness, direct effects of lightning (DEL), and indirect effects of lightning (IEL). 

Testing for the second-generation panels was conducted in the same manner as for the first-generation 

panels. The test results are separated into three parts: shielding effectiveness, IEL and DEL. Data graphs, 

pictures, and test log scans are provided in the following subsections and the attached appendices. 

8.3.1 Test Articles 

The second-generation lightning strike test articles were built with the materials described in Table 77. 

The measured and calculated weights to determine the areal density of the protective skins are shown in 

Table 90. The protective skin weight shown here is without the backing on the double-sided tape on the 

test articles. 

Table 90 - Second-Generation Lightning Strike Test Article Weights 

8.3.2 Transmissivity/Shielding Effectiveness (HIRF) 

The transmissivity testing for the second-generation panels was conducted in exactly the same way 

with exactly the same test equipment as the first-generation panels. The panels were installed in the 

window of the reverberation chambers with the protective skin side layer facing the transmitter antenna in 

the larger reverberation chamber using a frame fabricated at Cessna. All panels were taped with copper 

tape with conducting adhesive to prevent currents from wrapping around the other side of the frame. 

The aluminum panel used to generate results for comparison is shown mounted in the chamber in 

Figure 151. The second-generation plain base substrate panel (7-layered carbon fiber composite panel 

without any protective skin including lightning strike protection) mounted in the chamber is shown in 

Figure 152. Figure 153 shows FLS-1 mounted in the chamber, FLS-2 is shown in Figure 154, FLS-3 is 

Test Article No. Panel No.

Total Weight 

(lbs)

Panel Weight 

(lbs)

Protective Skin 

Weight (lbs)

Areal Density* 

(lbs/ft^2)

FLS-1 18168 3.54 1.52 2.02 0.601

FLS-2 18163 3.38 1.50 1.88 0.559

FLS-3 18162 2.94 1.48 1.46 0.434

FLS-4 18170 3.74 1.50 2.24 0.666

FLS-5 18161 3.57 1.50 2.07 0.616

FLS-6 18169 2.19 1.50 0.69 0.205

*Aerial density based on 22" x 22" of protective skin area
208

shown in Figure 155, Figure 156 shows FLS-4 mounted in the chamber, FLS-5 is shown in Figure 157, 

and FLS-6 is shown mounted in the chamber in Figure 158. 

Figure 151: Aluminum panel installed in the window. 

Figure 152: CFC panel installed in the window. 
209

Figure 153: FLS-1 panel installed in the window. 

Figure 154: FLS-2 panel installed in the window. 
210

Figure 155: FLS-3 panel installed in the window. 

Figure 156: FLS-4 panel installed in the window. 
211

Figure 157: FLS-5 panel installed in the window. 

Figure 158: FLS-6 panel installed in the window. 
212

Baseline results were generated with the open window and window closed with 2024 T3 bare 24” x 

24” inch 0.063” aluminum (Al) skin. This represents the best case (metal sealed window) and worst case 

(open window) extremes for use in the relative measurement of the panels. The insertion loss of the 

reverberation chamber was measured using the top hat antenna in the main chamber and then used for the 

correction factor. Shielding effectiveness data in the following plots is represented using the first order 

correction where the chamber loss is added to the receive signal and plotted on the y-axis. Three test runs 

of the Al panel in the window on three different days showed variation in the range of 3-8GHz due to the 

setup. Hence comparison of the shielding effectiveness will be from 700MHz to 2 GHz. 

Figure 159 shows the comparison between the open window, the Al panel, and the second-generation 

base substrate panel. Addition of the protective skins is necessary to produce shielding effectiveness 

results closer to aluminum. Shielding effectiveness testing of the panels gives an insight into materials to 

be chosen to get close to the shielding effectiveness of aluminum. 

Figure 159: Shielding effectiveness of a base substrate panel. 

Figure 160 shows a plot of shielding effectiveness of with and without a software filter. All the data 

was filtered using a software filter with moving average of 5 points in MATLAB. Figure 161 shows the 

comparison of lightning strike materials LDS 50-01 and ALS interwoven in CFC with the same base core 

of 3mm Soric with Integument Film with PSA. These show that the difference at various frequencies is 

less than 1dBm transmissivity. 

10

2 103 104 105

-100

-80

-60

-40

-20

0

20

 Frequency(MHz) Power Received with first order correction(dBm)

Al Panel

Open

CFC
213

Figure 160: Shielding effectiveness of Panel FLS-1 with and without software filter.

Figure 161: Shielding effectiveness of lightning strike materials with 3mm Soric core with 

base substrate panel compared to an Al panel and open window. 

10

2 103 104 105

-90

-80

-70

-60

-50

-40

-30

-20

-10

 Frequency(MHz) Power Received with first order correction(dBm)

FLS-01:LDS 50-01-Innegra-3mm Soric core with filter

FLS-01:LDS 50-01-Innegra-3mm Soric core without filter

10

2 103 104 105

-100

-80

-60

-40

-20

0

20

 Frequency(MHz) Power Received with first order correction(dBm)

Al Open

FLS-01:LDS 50-01-Innegra-3mm Soric core

FLS-02:Carbon ALS-3mm Soric core
214

Figure 162 shows the shielding effectiveness of the panel with Polydamp core and LDS50-01 

lightning strike material compared to CFC and Aluminum. The shielding effectiveness for the Polydamp 

is less than CFC by 15 dBm at 3 GHz. Figure 163 shows the shielding effectiveness of different core 

materials with respect to the same lightning strike material LDS 50-01. In comparison, the power 

received is almost equivalent. Figure 164 compares the polyurathene core to honeycomb core where 

both use the LDS 50-01 lightning strike material. Figure 165 compares two different lightning strike 

materials with the polyurethane core. There is no substantial difference in the shielding effectiveness. 

Figure 166 and Figure 167 show the shielding effectiveness of all the panels. The minimum shielded 

panel is the bare CFC panel without any protective skin (including lightning strike material). 

Figure 162: Shielding effectiveness of panel FLS-6 with polydamp core with 

base substrate panel compared to an Al panel and open window. 

10

2 103 104 105

-100

-80

-60

-40

-20

0

20

 Frequency(MHz) Power Received with first order correction(dBm)

Al Open

CFC

FLS-06:LDS 50-01-Innegra-0.5" Polydamp
215

Figure 163: Shielding effectiveness of lightning strike material with 3mm Soric core and 

Polydamp core with base substrate panel compared to an Al panel and open window. 

Figure 164: Shielding effectiveness of lightning strike material with honeycomb and polyurethane core 

with base substrate panel compared to an Al panel and open window. 

10

2 103 104 105

-100

-80

-60

-40

-20

0

20

 Frequency(MHz) Power Received with first order correction(dBm)

Al Open CFC

FLS-01:LDS 50-01-Innegra-3mm Soric core

FLS-06:LDS 50-01-Innegra-0.5" Polydamp

10

2 103 104 105

-100

-80

-60

-40

-20

0

20

 Frequency(MHz) Power Received with first order correction(dBm)

Al Open CFC

FLS-03:LDS 50-01-Innegra-Metallic honeycomb

FLS-04:LDS 50-01-Innegra-0.25" 10#PU core
216

Figure 165: Shielding effectiveness of lightning strike material with polyurathene core with 

base substrate panel compared to an Al panel and open window. 

Figure 166: Shielding effectiveness of all panels with base substrate panel 

compared to an Al panel and open window. 

10

2 103 104 105

-100

-80

-60

-40

-20

0

20

 Frequency(MHz) Power Received with first order correction(dBm)

Al Open CFC

FLS-04:LDS 50-01-Innegra-0.25" 10#PU core

FLS-05:Carbon ALS -0.25" 10# PU core

10

2 103 104 105

-100

-80

-60

-40

-20

0

20

 Frequency(MHz) Power Received with first order correction(dBm) Al Open

FLS-01:LDS 50-01-Innegra-3mm Soric core

FLS-02:Carbon ALS-3mm Soric core

FLS-03:LDS 50-01-Innegra-Metallic honeycomb

FLS-04:LDS 50-01-Innegra-0.25" 10#PU core

FLS-05:Carbon ALS -0.25" 10# PU core

FLS-06:LDS 50-01-Innegra-0.5" Polydamp CFC
217

Figure 167 shows the shielding effectiveness of all panels as compared to Aluminum and CFC. The 

shielding effectiveness of the Al panel should be the lower bound of all the panels at all frequencies; 

however, due to the limitations of the setup the performance of the panels can be better evaluated in the 

range of 700MHz to 2 GHz. Figure 168 shows the shielding effectiveness of the old CFC (7 layers of 

uni-directional with all orientation) and with the new CFC panel (2 outer layers of plain weave with 5 

inner layers of unidirectional weave). In the range of interest (700MHz to 2 GHz) the performance of the 

new CFC was marginally better than the old CFC. 

Figure 167: Shielding effectiveness of all panels from 700MHz to 2 GHz with base 

substrate panel compared to an Al panel and open window. 

10

3

-100

-80

-60

-40

-20

0

 Frequency(MHz) Power Received with first order correction(dBm)

Al Open

LDS 50-01-Innegra-3mm soriccore Carbon ALS-3mm soriccore

LDS 50-01-Innegra-Metallic honeycomb

LDS 50-01-Innegra-0.25" 10#PU core Carbon ALS -0.25" 10# PU core

LDS 50-01-Innegra-0.5" polydamp CFC
218

Figure 168: Shielding effectiveness of new base panel CFC new compared with the old base panel 

8.3.3 Indirect Effects of Lightning 

The panels were evaluated for possible effects of indirect effects of lightning coupling factors into a 

known “standard” wire bundle, based on Section 22 of RTCA DO-160G for open circuit voltage (Voc) 

and closed circuit current (Isc) for a standard cable bundle using generic waveform. The test setup and 

test procedure was identical to that used for the first-generation panels. 

By looking at the waveform’s rate of rise and decay, as well as the amplitude of both the voltage and 

current, it is possible to infer panel characteristics which may be otherwise difficult to measure directly. 

Inductance and capacitance of the panel, for example, are difficult to measure directly, but have a large 

impact on the wave shape. By comparing to baseline panels such as aluminum and CFC, it is possible to 

predict which transient waveforms would be seen during a lightning strike. 

All the waveforms were tested to current level 3 with a peak equal to 616 A (Figure 169), and with 

the impedance of the panels the voltage (Figure 170) was tested to 800 V. This is the same as the 

first-generation panel testing. 

10

2 103 104 105

-100

-80

-60

-40

-20

0

20

 Frequency(MHz) Power Received with first order correction(dBm)

Al Panel Open

2

nd Gen CFC

1

st Gen CFC
219

Figure 169: Current calibration oscillogram input waveform with 616 A.

Figure 170: Voltage calibration oscillogram waveform with 800 V. 
220

The data collected for the six test articles and bare substrate panels are shown in Appendix K – 

Second-Generation Indirect Effects Test Data. The data is collected and summarized in Table 91 which 

shows results for different lightning strike protection materials for maximum peak current, maximum 

peak voltage and resistance between the bulkheads. These measurements were used to attempt to make a 

relative comparison of the important waveform parameters between the various materials. 

Table 91 - Panel Details with Peak Current and Voltage 

Panel 

ID Panel details with Lightning Strike Material Current(A)

Voltage

(V)

Resistance 

(m Ω)

Al Aluminum 622.5 808

CFC CFC 247.5 18 43.5

FLS-1 LDS 50-01-Innegra-3mm Soric core 460 20 11

FLS-2 Carbon ALS-3mm Soric core 420.5 20 30.6

FLS-3 LDS 50-01-Innegra-Metallic honeycomb 443.5 19.5 10.3

FLS-4 LDS 50-01-Innegra-0.25" 10 pcfPU core 464 21 12.2

FLS-5 Carbon ALS -0.25" 10 pcf PU core 420 19 40.3

FLS-6 LDS 50-01-Innegra-0.5" Polydamp 466 20.5 9.3

Table 93 summarizes panel performance with respect to wave shape distortion which may be seen 

during a lightning strike. When lightning attaches to a metal aircraft, the primary means of propagation is 

through the outer structure of the fuselage itself. The magnetic field created during this rapid current 

change can then induce a voltage (and subsequent current) on wire bundles installed inside the aircraft. In 

addition, the impedance between the entry and exit points of the lightning strike can create a potential 

difference seen between different sections of the aircraft. This potential difference will then generate a 

voltage between the two ends of a wire which is terminated at both ends and induce a current. 

Historically, the primary means of lightning induced transients on wire bundles for metal aircraft has been 

through magnetic field coupling. As the resistance of the airframe increases (e.g., beginning to install 

more composite material), the transient source seen on wire bundles begins to shift from magnetic field 

coupling to potential difference coupling. 

Table 92 for current and Error! Reference source not found. for voltage were obtained by digitizing 

measured signals of closed circuit current and open circuit voltage on the cable bundle. A Matlab script 

was written to pick the 10% time, 50% percent time and max time and amplitude. In the case of 10% 

time, due to the sharp rise it was difficult to sample digitized points and hence 10% time was predicted 

based on a linear curve between the triggered start to maximum amplitude in the software. The ratio 

columns gives the ratios (~10%) and (~50%) with respect to maximum peak amplitude. Peak voltage 

varied from 18V to 21V for all materials. 
221

Table 92 - Characteristics of Current Waveforms 

Panel Lightning 

protection 

material

Time 

for 

10% 

(μs)

Amplitude 

at 10%

(A)

Time at 

max (μs)

Max peak 

(A)

Time at 

50% 

(μs)

Amplitude 

50%

(A)

Al Aluminum 0.00 61.93 11.99 618.09 125.84 339.83

CFC None 0.00 25.39 4.60 246.21 12.52 132.49

FLS-1

LDS 50-01-

Innegra-3mm 

Soric core

0.37 47.94 11.48 451.58 54.27 247.01

FLS-2

Carbon ALS3mm Soric core 0.10 40.06 9.45 417.33 36.73 228.14

FLS-3

LDS 50-01-

Innegra-Metallic 

honeycomb

0.43 41.12 11.29 450.28 53.25 246.87

FLS-4

LDS 50-01-

Innegra-0.25" 10

pcfPU core

0.41 47.85 9.66 458.51 56.80 245.95

FLS-5

Carbon ALS -

0.25" 10 pcf PU 

core

0.75 41.40 7.53 414.05 35.86 226.17

FLS-6

LDS 50-01-

Innegra-0.5" 

Polydamp

0.10 40.91 11.28 448.56 58.71 244.44
222

Table 93 - Characteristics of Voltage Waveforms 

Panel Lightning 

protection 

material

Time 

for 10% 

(μs)

Amplitude at 

10%

(V)

Time 

at max 

(μs)

Max 

peak (V)

Time at 

50% 

(μs)

Amplitu

de 50%

(V)

Al Aluminum 0.00 78.10 0.04 780.97 1.92 418.86

Al Aluminum 0.00 81.33 0.04 813.32 1.87 437.08

CFC CFC 0.48 1.07 4.80 10.69 11.62 5.58

FLS-1

LDS 50-01-

Innegra-3mm 

Soric core 1.06 2.03 10.59 20.26 52.94 10.96

FLS-2

Carbon ALS3mm Soric 

core 0.83 1.87 8.30 18.70 35.08 9.82

FLS-3

LDS 50-01-

InnegraMetallic 

honeycomb 1.53 2.02 15.32 20.22 50.16 10.77

FLS-4

LDS 50-01-

Innegra-0.25" 

10 pcfPU core 1.01 2.08 10.05 20.82 50.14 11.42

FLS-5

Carbon ALS -

0.25" 10 pcf

PU core 0.02 1.66 7.67 17.79 32.56 9.73

FLS-6

LDS 50-01-

Innegra-0.5" 

Polydamp 0.13 1.98 7.71 19.78 52.72 10.66

The characteristics of the magnetic field coupled waveforms and the potential difference coupling 

while installed on an aircraft can be summarized as follows: magnetic field coupling has a higher rate of 

change, but shorter duration; potential difference coupling has a slower rate of change, but longer 

duration. Depending on the system or box of interest, one could present a more severe threat than the 

other (higher rate of change versus more average power). Because different systems may be susceptible 

to different threats in different ways, it is not the intent of this discussion to declare one installation 

“worst case” or one a “better performer.” It is instead to understand how the material might behave 

during a lightning strike. 

8.3.4 Direct Effects of Lightning 

Similar to the first-generation panels, the six second-generation panels were struck twice on each panel 

using current component D (APR 5412A) with an amplitude of 100 kA on the protective skin side of the 

composite panel. Additionally, two of these panels (FLS-1 and FLS-6) were struck a third time with 

200kA on the lightning strike protection material without the Integument film since the film was 

displaced due to prior strikes. The panels were tested according to applicable sections of SAE ARP5416. 
223

Testing was again conducted at DNB Engineering in Fullerton, California. Their complete test report, 

including pictures and test data, is presented in Appendix L – Direct Effects Test Data and Pictures 

(DNB). The Cessna pictures are shown on the following pages. 

Figure 171 and Figure 172 show a sample of pretest setup of FLS-1 with labels of the various 

components shown in Figure 171. 

Figure 171: Panel FLS-1 pre strike #1 (setup). 

Figure 172: Panel FLS-1 pre strike #1 (setup). 

Fuse 

wire

Conducting 

Non conducting plate

Cu

Trip 

wire
224

Figure 173 shows FLS-1 after the first strike while Figure 174 shows the panel prior to the second 

strike. What is important about Figure 174 is the placement of the trip wire relative to the first strike – it 

is located on the other side of the panel. In addition to changing sides, the trip wire is positioned to try to 

be away from the panel edge by six inches and to be centered between the overlapped layers of material. 

Figure 173: Panel FLS-1 post strike #1. 

Figure 174: Panel FLS-1 pre strike #2 (setup). 
225

Figure 175 shows FLS-1 after strikes 1 and 2. Figure 176 shows the panel before strike 3. The 

position of the trip wire has been moved to a spot which has not been struck before; the previous strikes 

have removed all of the Integument protective film. 

Figure 175: Panel FLS-1 post strike #1 and #2. 

Figure 176: Panel FLS-1 pre strike #3. 
226

FLS-1 after all three strikes is shown still mounted in the test fixture in Figure 177. The front of the 

panel is shown in Figure 178, and the back of the panel is shown in Figure 179. The back of the panel has 

dots indicating the target lightning strike location for each of the three strikes. As mentioned previously, 

the goal was to stay six inches from the edges and away from the overlapped layers of material. 

Figure 177: Panel FLS-1 post strike #1, #2, and #3. 

Figure 178: Front of panel FLS-1 post strike #1, #2, and #3. 
227

Figure 179: Back of panel FLS-1 post strike #1, #2, and #3. 

The same sequence of figures is presented in Figure 180 through Figure 187 for FLS-2, in Figure 188

through Figure 199 for FLS-3, in Figure 200 through Figure 206 for FLS-4, in Figure 207 through Figure 

214 for panel FLS-5, and in Figure 215 through Figure 224 for FLS-6. Panels FLS-2, FLS-3, FLS-4, and 

FLS-5 each had two strikes. Panel FLS-6 had three strikes. 

Figure 180: Panel FLS-2 pre strike #1 (setup). 

Approximate 

strike 

locations

1

3

2
228

Figure 181: Panel FLS-2 pre strike #1 (setup). 

Figure 182: Panel FLS-2 post strike #1. 
229

Figure 183: Panel FLS-2 pre strike #2 (setup). 

Figure 184: Panel FLS-2 post strike #1 and #2. 
230

Figure 185: Panel FLS-2 post strike #1 and #2. 

Figure 186: Front of panel FLS-2 post strike #1 and #2. 
231

Figure 187: Back of panel FLS-2 post strike #1 and #2. 

Figure 188: Panel FLS-3 pre strike (setup). 
232

Figure 189: Panel FLS-3 pre strike (setup). 

Figure 190: Panel FLS-3 pre strike (setup). 
233

Figure 191: Panel FLS-3 pre strike (setup). 

Figure 192: Panel FLS-3 post strike #1. 
234

Figure 193: Panel FLS-3 post strike #1. 

Figure 194: Panel FLS-3 pre strike #2 (setup). 
235

Figure 195: Panel LS-3 pre strike #2 (setup). 

Figure 196: Panel FLS-3 post strike #1 and #2. 
236

Figure 197: Panel FLS-3 post strike #1 and #2. 

Figure 198: Front of panel FLS-3 post strike #1 and #2. 
237

Figure 199: Back of panel FLS-3 post strike #1 and #2. 

Figure 200: Panel FLS-4 pre strike #1 (setup). 
238

Figure 201: Panel FLS-4 pre strike #1 (setup). 

Figure 202: Panel FLS-4 post strike #1. 
239

Figure 203: Panel FLS-4 pre strike #2 (setup). 

Figure 204: Panel FLS-4 post strike #1 and #2. 
240

Figure 205 - Front of panel FLS-4 post strike #1 and #2.

Figure 206: Back of panel FLS-4 post strike #1 and #2. 
241

Figure 207: Panel FLS-5 pre strike #1(setup). 

Figure 208: Panel FLS-5 pre strike #1(setup). 
242

Figure 209: Panel FLS-5 post strike #1. 

Figure 210: Panel FLS-5 post strike #1. 
243

Figure 211: Panel FLS-5 pre strike #2 (setup). 

Figure 212: Panel FLS-5 post strike #1 and #2. 
244

Figure 213: Front of panel FLS-5 post strike #1 and #2. 

Figure 214: Back of panel FLS-5 post strike #1 and #2. 
245

Figure 215: Panel FLS-6 pre strike #1(setup). 

Figure 216: Panel FLS-6 post strike #1. 
246

Figure 217: Panel FLS-6 pre strike #2 (setup). 

Figure 218: Panel FLS-6 post strike #1 and #2. 
247

Figure 219: Front of panel FLS-6 post strike #1 and #2. 

Figure 220: Back of panel FLS-6 post strike #1 and #2. 
248

Figure 221: Panel FLS-6 pre strike #3 (setup). 

Figure 222: Panel FLS-6 post strike #1, #2, and #3. 
249

Figure 223: Front of panel FLS-6 post strike #1, #2, and #3. 

Figure 224: Back of panel FLS-6 post strike #1, #2, and #3.
250

The convention for damage on the panel’s inner hole is a hole in the base substrate panel, and outer 

hole is a hole in the outer layers of the protective skin. Inner delamination (debond and delamination seen 

in the base substrate panel) and outer delamination (debond seen in the protective skin) were measured 

with thermography and tap test, respectively. Damage sizing was performed for the base substrate 

(backside) using thermography. The thermography report for all base substrate panels and lightning 

strike and impact test articles is provided in the document Appendix H - Thermography Report. 

Table 94 shows post-strike damage on the panels. All of the lightning strike panels were inspected 

from the front side. Tap tests were done to get an approximate measurement of debond in the core 

location. Due to the fact that these panels had lightning mesh and charred material followed by a tempera 

paint surface preparation (used for preparing panel for thermography), a reliable infrared thermography 

inspection of front-side protective skin damage could not be achieved [Appendix J – Second-Generation 

Thermography Report]. The inner delamination measurement presented is the equivalent diameter of a 

circle with the area found from the thermography inspection. 

Table 94 - Damage and Delamination for All Panels (Post Lightning Strike)

Panel 

number Strike Inner Hole (in)

Inner 

Delamination 

(in)

Inner 

damage 

(in)

Outer 

Hole 

(in)

Outer 

Delamination 

(in)

Current

(k A)

FLS-1 1 0 0 0 0 0 100

FLS-1 2 0 0 0 0 0 100

FLS-1 3 0 0 0 0 0 200

FLS-2 1 0 0 0 0.564 5.11 100

FLS-2 2 0 0 0 0 6.694/0.2* 100

FLS-3 1 0 0 0 0 0 100

FLS-3 2 0 0 0 0 0 100

FLS-4 1 0 0 0 0 0 100

FLS-4 2 0 0 0 0 0 100

FLS-5 1 0 0 0 1.14 3.1/0.9* 100

FLS-5 2 0 0 0 0 4.13/0.25* 100

FLS-6 1 0 0 0 0 0 100

FLS-6 2 0 1.15 0 0 0 100

FLS-6 3 0 0 0 0 0 200

*Broken Fiber in the CFC 

All of the panels passed visual inspection after direct strike testing for both the 100 and 200 kA 

strikes. Thermographic inspection showed that all panels except FLS-6 passed direct strike testing. 

Only panel FLS-6 did not pass the “no inner delamination” requirement with a 1.15 in2

debond (see 

Table 94); that failure was located in the area of the second 100 kA strike. No delamination was detected 

in the area of the 200 kA strike. Unfortunately, it was not possible to perform the thermographic 

inspection at DNB Engineering after each strike. All strikes were made, and the panels were returned to 

Cessna for inspection. Figure 225 shows the pre and post strike thermography for the base substrate 

panel used in FLS-6. Some delamination was present in the overlap areas before the strike as shown in 

the red ellipses on the left image. The proximity of strike #2 to an already delaminated area may have 

caused the delamination to change. The fact that strike #3, at twice the intensity of strikes #1 and #2, and 

in an area without prior delamination did not appear to cause delamination makes it difficult to eliminate 

the Polydamp Hydrophobic Melamine as a viable protective skin material. 
251

Figure 225: Pre and post strike thermographic images of 

base substrate panel for FLS-6. 

8.4 Aesthetics and Smoothing 

The purpose of this testing is to evaluate the second generation of STAR-C2protective skin test panels 

for aesthetics and smoothing. Testing for the second-generation panels was conducted in basically the 

same manner as for the first-generation panels although the base substrate panel design was modified 

from that used for the first-generation panels by removing the middle fastener size and the wire bundle 

simulations. The drawing for the second-generation modified base substrate panel is shown in Figure 

226. The first-generation modified base substrate panel was shown in Figure 93. The material 

composition of the second-generation panels was described in Section 8.1. 

In addition to the 24” x 24” test articles built specifically for aesthetics and smoothing testing (FAS-1 

through FAS-6), visual inspection was also conducted for the 48” x 48” acoustics test articles (FAC-1 

through FAC-6) to gather additional feedback from how the materials performed on the larger panel sizes. 

The specific combinations of material for the acoustic test articles were the same as for the Aesthetic and 

Smoothing panels. Data graphs, pictures, and test log scans are provided for each of these in the 

following subsections. 

#1

#2

#3
252

Figure 226: Base substrate for aesthetic and smoothing test panels showing fasteners and doublers.

8.4.1 Test Panel Assembly 

8.4.1.1 Aesthetics and Smoothing Panels 

The material combinations used for impact energy absorption, impact energy spreading, lightning 

strike protection and aesthetics and smoothing as listed in Table 80 were combined into single piece 

stack-ups prior to being applied to the modified base substrate panels. With the exception of the 

Polydamp based stack-up, these material stack-ups each included a layer of 3M 4950 VHB tape, which 

was used to adhere the stack-ups to the base substrates. The Polydamp was supplied with a layer of PSA 

applied by the supplier, which was used to adhere it to the base substrate. 

Application of the stack-ups to the base substrates necessitated the use of the fixture fabricated for the 

first-generation panels to accommodate the geometric features which were created on the underside of the 

base panels, namely the fasteners and aluminum shim stock that was used to accommodate the grip length 

of the blind fasteners. This fixture, shown in Figure 227, was manufactured from a piece of medium 
253

density fiberboard with a machined slot for the shim stock and additional holes in the required locations 

for the fasteners. The fixture allowed for the base panels to sit flat while the stack-ups were applied, as 

can be seen in Figure 228 and Figure 229. 

In order to allow for consistent application of the stack-ups to the base substrate panels, the application 

roller created for the first-generation test articles was used. The roller, shown in Figure 230 and Figure 

231, consisted of a 4” section of PVC pipe that was fitted with pressure fittings on either end. The pipe 

was filled with sand, tamped down, and refilled, until no more sand could be added. Water was then 

added to the sand, until saturation was achieved. The resulting application roller was approximately 30” 

in width and weighed 28.2 pounds. 

Application of the stack-ups to the modified base substrates was accomplished by removing the 

separator paper from the VHB tape, placing the stack-up on top of the modified base substrate loaded in 

the application fixture, and rolling the application roller from right to left and then bottom to top, as 

shown in Figures 3 through 6. In this orientation, the roller was first rolled over the two aluminum 

doublers and then the flush and protruding head fasteners on the first pass. The second pass was made to 

ensure that the stack-up was applied with pressure in both directions. 

Figure 227: Aesthetic and smoothing base substrate panel holder. 
254

Figure 228: Aesthetic and smoothing base substrate loaded for stack-up application. 

Figure 229: Stack-up applied to base substrate. 
255

Figure 230: Application of stack-up with pressure roller, left to right.

Figure 231: Application of stack-up with pressure roller, bottom to top.
256

8.4.1.2 Acoustic Panels 

The acoustic panel protective skins were manufactured in the same way as the aesthetics and 

smoothing protective skins. The tape was removed from the 3M 4950 VHB tape, and the protective skin 

was aligned with the base substrate panel and connected to the base substrate panel by hand. No special 

equipment was utilized. The acoustic test panels are 48” x 48.” 

8.4.2 Aesthetic and Smoothing Test Results 

8.4.2.1 Aesthetics and Smoothing Panels 

In order to gain some useful data with which to analyze the effectiveness of the stack-ups for 

aesthetics and smoothing, notes from visual examinations of the panels were recorded, a number of 

physical measurements of the panels were taken, and photographs of the panels were captured. The 

photographs are shown in the following pages, and generally show a front view, an edge view, and a 

shadowed front view of the panel. The shadowed front view is a new technique when compared to the 

methods used for the first-generation panels report, and assists in showing some of the translation of 

underlying surface features to the outer surface of the panel. Additional photos were taken of specific 

local surface deviations or phenomenon that were of interest and are also presented here. 

Figure 232: Panel FAS-1 front view. 
257

Figure 233: Panel FAS-1 edge view. 

Figure 234: Panel FAS-1 shaded front view. 
258

Figure 235: Panel FAS-2 front view. 

Figure 236: Panel FAS-2 edge view.
259

Figure 237: Panel FAS-2 Shaded Front View. 
260

Figure 238: Panel FAS-3 front view. 

Figure 239: Panel FAS-3 edge view. 
261

Figure 240: Panel FAS-3 shaded front view.
262

Figure 241: Panel FAS-4 front view. 

Figure 242: Panel FAS-4 edge view. 
263

Figure 243: Panel FAS-4 shaded front view. 
264

Figure 244: Panel FAS-5 front view. 

Figure 245: Panel FAS-5 edge view. 
265

Figure 246: Panel FAS-5 shaded front view. 
266

Figure 247: Panel FAS-5 tear (close-up view). 
267

Figure 248: Panel FAS-6 front view. 

Figure 249: Panel FAS-6 edge view. 
268

Figure 250: Panel FAS-6 shaded front view. 

The visual indications that were recorded consisted of whether or not the various fasteners were visible 

at the outer layer and whether the 0.020” and 0.040” aluminum doublers were visible at the surface. The 

summary from the visual examinations are presented in Table 95. As can be seen in the table, none of the 

combinations investigated completely covered the surface geometry deviations, without some translation 

to the surface. All of the panels did well hiding the flush fasteners. The panels with Soric and metallic 

honeycomb cores did not hide the protruding head fasteners. The polyurethane core had mixed results, 

with the Innegra impact spreading layer showing a slight translation of the fasteners to the surface, but the 

carbon impact spreading layer hiding them. The Polydamp core panel did not translate any of the fastener 

displacements to the surface. 

In order to further characterize these panels, physical measurements were taken for the following 

parameters: (1) panel deformation; (2) panel thickness over the 0.020” thick doubler; and (3) panel 

thickness over the 0.040” thick doubler. The overall panel deformation was measured by placing the 

panels on a flat table with the outer layer face down. The maximum height of the backside of the panel 

was measured along the bottom edge of the panel, and its height and location from the left edge were 

recorded. For characterization and data analysis, the nominal panel thickness was subtracted from the 

recorded value, to arrive at a computed value for the distance between the table and the outer layer of the 

panel. This value was compared across the various panel combinations and is shown in Figure 251. 
269

Table 95 - Visual Examination Results for Aesthetic and Smoothing Panels 

Panel ID: FAS-1 FAS-2 FAS-3 FAS-4 FAS-5 FAS-6

Core Material: 3 mm Soric 

LRC

3 mm Soric 

LRC

1⁄4” 3 pcf

metallic 

honeycomb

1/4" 10 pcf PU 1/4" 10 pcf PU Polydamp 

(1/2")

Impact Spreading Layer: Innegra Carbon ALS Innegra Innegra Carbon ALS Innegra

Lightning Strike Layer LDS 50-01 None LDS 50-01 LDS 50-01 None LDS 50-01

Aesthetic Layer: Integument 

Film

Integument 

Film

Integument 

Film

Integument 

Film

Integument 

Film

Integument 

Film

-4 Protruding Visible Visible Visible Slightly Visible Not Visible Not Visible

-6 Protruding Visible Visible Visible Slightly Visible Not Visible Not Visible

-5 Flush Not Visible Not Visible Not Visible Not Visible Not Visible Not Visible

0.020" Al Doubler Not Visible Visible Visible Slightly Visible Not Visible Visible

0.040" Al Doubler Not Visible Visible Visible Slightly Visible Slightly Visible Visible
270

Imact Absorbing Foam Layer

Impact Spreading Layer

Lightning Strike Material

Aesthetic Film

Polydamp (1/2")

3 mm Soric LRC

1/4" 10# PU

1/4'" 3# metallic honeycomb

InnegraInnegra

Carbon ALS

Innegra

Carbon ALS

Innegra

LDS 50-01LDS 50-01

None

LDS 50-01

None

LDS 50-01 Integument

IntegumentIntegumentIntegumentIntegumentIntegument

0.25

0.20

0.15

0.10

0.05

Maximum Panel Deflection (inches)

Figure 251: Computed maximum panel deformation. 
271

The panel thicknesses over the two doublers were measured with a digital caliper. For reporting 

purposes, the nominal thickness of the panel was subtracted from the recorded value, as was the thickness 

of the particular item at each location. The resulting values were used in the comparisons of the different 

panel configurations as shown in Figure 252 and Figure 253. 

There does not appear to be any strong correlation between panel deformation and impact absorbing 

layer as presented in Figure 251. There does appear to be a trend that shows that carbon fabric impact 

spreading layers may be creating larger deformations than the Innegra impact spreading layers for the 

core types where both spreading layers were used, but the sample size is likely too small to draw any 

definitive conclusions. It is surprising that the panel with the Polydamp impact absorbing layer has as 

much deformation as it does, as previous panels produced with this material showed much less 

deformation, but they were not coupled with the impact spreading layer. 

Similarly, Figure 252 and Figure 253 show the results for the 0.020” and 0.040” aluminum doublers 

respectively. For the most part, the panels show small increases over the doublers, although it is noted 

that no allowance was made mathematically for the paste adhesive bonding thickness used to bond the 

doublers to the base panels. Unlike the previous round of tests, no negative thickness values associated 

were encountered with the Polydamp panels, suggesting that having the impact spreading layer in the 

stack-up has made the thickness measurement more robust. 
272

Imact Absorbing Foam Layer

Impact Spreading Layer

Lightning Strike Material

Aesthetic Film

Polydamp (1/2")

3 mm Soric LRC

1/4" 10# PU

1/4'" 3# metallic honeycomb

InnegraInnegra

Carbon ALS

Innegra

Carbon ALS

Innegra

LDS 50-01LDS 50-01

None

LDS 50-01

None

LDS 50-01 Integument

IntegumentIntegumentIntegumentIntegumentIntegument

0.05

0.04

0.03

0.02

0.01

0.020" Doubler Deformation (inches)

Figure 252: Computed deformation over 0.020” doubler.
273

Imact Absorbing Foam Layer

Impact Spreading Layer

Lightning Strike Material

Aesthetic Film

Polydamp (1/2")

3 mm Soric LRC

1/4" 10# PU

1/4'" 3# metallic honeycomb

InnegraInnegra

Carbon ALS

Innegra

Carbon ALS

Innegra

LDS 50-01LDS 50-01

None

LDS 50-01

None

LDS 50-01 Integument

IntegumentIntegumentIntegumentIntegumentIntegument

0.08

0.07

0.06

0.05

0.04

0.03

0.040" Doubler Deformation (inches)

Figure 253: Computed deformation over 0.040” doubler.
274

8.4.2.2 Acoustic Panels 

The challenge with producing the acoustic panels was getting the Integument film applied in an 

aesthetically pleasing manner. The panels were 48” x 48”. The Integument film was in a roll 24” wide 

by 110’ long. Some kind of seam in the film was necessary. Two types of seams were tried (butt splice 

and overlapping).As will be seen in the pictures that follow, producing a seam that looks good was 

difficult. 

The other problem was covering the entire panel without wrinkles or bubbles. Some of the panels had 

a slight curvature from the manufacturing process. Also, the panels were large. As shown in the pictures, 

wrinkles were a common occurrence while bubbles very occasionally appeared. 

Pictures were taken of the acoustic test panels in direct sunlight. Those pictures are shown in Figure 

254 through Figure 271. 

Figure 254: Panel FAC-1 front view. 
275

Figure 255: Panel FAC-1 close-up view 1. 
276

Figure 256: Panel FAC-1 close-up view 2. 
277

Figure 257: Panel FAC-2 front view. 
278

Figure 258: Panel FAC-2 side view. 
279

Figure 259: Panel FAC-3 front view. 
280

Figure 260: Panel FAC-3 close-up view 1.
281

Figure 261: Panel FAC-3 close-up view 2. 
282

Figure 262: Panel FAC-4 front view.
283

Figure 263: Panel FAC-4 close-up view 1. 
284

Figure 264: Panel FAC-4 close-up view 2. 
285

Figure 265: Panel FAC-5 front view.
286

Figure 266: Panel FAC-5 close-up view 1. 
287

Figure 267: Panel FAC-5 close-up view 2. 
288

Figure 268: Panel FAC-5 close-up view 3. 
289

Figure 269: Panel FAC-6 angled view. 
290

Figure 270: Panel FAC-6 close-up view 1. 
291

Figure 271: Panel FAC-6 close-up view 2. 

The panels fabricated for the acoustic testing were visually examined for outer layer surface anomalies 

prior to being shipped to the acoustic test lab. The results of these examinations are captured in Table 96. 

All of the panels exhibited relatively smooth external surfaces, with the exceptions of a few areas of 

wrinkles that were introduced during the manufacturing process. Bubbles were not as large of an issue as 

they were in previous tests, as the aesthetic layer for all of these panels was supplied with PSA already 

applied from the supplier, which vastly minimized the potential of introducing bubbles in the stack-ups. 

Several of the panels did exhibit localized areas of wrinkles that were introduced during the application 

process. Working with these materials is very much an art, and several panels were able to be made 

without wrinkles, as shown in Table 96 and documented in the photos just presented. One of the panels, 

FAC-6, was produced with a butt splice in the aesthetic film layer, while all of the other panels were 

produced with overlap splices. Visually, the butt splice appears as a dark line at the intersection, whereas 

the overlap splices tend to stand out as a more opaque white stripe along the panel. Not all of the overlap 

splices were due to available film material sizes, as some were created when a significant amount of 

wrinkles were produced in the application, and local areas of the film were removed and new pieces 

spliced in to complete the application. 
292

Table 96 - Visual Examination Results for Acoustic Panels 

Panel ID

Core 

Material

Impact 

Spreading 

Layer

Lightning 

Strike 

Layer

Aesthetic 

Layer Smoothness Bubbles Wrinkles Splices

Other 

Issues

FAC-1

3 mm Soric 

LRC Innegra LDS 50-01

Integument 

Film Overall Good None Yes Overlap None

FAC-2

3 mm Soric 

LRC

Carbon 

ALS None Integument Film Overall Good None None Overlap None

FAC-3

1/4” 3 pcf

metallic 

honeycomb

Innegra LDS 50-

01

Integument 

Film Overall Good None Yes Overlap None

FAC-4

1/4" 10 pcf

PU Innegra LDS 50-01

Integument 

Film Overall Good None None Overlap Crease in core

FAC-5

1/4" 10 pcf

PU

Carbon 

ALS None Integument Film Overall Good None Yes Overlap Tear in surface

FAC-6

Polydamp 

(1/2") Innegra LDS 50-01

Integument 

Film Overall Good Yes, 1 Bubble None Butt

LDS 50-

01 cut 

short
293

From a purely visual perspective, the acoustic panels would not be satisfactory quality for a typical 

business jet application, but might have been acceptable for a commercial transport application. The 

visual aspects of how butt and overlap splices are clearly visible would require some additional 

consideration, but might be able to be overcome by producing a film that is more opaque to start with. 

8.5 Thermal Testing Results 

Thermal analysis testing was performed on the aesthetic and smoothing panels in order to characterize 

how the material stack-ups would perform as thermal insulation. In order to support this testing, the test 

fixture fabricated for first-generation testing was mounted in the door opening of a Blue M convection 

laboratory oven. The test fixture was mounted into the opening through the use of several rare earth 

magnets and was sealed against the internal frames of the oven to prevent air leaks. An opening allowed 

for the panels to be mounted into the fixture through the use of a ring doubler and toggle clamps. A 

surface thermocouple was placed on the back surface of the mounted test panel, and the temperature rise 

over time was recorded. Additional thermocouples were mounted to aluminum plates and placed adjacent 

to the oven and in the oven, so that ambient and oven air temperatures could be recorded respectively. 

The test setup is shown in Figure 272through Figure 274. 
294

Figure 272: Thermal performance test setup – mounting frame.
295

Figure 273: Thermal performance test setup – oven temperature. 
296

Figure 274: Thermal performance test setup – test in progress.
297

Prior to running a test, the oven was pre-heated to 160°F with a cover plate over the fixture opening. 

Once stabilized, a test panel was loaded into the fixture, and the digital data recorder for the 

thermocouples was started. Once the back-side temperatures of the panels stabilized, the recording was 

stopped and the process was repeated with the next panel. Throughout all of the thermal testing of the 

panels, the oven temperature remained within ±5° of the 160°F set point, and the ambient room 

temperature was fairly consistent. 

Figure 275 shows the graphical plot of the data generated from the aesthetic and smoothing series of 

panels. As expected, the primary driver of thermal insulation performance is the impact absorbing layer 

material. Comparison of FAS-1 to FAS-2 and FAS-4 to FAS-5 show a minor secondary effect of the 

impact spreading layer when placed on the same kind of impact absorbing layer, but it is not consistent 

between the two sets of panels. Furthermore, the Soric core-based panels show more disparity between 

themselves as compared to the Polyurethane base cores. This is possibly due to a difference in the 

amount of resin infused into the FAS-1 versus FAS-2 panel and process variation that might be 

encountered with the Soric material versus the Polyurethane core material. 
298

7 0

8 0

9 0

100

110

120

0:00:00 0:07:12 0:14:24 0:21:36 0:28:48

Backside Panel Temperature (°F)

Time (h:mm:ss)

FAS-1

FAS-2

FAS-3

FAS-4

FAS-5

FAS-6

Figure 275: Thermal performance of panels. 
299

Table 97 summarizes maximum temperatures obtained from each of the panels shown in Figure 275. 

In previous tests, an unmodified base substrate showed a maximum temperature of 125.4°F. The best 

performing core was the 1⁄2” Polydamp melamine foam with a maximum temperature of 95.0°F, and the 

worst performing core was the 1⁄4” thick metallic honeycomb based panel which had a temperature of 

118°F. The Soric was second worst, and the Polyurethane core was second best at providing thermal 

insulation.

Table 97 - Summary of Thermal Performance Trends from Aesthetic and Smoothing Panels 

Panel ID Core Type Max. Temp. (°F)

FAS-1 3mm Soric LRC 112.5

FAS-2 3mm Soric LRC 115.2

FAS-3 1⁄4” 3 pcf Aluminum Honeycomb 118.0

FAS-4 10 pcf Polyurethane 104.7

FAS-5 10 pcf Polyurethane 104.0

FAS-6 1⁄2” Polydamp 95.0

8.6 Acoustics 

The six STAR-C2

skin definitions were built into 48” x 48” test panels. The protective skin panels 

were compared to two bare base substrate composite panels and one conventional aluminum 

configuration. Transmission loss of each panel was measured per ASTM E90 and compared. The goal 

was to see if any of the six protective skin concepts were as effective at noise reduction as conventional 

aluminum construction. If so, the STAR-C2

 protective skin would not require any interior insulation, 

resulting in a weight savings compared to conventional configurations of today. 

A second set of tests were conducted with a variation of conventional noise reduction materials using 

one of the protective skins and the aluminum panel. This provided data on how effective each of the 

currently used interior insulating elements for aluminum fuselages is at contributing to transmission loss 

on both a STAR-C2skin and an aluminum skin. 

8.6.1 Test Panel Definition 

The STAR-C2

test panels consisted of two parts: the base substrate panels and the protective skins. 

The aluminum test panel simulated a current technology aluminum aircraft fuselage with conventional 

internal noise protection. All panels were manufactured to 48” x 48” and then cut down to 45” x 47” to 

allow the fiberglass insulation bags to fit exactly. 

8.6.1.1 Base Substrate Panel Definition and Actual Construction 

The base substrate panels were seven layers of carbon fiber material with the inner five layers unidirectional material at differing orientations and the outer layer a plain weave material as shown in Figure 

276. The only planned difference between these panels and the panels for the other testing was size – 

these were 48” x 48” instead of 24” x 24”. 
300

Figure 276: Base substrate panel drawing.
301

Unfortunately there was confusion with a specification and the manufacturing of the base substrate 

panels. The manufacturing specification on the drawing (SX512110) calls out an overlap between 0.5” 

to 2.0” of the material whenever it is necessary to place pieces of the material next to each other. That 

was the correct specification for the materials used to build the base substrate panels for the first round of 

testing (although the material was laid out so that overlaps were not necessary for that round of testing). 

The correct specification (CSAC005) says that butt splicing should be used whenever pieces of the 

material must be placed next to each other. Some panels were made with material overlaps of at least 

0.5” while others were made without those overlaps. 

A picture of the bag side of one of the acoustic panels with overlap was shown in Figure 116. The 

overlaps are clearly visible. The overlaps are also visible in the thermographic image which was shown 

in Figure 117. 

The goal was to have all of the acoustic panels made with overlaps so they would be consistent. 

However, an attempt to get impact panels made without overlaps resulted in acoustic panels also being 

made without overlaps (“no ol” as shown in Table 98). There is a difference of about 0.12 lbs (out of 

5.94 lbs). This is a 2% difference which was not expected to cause a difference in acoustic response. 

However, because the attachment of protective skins to panels with overlap and panels without overlap is 

somewhat random, there was no way to infer a difference based on differences between panels with 

protective skins. Therefore, one bare base substrate panel with overlaps and one without overlaps were 

tested for direct comparison. Testing showed there was no difference. If there had been a difference, a 

delta could have been determined to adjust the other panels for consistency. 

Table 98 - Acoustics Base Substrate Panel Weights 

Test Article 

Number

Base 

Substrate 

Panel 

Number

Bare Substrate Panel 

Weight, lbs

Bare Substrate Panel 

Areal Density, psf

FAC-1 18190 5.94 0.371

FAC-2

18129 (no 

ol) 5.82 0.364

FAC-3

19953 (no 

ol) 5.8 0.363

FAC-4 18193 5.95 0.372

FAC-5 18195 5.94 0.371

FAC-6

18194 (no 

ol) 5.82 0.364

FAC-7

18192 (no 

ol) 5.8 0.363

FAC-8 18191 5.94 0.371

The conventional aluminum fuselage simulation (Panel FAC-9) was a 0.040” sheet of aluminum. The 

areal density of the aluminum is 0.547 psf. 

The fuselage frames and stringers were simulated using wooden pieces glued onto the back of the base 

substrate panel and aluminum panel. Surface preparation of the carbon fiber base substrate panel was 

necessary. The drawing of the frames and stringers arrangement is shown in Figure 277. A picture of a 
302

panel with frames and stringers laid out is shown in Figure 278. A close-up view of the wooden frame is 

shown in Figure 279. The frame is a “C” section to minimize weight, provide some stiffness similar to a 

composite frame, and provide a continuous surface on which to mount the isolators. A close-up view of 

the wooden stringer is shown in Figure 280. Wood was also removed from the center of the stringer to 

minimize weight. The weight concern was driven by minimizing the amount of acoustic energy absorbed 

by the wood. 

Figure 277: Frame/stringer/fuselage representation drawing. 

Figure 278: Frame/stringer arrangement. 
303

Figure 279: Close-up view of frame. 

Figure 280: Close-up view of stringer.

8.6.1.2 Protective Skin Definition 

The six protective skin definitions for the STAR-C2

panels are shown in Table 99. Two of the panels 

used Soric, two used 0.25” 10-lb polyurethane foam, one used 0.25” 3-lb metallic honeycomb, and one 
304

used 0.25” Polydamp Hydrophobic Melamine for the impact absorbing layer. The impact 

spreading/lightning protection layer(s) were either Innegra with LDS 50-01 or Carbon ALS. All panels 

had Integument film as the outer covering. All except the Polydamp were bonded to the base substrate 

panel using 3M 4950 double-sided tape; the Polydamp had a pressure-sensitive adhesive on both sides to 

attach to the base substrate panel and the Innegra. A drawing of the protective skins is shown in Figure 

281. 
305

Table 99 - Protective Skin Definitions 

Panel # Interface Impact Absorbing Layer Interface Impact Spreading Layer Interface Lightning Strike Aesthetic Film

FAC-1 3M 4950 3 mm Soric LRC CSAC006 Type 1 Resin Innegra CSAC006 Type 1 Resin LDS 50-01 Integument Film with PSA

FAC-2 3M 4950 3 mm Soric LRC CSAC006 Type 1 Resin Carbon ALS None None Integument Film with PSA

FAC-3 3M 4950 1/4' 3# metallic honeycomb Grade 30 Adhesive Innegra CSAC006 Type 1 Resin LDS 50-01 Integument Film with PSA

FAC-4 3M 4950 1/4" 10# PU CSAC006 Type 1 Resin Innegra CSAC006 Type 1 Resin LDS 50-01 Integument Film with PSA

FAC-5 3M 4950 1/4" 10# PU CSAC006 Type 1 Resin Carbon ALS None None Integument Film with PSA

FAC-6 None Polydamp (1/2") None Innegra CSAC006 Type 1 Resin LDS 50-01 Integument Film with PSA
306

Figure 281: Protective skins definition drawing.
307

The noise protection scheme for the conventional aluminum fuselage is shown in Figure 282. There 

were no materials on the outside of the aluminum. The frame and stringer simulation was bonded to the 

inside of the aluminum. Between the frames next to the aluminum was ADC-324 damping material. 

Between-frame treatment (on top of the ADC-324) was 2” of 0.6 psf bagged fiberglass. Over-frame 

treatment (on top of the fiberglass) was a 0.25” layer of Nomex with holes to accommodate the isolators. 

Figure 282: Schematic of conventional aluminum baseline panel. 

The test article was closed out with an interior acoustic trim panel which is identical to the panel 

currently used on Cessna Citation jets to close out the space between the side of fuselage and the interior 

of the aircraft. The panel manufactured for this effort was made 48” x 48” and cut down to 45” x 47”. A 

side view of the layers of the panel is shown in Figure 283. The layers shown in the figure are defined in 

Table 100. The notes in Table 100 are shown in Table 101. The trim panel was attached with 4 isolators 

(LORD part number J-7444-14) by quarter turn fasteners. 

Damping 

(ADC-324)

1⁄4” Nomex

2” Thick 

Fiberglass Bag Isolators Interior Trim Panel

Aluminum Outer 

Skin

Frames

Outside

Cabin
308

Figure 283: Interior trim panel ply arrangement. 

Table 100 - Interior Trim Panel Ply Table 
309

Table 101 - Notes Definitions 

The definitions of test panel configurations for comparison of STAR-C2protective skins to 

conventional construction are shown in Table 102. FAC-1 through FAC-6a are the STAR-C2protective 

skins. They only had the interior trim panel as shown in Figure 284. The two panels to compare the 

effects of overlap versus no overlap were FAC-7 and FAC-8. Their test configuration is shown in Figure 

285. They also had the interior trim panel. Results from FAC-7 and FAC-8 were compared to see if the 

overlap and additional base substrate panel mass had any effect on noise reduction. FAC-1 through 

FAC-6a were compared to FAC-9e, the conventional aluminum noise insulation panel. 

In addition to comparing the protective skin panels to a traditional aluminum fuselage arrangement, 

data was collected on how the various noise insulation materials (besides the STAR-C2

protective skins) 

affect the transmission loss. One protective skin was used for comparison. FAC-6 was the preferred 

candidate because the Polydamp Hydrophobic Melamine (impact absorbing layer) is a material currently 

used for interior noise insulation and because the Melamine was the favorite material from the firstgeneration skins. Speculation was that FAC-6 would provide the greatest noise reduction of any of the 

protective skins. The aluminum was also used to do an insulation material buildup. 
310

Table 102 - Test Matrix to Compare STAR-C2 Panels to Conventional Construction 

Figure 284: Protective skin test panel configuration.

Panel # Panel Damping Between Frame Treatment Overframe Treatment Interior Trim Panel

FAC-1 Composite - overlap Protective Skin None None Yes

FAC-2 Composite - no overlap Protective Skin None None Yes

FAC-3 Composite - no overlap Protective Skin None None Yes

FAC-4 Composite - overlap Protective Skin None None Yes

FAC-5 Composite - overlap Protective Skin None None Yes

FAC-6a Composite - no overlap Protective Skin None None Yes

FAC-7 Composite - no overlap Plain None None Yes

FAC-8 Composite - overlap Plain None None Yes

FAC-9e Aluminum ADC-324 2" - 0.6 psf Fiberglass 1/4" Nomex Yes

Protective 

Skin

Interior Trim Panel

Carbon Fiber 

Primary Structure

Isolators

Frames

Outside

Cabin

Panel FAC-1-6
311

Figure 285: Overlap versus no overlap test panel configuration. 

The definition of the panel configurations to conduct the transmission loss material build-ups is shown 

in Table 103. FAC-6a was the baseline STAR-C2panel; it was shown conceptually in Figure 284. 

FAC-6b added the 0.25” Nomex (shown in Figure 286). FAC-6c added the 2” 0.6 lbs/ft2 Fiberglass bag 

as shown in Figure 287. Finally, FAC-6d left the Fiberglass bag while removing the Nomex (see Figure 

288). Configurations FAC-9a through FAC-9f were the same idea using the aluminum skin rather than 

the base substrate panel and protective skins. Configuration 9e was the conventional aluminum noise 

protection construction. Configuration 9f was the same as the baseline conventional aluminum 

construction except the Nomex was replaced with a layer of 1” Fiberglass. FAC-9h replaced the 1” 

Fiberglass with a 1” Fiberglass with Septum (essentially a heavy vinyl inside the Fiberglass bag). In 

addition to the noise reduction provided by each of these configurations, weight of the overall 

configuration was also a critical test result. 

Interior Trim Panel

Carbon Fiber 

Primary Structure

Isolators

Frames

Outside

Cabin

Panel FAC-7 

and FAC-8
312

Table 103 - Transmission Loss Material Build-Up Study Panel Definitions 

Panel # Panel Damping Between Frame Treatment Overframe Treatment Isolated Trim Panel

FAC-6a Composite Protective Skin None None Yes

FAC-6b Composite Protective Skin None 1/4" Nomex Yes

FAC-6c Composite Protective Skin 2" - 0.6 lb/sqrft Fiberglass 1/4" Nomex Yes

FAC-6d Composite Protective Skin 2" - 0.6 lb/sqrft Fiberglass None Yes

FAC-9a Aluminum None None None None

FAC-9b Aluminum None None None Yes

FAC-9c Aluminum ADC-324 None None Yes

FAC-9d Aluminum ADC-324 None 1/4" Nomex Yes

FAC-9e Aluminum ADC-324 2" - 0.6 lb/sqrft Fiberglass 1/4" Nomex Yes

FAC-9f Aluminum ADC-324 2" - 0.6 lb/sqrft Fiberglass None Yes

FAC-9g Aluminum ADC-324 2" - 0.6 lb/sqrft Fiberglass 1" Fiberglass Yes

FAC-9h Aluminum ADC-324 2" - 0.6 lb/sqrft Fiberglass 1" Fiberglass with Septum Yes
313

Figure 286: Panel FAC-6b layout (add over-frame Nomex). 

Figure 287: Panel FAC-6c layout (add between-frame fiberglass).

Protective 

Skin

Interior Trim Panel Isolators

Frames

Outside

Cabin

Carbon Fiber 

Primary Structure

Panel FAC-6b

1⁄4” Nomex

Protective 

Skin

Interior Trim Panel

Carbon Fiber 

Primary Structure

Isolators

Frames

Outside

Cabin

Panel FAC-6c

1⁄4” Nomex

2” Thick 

Fiberglass Bag
314

Figure 288: Panel FAC-6d Layout (Remove over-frame Nomex).

A total of 20 runs with various configurations of fuselage simulations and noise insulation materials 

was identified to cover all of the conditions in Table 102 and Table 103. In order to minimize test time, 

the runs were organized to minimize changes between runs. The testing run table is shown in Table 104. 

Run 13 description was changed to add the trim panel and not add damping to allow a comparison of 

damping performance on an aluminum panel with the trim panel. 

Protective 

Skin

Interior Trim Panel

Carbon Fiber 

Primary Structure

Isolators

Frames

Outside

Cabin

Panel FAC-6d

2” Thick 

Fiberglass Bag
315

Table 104 - Test Sequence 

Run # Panel # Panel Damping

Between Frame 

Treatment Overframe Treatment

Isolated Trim 

Panel Change

1 FAC-6a Composite - no overlap Protective Skin None None Yes

2 FAC-6b Composite - no overlap Protective Skin None 1/4" Nomex Yes Add Nomex

3 FAC-6c Composite - no overlap Protective Skin 2" - 0.6 lb/sqrft Fiberglass 1/4" Nomex Yes Add 2" Fiberglass

4 FAC-6d Composite - no overlap Protective Skin 2" - 0.6 lb/sqrft Fiberglass None Yes Remove Nomex

5 FAC-1 Composite - overlap Protective Skin None None Yes Change Structural Panel

6 FAC-2 Composite - no overlap Protective Skin None None Yes Change Structural Panel

7 FAC-3 Composite - no overlap Protective Skin None None Yes Change Structural Panel

8 FAC-4 Composite - overlap Protective Skin None None Yes Change Structural Panel

9 FAC-5 Composite - overlap Protective Skin None None Yes Change Structural Panel

10 FAC-7 Composite - no overlap Plain None None Yes Change Structural Panel

11 FAC-8 Composite - overlap Plain None None Yes Change Structural Panel

12 FAC-9a Aluminum None None None None Change Structural Panel

13 FAC-9b Aluminum None None None Yes Add Trim Pannel

14 FAC-9c Aluminum ADC-324 None None Yes Add Skin Damping

15 FAC-9d Aluminum ADC-324 None 1/4" Nomex Yes Add Nomex

16 FAC-9e Aluminum ADC-324 2" - 0.6 lb/sqrft Fiberglass 1/4" Nomex Yes Add 2" Fiberglass

17 FAC-9f Aluminum ADC-324 2" - 0.6 lb/sqrft Fiberglass None Yes Remove Nomex

18 FAC-9g Aluminum ADC-324 2" - 0.6 lb/sqrft Fiberglass 1" Fiberglass Yes

Move Panel Isolator Brackets 

and Add 1" Fiberglass

19 FAC-9h Aluminum ADC-324 2" - 0.6 lb/sqrft Fiberglass 1" Fiberglass w ith Septum Yes

Replace 1" fiberglass w ith 1" 

Fiberglass w ith Septum

20 FAC-6a Composite - no overlap Protective Skin None None Yes

Repeat of First Panel For 

Check on Variation
316

8.6.2 Testing 

8.6.2.1 Test Facility 

The ETS-Lindgren Acoustic Research Laboratory located in Cedar Park, Texas was used for this 

testing. Sound transmission loss measurement at ETS-Lindgren is measured in accordance with ASTM 

E90 “Standard Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of 

Building Partitions and Elements” (ref. 20). The test facility is a NVLAP (National Voluntary Laboratory 

Accreditation Program)-accredited laboratory with Scope of Accreditation under Lab Code 100286-0. 

8.6.2.2 Test Setup 

The test specimens were mounted in a test window opening between two reverberation chambers. The 

test window was sized to fit the 47”x45” panels with 1/16” edge margin. A 1⁄4” lip with 1/8” thick foam 

was provided on the source side of the test opening to provide a stop for consistent panel placement in the 

opening to 45-1/8” x 47-1/8”. All edges of the panel on the receiver side of the opening were sealed with 

duct putty. Pictures of the various panels installed from both the source room and the receiver room 

viewpoint are shown in Figure 289 through Figure 300. Each figure title identifies the perspective from 

which the picture was taken. 

Figure 289: FAC-1 installed in test window - source room. 
317

Figure 290: Close-up showing rubber seal - source room. 

Figure 291: FAC-9 installed in test window - source room. 
318

Figure 292: FAC-6 installed in test opening - receiver room. 

Figure 293: Putty sealing panel to test window - receiver room. 
319

Figure 294: Trim panel installed in test window - receiver room. 

Figure 295: Putty sealing trim panel to test window - receiver room. 
320

Figure 296: Between frame Fiberglass installed on panel - receiver room. 

Figure 297: Damping being applied to FAC-9 - receiver room. 
321

Figure 298: Between frame Fiberglass being applied to panel - receiver room. 

Figure 299: Over-frame Nomex being applied to panel - receiver room. 
322

Figure 300: Over-frame Fiberglass being applied to panel - receiver room. 

8.6.2.3 Test Procedures 

Broad band noise was generated on one side of the specimen and then the space/time average of the 

noise was measured in 1/3 octave bands on both sides of the partition. The difference between these 

levels is the noise reduction (NR). In the receiving room, the rate of decay of noise was measured in each 

1/3 octave band. Using these decay rates and the volume of the receiving room, the area of the specimen, 

and the measured NR, the transmission loss (TL) was calculated. 

The ASTM E90 frequency range is from 63 to 5,000 Hertz. However, data was provided from 50 to 

10,000 Hertz with uncertainties and data correction notes shown in Appendix M – Acoustic Test Data 

Uncertainty. The noise was produced using an electronic noise source, filters, an amplifier, and a large 

loudspeaker. The noise levels were measured using a continuously rotating microphone system and an 

analyzer. The decay rates in the receiving room were also measured utilizing the rotating microphone 

system. The test results include the single number ratings of Sound Transmission Class (STC), OutdoorIndoor Transmission Class (OITC), and Airborne Sound Reduction Index (Rw). All of the data was fed 

into a computer which calculates and prints the transmission loss results. 

8.6.2.4 Test Results

8.6.2.4.1 Test Results for All Panels 

TL for all 20 runs is plotted in Figure 301. The outlier is panel FAC-9a which is bare aluminum with 

no noise treatment. The preferred panel from previous tests was FAC-6a. Since the concept aircraft is a 

propeller driven aircraft, airborne noise from propeller tips impinging on the sidewall is expected to be 

the most dominant sound transmission into the cabin. The frequency of airborne noise from the 
323

propellers is blade passage plus harmonics. If the propeller has 8 blades with an rpm of 1165, blade 

passage would be 155 hertz with the first five harmonics at 311, 466, 621, 777 and 932 hertz. This 

frequency range from 150 to 1,000 hertz is important to control cabin transmission loss for a comfortable 

cabin. The TL data quality in this frequency range is good as shown in Appendix M – Acoustic Test Data 

Uncertainty. 

Figure 301: Results from all 20 runs. 

8.6.2.4.2 Panel Transmission Loss Performance 

All protective skin panels were compared to the baseline conventional aluminum panel with 

conventional treatment (FAC-9e) in Figure 302. A higher level of transmission loss indicates less noise 

transmission and a quieter cabin. FAC-6a was the preferred panel from previous test series. However, it 

had significantly lower transmission loss performance in the 150 to 1000 Hertz frequency range when 

compared to the other 5 panels tested as shown in Figure 302. In the key frequency range of 150 to 1000 

Hertz, the top performing panel was FAC-1 with similar performance from FAC-2, FAC-3, FAC-4 and 

FAC-5 as shown in Figure 303. This is not surprising given that FAC-6 has the lowest mass as shown in 

Table 105 and Table 106. Also, subjectively, the stiffness was very low for the FAC-6 protective skin 

when compared to the other protective skins. 

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0

5 06 38 0

100125160200250315400500630800

1000125016002000250031504000500063008000

10000

Transmission Loss - dB

Third Octave Frequency - Hertz

All Panels

FAC-6 a

FAC-6 b

FAC-6 c

FAC-6 d

FAC-1

FAC-2

FAC-3

FAC-4

FAC-5

FAC-7

FAC-8

FAC-9 a

FAC-9 b

FAC-9 c

FAC-9 d

FAC-9 e

FAC-9 f

FAC-9 g

FAC-9 h

FAC-6 a
324

Figure 302: Protective skin panels compared to baseline panel.

Figure 303: Best Protective Skin Panels Compared – Key Frequencies. 

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0

Transmission Loss - dB

Third Octave Frequency - Hertz

FAC-9e

FAC-1

FAC-2

FAC-3

FAC-4

FAC-5

FAC-6a

1 4

1 9

2 4

2 9

3 4

3 9

4 4

125 160 200 250 315 400 500 630 800 1000 1250 Transmission Loss - dB

Third Octave Frequency - Hertz

FAC-1

FAC-2

FAC-3

FAC-4

FAC-5
325

Table 105 - Component Weights 

Component 

Weight 

(lbs)

Areal 

Density (psf) Used in Run Number

FAC-1* 21.0 1.430 5

FAC-2* 19.8 1.348 6

FAC-3* 17.9 1.219 7

FAC-4* 21.5 1.464 8

FAC-5* 20.7 1.409 9

FAC-6* 14.7 1.001 1-4,20

FAC-7* 10.8 0.735 10

FAC-8* 11.2 0.763 11

FAC-9* 14.3 0.974 12-19

Interior Trim Panel 6.5 0.443 All except 12 and 13

ADC 324 Damping 2.8 0.191 13-19

Between Frame Fiberglass 1.9 0.129 3, 4, 16, 17, 18 and 19

Nomex 1.9 0.129 2,3,15,16

Overframe Fiberglass 1.1 0.075 18

Overframe Fiberglass w/Septum 5.2 0.354 19

*Panel, Frames, Stinger & Isolators Only 
326

Table 106 - Total Test Sample Weight and Partition Noise Metrics 

Run Number Panel Number

Tested Weight 

(lb) STC OITC Rw

1 FAC-6a 21.2 27 20 27

2 FAC-6b 23.1 29 21 29

3 FAC-6c 25.0 31 22 33

4 FAC-6d 23.1 31 22 32

5 FAC-1 27.5 31 23 31

6 FAC-2 26.3 31 23 31

7 FAC-3 24.4 30 22 30

8 FAC-4 28.0 31 23 31

9 FAC-5 27.2 31 23 31

10 FAC-7 17.3 24 18 25

11 FAC-8 17.7 24 18 26

12 FAC-9a 14.3 22 18 22

13 FAC-9b 20.8 27 20 28

14 FAC-9c 23.6 30 22 29

15 FAC-9d 25.5 31 23 31

16 FAC-9e 27.4 33 23 34

17 FAC-9f 25.5 33 23 33

18 FAC-9g 26.6 35 23 35

19 FAC-9h 30.8 34 23 34

20 FAC-6a 21.2 27 20 27

Each panel with frames, stingers and isolators was weighed. Also, each treatment package and the 

trim panel were weighed separately; those weights are shown in Table 105. The total sample test weight 

for each run is shown in Table 106 along with Sound Transmission Class (STC), Outdoor-Indoor 

Transmission Class (OITC), and Airborne Sound Reduction Index (Rw). 

A comparison of baseline aluminum (FAC-9b) and composite (FAC-7 & FAC-8) panels with no 

damping and with a trim panel is shown in Figure 304 where it can be seen that undamped aluminum has 

higher TL than the undamped composite panels. An aluminum panel with no damping or trim panel 

(FAC-9a) and a baseline aluminum panel with conventional treatment (FAC-9e) are included for 

reference. The transmission loss is primarily a function of weight – the composite panels FAC-7 and 

FAC-8 have areal densities of 0.363 and 0.371 psf, respectively while the aluminum panel FAC-9 has an 

areal density of 0.549 psf. The frame/stringer simulation contributed an equal 0.42 psf to all panels, and 

the interior trim panel added 0.443 psf. 
327

Figure 304: Undamped aluminum and composite compared. 

STC is based on a noise spectrum targeting speech sounds from 125 to 4000 Hertz. Rw is similar but 

STC is the preferred metric for walls and partitions in the United States. The basic method for both 

measurements and the mathematical calculations behind both standards are similar. However, they 

diverge to a significant degree in the detail and in the numerical results produced. OITC utilizes a source 

noise spectrum that considers frequencies down to 80 Hz (aircraft/rail/truck traffic) and is weighted more 

to lower frequencies. 

Plotting test sample weight vs. STC shows that most points lie very close to the weight vs STC trend 

line as shown in Figure 305. This plot can be used to assess the treatment weight effectiveness. A test 

sample that is above the trend line indicates a better than typical sound reduction per pound. Test samples 

below the trend line indicates a poorer than typical sound reduction per pound. FAC-6d, FAC-9f, and 

FAC-9g all have better than typical sound reduction per pound. FAC-1, FAC-4, FAC-5, and FAC-9h all 

had poorer than typical sound reduction per pound. 

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0 5 06 38 0 100 125 160 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 3150 4000 5000 6300 8000 10000 Transmission Loss - dB

Third Octave Frequency - Hertz

FAC-7

FAC-8

FAC-9a

FAC-9b

FAC-9e
328

Figure 305: Treatment weight effectiveness. 

8.6.2.4.3 Protective Skin Panel Treatment Options 

The expectation was that at least one of the protective skin panels would have transmission loss values 

equal to or greater than the baseline conventional panel. This would provide a weight savings by 

eliminating the need for acoustic treatment. However, this is not the case. The best performing panel 

requires additional treatment in addition to the mass and damping provided by the protective skin in order 

to match the TL of the baseline conventional panel. Additional TL required in the key frequency range 

varies from -3 to +10 dB as shown in Figure 306. Treatments of between-frame Fiberglass (FAC-6d), 

over-frame Nomex (FAC6-b), and between-frame Fiberglass with over-frame Nomex (FAC-6c) were 

applied to FAC-1 numerically by subtracting those treatments’ TL from the untreated panel (FAC-6a) TL 

and adding them to FAC-1 as shown in Figure 307. TL of these treatments on FAC-6 is also shown in 

Figure 308. The result of these comparisons is that FAC-1 requires between-frame Fiberglass to be added 

to perform as well as the baseline panel. Similar results are shown for panels FAC-2, FAC-3, FAC4 and 

FAC-5 in Figure 309. FAC-6 with the heaviest treatment of between frame fiberglass and overframe 

Nomex still has less TL than required to match the baseline panel as shown in Figure 310. Treatment 

options applied to the baseline aluminum panel are shown in Figure 311 for reference. 

2 0

2 2

2 4

2 6

2 8

3 0

3 2

3 4

3 6

10.0 15.0 20.0 25.0 30.0 35.0

STC

Tested Weight

FAC-6 a

FAC-6 b

FAC-6 c

FAC-6 d

FAC-1

FAC-2

FAC-3

FAC-4

FAC-5

FAC-7

FAC-8

FAC-9 a

FAC-9 b

FAC-9 c

FAC-9 d

FAC-9 e

FAC-9 f

FAC-9 g

FAC-9 h
329

Figure 306: Additional transmission loss required from FAC-1.

Figure 307: Best panel with treatment options. 

-4

-2

0

2

4

6

8

1 0

1 2

125 160 200 250 315 400 500 630 800 1000 1250

Transmission Loss - dB

Third Octave Frequency - Hertz

FAC-9e - FAC-1

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0 Transmission Loss - dB

Third Octave Frequency - Hertz

FAC-9e

FAC-1

FAC-1 + Fiberglass

FAC-1 + Nomex 

FAC-1 + Fiberglass and Nomex 
330

Figure 308: Preferred panel FAC-6 with treatment options. 

Figure 309: FAC-1 and FAC-6 with treatment options delta to baseline.

 

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0 Transmission Loss - dB

Third Octave Frequency - Hertz

FAC-6a

FAC-6b

FAC-6c

FAC-6d

FAC-9e

-8

-6

-4

-2

0

2

4

6

125 160 200 250 315 400 500 630 800 1000 1250 Transmission Loss - dB

Third Octave Frequency - Hertz

FAC-6c - FAC-9e

FAC-1 with Fiberglass - FAC-9e
331

Figure 310: Other panels with treatment. 

Figure 311: Baseline aluminum panel with treatment options. 

8.6.2.4.4 Test Result and Test Sample Variation 

The repeatability of the test was evaluated by measuring the transmission loss of FAC-6a at the 

beginning and end of the 20 run test sequence. The test repeatability is very good as shown in Figure 

312. 

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0

Transmission Loss - dB

Third Octave Frequency - Hertz

FAC-9e

FAC-2 + Fiberglass

FAC-3 + Fiberglass

FAC-4 + Fiberglass

FAC-5 + Fiberglass

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0 506380 100 125 160 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 3150 4000 5000 6300 8000 10000 Transmission Loss - dB

Third Octave Frequency - Hertz

FAC-9c

FAC-9d

FAC-9e

FAC-9f

FAC-9g

FAC-9h
332

Figure 312: Repeatability of test method. 

Also, due to different composite panel layup techniques used in manufacturing the base substrate 

panels, FAC-1, FAC-4, and FAC-5 had overlap while the others did not. To determine if this difference 

would affect the transmission loss test results, two additional panels were constructed without protective 

skins. FAC-7 was constructed without overlap and FAC-8 was constructed with overlap. Overlap did not 

significantly affect the results as shown in Figure 313. 

A note was added to the test results for TL at 80 hertz and mostly above 2000 Hertz that states that 

“specimen TL too close to laboratory filler wall”. This is evident especially in the TL data above 2000 

Hertz where all the results are similar. However, this is not the case for the protective skin test panels in 

the key frequency range of 150 to 1000 Hertz as shown in Appendix M. 

0

1 0

2 0

3 0

4 0

5 0

6 0

7 0

Transmission Loss - dB

Third Octave Frequency - Hertz

FAC-6a

FAC-6a
333

Figure 313: Effect of composite overlap.

8.6.3 Acoustics Conclusion 

The test results show that FAC-1 through FAC-5 had similar transmission loss while FAC-6 had 

poorer TL performance in the key frequency range of 150 to 1000 Hertz. None of the protective skin 

panels had sufficient TL without additional treatment when compared to the baseline convention 

aluminum panel. However, five (FAC-1 through FAC-5) of the six protective skin panels all had similar 

TL to the baseline panel with only between-frame Fiberglass added. Of the five protective skin panels 

with similar performance, FAC-1 achieved the highest TL. 

9 Conclusions 

Under an N+3 Phase 2 contract from NASA’s Fundamental Aeronautics Program/Subsonic Fixed 

Wing Project, the Cessna Aircraft Company has conducted a research program to determine the feasibility 

of STAR-C2Protective Skins for Composite Airliners. The STAR-C2concept was conceived to create a 

step change in the weight of composite aircraft structures in the 2035 timeframe. Requirements and 

metrics were defined, a material search was undertaken, a first generation of test articles was designed, 

built and tested, and using the lessons learned from those first-generation test articles, a second generation 

was designed, built and tested.

Based on these results, the STAR-C2concept does appear to be feasible (perhaps sooner than 2035). A 

material combination (Polydamp hydrophobic melamine impact absorbing layer with Innegra impact 

spreading layer) was found which appeared to both meet the main requirements and have an areal density 

less than the target. The impact spreading layer helps to minimize thickness and weight of the protective 

skin but does hurt the aesthetics and smoothing for the Polydamp panel. Innegra did a better job as the 

impact spreading layer than Carbon ALS for both impact depth and aesthetics. The Carbon ALS did 

provide adequate lightning strike protection while eliminating a painful manufacturing step with the 

0

1 0

2 0

3 0

4 0

5 0

6 0

Transmission Loss - dB

Third Octave Frequency - Hertz

FAC-7

FAC-8
334

LDS 50-01. Eliminating paint was a significant factor in reducing the magnitude of the lightning strike 

problem. 

There are at least five items which cast some doubt on the feasibility of the protective skins: 

 There was uncertainty about the source of delamination in the Polydamp hydrophobic melamine 

after two 100 kAmp strikes and one 200 kAmp strike. The panel delamination could have been 

the result of a manufacturing flaw. Because thermographic testing did not occur after each strike, 

there is uncertainty about which strike caused the delamination. The delamination was closest to 

the second Zone 2A strike but the Zone 1A strike was twice as strong. 

 There was a difference in weight and performance depending on the manufacturing process (wet 

layup versus VARTM). VARTM eliminated the difficulty of getting fabrics fully wetted but it 

also made the protective skins heavier and apparently more brittle. 

 Resin which required a high cure temperature caused protective skin warpage. Reducing the cure 

temperature of the selected resin while increasing the cure time helped reduce the warpage but 

may not have given the best mechanical properties. 

 The VHB tape interface caused uncertainty. The tape was heavy but could add some impact 

absorbing capability. The tape was an excellent way to attach the protective skin panels to the 

base substrate panels. Once stuck, they stayed stuck. However, lifetime of the tape in actual 

application is uncertain. 

 There were questions about long-term durability of the protective skins based on experience with 

handling damage. Dents in the protective skin, tears in the aesthetic film, and other “road rash” 

left some doubt about long-term durability. 

The research project also identified some aspects of the protective skins which were not successful: 

 No material combination was found which would hide fasteners, doublers, and wires. Some 

combinations were better than others, but none was perfect. The business jet aesthetics 

requirements may be too stringent for an airliner. 

 Another unsuccessful aspect of the protective skins was acoustics. No special action was taken to 

try to minimize noise reduction through the protective skins. The transmission loss was all about 

weight – where heavier was better. 

 A simple manufacturing solution was not identified. To be successful the protective skins need to 

be easy to make for practical airplane shapes. The aesthetic film needs to be applied with no 

wrinkles or bubbles in a manner that does not interrupt the natural laminar flow facilitated by the 

skins. The seams need to look good and function as a moisture block. Closely associated with 

manufacturing process is the repair process. 

10 Recommendations 

Cessna Aircraft Company has expertise and core competencies in material qualification, purchase, and 

usage. The choices of materials to demonstrate the feasibility of the STAR-C2

concept was based on the 
335

materials more than on the properties of the materials and how they would be combined. The next steps 

need to be down a level at the material chemistry and material combination level. For example, a resin 

with strong mechanical properties resulting from a room temperature cure would be helpful. Room 

temperature cure resins currently exist; the question is their mechanical properties when cured. A resin 

tailoring process for VARTM to make sure the Soric LRC and Innegra are uniformly wetted but not so 

resin infused that they become brittle could be very useful. 

A very useful step (with near-term application in current materials) is the integration of the ALS 

(Aluminum Lightning Strike) system in Innegra. Innegra, like carbon, is a woven fiber. The inclusion of 

the thin aluminum wire should be achievable. Cessna had the opportunity to suggest this to Innegra 

Research and Development personnel. They (and their fabric weaving company) liked the idea and 

thought it was achievable. An added benefit is that there is no adverse chemical reaction between Innegra 

and aluminum like there is between carbon and aluminum. For STAR-C2protective skins, the existence 

of an Innegra ALS system would eliminate a manufacturing step with a very hard-to-handle material. 

The proverbial recommendation which no research project can be without is to reduce weight while 

maintaining mechanical properties. The closer the STAR-C2protective skins to the target (or even below), 

the more likely the fuel and weight savings can be realized. 

The final recommendation is much more global. Aircraft manufacturers are just becoming comfortable 

with certification requirements for traditional composite materials. It took a lot of work to get to this 

point. STAR-C2

protective skins change the paradigm. Research is necessary to demonstrate what the 

requirements must be, what the properties of the protective skins must be, and what means of showing 

compliance may be used to demonstrate that an aircraft with STAR-C2protective skins is safe. This is the 

proverbial chicken and egg problem. Without a path to show compliance, manufacturers will not invest in 

the development of aircraft with protective skins. Without manufacturers with a need to show compliance, 

certification regulations will not be developed. The definition of the next phase of work on STAR-C2

protective skins should include both the development of the skins and the certification requirements. 
336

11 References 

1 D’Angelo, M. M. et al: “N+3 Small Commercial Efficient and Quiet Transportation for Year 2030-2035”, Final 

Report for NASA Contract NNC08CA85C, NASA Contractor Report CR-2010-216691, May 2010. 

2 Federal Aviation Administration: Composite Aircraft Structure. AC 20-107B, September 8, 2009. 

3 Fawcett, Allen J.; and Oakes, Gary D.: Boeing Composite Airframe Damage Tolerance and Service Experience. 

Retrieved from 

http://www.dmpa.upm.es/UserFilesQM/File/2009/Composite%20Damage%20Tolerance%20MaintenanceBoei

ng.pdf

4 Holmes, Bruce J.; Obara, Clifford J.; Martin, Glenn L.; and Domack, Christopher S.: Manufacturing Tolerances 

for Natural Laminar Flow Airframe Surfaces. SAE Paper 850863, April 1985. 

5 Drake, Aaron; Bender, Anne M.; Solomon, William D., Jr.; and Vavra, Andrea J.: Air Vehicles Technology 

Integration Program (AVTIP), Delivery Order 0020: Prediction of Manufacturing Tolerances for Laminar 

Flow. AFRL-VA-WP-TR-2005-3060, June 2005. 

6 RTCA Specification DO-160G, “Environmental Conditions and Test Procedures for Airborne Equipment,” dated 

January 2011. 

7 14CFR Part 25, Airworthiness Standards: Transport Category Airplanes. 

8 Preliminary SE Appearance Spec Oct 19, Cessna Aircraft Company, Draft CPFS007, internal communication 

from David Heinrich, January 25, 2011. 

9 Plastic Material, Pressure Sensitive Adhesive, for Aerospace Identification and Marking. A-A-59485 (superseding 

MIL-P-38477A), August 30, 1973. 

10 Advanced General Aviation Transport Experiments Materials Data. Retrieved from 

http://www.niar.twsu.edu/agate/. 

11 Ganes, Rick: Airplane Cabin Heating, Cooling and Comfort Analysis. Report Number EV-GEN-120, Rev -, 

Cessna Aircraft Company, August 11, 2004. 

12 NASA SP-8105: Spacecraft Thermal Control. National Aeronautics and Space Administration, May 1973.

13 Marentic, Francis J.; and Morris, Terry L.: Drag Reduction Article. U.S. Patent Number 5,133,516, July 28, 

1992.

14 Rupke, Ed: Lightning Direct Effects Handbook. AGATE-WP3.1-031027-043-Design Guideline for Work 

Package Title: WBS3.0 Integrated Design and Manufacturing. Lightning Technologies Inc. March 1, 2002. 

Retrieved from http://www.niar.wichita.edu/agate/Documents/Lightning/WP3.1-031027-043.pdf. 

15 SAE ARP 5412A, “Aircraft Lightning Environment and Related Test Waveforms. SAE International, February 

21, 2005. 

16 SAE ARP 5416, Aircraft Lightning Test Methods. SAE International, March 17, 2003. 

17 Salem, David R.: Unique Microstructural Features of InnegraTM High Modulus Polypropylene Fibers. A report 

to Innegrity LLC. October 2008, ppgs 11-12, retrieved from 

http://www.innegratech.com/file/885113991whitepapersalem.pdf on November 22, 2013. 

18 10 Things You Need to Know About Carbon Fiber & How to Care for It. Motocross Action Magazine. 

Retrieved from http://motocrossactionmag.com/Reviews/News/10-THINGS-YOU-NEED-TO-KNOWABOUT-CARBON-FIBER-HOW-4644.aspx on November 22, 2013. 
337

19 Cverna, Fran (Technical Editor): ASM Ready Reference: Thermal Properties of Metals (#06702G). ASM 

Materials Data Series, 2002. Retrieved from http://www.owlnet.rice.edu/~msci301/ThermalExpansion.pdf on 

November 22, 2013. 

20 Standard Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions 

and Elements, ASTM E90, 7/1/09. 
A-1 

Appendix A - 

Links to Information About Materials Used 
A-2 

Table 1 - Links to Information About Asthetic Materials 

Aesthetic 

Layers Information Links

Integume

nt Film http://integument.com/

3m 5004

http://solutions.3m.com/wps/portal/3M/en_US/Aerospace/Aircraft/Prod_Info/Prod_Catalog/?PC_7_RJ

H9U5230GE3E02LECIE20SOG5_nid=60TTNMF70Rbe90657JDCX3gl

Halar

multiple commercial sources, http://www.welchfluorocarbon.com/techdata.htm, 

http://www.cshyde.com/Films/halarfilm.htm

Aptiv http://www.victrex.com/en/products/aptiv-films/aptiv-films.php

Kapton http://cshyde.thomasnet.com/viewitems/films/kapton-polyimide-film-type-hn?&bc=100|1002

Table 2 - Links to Information about Impact Materials 

Energy Absorbing Information Links

10 pcf PU core, FR-4500 or FR-7100 http://www.generalplastics.com/solutions/product-lines/rigid-foams/

20 pcf PU core, , FR-4500 or FR-7100 http://www.generalplastics.com/solutions/product-lines/rigid-foams/

30 pcf PU core, , FR-4500 or FR-7100 http://www.generalplastics.com/solutions/product-lines/rigid-foams/

4 pcf non-metallic honeycomb core

http://hexcel.com/Resources/DataSheets/Honeycomb-DataSheets/HRH_10_us.pdf

3 pcf metallic honeycomb core

http://hexcel.com/Resources/DataSheets/Honeycomb-DataSheets/CR3_us.pdf

6 pcf metallic honeycomb core

http://hexcel.com/Resources/DataSheets/Honeycomb-DataSheets/CR3_us.pdf

9 pcf metallic honeycomb core

http://hexcel.com/Resources/DataSheets/Honeycomb-DataSheets/CR3_us.pdf

Soric LRC http://lantor.nl/index.php/id_pagina/29359/product-data-sheets.html

Soric XF http://lantor.nl/index.php/id_pagina/29359/product-data-sheets.html

Polydamp with metallized PEEK http://www.polytechinc.com/products/aircrafts.php

Table 3 - Links to Information about Impact Spreading Materials 

Impact Spreading Layer Information Links

Innegra http://www.innegrity.com/innegra-s.php

Tegris http://www.milliken2.com/MFT/MFThtml.nsf/page/home.htm

Aluminum common industry material

Carbon Epoxy common industry material
A-3 

Table 4 - Links to Information about Lightning Strike Materials 

Lightning Strike Protection Information Links

Integument with lightning strike protection http://integument.com/

0.016 psf expanded aluminum foil

several sources, http://www.dexmet.com/Expanded-Metals.html 

or http://www.astrosealproducts.com

0.029 psf expanded copper foil

several sources, http://www.dexmet.com/Expanded-Metals.html 

or http://www.astrosealproducts.com

LDS 40-03(N) 0.0016 psf nickel coated copper http://www.lightningdiversion.com/Products.htm

LDS 50-01 0.007 psf aluminum http://www.lightningdiversion.com/Products.htm

Proprietary spray material N/A
B-1 

Appendix B - 

First-Generation Base Panel Inspection Results 
B-2 

Table B-1 - First-Generation Base Panel Weights and Dimensions (1 of 8) 

0.01 lbs 0.05 in lb/ft^2

Panel 

Number

Bare Panel 

Weight L1 L2 L3 L4 L5 Avg Std Dev W1 W2 W3 W4 W5 Avg Std Dev

Aerial 

Weight

1 1.33 24.20 24.20 24.20 24.20 24.15 24.19 0.0224 24.10 24.10 24.10 24.10 24.10 24.10 0.0000 0.329

2 1.32 24.00 24.00 24.00 24.00 24.00 24.00 0.0000 24.00 24.00 24.00 24.00 24.00 24.00 0.0000 0.330

3 1.32 24.05 24.00 24.00 24.00 24.00 24.01 0.0224 24.15 24.10 24.15 24.15 24.20 24.15 0.0354 0.328

4 1.32 24.10 24.00 24.00 24.00 24.00 24.02 0.0447 24.15 24.15 24.15 24.15 24.20 24.16 0.0224 0.328

5 1.32 24.00 24.00 24.00 24.00 24.05 24.01 0.0224 24.10 24.10 24.10 24.10 24.10 24.10 0.0000 0.328

6 1.32 24.00 24.00 24.00 24.00 24.00 24.00 0.0000 24.10 24.10 24.10 24.10 24.10 24.10 0.0000 0.329

7 1.32 24.05 24.05 24.10 24.10 24.15 24.09 0.0418 24.10 24.10 24.10 24.10 24.10 24.10 0.0000 0.327

8 1.32 24.10 24.10 24.10 24.10 24.10 24.10 0.0000 24.15 24.15 24.15 24.15 24.15 24.15 0.0000 0.327

9 1.32 24.10 24.10 24.10 24.10 24.10 24.10 0.0000 24.00 24.00 24.00 24.00 24.00 24.00 0.0000 0.329

10 1.35 24.25 24.20 24.20 24.20 24.20 24.21 0.0224 24.20 24.20 24.20 24.20 24.15 24.19 0.0224 0.332

11 1.33 24.00 24.00 24.05 24.10 24.10 24.05 0.0500 24.30 24.30 24.30 24.25 24.25 24.28 0.0274 0.328

12 1.30 23.95 23.95 23.95 24.00 24.00 23.97 0.0274 24.00 24.00 24.00 24.05 24.00 24.01 0.0224 0.325

13 1.32 24.10 24.10 24.10 24.15 24.10 24.11 0.0224 24.20 24.20 24.20 24.20 24.20 24.20 0.0000 0.326

14 1.33 24.10 24.10 24.10 24.10 24.05 24.09 0.0224 24.20 24.20 24.20 24.20 24.20 24.20 0.0000 0.329

15 1.32 24.00 24.00 24.00 24.05 24.10 24.03 0.0447 24.15 24.15 24.15 24.20 24.20 24.17 0.0274 0.327

16 1.32 24.05 24.05 24.05 24.10 24.10 24.07 0.0274 24.20 24.20 24.20 24.20 24.20 24.20 0.0000 0.326

17 1.36 24.20 24.20 24.20 24.20 24.10 24.18 0.0447 24.20 24.20 24.25 24.25 24.30 24.24 0.0418 0.334

18 1.34 24.10 24.10 24.10 24.05 24.00 24.07 0.0447 24.25 24.25 24.25 24.30 24.30 24.27 0.0274 0.330

19 1.30 24.05 24.05 24.10 24.10 24.10 24.08 0.0274 24.00 24.00 24.00 24.00 24.00 24.00 0.0000 0.324

20 1.28 23.75 23.75 23.75 23.75 23.80 23.76 0.0224 24.00 23.95 23.00 23.90 23.90 23.75 0.4213 0.327

21 1.30 24.00 24.00 24.00 24.00 24.00 24.00 0.0000 24.05 24.05 24.00 24.00 24.00 24.02 0.0274 0.325

22 1.34 24.20 24.20 24.25 24.25 24.25 24.23 0.0274 24.20 24.20 24.20 24.20 24.20 24.20 0.0000 0.329

23 1.32 24.20 24.15 24.15 24.20 24.20 24.18 0.0274 24.20 24.20 24.20 24.20 24.20 24.20 0.0000 0.325

24 1.34 24.10 24.15 24.20 24.20 24.15 24.16 0.0418 24.15 24.15 24.15 24.20 24.20 24.17 0.0274 0.330

25 1.32 24.10 24.10 24.10 24.10 24.10 24.10 0.0000 24.15 24.15 24.15 24.15 24.15 24.15 0.0000 0.327
B-3 

Table B-1 - First-Generation Base Panel Weights and Dimensions (2 of 8) 

0.01 lbs 0.05 in lb/ft^2

Panel 

Number

Bare Panel 

Weight L1 L2 L3 L4 L5 Avg

Std 

Dev W1 W2 W3 W4 W5 Avg

Std 

Dev

Aerial 

Weight

26 1.34 24.15 24.15 24.15 24.10 24.10 24.13 0.0274 24.15 24.15 24.15 24.10 24.10 24.13 0.0274 0.331

27 1.33 24.20 24.20 24.20 24.20 24.20 24.20 0.0000 24.00 24.00 24.05 24.00 24.00 24.01 0.0224 0.330

28 1.32 24.00 24.00 24.05 24.05 24.05 24.03 0.0274 24.25 24.25 24.30 24.20 24.15 24.23 0.0570 0.326

29 24.00 24.05 24.10 24.10 24.00 24.05 0.0500 23.95 23.95 23.95 23.90 23.90 23.93 0.0274

30 1.32 24.10 24.10 24.10 24.10 24.15 24.11 0.0224 24.15 24.15 24.15 24.15 24.20 24.16 0.0224 0.326

31 1.32 24.10 24.10 24.10 24.10 24.15 24.11 0.0224 24.10 24.10 24.10 24.10 24.15 24.11 0.0224 0.327

32 1.34 24.15 24.15 24.10 24.10 24.10 24.12 0.0274 24.20 24.20 24.20 24.20 24.20 24.20 0.0000 0.331

33 1.32 24.10 24.10 24.10 24.00 24.00 24.06 0.0548 24.01 24.00 24.00 24.00 24.00 24.00 0.0022 0.329

34 1.33 24.10 24.10 24.10 24.10 24.20 24.12 0.0447 24.05 24.05 24.05 24.00 24.00 24.03 0.0274 0.330

35 1.33 24.20 24.20 24.20 24.20 24.25 24.21 0.0224 24.05 24.05 24.05 24.05 24.05 24.05 0.0000 0.329

36 1.30 24.10 24.10 24.05 24.00 24.00 24.05 0.0500 24.00 24.00 24.00 24.00 24.00 24.00 0.0000 0.324

37 1.30 24.00 24.00 24.05 24.05 24.05 24.03 0.0274 24.05 24.05 24.05 24.05 24.05 24.05 0.0000 0.324

38 1.32 24.00 24.00 24.00 24.00 23.95 23.99 0.0224 24.20 24.20 24.20 24.20 24.20 24.20 0.0000 0.327

39 1.32 24.10 24.10 24.10 24.10 24.10 24.10 0.0000 24.15 24.15 24.15 24.20 24.20 24.17 0.0274 0.326

40 1.34 24.15 24.15 24.15 24.15 24.20 24.16 0.0224 24.10 24.10 24.10 24.10 24.10 24.10 0.0000 0.331

41 1.33 24.20 24.15 24.15 24.15 24.20 24.17 0.0274 24.10 24.10 24.05 24.00 24.00 24.05 0.0500 0.329

42 1.34 24.20 24.20 24.25 24.20 24.20 24.21 0.0224 24.15 24.15 24.20 24.20 24.20 24.18 0.0274 0.330

43 1.34 24.20 24.20 24.20 24.15 24.20 24.19 0.0224 24.20 24.15 24.10 24.10 24.10 24.13 0.0447 0.331

44 1.30 24.15 24.15 24.10 24.10 24.15 24.13 0.0274 24.10 24.00 24.00 24.00 24.00 24.02 0.0447 0.323

45 23.95 23.90 24.00 24.00 24.05 23.98 0.0570 24.20 24.20 24.20 24.20 24.20 24.20 0.0000

46 1.32 24.10 24.10 24.10 24.10 24.10 24.10 0.0000 24.20 24.15 24.15 24.15 24.20 24.17 0.0274 0.326

47 1.32 24.10 24.05 24.05 24.05 24.00 24.05 0.0354 24.15 24.15 24.15 24.10 24.15 24.14 0.0224 0.327

48 1.32 24.10 24.10 24.10 24.10 24.15 24.11 0.0224 24.10 24.10 24.10 24.10 24.10 24.10 0.0000 0.327

49 1.36 24.25 24.25 24.25 24.25 24.20 24.24 0.0224 24.30 24.30 24.30 24.30 24.25 24.29 0.0224 0.333

50 1.34 24.15 24.15 24.10 24.05 24.05 24.10 0.0500 24.20 24.20 24.20 24.20 24.20 24.20 0.0000 0.331
B-4 

Table B-1 - First-Generation Base Panel Weights and Dimensions (3 of 8)

0.01 lbs 0.05 in lb/ft^2

Panel 

Number

Bare Panel 

Weight L1 L2 L3 L4 L5 Avg

Std 

Dev W1 W2 W3 W4 W5 Avg

Std 

Dev

Aerial 

Weight

51 23.95 23.95 23.90 23.90 23.90 23.92 0.03 24.05 24.05 24.05 24.10 24.10 24.07 0.03

52 1.34 24.20 24.20 24.20 24.20 24.20 24.20 0.00 24.15 24.15 24.15 24.15 24.15 24.15 0.00 0.330

53 1.34 24.20 24.20 24.20 24.15 24.10 24.17 0.04 24.15 24.15 24.15 24.15 24.15 24.15 0.00 0.331

54 1.33 24.10 24.10 24.00 24.00 24.00 24.04 0.05 24.10 24.05 24.10 24.00 24.00 24.05 0.05 0.331

55 1.30 24.00 24.05 24.05 24.05 24.10 24.05 0.04 23.90 23.95 24.00 23.95 24.00 23.96 0.04 0.325

56 1.32 24.00 24.05 24.05 24.00 24.00 24.02 0.03 24.15 24.10 24.10 24.15 24.15 24.13 0.03 0.328

57 1.32 24.20 24.15 24.15 24.10 24.10 24.14 0.04 24.00 24.00 24.00 24.00 24.00 24.00 0.00 0.328

58 1.34 24.10 24.10 24.10 24.10 24.10 24.10 0.00 24.20 24.20 24.20 24.20 24.20 24.20 0.00 0.331

59 1.34 24.05 24.05 24.05 24.05 24.05 24.05 0.00 24.00 24.05 24.05 24.00 24.00 24.02 0.03 0.334

60 1.34 24.20 24.20 24.20 24.20 24.20 24.20 0.00 24.10 24.10 24.15 24.10 24.10 24.11 0.02 0.331

61 1.34 24.20 24.15 24.15 24.15 24.15 24.16 0.02 24.20 24.20 24.20 24.20 24.20 24.20 0.00 0.330

62 1.32 24.10 24.05 24.1 24.10 24.10 24.09 0.02 24.10 24.10 24.05 24.00 24.05 24.06 0.04 0.328

63 1.34 24.10 24.15 24.15 24.15 24.15 24.14 0.02 24.15 24.15 24.15 24.15 24.20 24.16 0.02 0.331

64 1.32 24.20 24.15 24.15 24.15 24.15 24.16 0.02 24.00 24.05 24.00 24.05 24.05 24.03 0.03 0.327

65 1.34 24.15 24.20 24.15 24.15 24.15 24.16 0.02 24.20 24.20 24.20 24.20 24.20 24.20 0.00 0.330

66 1.32 24.10 24.10 24.1 24.05 24.05 24.08 0.03 24.00 24.00 24.05 24.05 24.00 24.02 0.03 0.329

67 1.32 24.20 24.20 24.2 24.20 24.15 24.19 0.02 24.00 24.00 24.00 24.00 24.00 24.00 0.00 0.327

68 1.32 24.15 24.10 24.1 24.05 24.00 24.08 0.06 24.10 24.10 24.10 24.10 24.10 24.10 0.00 0.328

69 1.33 24.10 24.10 24.1 24.15 24.20 24.13 0.04 24.20 24.20 24.20 24.20 24.25 24.21 0.02 0.328

70 1.32 24.00 24.10 24.1 24.10 24.10 24.08 0.04 24.10 24.10 24.10 24.10 24.10 24.10 0.00 0.328

71 1.34 24.20 24.10 24.20 24.10 24.10 24.14 0.05 24.20 24.15 24.20 24.20 24.20 24.19 0.02 0.330

72 1.32 24.10 24.10 24.10 24.10 24.10 24.10 0.00 24.20 24.15 24.15 24.15 24.15 24.16 0.02 0.326

73 1.30 24.10 24.10 24.10 24.10 24.10 24.10 0.00 24.10 24.05 24.00 24.00 24.00 24.03 0.04 0.323

74 1.32 24.20 24.15 24.10 24.10 24.15 24.14 0.04 24.20 24.20 24.20 24.20 24.20 24.20 0.00 0.325

75 24.20 24.20 24.15 24.15 24.15 24.17 0.03 23.90 23.95 24.00 24.00 23.95 23.96 0.04
B-5 

Table B-1 - First-Generation Base Panel Weights and Dimensions (4 of 8)

0.01 lbs 0.05 in lb/ft^2

Panel 

Number

Bare Panel 

Weight L1 L2 L3 L4 L5 Avg

Std 

Dev W1 W2 W3 W4 W5 Avg

Std 

Dev

Aerial 

Weight

76 1.30 24.15 24.10 24.10 24.10 24.10 24.11 0.02 23.95 24.00 24.00 24.00 24.00 23.99 0.02 0.324

77 1.32 24.10 24.10 24.10 24.10 24.10 24.10 0.00 24.00 24.00 24.00 24.00 24.05 24.01 0.02 0.328

78 1.30 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.20 24.15 24.10 24.10 24.10 24.13 0.04 0.323

79 1.34 24.10 24.20 24.20 24.20 24.20 24.18 0.04 24.10 24.10 24.10 24.10 24.10 24.10 0.00 0.331

80 1.34 24.10 24.10 24.15 24.15 24.10 24.12 0.03 24.30 24.25 24.30 24.25 24.25 24.27 0.03 0.330

81 1.32 24.10 24.10 24.10 24.10 24.10 24.10 0.00 24.10 24.05 24.05 24.05 24.00 24.05 0.04 0.328

82 1.34 24.20 24.20 24.20 24.20 24.20 24.20 0.00 24.20 24.20 24.20 24.20 24.20 24.20 0.00 0.329

83 1.34 24.20 24.15 24.15 24.15 24.15 24.16 0.02 24.15 24.15 24.15 24.20 24.20 24.17 0.03 0.330

84 1.34 24.20 24.20 24.20 24.20 24.20 24.20 0.00 24.10 24.10 24.10 24.10 24.10 24.10 0.00 0.331

85 1.32 24.05 24.10 24.10 24.10 24.15 24.10 0.04 24.00 24.00 24.00 24.05 24.00 24.01 0.02 0.328

86 1.32 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.10 24.00 24.05 24.05 24.00 24.04 0.04 0.329

87 1.32 24.20 24.15 24.20 24.10 24.10 24.15 0.05 24.00 24.00 24.00 24.00 24.05 24.01 0.02 0.328

88 24.00 23.95 24.00 24.00 24.00 23.99 0.02 24.00 23.95 23.95 23.95 24.00 23.97 0.03

89 1.34 24.05 24.00 24.00 24.00 24.05 24.02 0.03 24.20 24.15 24.15 24.10 24.20 24.16 0.04 0.333

90 1.34 24.25 24.25 24.20 24.20 24.20 24.22 0.03 24.25 24.25 24.25 24.20 24.25 24.24 0.02 0.329

91 1.32 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.00 24.00 24.05 24.01 0.02 0.330

92 1.34 24.25 24.25 24.20 24.20 24.25 24.23 0.03 24.00 24.00 24.00 24.10 24.10 24.04 0.05 0.331

93 1.34 24.10 24.10 24.05 24.00 24.05 24.06 0.04 24.20 24.15 24.15 24.10 24.10 24.14 0.04 0.332

94 1.34 24.20 24.20 24.20 24.20 24.20 24.20 0.00 24.05 24.05 24.05 24.05 24.05 24.05 0.00 0.332

95 1.32 24.20 24.20 24.20 24.20 24.20 24.20 0.00 24.00 23.95 23.95 24.00 24.00 23.98 0.03 0.328

96 1.34 24.10 24.15 24.15 24.15 24.20 24.15 0.04 24.20 24.20 24.20 24.15 24.20 24.19 0.02 0.330

97 1.32 24.25 24.20 24.20 24.20 24.10 24.19 0.05 24.00 24.10 24.10 24.05 24.05 24.06 0.04 0.327

98 1.32 24.21 24.10 24.15 24.10 24.10 24.13 0.05 24.15 24.15 24.15 24.10 24.15 24.14 0.02 0.326

99 1.31 24.10 24.10 24.15 24.10 24.10 24.11 0.02 24.00 24.00 24.00 24.00 24.00 24.00 0.00 0.326

100 1.30 24.00 24.00 24.05 24.05 24.05 24.03 0.03 24.10 24.15 24.15 24.15 24.15 24.14 0.02 0.323
B-6 

Table B-1 - First-Generation Base Panel Weights and Dimensions (5 of 8)

0.01 lbs 0.05 in lb/ft^2

Panel 

Number

Bare Panel 

Weight L1 L2 L3 L4 L5 Avg

Std 

Dev W1 W2 W3 W4 W5 Avg

Std 

Dev

Aerial 

Weight

101 1.34 24.25 24.20 24.20 24.20 24.20 24.21 0.02 24.25 24.25 24.25 24.20 24.20 24.23 0.03 0.329

102 24.00 24.00 24.00 24.00 23.95 23.99 0.02 23.90 23.90 23.90 23.90 23.85 23.89 0.02

103 1.34 24.20 24.20 24.25 24.25 24.25 24.23 0.03 24.25 24.25 24.25 24.20 24.20 24.23 0.03 0.329

104 1.34 24.20 24.20 24.20 24.20 24.20 24.20 0.00 24.15 24.15 24.15 24.10 24.10 24.13 0.03 0.330

105 1.34 24.15 24.15 24.20 24.20 24.15 24.17 0.03 24.05 24.05 24.05 24.05 24.05 24.05 0.00 0.332

106 1.32 24.15 24.15 24.20 24.15 24.15 24.16 0.02 24.10 24.10 24.10 24.10 24.10 24.10 0.00 0.326

107 1.34 24.20 24.20 24.20 24.20 24.20 24.20 0.00 24.10 24.15 24.15 24.15 24.10 24.13 0.03 0.330

108 1.32 24.10 24.15 24.15 24.15 24.20 24.15 0.04 23.95 23.95 23.95 23.95 23.95 23.95 0.00 0.329

109 1.34 24.20 24.20 24.20 24.20 24.20 24.20 0.00 24.00 24.00 24.00 24.05 24.00 24.01 0.02 0.332

110 1.32 24.15 24.15 24.15 24.10 24.10 24.13 0.03 24.20 24.20 24.20 24.15 24.10 24.17 0.04 0.326

111 1.32 24.10 24.10 24.10 24.10 24.10 24.10 0.00 24.20 24.20 24.20 24.20 24.20 24.20 0.00 0.326

112 1.34 24.15 24.15 24.20 24.20 24.20 24.18 0.03 24.20 24.20 24.20 24.20 24.20 24.20 0.00 0.330

113 1.28 23.90 23.90 23.85 23.85 23.80 23.86 0.04 23.80 23.80 23.80 23.80 23.80 23.80 0.00 0.325

114 1.30 23.90 23.95 24.00 24.00 24.00 23.97 0.04 23.95 24.00 24.00 24.00 24.10 24.01 0.05 0.325

115 1.32 24.20 24.20 24.20 24.15 24.15 24.18 0.03 24.00 24.00 24.00 24.00 24.00 24.00 0.00 0.328

116 1.32 24.10 24.10 24.10 24.10 24.10 24.10 0.00 24.00 24.00 23.95 23.95 23.95 23.97 0.03 0.329

117 1.32 24.10 24.15 24.15 24.15 24.15 24.14 0.02 23.90 23.95 23.95 23.95 23.95 23.94 0.02 0.329

118 1.32 24.10 24.10 24.10 24.05 24.05 24.08 0.03 24.00 24.00 24.00 24.00 24.00 24.00 0.00 0.329

119 1.32 24.10 24.10 24.05 24.00 24.05 24.06 0.04 24.15 24.15 24.15 24.15 24.15 24.15 0.00 0.327

120 1.32 24.05 24.10 24.10 24.05 24.00 24.06 0.04 24.15 24.20 24.20 24.20 24.20 24.19 0.02 0.327

121 1.32 24.10 24.15 24.15 24.15 24.15 24.14 0.02 24.00 24.00 24.00 24.00 24.00 24.00 0.00 0.328

122 1.34 24.10 24.15 24.20 24.20 24.20 24.17 0.04 24.20 24.20 24.15 24.15 24.15 24.17 0.03 0.330

123 1.35 24.20 24.25 24.20 24.20 24.20 24.21 0.02 24.25 24.25 24.25 24.25 24.30 24.26 0.02 0.331

124 1.34 24.20 24.20 24.15 24.10 24.05 24.14 0.07 24.10 24.10 24.10 24.10 24.10 24.10 0.00 0.332

125 1.34 24.15 24.20 24.20 24.15 24.10 24.16 0.04 24.20 24.20 24.20 24.20 24.20 24.20 0.00 0.330
B-7 

Table B-1 - First-Generation Base Panel Weights and Dimensions (6 of 8)

0.01 lbs 0.05 in lb/ft^2

Panel 

Number

Bare Panel 

Weight L1 L2 L3 L4 L5 Avg

Std 

Dev W1 W2 W3 W4 W5 Avg

Std 

Dev

Aerial 

Weight

126 1.32 24.10 24.10 24.15 24.10 24.10 24.11 0.02 24.10 24.10 24.10 24.05 24.05 24.08 0.03 0.327

127 1.34 24.15 24.15 24.15 24.15 24.15 24.15 0.00 24.20 24.20 24.20 24.20 24.20 24.20 0.00 0.330

128 1.32 24.20 24.20 24.20 24.20 24.20 24.20 0.00 24.10 24.10 24.10 24.10 24.10 24.10 0.00 0.326

129 1.32 24.15 24.20 24.20 24.15 24.15 24.17 0.03 24.15 24.15 24.20 24.15 24.15 24.16 0.02 0.326

130 1.32 24.15 24.15 24.15 24.15 24.15 24.15 0.00 23.95 24.00 24.05 24.00 24.10 24.02 0.06 0.328

131 1.32 24.15 24.15 24.15 24.10 24.10 24.13 0.03 24.10 24.10 24.10 24.05 24.05 24.08 0.03 0.327

132 1.30 24.10 24.10 24.10 24.10 24.10 24.10 0.00 24.00 24.00 24.05 24.00 24.05 24.02 0.03 0.323

133 1.30 24.15 24.15 24.15 24.15 24.15 24.15 0.00 24.00 24.00 24.05 24.00 24.00 24.01 0.02 0.323

134 1.34 24.15 24.15 24.15 24.15 24.10 24.14 0.02 24.05 24.05 24.10 24.10 24.10 24.08 0.03 0.332

135 1.34 24.15 24.15 24.20 24.15 24.15 24.16 0.02 24.10 24.10 24.10 24.10 24.10 24.10 0.00 0.331

136 1.32 24.15 24.20 24.20 24.15 24.15 24.17 0.03 23.90 23.90 23.90 23.90 23.85 23.89 0.02 0.329

137 1.32 24.15 24.15 24.15 24.15 24.15 24.15 0.00 23.95 23.90 23.90 23.90 24.05 23.94 0.07 0.329

138 1.34 24.20 24.20 24.15 24.10 24.10 24.15 0.05 24.15 24.15 24.20 24.10 23.95 24.11 0.10 0.331

139 1.32 24.05 24.05 24.10 24.10 24.15 24.09 0.04 24.05 24.05 24.00 24.00 24.05 24.03 0.03 0.328

140 1.33 24.00 24.10 24.15 24.15 24.15 24.11 0.07 24.15 24.15 24.15 24.20 24.20 24.17 0.03 0.329

141 1.32 24.05 24.20 24.20 24.20 24.20 24.17 0.07 24.20 24.20 24.20 24.20 24.20 24.20 0.00 0.325

142 1.30 24.15 24.15 24.15 24.10 24.15 24.14 0.02 24.00 24.00 24.00 23.95 23.90 23.97 0.04 0.324

143 1.32 24.00 24.00 24.00 24.00 24.05 24.01 0.02 24.10 24.10 24.10 24.10 24.10 24.10 0.00 0.328

144 1.34 24.10 24.05 24.05 24.05 24.10 24.07 0.03 24.25 24.20 24.20 24.20 24.20 24.21 0.02 0.331

145 1.34 24.10 24.10 24.10 24.05 24.10 24.09 0.02 24.25 24.20 24.25 24.20 24.20 24.22 0.03 0.331

146 1.30 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.00 24.00 24.05 24.00 24.00 24.01 0.02 0.325

147 1.30 24.00 24.00 24.05 24.05 24.05 24.03 0.03 24.05 24.05 24.10 24.10 24.00 24.06 0.04 0.324

148 1.34 24.20 24.20 24.20 24.15 24.15 24.18 0.03 24.20 24.20 24.25 24.25 24.25 24.23 0.03 0.329

149 1.32 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.20 24.25 24.25 24.20 24.20 24.22 0.03 0.327

150 1.34 24.15 24.15 24.15 24.15 24.15 24.15 0.00 24.20 24.15 24.15 24.15 24.15 24.16 0.02 0.331
B-8 

Table B-1 - First-Generation Base Panel Weights and Dimensions (7 of 8)

0.01 lbs 0.05 in lb/ft^2

Panel 

Number

Bare Panel 

Weight L1 L2 L3 L4 L5 Avg

Std 

Dev W1 W2 W3 W4 W5 Avg

Std 

Dev

Aerial 

Weight

151 1.32 24.05 24.00 24.00 23.90 23.80 23.95 0.10 24.20 24.15 24.15 24.10 24.05 24.13 0.06 0.329

152 1.34 24.20 24.20 24.15 24.15 24.10 24.16 0.04 24.20 24.20 24.20 24.20 24.15 24.19 0.02 0.330

153 1.32 23.80 23.80 23.80 23.80 23.80 23.80 0.00 24.20 24.20 24.20 24.10 24.00 24.14 0.09 0.331

154 1.32 24.10 24.10 24.10 24.00 23.95 24.05 0.07 24.20 24.20 24.20 24.20 24.20 24.20 0.00 0.327

155 1.34 24.20 24.20 24.20 24.20 24.05 24.17 0.07 24.20 24.20 24.20 24.20 24.20 24.20 0.00 0.330

156 1.34 24.15 24.15 24.10 24.10 24.00 24.10 0.06 24.15 24.15 24.10 24.10 24.10 24.12 0.03 0.332

157 1.36 24.15 24.20 24.20 24.15 24.15 24.17 0.03 24.20 24.20 24.20 24.20 24.20 24.20 0.00 0.335

158 1.33 24.00 24.05 24.05 24.10 24.10 24.06 0.04 24.10 24.15 24.20 24.15 24.10 24.14 0.04 0.330

159 1.34 24.15 24.10 24.10 24.10 24.15 24.12 0.03 24.20 24.15 24.10 24.10 24.15 24.14 0.04 0.331

160 1.34 24.10 24.20 24.20 24.20 24.15 24.17 0.04 24.00 24.00 24.00 24.00 24.05 24.01 0.02 0.333

161 1.36 24.20 24.20 24.20 24.20 24.20 24.20 0.00 24.20 24.20 24.20 24.20 24.20 24.20 0.00 0.334

162 1.34 23.80 23.80 23.80 23.75 23.75 23.78 0.03 24.10 24.15 24.20 24.20 24.25 24.18 0.06 0.336

163 1.36 24.20 24.20 24.20 24.20 24.20 24.20 0.00 24.20 24.20 24.20 24.20 24.20 24.20 0.00 0.334

164 1.34 24.00 24.10 24.15 24.15 24.20 24.12 0.08 24.20 24.25 24.20 24.20 24.20 24.21 0.02 0.330

165 1.34 24.20 24.20 24.20 24.15 24.15 24.18 0.03 24.20 24.20 24.20 24.20 24.20 24.20 0.00 0.330

166 1.34 24.20 24.20 24.20 24.15 24.10 24.17 0.04 24.15 24.15 24.15 24.15 24.10 24.14 0.02 0.331

167 1.34 24.20 24.20 24.20 24.20 24.20 24.20 0.00 24.15 24.15 24.10 24.10 24.05 24.11 0.04 0.331

168 1.36 24.20 24.20 24.20 24.20 24.15 24.19 0.02 24.20 24.20 24.20 24.20 24.20 24.20 0.00 0.335

169 1.36 24.10 24.10 24.15 24.15 24.20 24.14 0.04 24.00 24.10 24.10 24.00 23.80 24.00 0.12 0.338

170 1.35 24.15 24.20 24.15 24.15 24.15 24.16 0.02 24.15 24.20 24.20 24.20 24.20 24.19 0.02 0.333

171 1.34 24.20 24.20 24.20 24.20 24.20 24.20 0.00 24.20 24.20 24.20 24.20 24.20 24.20 0.00 0.329

172 1.36 24.10 24.15 24.15 24.15 24.10 24.13 0.03 24.20 24.20 24.20 24.20 24.20 24.20 0.00 0.335

173 1.34 24.15 24.20 24.20 24.25 24.20 24.20 0.04 23.90 23.95 24.00 23.95 23.90 23.94 0.04 0.333

174 1.34 24.10 24.15 24.15 24.20 24.20 24.16 0.04 24.20 24.20 24.20 24.20 24.20 24.20 0.00 0.330

175 1.34 24.20 24.20 24.20 24.20 24.20 24.20 0.00 24.00 24.05 24.05 24.00 23.95 24.01 0.04 0.332
B-9 

Table B-1 - First-Generation Base Panel Weights and Dimensions (8 of 8) 

0.01 lbs 0.05 in lb/ft^2

Panel 

Number

Bare Panel 

Weight L1 L2 L3 L4 L5 Avg

Std 

Dev W1 W2 W3 W4 W5 Avg

Std 

Dev

Aerial 

Weight

176 1.32 24.00 24.00 24.00 24.00 24.00 24.00 0.00 24.15 24.15 24.15 24.15 24.20 24.16 0.02 0.328

177 1.32 24.10 24.10 24.10 24.10 24.10 24.10 0.00 24.00 24.05 24.10 24.10 24.05 24.06 0.04 0.328

178 1.31 23.95 23.95 23.95 23.95 24.00 23.96 0.02 24.00 24.05 24.10 24.05 24.00 24.04 0.04 0.328

179 1.32 23.90 23.90 23.90 23.95 23.95 23.92 0.03 24.10 24.10 24.10 24.15 24.10 24.11 0.02 0.330

180 1.32 24.10 24.10 24.05 24.05 24.00 24.06 0.04 23.90 23.90 23.95 23.95 23.90 23.92 0.03 0.330

181 1.34 24.10 24.10 24.10 24.15 24.15 24.12 0.03 24.00 24.05 24.05 24.05 24.05 24.04 0.02 0.333

182 1.32 23.95 24.00 24.00 24.00 24.00 23.99 0.02 24.10 24.10 24.10 24.10 24.10 24.10 0.00 0.329

183 1.30 24.05 24.05 24.05 24.00 24.00 24.03 0.03 24.00 24.00 24.05 24.05 24.05 24.03 0.03 0.324

184 1.30 23.90 23.95 23.95 24.00 23.95 23.95 0.04 23.95 23.95 24.00 24.05 24.05 24.00 0.05 0.326

185 1.30 24.00 24.00 24.00 24.05 24.10 24.03 0.04 24.00 24.00 24.00 24.00 24.00 24.00 0.00 0.325

186 1.32 24.05 24.00 24.00 24.00 24.00 24.01 0.02 24.05 24.05 24.00 24.05 24.05 24.04 0.02 0.329

187 1.30 23.90 23.90 23.90 23.85 23.85 23.88 0.03 23.90 23.90 23.95 24.00 24.00 23.95 0.05 0.327

188 1.31 23.90 23.90 23.95 23.95 23.90 23.92 0.03 24.05 24.05 24.10 24.05 24.00 24.05 0.04 0.328

189 1.30 23.90 23.90 23.90 23.95 23.95 23.92 0.03 24.05 24.05 24.05 24.05 24.05 24.05 0.00 0.325

190 1.31 24.05 24.05 24.10 24.00 24.05 24.05 0.04 24.00 23.95 23.95 23.95 23.95 23.96 0.02 0.327

191 1.32 24.05 24.05 24.05 24.05 24.00 24.04 0.02 24.00 24.10 24.10 24.10 24.10 24.08 0.04 0.328
C-1 

Appendix C - 

First-Generation Thermography Report 
C-2 

REPORT TITLE: NDI of NASA STAR-C

2 Test Article CFRP Panels

REPORT #: 12-359-006 Rev. B DATE: 6/7/12

TO: Vicki Johnson FROM: Scott Brown

cc: R. Boone M. Daehling I. Nelson

Approved by: Jay Amos

Subject Information 

P/N: NASA STAR-C^2 Test Articles S/N:

Part description: 7 plies Uni 0/45/90 F990201 

(~.043” CPT): Oven-cured

Model:

Inspector S. Brown, M. Daehling, J. Amos Charge #: 46002542

Inspector Level 2, 3

Material Type NCT321-G150/NAS-S-12K-UNI

Type of Inspection UT TTU Gantry, Pulse Echo & 

Thermography (IRT)

Thru-transmission ultrasonic (TTU) gantry scans at 5 MHz with 0.08” index were completed pre-test 

and before any surface treatments applied. Panel labels are located in the lower-right corner of the Cscans. Some of the panels appeared to have significant mold release which affected UT couplant 

wetting. Wetting agent was applied to 3 different panels as a test with UT signal height observed before 

and after application with no dB change noticed. Water/Water reference amplitude was 32 dB @ 100% 

Full Screen Height (FSH). Scanning gain was set at 35 and 41 dB. Reference standard #3283000-1 was 

scanned with the panels for standardization. 

Table 1 records the disposition in three categories (Passing Level 1, Passing Level 2 or Failing Level 

2) of anomaly severity per CSTI009 - Level 2 acceptance size limit is 0.25 sq.in. UT attenuation values 

recorded in the table are not the worst areas on the panel, but an averaged value. 

Post-impact grading levels were chosen as Grade 1: 0.063-0.25 sq.in., Grade 2: >0.25-0.56 sq.in. and 

Grade 3: >0.56-1.00 sq.in. of impact damage area. 

Panels were selected from the lot for complementary thermography (2 ms flash duration) scans. 

Since IRT was done from the tool-side for pre-impact, these images were mirrored to align with the 
C-3 

gantry TTU C-scan orientation. For the sake of expediency, ~1.5” on the top and bottom edges of the 

panel were not covered in the IRT inspection. 

Some panels were very clean, but quite a number contained high levels of scattered porosity. 

Potential causes were investigated in the TAM fabrication related to process conditions or material shelf 

life extension (prepreg apparently life extended at least once), but nothing conclusive could be found. 

Photomicrography analysis (Figs. 268-270) revealed porosity levels up to 8.4% (local spots ~0.18” 

long) and averaging up to 3.9% (over a 1” area) in some of the most attenuative areas. The porosity 

tends to be linearly aligned as often found in UNI laminates. Therefore the same average porosity 

content typically has a higher detriment on both NDI & mechanical strength, as compared to uniformly 

distributed spherical porosity typically found in woven fabric composites. 

TTU C-scans of the panels are oriented from the bag-side with the ID tag in the lower right corner 

(these Panel #’s re-numbered from the embedded ID tag #’s). 

Figure 1. Ultrasonic C-Scan Plot Palette 

In many of these panels the post-test detection of very small delaminations is not reliable (<~0.025 

sq.in.) due to the generally higher levels of porosity content, in the lighting strike test panels in particular 

since higher quality panels were selected for impact. 

Forty-four panels were used for lightning strike studies with damage sizing performed for the 

laminate substrate (back) side in thermography. Some of the lightning strike panels were inspected from 

the front side, but core or mesh damage was not typically sized due to the large degree of damage to the 

front surface. Without removal of any damaged protective clear film, lightning mesh and charred 

material followed by a tempera paint surface preparation, a reliable IRT inspection of front-side core 

damage could not be done. 
C-4 

Table 1. Baseline CSTI009 Disposition & Ultrasonic dB loss 

(5.0 MHz Pulse Echo 1⁄2” dia. transducer)

Panel ID # D isposit ion

PE- U T 

average max 

at t enuat ion 

vs. ref . st d. 

( dB )

Panel ID # D isposit ion

PE- U T 

average max 

at t enuat ion 

vs. ref . st d. 

( dB )

Panel ID # D isposit ion

PE- U T 

average max 

at t enuat ion 

vs. ref . st d. 

( dB )

1 Pass Level 2 5 70 Pass Level 1 3 139 Fail Level 2 6

2 Pass Level 1 5 71 Fail Level 2 8 140 Pass Level 2 6

3 Pass Level 1 2 72 Fail Level 2 2 with 4" x1" void 141 Fail Level 2 9

4 Pass Level 1 1 73 Fail Level 2 8 142 Fail Level 2 6

5 Fail Level 2 7 74 Pass Level 1 2 143 Pass Level 1 3

6 Pass Level 2 6 75 Fail Level 2 8 144 Pass Level 1 3

7 Pass Level 2 5 76 Pass Level 2 6 145 Pass Level 1 3

8 Pass Level 2 3 77 Fail Level 2 6 146 Pass Level 1 2

9 Pass Level 2 6 78 Pass Level 1 2 147 Pass Level 1 3

10 Pass Level 1 2 79 Pass Level 1 2 148 Pass Level 1 2

11 Pass Level 1 4 8 0 Pass Level 1 3 149 Pass Level 1 3

12 Pass Level 1 1 8 1 Fail Level 2 6 150 Fail Level 2 5

13 Pass Level 1 3 8 2 Pass Level 1 3 AS151 Pass Level 1 4

14 Pass Level 1 1 8 3 Fail Level 2 4 152 Pass Level 1 3

15 Pass Level 1 2 8 4 Pass Level 1 2 AS153 Fail Level 2 5

16 Pass Level 1 1 8 5 Fail Level 2 9 154 Pass Level 1 3

17 Pass Level 1 0 8 6 Pass Level 1 2 155 Fail Level 2 6

18 Pass Level 1 1 8 7 Fail Level 2 7 156 Fail Level 2 8

19 Pass Level 1 2 AS88 Fail Level 2 0 157 Pass Level 1 4

AS20 Pass Level 1 0 8 9 Pass Level 1 2 158 Fail Level 2 8

2 1 Pass Level 1 1 9 0 Pass Level 1 5 159 Fail Level 2 9

2 2 Pass Level 1 1 9 1 Pass Level 1 3 160 Pass Level 1 3

2 3 Fail Level 2 10 9 2 Pass Level 1 4 161 Pass Level 1 2

2 4 Fail Level 2 7 9 3 Pass Level 1 2 AS162 Pass Level 1 1

2 5 Fail Level 2 8 9 4 Fail Level 2 8 163 Pass Level 1 2

2 6 Fail Level 2 8 9 5 Pass Level 1 4 164 Pass Level 2 5

2 7 Fail Level 2 8 9 6 Fail Level 2 8 165 Fail Level 2 6

2 8 Pass Level 1 1 9 7 Pass Level 1 5 166 Fail Level 2 6

AS29 Fail Level 2 6 9 8 Fail Level 2 8 167 Pass Level 1 3

3 0 Fail Level 2 7 9 9 Fail Level 2 9 168 Pass Level 1 2

3 1 Pass Level 1 3 100 Pass Level 1 3 AS169 Pass Level 2 6

3 2 Fail Level 2 9 101 Fail Level 2 7 170 Fail Level 2 11

3 3 Fail Level 2 5 AS102 Pass Level 1 2 171 Fail Level 2 14

3 4 Fail Level 2 10 103 Pass Level 1 3 172 Pass Level 1 2

3 5 Pass Level 1 4 104 Fail Level 2 9 AS173 Pass Level 1 1

3 6 Pass Level 1 3 105 Fail Level 2 9 174 Pass Level 1 2

3 7 Pass Level 1 1 106 Fail Level 2 9 175 Pass Level 1 5

3 8 Pass Level 1 2 107 Fail Level 2 9 176 Fail Level 2 6

3 9 Pass Level 1 2 AS108 Fail Level 2 7 177 Pass Level 1 3

4 0 Pass Level 1 1 109 Fail Level 2 7 178 Fail Level 2 6

4 1 Pass Level 1 2 110 Fail Level 2 7 179 Fail Level 2 3

4 2 Pass Level 1 1 111 Fail Level 2 9 180 Pass Level 1 3

4 3 Pass Level 1 2 112 Fail Level 2 7 181 Pass Level 2 2

4 4 Pass Level 2 6 AS113 Pass Level 1 1 182 Fail Level 2 6

AS45 Pass Level 1 0 114 Pass Level 1 5 183 Pass Level 2 6

4 6 Pass Level 2 7 115 Fail Level 2 6 185 Pass Level 2 2

4 7 Pass Level 1 1 116 Fail Level 2 6 186 Pass Level 1 2

4 8 Pass Level 1 3 117 Fail Level 2 7 187 Pass Level 2 2

4 9 Pass Level 1 1 118 Pass Level 1 5 188 Pass Level 1 3

50 Pass Level 2 4 119 Pass Level 1 4 189 Pass Level 1 3

AS51 Fail Level 2 7 120 Pass Level 1 5 190 Pass Level 1 1

52 Pass Level 1 1 121 Pass Level 1 4 191 Pass Level 2 2

53 Fail Level 2 8 122 Pass Level 1 5 192 Fail Level 2 6

54 Pass Level 1 1 123 Pass Level 1 4

55 Fail Level 2 6 124 Fail Level 2 7

56 Pass Level 1 2 125 Fail Level 2 8

57 Fail Level 2 8 126 Fail Level 2 7

58 Pass Level 1 2 127 Fail Level 2 8

59 Pass Level 1 1 128 Fail Level 2 10

6 0 Pass Level 1 1 129 Fail Level 2 10

6 1 Fail Level 2 7 130 Fail Level 2 9

6 2 Fail Level 2 6 131 Fail Level 2 8

6 3 Fail Level 2 8 132 Fail Level 2 7

6 4 Fail Level 2 9 133 Fail Level 2 6

6 5 Fail Level 2 8 134 Pass Level 2 7

6 6 Fail Level 2 9 135 Fail Level 2 6

6 7 Fail Level 2 6 AS136 Pass Level 2 6

6 8 Pass Level 1 3 AS137 Pass Level 2 6

6 9 Fail Level 2 7 138 Pass Level 2 6
C-5 

Figure 2. 5 MHz TTU Panel 1, 2, 3, 4 

Figure 3. Thermography Panel 1 (1st Derv. - 0.42 & 0.94 sec) 

Figure 4. Post-Impact Thermography Panel 1 {IM-78} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 5. 5 MHz TTU Panel 5, 6, 7, 8 

Acceptable 

Level 2

Acceptable 

Level 2

Acceptable 

Level 2

Resin-rich surface areas shown as darker 

spots in early vs. late time images.

Pass Level 2

Two > Grade 3
C-6 

Figure 6. Post-Impact Thermography Panel 5 {IM-14} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 7. Post-Impact Thermography Panel 6 {IM-99} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 8. Post-Impact Thermography Panel 7 {IM-55} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 9. Post-Impact Thermography Panel 8 {IM-15} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

One > Grade 3

One Grade 3 & Two > Grade 3

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 

No Damage

1.17, 0.084, >1.0, 0.83 sq.in.
C-7 

Figure 10. 5 MHz TTU Panel 9, 10, 11, 12 

Figure 11. Post-Impact Thermography Panel 9 {IM-24} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 12. Post-Impact Thermography adhered Panel 12 {IM-88} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 13. 5 MHz TTU Panel 13, 14, 15, 16 

Acceptable 

Level 2

Four Multiple Hits together: > Grade 3

No Damage
C-8 

Figure 14. Post-Impact Thermography adhered Panel 13 {IM-65} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 15. Post-Impact Thermography adhered Panel 14 {IM-44} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 16. Post-Impact Thermography adhered Panel 15 {IM-58} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 17. Post-Impact Thermography adhered Panel 16 {IM-67} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Two Multiple Hits > Grade 3

Two Multiple Hits> Grade 3

Artifacts from contact by protective layer 

deformation – no damage

Resin-rich spots Artifacts from contact by protective layer 

deformation – no damage

Two Multiple Hits> Grade 3

Two sites; one > Grade 3

Difficult to judge damage from 

center impact due to UNI splits
C-9 

Figure 18. 5 MHz TTU Panel 17, 18, 19, 21 

 

Figure 19. Thermography Panel 20 (1st Derv. - 0.42s & 0.94s) 

Figure 20. 5 MHz TTU Panel 22, 23, 24, 25 

Figure 21. Thermography Panel 23 (1st Derv. - 0.3s & Peak Ampl.- Pos. 2nd Derv.) 

Dark areas in Peak Ampl are artifacts 

due to non-uniform cooling on backside. 

Sectioned for optical microscopy (Fig. 268) 

0

O

Fail Level 2

Pass Level 1
C-10

Figure 22. Post-Impact Thermography adhered Panel 24 {IM-4} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 23. Post-Impact Thermography adhered Panel 25 {IM-79} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 23. 5 MHz TTU Panel 26, 27, 28, 30 

Figure 24. Post-Impact Thermography Panel 26 {IM-32} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

One Grade 2 – 0.47 sq.in.

One > Grade 3

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 

One > Grade 3; 1.26 sq.in.
C-11

Figure 25. Post-Strike Thermography Back Panel 27 {LS-44} (1st Derv. – 0.08s, 0.42s, 0.94s) 

Figure 26. Post-Strike Thermography Front Panel 27 {LS-44} (1st Derv. – 0.4s & 8.66s) 

 

Figure 27. Thermography Panel 29 (1st Derv. - 0.42s & 0.94s) 

 

Figure 28. Post-Strike Thermography Back Panel 30 {LS-41} (1st Derv. – 0.08s, 0.42s, 0.94s) 

Fail Level 2

Dark areas in late time are artifacts due to 

non-uniform cooling on backside. 

Porosity from fabrication 

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 
C-12

Figure 29. Post-Strike Thermography Front Panel 30 {LS-41} (1st Derv. – 0.4s & 8.66s) 

Figure 30. 5 MHz TTU Panel 31, 32, 33, 34 

Figure 31. Post-Strike Thermography Back Panel 32 {LS-43} (1st Derv. – 0.08s, 0.42s, 0.94s) 

Figure 32. Post-Strike Thermography Front Panel 32 {LS-43} (1st Derv. – 0.4s & 8.66s) 

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 
C-13

Figure 33. Post-Impact Thermography Panel 33 {IM-18} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 34. Thermography Panel 34 (1st Derv. - 0.3s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 35. 5 MHz TTU Panel 35, 36, 37, 38 

Figure 36. Post-Impact Thermography adhered Panel 36 {IM-45} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Fail Level 2

Two Multiple 

Hits > Grade 3

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 

Artifacts from contact by protective layer deformation 
C-14

Figure 37. 5 MHz TTU Panel 39, 40, 41, 42 

Figure 38. Post-Impact Thermography adhered Panel 40 {IM-64} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 39. Post-Impact Thermography adhered Panel 41 {IM-94} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 40. Post-Impact Thermography adhered Panel 42 {IM-71} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Two Multiple 

Hits > Grade 3

One > Grade 3

Four Multiple Hits > Grade 3

Artifacts from contact by protective layer deformation 
C-15

Figure 41. 5 MHz TTU Panel 43, 44, 46, 47 

Figure 42. Post-Impact Thermography adhered Panel 43 {IM-68} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 43. Post-Impact Thermography Panel 44 {IM-72} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

 

Figure 44. Thermography Panel AS45 (1st Derv. - 0.42 & 0.94 sec) 

Acceptable 

Level 2

Acceptable 

Level 2

Pass Level 1

1.85, 0.26 sq.in.

Two > Grade 3

One Grade 2, 

One > Grade 3
C-16

Figure 45. Post-Impact Thermography Panel 46 {IM-27} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.) 

Figure 46. Post-Impact Thermography adhered Panel 47 {IM-62} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 47. 5 MHz TTU Panel 48, 49, 50, 52 

Figure 48. Post-Impact Thermography Panel 48 {IM-89} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Acceptable 

Level 2

Two Multiple Hits > Grade 3

Two Multiple Hits > Grade 3

One > Grade 3

No Damage
C-17

Figure 49. Post-Impact Thermography adhered Panel 49 {IM-93} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

 

Figure 50. Post-Impact Thermography Panel 50 {IM-21} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

 

Figure 51. Thermography Panel 51 (1st Derv. - 0.42 & 0.94 sec) <mirrored from tool-side> 

Figure 52. Post-Impact Thermography Panel 51 {MIM-1} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Fail Level 2

Porosity from fabrication 

Two Multiple Hits > Grade 3

One > Grade 3

0.93, 0.84, 0.09, 1.23 & 1.50 sq.in.

No Damage

Five impact damage sites; One Grade 1, Four > Grade 3
C-18

Figure 53. Post-Impact Thermography adhered Panel 52 {IM-90} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 54. 5 MHz TTU Panel 53, 54, 55, 56 

Figure 55. Post-Impact Thermography adhered Panel 54 {IM-92} (1st Derv. - 0.42, 0.94s & Peak Ampl) 

Figure 56. Post-Strike Thermography Back Panel 55 {LS-21} (1st Derv. – 0.08s, 0.42s, 0.94s) 

Two Multiple Hits > Grade 3

One > Grade 3

Two Multiple Hits > Grade 3

One > Grade 3

Difficult to judge damage from 

center impact due to UNI splits

Artifact from contact by coating layer damage

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 
C-19

Figure 57. Post-Strike Thermography Front Panel 55 {LS-21} (1st Derv. – 0.4s & 8.66s)

Figure 58. Post-Impact Thermography adhered Panel 56 {IM-61} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 59. 5 MHz TTU Panel 57, 58, 59, 60 

Figure 60. Post-Strike Thermography Back Panel 57 {LS-22} (1st Derv. – 0.08s, 0.42s, 0.94s) 

Two Multiple Hits > Grade 3

3M debond 

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 

Artifacts from contact by protective layer deformation 
C-20

Figure 61. Post-Strike Thermography Front Panel 57 {LS-22} (1st Derv. – 0.4s & 8.66s)

Figure 62. 5 MHz TTU Panel 61, 62, 63, 64 

Figure 63. Post-Strike Thermography Back Panel 61 {LS-38} (1st Derv. – 0.08s, 0.42s, 0.94s) 

Figure 64. Post-Strike Thermography Front Panel 61 {LS-28} (1st Derv. – 0.4s & 8.66s) 

0.56 sq.in damage

High porosity makes detection of small 

flaws difficult
C-21

Figure 65. Post-Strike Thermography Back Panel 62 {LS-27} (1st Derv. – 0.08s, 0.42s, 0.94s) 

Figure 66. Post-Strike Thermography Front Panel 62 {LS-27} (1st Derv. – 0.4s & 8.66s) 

Figure 67. Post-Strike Thermography Back Panel 63 {LS-28} (1st Derv. – 0.08s, 0.42s, 0.94s) 

Figure 68. Post-Strike Thermography Front Panel 63 {LS-28} (1st Derv. – 0.4s & 8.66s) 

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 
C-22

Figure 69. Thermography Panel 64 (1st Derv. - 0.3s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 70. Post-Impact Thermography Panel 64 {IM-20} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 71. 5 MHz TTU Panel 65, 66, 67, 68 

Figure 72. Post-Strike Thermography Back Panel 65 {LS-46} (1st Derv. – 0.08s, 0.42s, 0.94s) 

Acceptable 

Level 2

Fail Level 2

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 

Multiple delams total = 2.22 sq.in. 
C-23

Figure 73. Thermography Panel 66 (1st Derv. - 0.3s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 74. Post-Impact Thermography Panel 66 {IM-86} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Figure 75. Post-Strike Thermography Back Panel 67 {LS-42} (1st Derv. – 0.08s, 0.42s, 0.94s) 

Figure 76. Post-Strike Thermography Front Panel 67 {LS-42} (1st Derv. – 0.4s & 8.66s) 

Fail Level 2

0.71, 1.58, 1.05 sq.in.

One Grade 3, Two > Grade 3

No Damage
C-24

Figure 77. 5 MHz TTU Panel 69, 70, 71, 72 

Figure 78. Post-Strike Thermography Back Panel 69 {LS-47} (1st Derv. – 0.08s, 0.42s, 0.94s) 

Figure 79. Thermography Panel 72 (1st Derv. - 0.42 & 0.94 sec) 

Figure 80. 5 MHz TTU Panel 73, 74, 76, 77 

Acceptable 

Level 2

Fail Level 2

2.2, 1.3 sq.in.

NDI from front not feasible due to 

damage to protective coating layer

Two damage sites; One Grade 1, Four > Grade 3
C-25

Figure 81. Post-Strike Thermography Back Panel 73 {LS-37} (1st Derv. – 0.08s, 0.42s, 0.94s) 

Figure 82. Post-Strike Thermography Front Panel 73 {LS-37} (1st Derv. – 0.4s & 8.66s) 

 

Figure 83. Thermography Panel 75 (1st Derv. - 0.42 & 0.94 sec) 

Figure 84. Post-Impact Thermography Panel 76 {IM-38} (1st Derv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Derv.) 

Fail Level 2

No Damage

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 
C-26

Figure 85a. Post-Strike Thermography Back Panel 77 {LS-25} (1st Derv. – 0.08s, 0.42s, 0.94s) 

 

Figure 85b. Post-Strike Thermography Front Panel 77 {LS-25} (1st Deriv. – 0.4s & 8.66s)

Figure 86. 5 MHz TTU Panel 78, 79, 80, 81 

Figure 87. Post-Strike Thermography Back Panel 81 {LS-39} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

Porosity from fabrication 

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 

Protective Coating Delam

No Damage
C-27

Figure 88. Post-Strike Thermography Front Panel 81 {LS-39} (1st Deriv. – 0.4s & 8.66s)

Figure 89. 5 MHz TTU Panel 82, 83, 84, 85 

Figure 90. Post-Impact Thermography Panel 82 {IM-53} (1st Deriv. - 0.42, 0.94s & Peak Ampl.) 

Figure 91. Post-Strike Thermography Back Panel 83 {LS-9} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

Two > Grade 3

Protective Coating Delam

Coating adhesive failed (red)

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 
C-28

Figure 92. Post-Strike Thermography Front Panel 83 {LS-9} (1st Deriv. – 0.4s & 8.66s) 

Figure 93. Post-Impact Thermography Panel 84 {IM-54} (1st Deriv. - 0.42, 0.94s & Peak Ampl) 

Figure 94. Post-Strike Thermography Back Panel 85 {LS-18} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

Figure 95. Post-Strike Thermography Front Panel 85 {LS-18} (1st Deriv. – 0.4s & 8.66s) 

0.40 sq.in.

One > Grade 3

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 

One damage site Grade 2
C-29

Figure 96. 5 MHz TTU Panel 86, 87, 89, 90 

Figure 97. Post-Strike Thermography Back Panel 87 {LS-20} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

Figure 98. Post-Strike Thermography Front Panel 87 {LS-20} (1st Deriv. – 0.4s & 8.66s) 

Figure 99. Post-Impact Thermography Panel 86 {IM-43} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

No Damage

Porosity from fabrication 

4.8 sq.in. lam damage > Grade 3
C-30

 

Figure 100. Thermography Panel 88 (1st Deriv. - 0.42 & 0.94 sec) 

Figure 101. Post-Impact Thermography Panel 89 {IM-40} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 102. Post-Impact Thermography Panel 90 {IM-29} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 103. 5 MHz TTU Panel 91, 92, 93, 94 

Fail Level 2

Linear Porosity

No Damage

No Damage

Surface artifact
C-31

Figure 104. Post-Impact Thermography Panel 91 {IM-48} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

 

Figure 105. Post-Impact Thermography Panel 92 {IM-33} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

 

Figure 106. Post-Impact Thermography Panel 93 {IM-96} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.) 

Figure 107. Post-Strike Thermography Back Panel 94 {LS-23} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

1.29 sq.in.

Two > Grade 3

Two > Grade 3

No Damage

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 
C-32

Figure 108. Post-Strike Thermography Front Panel 94 {LS-23} (1st Deriv. – 0.4s & 8.66s) 

Figure 109. 5 MHz TTU Panel 95, 96, 97, 98 

Figure 110. Post-Impact Thermography Panel 95 {IM-39} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.) 

Figure 111. Post-Strike Thermography Back Panel 96 {LS-32} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

No Damage

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 
C-33

Figure 112. Post-Impact Thermography Panel 97 {IM-51} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.) 

Figure 113. Post-Strike Thermography Back Panel 98 {LS-34} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

Figure 114. Post-Strike Thermography Front Panel 98 {LS-34} (1st Deriv. – 0.4s & 8.66s) 

Figure 115. 5 MHz TTU Panel 99, 100, 101, 103 

Two > Grade 3

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 
C-34

Figure 116. Post-Strike Thermography Back Panel 99 {LS-13} (1

st Deriv. – 0.08s, 0.42s, 0.94s) <rotated 90o

 CCW> 

Figure 117. Post-Strike Thermography Front Panel 99 {LS-13} (1st Deriv. – 0.4s & 8.66s) 

Figure 118. Post-Impact Thermography Panel 100 {IM-59} (1st Deriv. - 0.42, 0.94s & Peak Ampl) 

Figure 119. Post-Strike Thermography Back Panel 101 {LS-11} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

0.31, 0.79 sq.in.

One > Grade 3

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 

Actual core 

damage

No Apparent Damage – porosity is high 

Pre-existing porosity in region of interest (Fails Level 2) 

Pre-existing porosity

Two damage sites; One Grade 2, One Grade 3
C-35

Figure 120. Post-Strike Thermography Front Panel 101 {LS-11} (1st Deriv. – 0.4s & 8.66s) 

 

Figure 121. Thermography Panel 102 (1st Deriv. - 0.42 & 0.94 sec) 

Figure 122. Post-Impact Thermography Panel 103 {IM-50} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 123. 5 MHz TTU Panel 104, 105, 106, 107 

Pass Level 1

Two > Grade 3

Actual core 

damage
C-36

Figure 124. Post-Strike Thermography Back Panel 104 {LS-1} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

Figure 125. Post-Strike Thermography Front Panel 104 {LS-1} (1st Deriv. – 0.4s & 8.66s) 

Figure 126. Post-Strike Thermography Back Panel 105 {LS-5} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

 

Figure 127. Post-Strike Thermography Front Panel 105 {LS-5} (1st Deriv. – 0.4s & 8.66s) 

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 

Actual core 

damage
C-37

Figure 128. Post-Strike Thermography Back Panel 106 {LS-8} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

Figure 129. Post-Strike Thermography Front Panel 106 {LS-8} (1st Deriv. – 0.4s & 8.66s) 

 

Figure 130. Post-Strike Thermography Back Panel 107 {LS-7} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

 

Figure 131. Post-Strike Thermography Front Panel 107 {LS-7} (1st Deriv. – 0.4s & 8.66s) 

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) ?

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 
C-38

 

Figure 132. Thermography Panel AS108 (1st Deriv. - 0.42 & 0.94 sec) 

Figure 133. 5 MHz TTU Panel 109, 110, 111, 112 

Figure 134. Post-Impact Thermography Panel 109 {IM-17} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.) 

 

Figure 135. Post-Strike Thermography Back Panel 110 {LS-24} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

Fail Level 2

0.58 sq.in. One Grade 3

No Damage
C-39

Figure 136. Post-Strike Thermography Front Panel 110 {LS-24} (1st Deriv. – 0.4s & 8.66s) 

Figure 137. Post-Strike Thermography Back Panel 111 {LS-19} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

Figure 138. Post-Strike Thermography Back Panel 112 {LS-30} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

Figure 139. Post-Strike Thermography Front Panel 112 {LS-30} (1st Deriv. – 0.4s & 8.66s) 

0.48 sq.in. Damage

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2)
C-40

 

Figure 140. Thermography Panel AS113 (1st Deriv. - 0.42 & 0.94 sec) 

Figure 141. 5 MHz TTU Panel 114, 115, 116, 117 

Figure 142. Post-Impact Thermography Panel 114 {IM-22} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.) 

Figure 143. Post-Strike Thermography Back Panel 115 {LS-29} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

Pass Level 1

No Damage

No Damage
C-41

Figure 144. Post-Strike Thermography Front Panel 115 {LS-29} (1st Deriv. – 0.4s & 8.66s) 

Figure 145. Post-Strike Thermography Back Panel 116 {LS-36} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

Figure 146. Post-Strike Thermography Front Panel 116 {LS-36} (1st Deriv. – 0.4s & 8.66s) 

Figure 147. Post-Strike Thermography Back Panel 117 {LS-33} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

~2.2 sq.in. Damage

No Apparent Damage – porosity is high

in region of interest (Fails Level 2)
C-42

Figure 148. Post-Strike Thermography Front Panel 117 {LS-33} (1st Deriv. – 0.4s & 8.66s) 

Figure 149. 5 MHz TTU Panel 118, 119, 120, 121 

Figure 150. Post-Impact Thermography Panel 118 {IM-3} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.) 

Figure 151. Post-Impact Thermography Panel 119 {IM-97} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

1.13, 0.86, 1.3 sq.in.

0.91 sq.in.

One Grade 3; 

Three > Grade 3

One Grade 3; 

One > Grade 3
C-43

Figure 152. Post-Impact Thermography Panel 120 {IM-6} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 153. Post-Impact Thermography Panel 121 {IM-8} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 154. 5 MHz TTU Panel 122, 123, 124, 125 

Figure 155. Post-Impact Thermography Panel 122 {IM-10} (1st Deriv. - 0.42, 0.94s & Peak Ampl.) 

One > Grade 3

One > Grade 3

No Damage
C-44

Figure 156. Post-Impact Thermography Panel 123 {IM-13} (1st Deriv. - 0.42, 0.94s & Peak Ampl) 

Figure 157. Post-Strike Thermography Back Panel 124 {LS-35} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

Figure 158. Post-Strike Thermography Front Panel 124 {LS-35} (1st Deriv. – 0.4s & 8.66s)

 

Figure 159. Post-Strike Thermography Back Panel 125 {LS-15} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

No Damage

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 
C-45

Figure 160. Post-Strike Thermography Front Panel 125 {LS-15} (1st Deriv. – 0.4s & 8.66s) 

Figure 161. 5 MHz TTU Panel 126, 127, 128, 129 

Figure 162. Post-Strike Thermography Back Panel 126 {LS-16} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

Figure 163. Post-Strike Thermography Front Panel 126 {LS-16} (1st Deriv. – 0.4s & 8.66s) 

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 
C-46

Figure 164. Post-Strike Thermography Back Panel 127 {LS-26} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

Figure 165. Post-Strike Thermography Front Panel 127 {LS-26} (1st Deriv. – 0.4s & 8.66s) 

Figure 166. Post-Strike Thermography Back Panel 128 {LS-6} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

 

Figure 167. Post-Strike Thermography Front Panel 128 {LS-6} (1st Deriv. – 0.4s & 8.66s) 

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2)

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 
C-47

Figure 168. Post-Strike Thermography Back Panel 129 {LS-14} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

Figure 169. Post-Strike Thermography Front Panel 129 {LS-14} (1st Deriv. – 0.4s & 8.66s) 

Figure 170. 5 MHz TTU Panel 130, 131, 132, 133 

Figure 171. Post-Impact Thermography Panel 130 {IM-70} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) ?
C-48

Figure 172. Post-Impact Thermography Panel 131 {IM-11} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 173. Post-Impact Thermography Panel 132 {IM-98} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

 

One Grade 3- 0.93 sq.in; 

One > Grade 3

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 
C-49

Figure 174. Post-Impact Thermography Bare Panel 133 (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

 < from tool-side, opposite impact surface> 

Figure 175. Post-Impact Photo Bare Panel 133 (tool-side, opposite impact surface) 

Figure 176. Post-Impact Photo Bare Panel 133 Left & Right Sides (bag-side impact surface) 

Slight dent – Barely Visible Impact Damage 

(BVID) 

0.85, 0.48, 0.28. 

2.18 sq.in
C-50

Figure 177. 5 MHz TTU Panel 134, 135, 138, 139 

Figure 178. Post-Impact Thermography Panel 134 {IM-75} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 179. Post-Impact Thermography Panel 135 {IM-30} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

 

Figure 180. Thermography Panel AS136 (1st Deriv. - 0.42 & 0.94 sec) 

Acceptable 

Level 2 Acceptable 

Level 2

Pass Level 2

1.05 sq.in. Two > Grade 3

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 
C-51

 

Figure 181. Thermography Panel AS137 (1st Deriv. - 0.42 & 0.94 sec) 

Figure 182. Post-Impact Thermography Panel 138 {IM-60} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 183. Post-Impact Thermography Panel 139 {IM-95} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 184. 5 MHz TTU Panel 140, 141, 142, 143 

Acceptable 

Level 2

Pass Level 2

Porosity from fabrication 

0.29 sq.in.

One Grade 2; 

One > Grade 3

0.75, 0.99, 1.2 sq.in.

Two Grade 3, Four > Grade 3
C-52

Figure 185. Post-Impact Thermography Panel 140 {IM-83} (1st Deriv. - 0.42, 0.94s & Peak Ampl) 

Figure 186. Post-Impact Thermography Panel 141 {IM-41} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 187. Post-Impact Thermography Panel 142 {IM-63} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 188. Post-Impact Thermography Panel 143 {IM-52} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Two > Grade 3

No Damage Porosity from fabrication 

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 

Two > Grade 3
C-53

Figure 189. 5 MHz TTU Panel 144, 145, 146, 147 

Figure 190. Post-Impact Thermography Panel 144 {IM-73} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 191. Post-Impact Thermography Panel 145 {IM-31} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 192. Post-Impact Thermography Panel 146 {IM-12} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

No Damage

No Damage

Two > Grade 3
C-54

Figure 193. Post-Impact Thermography Panel 147 {IM-56} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 194. 5 MHz TTU Panel 148, 149, 150, 151 

Figure 195. Post-Impact Thermography Panel 148 {IM-2} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 196. Post-Impact Thermography Panel 149 {IM-19} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

0.14, 0.94 sq.in.

Two > Grade 3

Two > Grade 3

0.66 sq.in

One Grade 3

One Grade 1, One Grade 3
C-55

Figure 197. Post-Impact Thermography Panel 150 {IM-66} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

 

Figure 198. Thermography Panel AS151 (1st Deriv. - 0.42 & 0.94 sec) 

Figure 199. Post-Impact Thermography Panel 151 {IM-81} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 200. Post-Impact Thermography Panel 152 {IM-37} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Pass Level 1

No Damage

1.08 sq.in Two > Grade 3

Two > Grade 3
C-56

 

Figure 201. Thermography Panel AS153 (1st Deriv. - 0.42 & 0.94 sec) <mirrored from tool-side> 

Figure 202. Post-Impact Thermography Panel 153 {IM-46} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 203. 5 MHz TTU Panel 154, 155, 156, 157 

Figure 204. Post-Impact Thermography Panel 154 {IM-91} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Fail Level 2

Two > Grade 3; 1.23, 1.77 sq.in.

Two > Grade 3

Porosity from fabrication 
C-57

Figure 205. Post-Impact Thermography Panel 155 {IM-69} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 206. Thermography Panel 156 (1st Deriv. - 0.42 & 0.94 sec) 

Figure 207. Post-Impact Thermography Panel 156 {IM-82} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 208. Post-Impact Thermography Panel 157 {IM-9} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Fail Level 2

No Damage

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 

Porosity from fabrication 

No Apparent Damage – porosity is high in 

region of interest (Fails Level 2) 

Porosity from fabrication 
C-58

Figure 209. 5 MHz TTU Panel 158, 159, 160, 161 

Figure 210. Post-Strike Thermography Back Panel 158 {LS-2} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

Figure 211. Post-Strike Thermography Front Panel 158 {LS-2} (1st Deriv. – 0.4s & 8.66s)

 

Figure 212. Thermography 159 (1st Deriv. 0.42 & 0.94 sec and Peak Ampl.- Pos. 2nd Deriv) 

1⁄4 section in Fig. 214 1⁄4 section in Fig. 213

Sections A & B for optical microscopy (Fig. 268) 

Scattered porosity

0

O

Fail Level 2

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 

Actual core damage
C-59

Initial impact test results on Panel 160 quarter sections: 

Figure 213. Thermography Post-impact Tegris 3M VHB adhered top-right quarter Panel 160. 

(Peak Ampl.- Pos. 2nd Deriv. & 1st Deriv. - 0.94 sec). 

Figure 214a. Thermography Post-impact Tegris 3M VHB w/backing paper top-left quarter Panel 160 

(Peak Ampl.- Pos. 2nd Deriv. & 1st Deriv. - 0.94 sec). 

70”/1.75” 100”/1.75” 0.47” long possible rebound 

delam or pre-existing porosity.

No indications from blunt impacts 

1.22” long

0.76” long

3.0” long

65”/0.5” 50”/0.5”

50”/0.5” 65”/0.5”

4.83” long

70”/1.75” 100”/1.75”

No indications from blunt impacts 
C-60

Figure 214b. Thermography Post-impact Tegris 3M VHB w/backing paper top-left quarter Panel 160 <inner toolside mirror of figure above> (Peak Ampl.- Pos. 2nd Deriv. & 1st Deriv. - 0.3 sec) 

Protection layer adhered to the substrate doesn’t seem to pose any problems for thermography sensitivity or 

interpretation as long as it is uniform. However, in subsequent panels with 3M backing paper intact it was found 

that the varying degree of contact due to the protective layer impact damage, did leave artifacts in the IRT image 

of an undamaged laminate. 

 As is often the case, impact delamination is larger on the backside (bag-side), shown as 1.22” long in Fig. 214a, 

compared to 0.9” long near-surface laminate IR image in Fig. 214b. 

It is thought the variation in impact damage extent with 3M VHB backing paper in-place vs. removed & adhered 

has more to do with variation in the UNI porosity mophology between these panels & laminate quality, than 

influence of the protective layer adherence. It was also noted that the delaminations continued to grow hours 

after the impact due to residual stresses at the impacted surface with this UNI laminate material. 

Figure 215. Post-Strike Thermography Back Panel 161 {LS-45} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

No indications from blunt impacts on skin inner surface

0.9” long

50”/0.5”

No Damage 
C-61

Figure 216. Post-Strike Thermography Front Panel 161 {LS-45} (1st Deriv. – 0.4s & 8.66s) 

 

Figure 217. Thermography AS162 (1st Deriv. - 0.42 & 0.94 sec) 

Figure 218. 5 MHz TTU Panel 163, 164, 165, 166 

Figure 219. Post-Impact Thermography adhered Panel 163 {IM-100} (1st Deriv. - 0.42, 0.94s & Peak Ampl) 

Acceptable 

Level 2

Pass Level 1

Hit > Grade 3 Difficult to judge damage from two 

side impacts due to UNI splits

One > Grade 3

Artifacts from contact by coating layer damage 

- No PEUT loss in bottom center indication 
C-62

Figure 220. Post-Strike Thermography Back Panel 165 {LS-4} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

6

Figure 221. Post-Strike Thermography Front Panel 165 {LS-4} (1st Deriv. – 0.4s & 8.66s) 

Figure 222. Post-Strike Thermography Back Panel 166 {LS-10} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

Figure 223. Post-Strike Thermography Front Panel 166 {LS-10} (1st Deriv. – 0.4s & 8.66s) 

No Apparent Damage – porosity is high in region of interest (Fails Level 2) 

No Apparent Damage – porosity is high 

in region of interest (Fails Level 2) 
C-63

Figure 224. 5 MHz TTU Panel 167, 168, 170 

Figure 225. Thermography AS169 (1st Deriv. - 0.42 & 0.94 sec) 

Figure 226. Post-Strike Thermography Back Panel 170 {LS-12} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

Figure 227. Post-Strike Thermography Front Panel 170 {LS-12} (1st Deriv. – 0.4s & 8.66s) 

Pass Level 2

No Apparent Damage – porosity is high in region of interest (Fails Level 2) 
C-64

Figure 228. 5 MHz TTU Panel 171, 172, 173 

Figure 229. Post-Strike Thermography Back Panel 171 {LS-40} (1st Deriv. – 0.08s, 0.42s, 0.94s) 

Figure 230. Post-Impact Thermography Panel 172 {IM-57} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

 

Figure 231. Thermography AS173 (1st Deriv. - 0.42 & 0.94 sec) 

Pass Level 1

Multiple Hits together: > Grade 3

Damage 2.9 sq.in. @ 100, 3.2 sq.in @ 200
C-65

Figure 232. Post-Impact Thermography Panel 173 {IM-36} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 233. Post-Impact Thermography adhered Panel 174 {IM-47} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd

Deriv.) 

Figure 234. Post-Impact Thermography Panel 175 {IM-7} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Figure 235. 5 MHz TTU Panel 175

Multiple Hits together: > Grade 3

No Damage Porosity

One > Grade 3
C-66

 

Figure 236. Thermography AS176 (1st Deriv. - 0.42 & 0.94 sec) 

Figure 237. Post-Impact Thermography Panel 176 {IM-25} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

 

Figure 238. Thermography AS177 (1st Deriv. - 0.42 & 0.94 sec) 

Figure 239. Post-Impact Thermography Panel 177 {IM-76} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Fail Level 2

Pass Level 1

No Damage

Two > Grade 3
C-67

 (tool-side mirrored) 

Figure 240. Thermography AS178 (1st Deriv. - 0.42 & 0.94 sec) 

Figure 240. Post-Impact Thermography Panel 178 {IM-26} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

 

Figure 241. Thermography AS179 (1st Deriv. - 0.42 & 0.94 sec) 

Figure 242. Post-Impact Thermography Panel 179 {IM-16} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Fail Level 2

Fail Level 2

No Damage

No Damage
C-68

 

Figure 243. Thermography AS180 (1st Deriv. - 0.42 & 0.94 sec) 

Figure 244. Post-Impact Thermography Panel 180 {IM-87} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

 

Figure 245. Thermography AS181 (1st Deriv. - 0.42 & 0.94 sec) 

Figure 246. Post-Impact Thermography Panel 181 {IM-23} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Pass Level 1

Pass Level 2

No Damage

1.5, 0.86, 0.95, 0.96 sq.in.

Three Grade 3, Three > Grade 3 
C-69

 

Figure 247. Thermography AS182 (1st Deriv. - 0.42 & 0.94 sec) 

Figure 248. Post-Impact Thermography Panel 182 {IM-34} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

 

Figure 249. Thermography AS183 (1st Deriv. - 0.42 & 0.94 sec) 

Figure 250. Post-Impact Thermography Panel 183 {IM-35} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Fail Level 2

Pass Level 2

No Damage

No Damage
C-70

 

Figure 251. Thermography AS184 (1st Deriv. - 0.42 & 0.94 sec) 

 

Figure 252. Thermography AS185 (1st Deriv. - 0.42 & 0.94 sec) 

Figure 253. Post-Impact Thermography Panel 185 {IM-85} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

 

Figure 254. Thermography AS186 (1st Deriv. - 0.42 & 0.94 sec) 

Pass Level 1

Pass Level 1

Fail Level 2

No Damage
C-71

Figure 255. Post-Impact Thermography Panel 186 {IM-74} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

 

Figure 256. Thermography AS187 (1st Deriv. - 0.42 & 0.94 sec)

Figure 257. Post-Impact Thermography Panel 187 {IM-84} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

 

Figure 258. Thermography AS188 (1st Deriv. - 0.42 & 0.94 sec) 

Pass Level 2

Pass Level 1

One Grade 1; 

One > Grade 3

No Damage
C-72

Figure 259. Post-Impact Thermography Panel 188 {IM-49} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

 

Figure 260. Thermography AS189 (1st Deriv. - 0.42 & 0.94 sec) 

Figure 261. Post-Impact Thermography Panel 189 {IM-80} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

 

Figure 262. Thermography AS190 (1st Deriv. - 0.42 & 0.94 sec) 

Pass Level 1

Pass Level 1

One Grade 1; 

One > Grade 3

Two > Grade 3
C-73

Figure 263. Post-Impact Thermography Panel 190 {IM-77} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

 

Figure 264. Thermography AS191 (1st Deriv. - 0.42 & 0.94 sec) 

Figure 265. Post-Impact Thermography Panel 191 {IM-5} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

 

 (tool-side mirrored) 

Figure 266. Thermography AS192 (1st Deriv. - 0.42 & 0.94 sec) 

Pass Level 2

Fail Level 2

1.05 sq.in. Two > Grade 3

0.29 sq.in.

One Grade 2, 0.29 sq.in; One > Grade 3
C-74

Figure 267. Post-Impact Thermography Panel 192 {IM-28} (1st Deriv. - 0.42s, 0.94s & Peak Ampl.- Pos. 2nd Deriv.) 

Optical photomicrographs were taken from 3 sections (in Panels #23 & #159) correlated to areas of 

high UT attenuation. Many outside studies have found a linear relation between attenuation, porosity 

and mechanical strength - if porosity voids are spherically shaped and uniformly distributed (e.g. in 

fabric). However, with UNI laminates the porosity size, shape (often cigar shaped) and distribution 

dramatically affects void content correlation to UT attenuation - and porosity content to mechanical 

strengths as well. 

No Damage
C-75

Table 2. PE 5 MHz UT Attenuation vs. Void Content (Optical) 

Panel ID #

Porosity averaged 

over ~1 sq.in.

(% VC)

Local PE-UT 

Attenuation

(dB)

Average Max Attenuation 

in Entire Panel

(dB)

159A 3.7 -20 -9

159B 2.9 -18 -9

23 3.9 -19 -10

Photomicrography Analysis for Void Content (Polishes taken in orthogonal directions):

0° → 

#159 A – min 3.5%, max 7.28%, average 5.4% 

#159 B – min 1.4%, max 3.97%, average 2.4 % 

#23 C – min 2.96%, max 6.49%, average 4.05% 

90° → 

#159 A – min 2.58%, max 3.7%, average 3.2% 

#159 B – min 1.3%, max 2.9%, average 2.1% 

#23 C – min 2.23%, max 4.1%, average 3.62% 

Scale: 0.18”
C-76

Figure 268. Photomicrographs of sections from Panel 159 (A & B) and Panel 23 (C) {1st polish} 

0° → 

#159 A – min 1.1%, max 4.0%, average 2.8% 

#159 B – min 2.45%, max 6.4%, average 4.13% 

#23 C – min 2.6%, max 3.45%, average 2.94% 
C-77

90° → 

#159 A – min 2.1%, max 2.76%, average 2.43% 

#159 B – min 1.4%, max 3.78%, average 2.59% 

#23 C – min 2.89%, max 8.46%, average 4.86% 

1 4 

Figure 269. Photomicrographs of sections from Panel 159 (A & B) and Panel 23 (C) {2nd polish} 

0° → 

#159 A – min 2.9%, max 4.4%, average 3.7% 

#159 B – min 2.5%, max 3.4%, average 2.8% 

Figure 270. Photomicrographs of sections from Panel 159 (A & B) {3rd polish} 
D-1 

Appendix D - 

First-Generation Test Article Impact Testing Pictures 
D-2 

Purpose 

This appendix presents the pictures taken of the impact panels before and after impact testing. 

In some cases where something visually interesting can be seen by looking at the impact test 

article from an angle, those pictures are presented. Some of the surfaces (especially the carbon 

epoxy and aluminum) were very shiny, making it difficult to get good images. 
D-3 

Pictures 

Figure D-1: Before and after pictures of the front of IM-2.

Figure D-2: Before and after pictures of the back of IM-2.
D-4 

Figure D-3: Before and after pictures of the front of panel IM-3.

Figure D-4: After picture of the back of panel IM-3.
D-5 

Figure D-5: Before and after pictures of the front of panel IM-4.

Figure D-6: Before and after pictures of the back of panel IM-4.
D-6 

Figure D-7: Before and after pictures of the front of panel IM-5.

Figure D-8: Before and after pictures of the back of panel IM-5.
D-7 

Figure D-9: Before and after pictures of front of panel IM-6.

Figure D-10: Before and after pictures of back of panel IM-6.
D-8 

Figure D-11: Before and after pictures of front of panel IM-7.

Figure D-12: Before and after pictures of back of panel IM-7.
D-9 

Figure D-13: Before and after pictures of the front of panel IM-8.

Figure D-14: Before and after pictures of the back of panel IM-8.
D-10

Figure D-15: Before and after pictures of the front of panel IM-9.

Figure D-16: Before and after pictures of the back of panel IM-9.
D-11

Figure D-17: Before and after pictures of the font of panel IM-10.

Figure D-18: Before and after pictures of the back of panel IM-10.
D-12

Figure D-19: Before and after pictures of the front of panel IM-11.

Figure D-20: Before and after pictures of the back of panel IM-11.
D-13

Figure D-21: Before and after pictures of the front of panel IM-12.

Figure D-22: Before and after pictures of the back of panel IM-12.
D-14

Figure D-23: Before and after pictures of the front of IM-13.

Figure D-24: Before and after pictures of the back of IM-13.
D-15

Figure D-25: Before and after pictures of front of panel IM-14.

Figure D-26: View of double-sided tape with cut lines on back of panel IM-14.
D-16

Figure D-27: Before and after pictures of back of panel IM-14.

Figure D-28: Before and after pictures of the front of panel IM-15.
D-17

Figure D-29: Before and after pictures of the back of panel IM-15.

Figure D-30: Before and after pictures of the front of IM-16. 
D-18

Figure D-31: Before and after pictures of the back of IM-16.

Figure D-32: Before and after pictures of the front of panel IM-17.
D-19

Figure D-33: Before and after pictures of the back of panel IM-17.

Figure D-34: Before and after pictures of the front of panel IM-18.
D-20

Figure D-35: Before picture of panel IM-18 mounted on test fixture. 

Figure D-36: Before and after pictures of the back of panel IM-18.
D-21

Figure D-37: Before and after pictures of the front of panel IM-19.

Figure D-38: Before and after pictures of the back of panel IM-19.
D-22

Figure D-39: Before and after pictures of the front of panel IM-20.

Figure D-40: Before and after pictures of the back of panel IM-20.
D-23

Figure D-41: Before and after pictures of the front of panel IM-21.

Figure D-42: Before and after pictures of the back of panel IM-21.
D-24

Figure D-43: Before and after pictures of the front of panel IM-22.

Figure D-44: Before and after pictures of the back of panel IM-22.
D-25

Figure D-45: Before and after pictures of the front of panel IM-23.

Figure D-46: Before and after pictures of the back of panel IM-23.
D-26

Figure D-47: Before and after pictures of the front of panel IM-24.

Figure D-48: Before and after pictures of the back of panel IM-24.
D-27

Figure D-49: Before and after pictures of the front of panel IM-25.

Figure D-50: Before and after pictures of the back of panel IM-25.
D-28

Figure D-51: Before and after pictures of the front of panel IM-26.

Figure D-52: Before and after pictures of the back of panel IM-26.
D-29

Figure D-53: Before and after pictures of the front of panel IM-27.

Figure D-54: Before and after pictures of the back of panel IM-27.
D-30

Figure D-55: Before and after pictures of the front of panel IM-28.

Figure D-56: Before and after pictures of the back of panel IM-28.
D-31

Figure D-57: Cuts in double-sided tape to flatten panel IM-28. 
D-32

Figure D-58: Before and after pictures of the front of panel IM-29.

Figure D-59: Before and after pictures of the back of panel IM-29.
D-33

Figure D-60: Before and after pictures of the front of panel IM-30.

Figure D-61: Before and after pictures of the back of panel IM-30.
D-34

Figure D-62: Before and after pictures of the front of panel IM-31.

Figure D-63: Before and after pictures of the back of panel IM-31.
D-35

Figure D-64: Before and after pictures of the front of panel IM-32.

Figure D-65: After impact picture of back of panel IM-32.
D-36

Figure D-66: Before and after pictures of the front of panel IM-33.

Figure D-67: Before and after pictures of the back of panel IM-33.
D-37

Figure D-68: Before and after pictures of the front of panel IM-34.

Figure D-69: Before and after pictures of the back of panel IM-34.
D-38

Figure D-70: Before and after pictures of the front of panel IM-35.

Figure D-71: Before and after pictures of the back of panel IM-35.
D-39

Figure D-72: Before and after pictures of the front of panel IM-36.

Figure D-73: Before and after pictures of the back of panel IM-36.
D-40

Figure D-74: Before and after pictures of the front of panel IM-37.

Figure D-75: Before and after pictures of the back of panel IM-37.
D-41

Figure D-76: Before and after pictures of the front of panel IM-38.

Figure D-77: Before and after pictures of the back of panel IM-38.
D-42

Figure D-78: Before and after pictures of the front of panel IM-39.

Figure D-79: Before and after pictures of the back of panel IM-39.
D-43

Figure D-80: Before and after pictures of the front of panel IM-40.

Figure D-81: Before and after pictures of the back of panel IM-40.
D-44

Figure D-82: Before and after pictures of the front of panel IM-41.

Figure D-83: Before and after pictures of the back of panel IM-41.
D-45

Figure D-84: Before and after pictures of the front of panel IM-43.

Figure D-85: Before and after pictures of the back of panel IM-43.
D-46

Figure D-86: Before and after pictures of the front of panel IM-44.

Figure D-87: Before and after pictures of the back of panel IM-44.
D-47

Figure D-88: Side view of back of panel IM-44.
D-48

Figure D-89: Before and after pictures of the front of panel IM-45.

Figure D-90: Before and after pictures of the back of panel IM-45.
D-49

Figure D-91: 0.5" impactor at 250 in-lbs penetrating base panel IM-45. 
D-50

Figure D-92: Before and after pictures of the front of panel IM-46.

Figure D-93: Before and after pictures of the back of panel IM-46.
D-51

Figure D-94: Before and after pictures of the front of panel IM-47.

Figure D-95: Before and after pictures of the back of panel IM-47.
D-52

Figure D-96: Split from 0.5" impactor at 250 in-lbs in panel IM-47.
D-53

Figure D-97: Before and after pictures of the front of panel IM-48.

Figure D-98: Before and after pictures of the back of panel IM-48.
D-54

Figure D-99: Before and after pictures of the front of panel IM-49.

Figure D-100: Before and after pictures of the back of panel IM-49.
D-55

Figure D-101: Before and after pictures of the front of panel IM-50.

Figure D-102: Before and after pictures of the back of panel IM-50.
D-56

Figure D-103: Before and after pictures of the front of panel IM-51.

Figure D-104: Before and after pictures of the back of panel IM-51.
D-57

Figure D-105: Side view of front of panel IM-51 after impact. 
D-58

Figure D-106: Before and after pictures of front of panel IM-52.

Figure D-107: Before and after pictures of the back of panel IM-52.
D-59

Figure D-108: Before and after pictures of the front of panel IM-53.

Figure D-109: Before and after pictures of the back of panel IM-53.
D-60

Figure D-110: Before and after pictures of the front of panel IM-54.

Figure D-111: Before and after pictures of the back of panel IM-54.
D-61

Figure D-112: Up close picture of front of panel IM-54 after impact. 
D-62

Figure D-113: Before and after pictures of the front of panel IM-55.

Figure D-114: Before and after pictures of the back of panel IM-55.
D-63

Figure D-115: Before and after pictures of the front of panel IM-56.

Figure D-116: Before and after pictures of the back of panel IM-56.
D-64

Figure D-117: Before and after pictures of the front of panel IM-57.

Figure D-118: Before and after pictures of the back of panel IM-57.
D-65

Figure D-119: Side close up of back of panel IM-57.
D-66

Figure D-120: Before and after pictures of front of panel IM-58.

Figure D-121: Before and after pictures of the back of panel IM-58.
D-67

Figure D-122: Side close up of front of panel IM-58.
D-68

Figure D-123: Side close up of back of panel IM-58.
D-69

Figure D-124: Before and after pictures of the front of panel IM-59.

Figure D-125: Before and after pictures of the back of panel IM-59.
D-70

Figure D-126: Before and after pictures of the front of panel IM-60.

Figure D-127: Before and after pictures of the back of panel IM-60.
D-71

Figure D-128: Before and after pictures of the front of panel IM-61.

Figure D-129: Before and after pictures of the back of panel IM-61.
D-72

Figure D-130: Before and after pictures of the front of panel IM-62.

Figure D-131: Before and after pictures of the back of panel IM-62.
D-73

Figure D-132: Back of panel IM-62 after 250 in-lb with 0.5” impactor. 
D-74

Figure D-133: Before and after pictures of the front of panel IM-63.

Figure D-134: Before and after pictures of the back of panel IM-63.

30
D-75

Figure D-135: Before and after pictures of the front of panel IM-64.

Figure D-136: Before and after pictures of the back of panel IM-64.
D-76

Figure D-137: Before and after pictures of the front of panel IM-65.

Figure D-138: Before and after pictures of the back of panel IM-65.
D-77

Figure D-139: Before and after pictures of the front of panel IM-66.

Figure D-140: Before and after pictures of the back of panel IM-66.
D-78

Figure D-141: Before and after pictures of the front of panel IM-67.

Figure D-142: Before and after pictures of the back of panel IM-67.
D-79

Figure D-143: Before and after pictures of the front of panel IM-68.

Figure D-144: Before and after pictures of the back of panel IM-68.
D-80

Figure D-145: Side view of front of panel IM-68 after impact. 
D-81

Figure D-146: Before and after pictures of the front of panel IM-69.

Figure D-147: Before and after pictures of the back of panel IM-69.
D-82

Figure D-148: Before and after pictures of the front of panel IM-70.

Figure D-149: Before and after pictures of the back of panel IM-70.
D-83

Figure D-150: Before and after pictures of the front of panel IM-71.

Figure D-151: Before and after pictures of the back of panel IM-71.
D-84

Figure D-152: Side view of the back of panel IM-71 after impact. 
D-85

Figure D-153: Before and after pictures of the front of panel IM-72.

Figure D-154: Before and after pictures of the back of panel IM-72.
D-86

Figure D-155: Before and after pictures of the front of panel IM-73.

Figure D-156: Before and after pictures of the back of panel IM-73.
D-87

Figure D-157: Before and after pictures of the front of panel IM-74.

Figure D-158: Before and after pictures of the back of panel IM-74.
D-88

Figure D-159: Before and after pictures of the front of panel IM-75.

Figure D-160: Before and after pictures of the back of panel IM-75.
D-89

Figure D-161: Before and after pictures of the front of panel IM-76.

Figure D-162: Before and after pictures of the back of panel IM-76.
D-90

Figure D-163: Before and after pictures of the front of panel IM-77.

Figure D-164: Before and after pictures of the back of panel IM-77.
D-91

Figure D-165: Before and after pictures of the front of panel IM-78.

Figure D-166: Before and after pictures of the back of panel IM-78.
D-92

Figure D-167: Before and after pictures of the front of panel IM-79.

Figure D-168: Before and after pictures of the back of panel IM-79.
D-93

Figure D-169: Before and after pictures of the front of panel IM-80.

Figure D-170: Before and after pictures of the back of panel IM-80.
D-94

Figure D-171: Before and after pictures of the front of panel IM-81.

Figure D-172: Before and after pictures of the back of panel IM-81.
D-95

Figure D-173: Before and after pictures of the front of panel IM-82.

Figure D-174: Before and after pictures of the back of panel IM-82.
D-96

Figure D-175: Before and after pictures of the front of panel IM-83.

Figure D-176: Before and after pictures of the back of panel IM-83.
D-97

Figure D-177: Before and after pictures of the front of panel IM-84.

Figure D-178: Before and after pictures of the back of panel IM-84.
D-98

Figure D-179: Before and after pictures of the front of panel IM-85.

Figure D-180: Before and after pictures of the back of panel IM-85.
D-99

Figure D-181: Before and after pictures of the front of panel IM-86.

Figure D-182: Before and after pictures of the back of panel IM-86.
D-100

Figure D-183: Before and after pictures of the front of panel IM-87.

Figure D-184: Before and after pictures of the back of panel IM-87.
D-101

Figure D-185: Before and after pictures of the front of panel IM-88.

Figure D-186: Before and after pictures of the back of panel IM-88.
D-102

Figure D-187: Before and after pictures of the front of panel IM-89.

Figure D-188: Before and after pictures of the back of panel IM-89.
D-103

Figure D-189: Side view of the back of panel IM-89 after impact. 
D-104

Figure D-190: Before and after pictures of the front of panel IM-90.

Figure D-191: Before and after pictures of the back of panel IM-90.
D-105

Figure D-192: Before and after pictures of the front of panel IM-91.

Figure D-193: Before and after pictures of the back of panel IM-91.
D-106

Figure D-194: Before and after pictures of the front of panel IM-92.

Figure D-195: Before and after pictures of the back of panel IM-92.
D-107

Figure D-196: Before and after pictures of the front of panel IM-93.

Figure D-197: Before and after pictures of the back of panel IM-93.
D-108

Figure D-198: Side view of back of panel IM-93 after impact. 
D-109

Figure D-199: Before and after pictures of the front of panel IM-94.

Figure D-200: Before and after pictures of back of panel IM-94.
D-110

Figure D-201: Side view of back of panel IM-94 after impacts. 
D-111

Figure D-202: Before and after pictures of the front of panel IM-95.

Figure D-203: Before and after pictures of the back of panel IM-95.
D-112

Figure D-204: Before and after pictures of the front of panel IM-96.

Figure D-205: Before and after pictures of the back of panel IM-96.
D-113

Figure D-206: Before and after pictures of the front of panel IM-97.

Figure D-207: Before and after pictures of the back of panel IM-97.
D-114

Figure D-208: Before and after pictures of the front of panel IM-98.

Figure D-209: Before and after pictures of the back of panel IM-98.
D-115

Figure D-210: Before and after pictures of the front of panel IM-99.

Figure D-211: Before and after pictures of the back of panel IM-99.
D-116

Figure D-212: Before and after pictures of the front of panel IM-100.

Figure D-213: Before and after pictures of the back of panel IM-100.
D-117

Figure D-214: 1.0" impactor penetrating panel after 180 in-lb impact (top side and bottom view). 

Figure D-215: Panel IM-100 installed on test platform. 
D-118

Figure D-216: Panel IM-100 installed in test facility.
E-1 

 

Appendix E - 

First-Generation Shielding Effectiveness Test Setup 
E-2 

Figure E-1: Top hat antenna in the main chamber. 
E-3 

Figure E-2: Top hat antenna in the main chamber. 

Figure E-3: Top hat antenna in the main chamber. 
E-4 

Figure E-4: Main reverberation chamber. 
E-5 

Figure E-5: Top hat antenna in the main chamber. 
E-6 

Figure E-6: Top hat antenna in the shielded room. 
E-7 

Figure E- 7: Panel mounted in transmissivity frame. 
E-8 

Figure E-8: Side view of panel mounted in transmissivity frame. 
E-9 

Figure E-9: Aluminum panel mounted in test chamber. 
E-10

Figure E-10: Bare CFC (carbon fiber composite) panel (no lightning strike protection).

Figure E-11: Panel LS-1 mounted in chamber. 
E-11

Figure E-12: Panel LS-2 mounted in chamber. 

Figure E-13: Panel LS-4 mounted in chamber (without copper tape on top of core). 
E-12

Figure E-14: Panel LS-4 mounted in chamber (with copper tape on top of core). 

Figure E-15: Panel LS-5 mounted in chamber.
E-13

Figure E-16: Panel LS-6 mounted in chamber. 
E-14

Figure E-17: Panel LS-7 mounted in chamber. 

Figure E-18: Panel LS-8 mounted in chamber. 
E-15

Figure E-19: Panel LS-9 mounted in chamber (mislabeled as10). 

Figure E-20: Panel LS-10 mounted in chamber. 
E-16

Figure E-21: Panel LS-11 mounted in chamber. 
E-17

Figure E-22: Panel LS-12 mounted in chamber. 

Figure E-23: Panel LS-13 mounted in chamber. 
E-18

Figure E-24: Panel LS-14 mounted in chamber. 

Figure E-25: Panel LS-15 mounted in chamber. 
E-19

Figure E-26: Panel LS-18 showing flaw in LDS 50-01.

Figure E-27: Panel LS-18 with copper tape ready for chamber. 
E-20

Figure E-28: Panel LS-18 mounted in chamber. 

Figure E-29: Panel LS-20 mounted in chamber. 
E-21

Figure E-30: Panel LS-21 mounted in chamber. 

Figure E-31: Panel LS-22 mounted in chamber. 
E-22

Figure E-32: Panel LS-23 mounted in chamber. 

Figure E-33: Panel LS-24 mounted in chamber. 
E-23

Figure E-34: Panel LS-25 mounted in chamber. 

Figure E-35: Panel LS-26 mounted in chamber. 
E-24

Figure E-36: Panel LS-27 mounted in chamber. 

Figure E-37: Panel LS-29 mounted in chamber. 
E-25

Figure E-38: Panel LS-30 mounted in chamber. 

Figure E-39: Panel LS-32 mounted in chamber. 
E-26

Figure E-40: Panel LS-33 mounted in chamber. 
E-27

Figure E-41: Panel LS-34 mounted in chamber. 

Figure E-42: Panel LS-35 mounted in chamber. 
E-28

Figure E-43: Panel LS-36 mounted in chamber. 

Figure E-44: Panel LS-37 mounted in chamber. 
E-29

Figure E-45: Panel LS-38 mounted in chamber. 

Figure E-46: Panel LS-39 mounted in chamber. 
E-30

Figure E-47: Panel LS-40 mounted in chamber. 

Figure E-48: Panel LS-41 mounted in chamber. 
E-31

Figure E-49: Panel LS-42 mounted in chamber. 

Figure E-50: Panel LS-43 mounted in chamber. 
E-32

Figure E-51: Panel LS-44 mounted in chamber. 

Figure E-52: Panel LS-45 mounted in chamber. 
E-33

Figure E-53: Panel LS-46 mounted in chamber. 

Figure E-54: Panel LS-47 mounted in chamber. 
F-1 

Appendix F 

First-Generation Shielding Effectiveness Test Data
F-2 

Figure F-1: Panel LS-1shielding effectiveness data plot. 

Figure F-2: Panel LS-2 shielding effectiveness data plot. 

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -1

LS -1

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -2

LS -2
F-3 

Figure F-3: Panel LS-4 shielding effectiveness data plot. 

Figure F-4: Panel LS-5 shielding effectiveness data plot. 

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -4

LS -4

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -5

LS -5
F-4 

Figure F-5: Panel LS-6 shielding effectiveness data plot. 

Figure F-6: Panel LS-7 shielding effectiveness data plot. 

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -6

LS -6

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -7

LS -7
F-5 

Figure F-7: Panel LS-8 shielding effectiveness data plot. 

Figure F-8: Panel LS-9 shielding effectiveness test data. 

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -8

LS -8
F-6 

Figure F-9: Panel LS-10 shielding effectiveness data plot. 

Figure F-10: Panel LS-11 shielding effectiveness data plot. 

-120

-100

-80

-60

-40

-2 0

0

100 1000 10000 100000

LS -10

LS -10

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -11

LS -11
F-7 

Figure F-11: Panel LS-12 shielding effectiveness data plot. 

Figure F-12: Panel LS-13 shielding effectiveness data plot. 

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -12

LS -12

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -13

LS -13
F-8 

Figure F-13: Panel LS-14 shielding effectiveness data plot. 

Figure F-14: Panel LS-15 shielding effectiveness data plot. 

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -14

LS -14

-100

-90

-8 0

-70

-6 0

-50

-4 0

-3 0

-2 0

-1 0

0

100 1000 10000 100000

LS -15

LS -15
F-9 

Figure F-15: Panel LS-16 shielding effectiveness data plot. 

Figure F-16: Panel LS-18 shielding effectiveness data plot. 

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -16

LS -16

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -18

LS -18
F-10

Figure F-17: Panel LS-19 shielding effectiveness test data. 

Figure F-18: Panel LS-20 shielding effectiveness test data. 

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -20

LS -20
F-11

Figure F-19: Panel LS-21 shielding effectiveness test data. 

Figure F-20: Panel LS-22 shielding effectiveness test data. 

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -21

LS -21

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -22

LS -22
F-12

Figure F-21: Panel LS-23 shielding effectiveness data. 

Figure F-22: Panel LS-24 shielding effectiveness test data. 

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -23

LS -23

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -24

LS -24
F-13

Figure F-23: Panel LS-25 shielding effectiveness test data. 

Figure F-24: Panel LS-26 shielding effectiveness test data. 

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -25

LS -25

-120

-100

-80

-60

-40

-2 0

0

100 1000 10000 100000

LS -26

LS -26
F-14

Figure F-25: Panel LS-27 shielding effectiveness test data. 

Figure F-26: Panel LS-28 shielding effectiveness test data. 

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -27

LS -27

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -28

LS -28
F-15

Figure F-27: Panel LS-29 shielding effectiveness test data. 

Figure F-28: Panel LS-30 shielding effectiveness test data. 

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -29

LS -29

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -30

LS -30
F-16

Figure F-29: Panel LS-32 shielding effectiveness test data.

Figure F-30: Panel LS-33 shielding effectiveness test data. 

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -32

LS -32

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -33

LS -33
F-17

Figure F-31: Panel LS-34 shielding effectiveness test data. 

Figure F-32: Panel LS-35 shielding effectiveness test data. 

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -34

LS -34

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -35

LS -35
F-18

Figure F-33: Panel LS-36 shielding effectiveness test data. 

Figure F-34: Panel LS-37 shielding effectiveness test data. 

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -36

LS -36

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -37

LS -37
F-19

Figure F-35: Panel LS-38 shielding effectiveness test data. 

Figure F-36: Panel LS-39 shielding effectiveness test data. 

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -38

LS -38

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -39

LS -39
F-20

Figure F-37: Panel LS-40 shielding effectiveness test data. 

Figure F-38: Panel LS-41 shielding effectiveness test data. 

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -40

LS -40

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -41

LS -41
F-21

Figure F-39: Panel LS-42 shielding effectiveness data. 

Figure F-40: Panel LS-43 shielding effectiveness test data. 

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -42

LS -42

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -43

LS -43
F-22

Figure F-41: Panel LS-44 shielding effectiveness data. 

Figure F-42: Panel LS-45 shielding effectiveness data. 

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -44

LS -44

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -45

LS -45
F-23

Figure F-43: Panel LS-46 shielding effectiveness test data. 

Figure F-44: Panel LS-47 shielding effectiveness test data.

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -46

LS -46

-100

-90

-8 0

-70

-6 0

-50

-4 0

-30

-2 0

-10

0

100 1000 10000 100000

LS -47

LS -47
G-1 

APPENDIX G 

First-Generation Indirect Effects Test Data (RTCA/DO-160F Section 22.0)
G-2 

Figure G-45: Isc calibration WVFM 1 level 3 Pos 608 A (file 000). 

Figure G-46: Voc Calibration WVFM 2 level 3 Pos 1.2 kV (file 001). 
G-3 

Figure G-47: isc(file 034) 

Figure G-48: voc (file 035). 
G-4 

Figure G-49: Isc (file 068). 

Figure G-50: Voc (file 069). 
G-5 

Figure G-51: Al Panel Neg -425 A 0.97(file 046). 

Figure G-52: Al Panel 441 A 0.97(file 047). 
G-6 

Figure G-53: Carbon Panel WFM 4 & 1 level 3 Pos 358 A and 17 V with 41.4 mΩ resistance (file 090). 

Figure G-54: Carbon Panel WFM 4 & 1 level 3 Neg -358 A and 17 V with 41.4 mΩ resistance (file 091). 
G-7 

Figure G-55: LS-01 WFM 4 & 1 level 3 Pos 433 A and 17 V with 5.9 mΩ resistance (file 048). 

Figure G-56: LS-01 WFM 4 & 1 level 3 Neg -416 A and 17 V with 5.9 mΩ resistance (file 049). 
G-8 

Figure G-57: LS-02 WFM 4 & 1 level 3 Pos 433 A and 17 V with 8.6 mΩ resistance (file 044). 

Figure G-58: LS-02 WFM 4 & 1 level 3 Neg -416 A and 17 V with 8.6 mΩ resistance (file 045). 
G-9 

Figure G-59: LS-04 WFM 4 & 1 level 3 Pos 416 A and 17 V with 17.1 mΩ resistance (file 064). 

Figure G-60: LS-04 WFM 4 & 1 level 3 Neg -416 A and 17 V with 17.1 mΩ resistance (file 065).
G-10

Figure G-61: LS-05 WFM 4 & 1 level 3 Pos 425 A and 17 V with 12.8 mΩ resistance (file 036). 

Figure G-62: LS-05 WFM 4 & 1 level 3 Neg -425 A and 17 V with 12.8 mΩ resistance (file 037). 
G-11

Figure G-63: LS-06 WFM 4 & 1 level 3 Neg -375 A and 17 V with 20.2 mΩ resistance (file 062). 

Figure G-64: LS-06 WFM 4 & 1 level 3 Pos 366 A and 17 V with 20.2 mΩ resistance (file 063). 
G-12

Figure G-65: LS-07 WFM 4 & 1 level 3 Neg -425 A and 17 V with 7.9 mΩ resistance (file 028). 

Figure G-66: LS-07 WFM 4 & 1 level 3 Pos 425 A and 17 V with 7.9 mΩ resistance (file 029). 
G-13

Figure G-67: LS-8 WFM 4 & 1 level 3 Pos Neg -416A and -18 V with 11.2 mΩ resistance (file 024). 

Figure G-68: LS-8 WFM 4 & 1 level 3 Pos 425 A and 18 V with 11.2 mΩ resistance (file 025). 
G-14

Figure G-69: LS-09 WFM 4 & 1 level 3 Pos 408 A and 17 V with 18.5 mΩ resistance (file 030). 

Figure G-70: LS-09 WFM 4 & 1 level 3 Neg -408 A and 17 V with 18.5 mΩ resistance (file 031). 
G-15

Figure G-71: LS-10 WFM 4 & 1 level 3 Pos 433 A and 18 V with 6.9 mΩ resistance (file 022). 

Figure G-72: LS-10 WFM 4 & 1 level 3 Neg -425 A and -18 V with 6.9 mΩ resistance (file 023). 
G-16

Figure G-73: LS-11 WFM 4 & 1 level 3 Pos 425 A and 17 V with 21.1 mΩ resistance (file 052). 

Figure G-74: LS-11 WFM 4 & 1 level 3 Neg -416 A and 17 V with 21.1 mΩ resistance (file 053). 
G-17 

Figure G-75: LS-12 WFM 4 & 1 level 3 Pos 425 A and 17 V with 7.7 mΩ resistance (file 026). 

Figure G-76: LS-12 WFM 4 & 1 level 3 Neg -425 A and 17 V with 7.7 mΩ resistance (file 027). 
G-18

Figure G-77: LS-13 WFM 4 & 1 level 3 Pos 425 A and 17 V with 9.8 mΩ resistance (file 040). 

Figure G-78: LS-13 WFM 4 & 1 level 3 Neg -425 A and 17 V with 9.8 mΩ resistance (file 041). 
G-19

Figure G-79: LS-14 WFM 4 & 1 level 3 Neg -408 A and 17 V with 7.9 mΩ resistance (file 032). 

Figure G-80: LS-14 WFM 4 & 1 level 3 Pos 433 A and 17 V with 7.9 mΩ resistance (file 033). 
G-20

Figure G-81: LS-15 WFM 4 & 1 level 3 Neg -425 A and 17 V with 35.6 mΩ resistance (file 076). 

Figure G-82: LS-15 WFM 4 & 1 level 3 Neg 433 A and 17 V with 35.6 mΩ resistance (file 077). 
G-21

Figure G-83: LS-16 WFM 4 & 1 level 3 Neg -425 A and 17 V with 8.3 mΩ resistance (file 080). 

Figure G-84: LS-16 WFM 4 & 1 level 3 Pos 433 A and 17 V with 8.3 mΩ resistance (file 081). 
G-22

Figure G-85: LS-18 WFM 4 & 1 level 3 Neg -425 A and 17 V with 22.6 mΩ resistance (file 038). 

Figure G-86: LS-18 WFM 4 & 1 level 3 Pos 425 A and 17 V with 22.6 mΩ resistance (file 039). 
G-23

Figure G-87: LS-19 WFM 4 & 1 level 3 Pos 425 A and 17 V with 8.1 mΩ resistance (file 078). 

Figure G-88: LS-19 WFM 4 & 1 level 3 Neg -425 A and 17 V with 8.1 mΩ resistance (file 079). 
G-24

Figure G-89: LS-20 WFM 4 & 1 level 3 Neg -375 A and 17 V with 37.5 mΩ resistance (file 042). 

Figure G-90: LS-20 WFM 4 & 1 level 3 Pos 366 A and 17 V with 37.5 mΩ resistance (file 043). 
G-25

Figure G-91: LS-21 WFM 4 & 1 level 3 Neg -416 A and 17 V with 6.4 mΩ resistance (file 084). 

Figure G-92: LS-21 WFM 4 & 1 level 3 Pos 433 A and 17 V with 6.4 mΩ resistance (file 085). 
G-26

Figure G-93: LS-22 WFM 4 & 1 level 3 Pos 425 A and 17 V with 15.0 mΩ resistance (file 074). 

Figure G-94: LS-22 WFM 4 & 1 level 3 Neg -425 A and 17 V with 15.0 mΩ resistance (file 075). 
G-27

Figure G-95: LS-23 WFM 4 & 1 level 3 Pos 425 A and 17 V with 13.5 mΩ resistance (file 060). 

Figure G-96: LS-23 WFM 4 & 1 level 3 Neg -408 A and 17 V with 13.5 mΩ resistance (file 061). 
G-28

Figure G-97: LS-24 WFM 4 & 1 level 3 Neg -416 A and 17 V with 8.4 mΩ resistance (file 058). 

Figure G-98: LS-24 WFM 4 & 1 level 3 Pos 433 A and 17 V with 8.4 mΩ resistance (file 059). 
G-29

Figure G-99: LS-25 WFM 4 & 1 level 3 Neg -416 A and -18 V with 14.4 mΩ resistance (file 020). 

Figure G-100: LS-25 WFM 4 & 1 level 3 Pos 416 A and 17 V with 13.6 mΩ resistance (file 021). 
G-30

Figure G-101: LS-26 WFM 4 & 1 level 3 Pos 433 A and 17 V with 6.7 mΩ resistance (file 082). 

Figure G-102: LS-26 WFM 4 & 1 level 3 Neg -416 A and 17 V with 6.7 mΩ resistance (file 083). 
G-31

Figure G-103: LS-27 WFM 4 & 1 level 3 Pos 425 A and 18 V with 8.4 mΩ resistance (file 018). 

Figure G-104: LS-27 WFM 4 & 1 level 3 Neg -425 A and -18 V with 14.4 mΩ resistance (file 019). 
G-32

Figure G-105: LS-28 WFM 4 & 1 level 3 Neg -408 A and 17 V with 11.2 mΩ resistance (file 054). 

Figure G-106: LS-28 WFM 4 & 1 level 3 Pos 425 A and 17 V with 11.2 mΩ resistance (file 055). 
G-33

Figure G-107: LS-29 WFM 4 & 1 level 3 Pos 433 A and 17 V with 12.8 mΩ resistance (file 094). 

Figure G-108: LS-29 WFM 4 & 1 level 3 Neg -433 A and 17 V with 12.8 mΩ resistance (file 095). 
G-34

Figure G-109: LS-30 WFM 4 & 1 level 3 Neg -425 A and 17 V with 12.3 mΩ resistance (file 092). 

Figure G-110: LS-30 WFM 4 & 1 level 3 Pos 425 A and 17 V with 12.3 mΩ resistance (file 093). 
G-35

Figure G-111: LS-32 WFM 4 & 1 level 3 Neg -416 A and 17 V with 11.7 mΩ resistance (file 050). 

Figure G-112: LS-32 WFM 4 & 1 level 3 Pos 433 A and 17 V with 11.7 mΩ resistance (file 051). 
G-36

Figure G-113: LS-33 WFM 4 & 1 level 3 Neg -416 A and 17 V with 20.4 mΩ resistance (file 096). 

Figure G-114: LS-33 WFM 4 & 1 level 3 Pos 400 A and 17 V with 20.4 mΩ resistance (file 097). 
G-37

Figure G-115: LS-34 WFM 4 & 1 level 3 Pos 366 A and 17 V with 19.3 mΩ resistance (file 086). 

Figure G-116: LS-34 WFM 4 & 1 level 3 Neg -358 A and 17 V with 19.3 mΩ resistance (file 087). 
G-38

Figure G-117: LS-35 WFM 4 & 1 level 3 Pos 425 A and 17 V with 9.2 mΩ resistance (file 098). 

Figure G-118: LS-35 WFM 4 & 1 level 3 Neg -433 A and 17 V with 9.2 mΩ resistance (file 099). 
G-39

Figure G-119: LS-36 WFM 4 & 1 level 3 Neg -425 A and 17 V with 8.3 mΩ resistance (file 066). 

Figure G-120: LS-36 WFM 4 & 1 level 3 Pos 425 A and 17 V with 8.3 mΩ resistance (file 067). 
G-40

17

Figure G-121: LS-37 WFM 4 & 1 level 3 Pos 400 A and 17 V with 13.6 mΩ resistance (file 010). 

Figure G-122: LS-37 WFM 4 & 1 level 3 Neg -416 A and -18 V with 13.6 mΩ resistance (file 011). 
G-41

Figure G-123: LS-38 WFM 4 & 1 level 3 Pos 433 A and 17 V with 6.9 mΩ resistance (file 056). 

Figure G-124: LS-38 WFM 4 & 1 level 3 Neg -416 A and 17 V with 6.9 mΩ resistance (file 057). 
G-42

Figure G-125: LS-39 WFM 4 & 1 level 3 Neg -425 A and 17 V with 10.2 mΩ resistance (file 088). 

Figure G-126: LS-39 WFM 4 & 1 level 3 Pos 425 A and 17 V with 10.2 mΩ resistance (file 089). 
G-43

Figure G-127: LS-40 WFM 1 & 4 level 3 Pos 425 A and 18 V with 11.3 mΩ resistance file (002). 

Figure G-128: LS-40 WFM 1 & 4 level 3 Neg -433 A and -19 V with 11.3 mΩ resistance file (003). 
G-44

Figure G-129: LS-41 WFM 4 & 1 level 3 Neg -408 A and -18 V with 14.6 mΩ resistance (file 012). 

Figure G-130: LS-41 WFM 4 & 1 level 3 Pos 416 A and 18 V with 14.6 mΩ resistance (file 013). 
G-45

Figure G-131: LS-42 WFM 4 & 1 level 3 Neg -425 A and -18 V with 6.6 mΩ resistance (file 016). 

Figure G-132: LS-42 WFM 4 & 1 level 3 Pos 425 A and 18 V with 6.6 mΩ resistance (file 017). 
G-46

Figure G-133: LS-43 WFM 4 & 1 level 3 Neg -425 A and 17 V with 7.4 mΩ resistance (file 072). 

Figure G-134: LS-43 WFM 4 & 1 level 3 Neg 425 A and 17 V with 7.4 mΩ resistance (file 073). 
G-47

Figure G-135: LS-44 WFM 4 & 1 level 3 Pos 416 A and 17 V with 13.2 mΩ resistance (file 070). 

Figure G-136: LS-44 WFM 4 & 1 level 3 Neg -408 A and 17 V with 13.2 mΩ resistance (file 071). 
G-48

Figure G-137: LS-45 WFM 4 & 1 level 3 Neg -25 A and 17 V with 43.4 mΩ resistance (file 100). 

Figure G-138: LS-45 WFM 4 & 1 level 3 Pos 26 A and 17 V with 43.4 mΩ resistance (file 101). 
G-49

Figure G-139: LS-46 WFM 4 & 1 level 3 Neg -279 A and -12 V with 43.3 mΩ resistance file (004). 

Figure G-140: LS-46 WFM 4 & 1 level 3 Pos 283 A and 12 V with 43.3 mΩ resistance file (005). 
G-50

Figure G-141: LS-46 WFM 4 & 1 level 3 Pos 275 A and 12 V with 43.2 mΩ resistance file (006). 

Figure G-142: LS-46 WFM 4 & 1 level 3 Neg -275 A and -12 V with 43.2 mΩ resistance file (007). 
G-51

Figure G-143: LS-46 WFM 1 & 4 level 3 Neg -283 A and -12 V with 40.0 mΩ resistance (file 008). 

Figure G-144: LS-46 WFM 4 & 1 level 3 Pos 283 A and 12 V with 40.8 mΩ resistance (file 009). 
G-52

Figure G-145: LS-47 WFM 4 & 1 level 3 Pos 304 A and 13 V with 41.8 mΩ resistance (file 014). 

Figure G-146: LS-47 WFM 4 & 1 level 3 Neg -300 A and 13 V with 41.8 mΩ resistance (file 015).
H-1 

Appendix H 

First-Generation Direct Effects (DNB) Report
H-2 
H-3 

TABLE OF CONTENTS

Paragraph

Test Completion Record

1.0 Introduction

2.0 Test Requirements

3.0 Test Equipment

4.1 Summary of Test Results

4.2 Lightning Direct Effects, SAE ARP5416

5.0 Test Description

6.0 Conclusions

Page

4

5

5

5

5

5

7

8

SIZE

A

CAGE CODE

63242

DRAWIN G NO.

TR056893

SCALE: NONE REV LTR - SHEET 2

DNB ENGINEERING, INC. 3535 W. COMMONWEALTH AVE. FULLERTON, CA 92833 (714) 870-7781 FAX (714) 870-5081 www.dnbenginc.com
H-4 

APPENDICES

Appendix Title

A Test Log

B Test Equipment Log

C Transducer Factors

D Test Data

E Photographs

Page 

A1 – A4

B1 – B2

C1

D1 – D153

E1 – E101

SIZE

A

CAGE CODE

63242

DRAWING NO.

TR056893

SCALE: NONE REV LTR - SHEET 3

DNB ENGINEERING, INC. 3535 W. COMMONWEALTH AVE. FULLERTON, CA 92833 (714) 870-7781 FAX (714) 870-5081 www.dnbenginc.com
H-5 
H-6 
H-7 
H-8 
H-9 
H-10
H-11

LIGHTNING TEST LOG 

CUSTOMER: CESSNA TEST SAMPLE: PANELS

TEST ENGINEER: STEVE COOK CUSTOMER REP: BILLY MARTIN

DATE TIME TEST DESCRIPTION

4-18-12 10:50 LS-19 – Zone 2A 30 awg fuse opened

11:30 LS-15 – Zone 2A

11:55 LS-11 – Zone 2A

2:05 LS-12 – Zone 2A

2:30 LS-14 – Zone 2A

2:55 LS-27 – Zone 2A

3:20 LS-37 – Zone 2A

3:45 LS-41 – Zone 2A

4:05 LS-25 – Zone 2A

4:30 LS-46 Side 1 – Zone 2A

5:20 LS-42 – Zone 2A

6:00 End testing for 4-18-12.

4-19-12 8:00 Continue high current test.

8:20 LS-8 – Zone 2A

8:40 LS-43 – Zone 2A

9:05 LS-38 – Zone 2A

9:25 LS-5 – Zone 2A

9:45 LS-18 – Zone 2A

10:10 LS-26 – Zone 2A

10:35 LS-7 – Zone 2A

11:05 LS-28 – Zone 2A

11:30 LS-47 – Zone 2A

2:10 LS-9 – Zone 2A

2:30 LS-24 – Zone 2A

3:00 LS-10 – Zone 2A

3:25 LS-23 – Zone 2A

4:10 LS-34 – Zone 1A

4:45 LS-40 – Zone 1A
H-12

LIGHTNING TEST LOG 

CUSTOMER: CESSNA TEST SAMPLE: PANELS

TEST ENGINEER: STEVE COOK CUSTOMER REP: BILLY MARTIN

DATE TIME TEST DESCRIPTION

4-19-12 5:00 End testing for 4-19-12.

4-20-12 8:00 Continue high current testing.

8:55 Panel LS-39 – Zone 1A

10:00 Testing completed.
H-13
H-14
H-15

MANUFACTURER DESCRIPTION MODEL NO. SERIAL NO. CAL DUE

DNB COMPONENT A/D 

GENERATOR

100KV200KA 001 CPT

DNB COMPONENT B GENERATOR 15KV2160 001 CPT

DNB COMPONENT C GENERATOR 72900VDC 001 CPT

PEARSON CURRENT PROBE – A/D 1423 2343 11-30-12

PEARSON CURRENT PROBE – B 301X 1212 10-24-12

DNB CURRENT PROBE – C HMHB100 12364 12-14-13

YOKOGAWA SCOPECORDER DL750 12B07030H 1-16-14

BIRD 20 dB ATTENUATOR 150-SA-FFN-20 162467 8-31-12

BIRD 20 dB ATTENUATOR 150-SA-FFN-20 0219 8-31-12

TEST EQUIPMENT LOG 

DIRECT EFFECT LIGHTNING 

CPT – Calibration performed prior to test. 
H-16
H-17
H-18
H-19

DIRECT EFFECT LIGHTNING TEST SUMMARY 

Test Panel Comp. A/D

Ip (KA)

Comp. A/D

AI (A

2

S)

Comp. B Iavg 

(Amps)

Comp. B CT 

(C)

Comp. C* Ip 

(Amps)

Comp. C* CT 

(C)

Cal 95.8 282940 2192 10.958 394 4.0

LS-1 94.3 269300 2310 11.552 345 5.2

LS-2 93.7 266070 2268 11.338 306 2.2

LS-4 92.8 254970 2192 10.960 223 1.1

LS-5 95.2 273070 2116 10.579 84 0.2

LS-6-1 92.5 262390 2197 10.985 281 0.82

LS-6-2 91.8 249880 2252 11.260 261 5.9

LS-7 95.2 275000 2213 11.064 303 5.6

LS-8 94.8 270680 2189 10.947 301 5.4

LS-9 92.5 238070 2234 11.171 288 5.1

LS-10 95.7 276650 2082 10.408 146 0.17

LS-11 94.7 262030 2051 10.256 242 3.7

LS-12 95.0 269070 2266 11.329 283 6.0

LS-13 92.7 256770 2163 10.814 365 12.3

LS-14 95.0 273060 2174 10.872 354 4.4

LS-15 95.5 273200 2295 11.475 358 4.3

LS-16 95.2 271810 2343 11.713 325 5.3

LS-18 94.2 269380 2154 10.768 225 5.4

LS-19 95.2 270740 2246 11.228 267 5.9

LS-20-1 90.5 247740 2152 10.761 297 16.6

LS-20-2 99.7 297860 2014 10.068 243 0.66

LS-21 93.7 267580 2168 10.840 367 4.3

LS-22 94.5 270350 2220 11.099 289 5.9

LS-23 95.8 277130 2332 11.662 230 3.2

LS-24 95.2 275240 2235 11.174 264 6.4

LS-25 94.3 267390 2223 11.117 317 4.3

LS-26 95.5 275530 2091 10.454 294 6.1

LS-27 94.0 262530 2094 10.468 270 6.5

LS-28 93.0 259950 2203 11.013 327 5.3

LS-29 94.0 271020 2287 11.437 297 5.3

LS-30 94.0 266340 2218 11.092 330 5.1

LS-32 91.8 251710 2133 10.666 329 4.7
H-20

DIRECT EFFECT LIGHTNING TEST SUMMARY 

Test Panel Comp. A/D

Ip (KA)

Comp. A/D

AI (A

2

S)

Comp. B Iavg 

(Amps)

Comp. B CT 

(C)

Comp. C Ip 

(Amps)

Comp. C* CT 

(C)

LS-33 93.7 267780 2221 11.105 258 6.7

LS-34 91.3 249210 2224 11.120 277 2.9

LS-35 94..0 268530 2079 10.397 299 6.1

LS-36 94.0 267970 2150 10.752 305 5.6

LS-37 93.3 253830 2178 10.890 183 0.70

LS-38 94.8 270310 2177 10.887 343 4.9

LS-39 92.2 251850 2257 11.283 293 6.0

LS-40 92.8 263700 2140 10.698 253 1.3

LS-41 93.7 260300 2285 11.426 239 5.4

LS-42 93.7 262790 2300 11.498 296 5.8

LS-43 94.2 262250 2136 10.681 181 0.54

LS-44 93.3 262610 2150 10.751 317 5.0

LS-45 90.8 253010 2046 10.230 6.0 0.009

LS-46 68.5 132140 2099 10.494 0 0

LS-47 70.7 140320 1829 9.146 1.3 0.004

LS-34 182.5 1.4532E6 2328 11.642 353 1.8

LS-39 175.0 1.4158E6 2150 10.750 267 1.1

LS-40 187.7 1.8343E6 2267 11.335 342 5.5
H-21

HIGH CURRENT – COMPONENT D Ip = 95.8 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 282940 A

2

-S

CALIBRATION
H-22

HIGH CURRENT – COMPONENT B

IP = 5260 Amps

Iavg = 2192 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.958 Coulombs

CALIBRATION
H-23

HIGH CURRENT – COMPONENT C* Ip = 394 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 4.0 Coulombs

CALIBRATION
H-24

HIGH CURRENT – COMPONENT D Ip = 94.3 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 269300 A

2

-S

PANEL: LS-1
H-25

HIGH CURRENT – COMPONENT B

IP = 5567 Amps

Iavg = 2310 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.552 Coulombs

PANEL: LS-1
H-26

HIGH CURRENT – COMPONENT C* Ip = 345 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 5.2 Coulombs

PANEL: LS-1
H-27

HIGH CURRENT – COMPONENT D Ip = 93.7 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 266070 A

2

-S

PANEL: LS-2
H-28

HIGH CURRENT – COMPONENT B

IP = 5487 Amps

Iavg = 2268 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.338 Coulombs

PANEL: LS-2
H-29

HIGH CURRENT – COMPONENT C* Ip = 306 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 2.2 Coulombs

PANEL: LS-2
H-30

HIGH CURRENT – COMPONENT D Ip = 92.8 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 254970 A

2

-S

PANEL: LS-4
H-31

HIGH CURRENT – COMPONENT B

IP = 5207 Amps

Iavg = 2192 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.960 Coulombs

PANEL: LS-4
H-32

HIGH CURRENT – COMPONENT C* Ip = 223 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 1.1 Coulombs

PANEL: LS-4
H-33

HIGH CURRENT – COMPONENT D Ip = 95.2 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 273070 A

2

-S

PANEL: LS-5
H-34

HIGH CURRENT – COMPONENT B

IP = 5427 Amps

Iavg = 2116 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.579 Coulombs

PANEL: LS-5
H-35

HIGH CURRENT – COMPONENT C* Ip = 84 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 0.2 Coulombs

PANEL: LS-5
H-36

HIGH CURRENT – COMPONENT D Ip = 92.5 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 262390 A

2

-S

PANEL: LS-6
H-37

HIGH CURRENT – COMPONENT B

IP = 5320 Amps

Iavg = 2197 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.985 Coulombs

PANEL: LS-6
H-38

HIGH CURRENT – COMPONENT C* Ip = 281 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 0.82 Coulombs

PANEL: LS-6
H-39

HIGH CURRENT – COMPONENT D Ip = 91.8 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 249880 A

2

-S

PANEL: LS-6 Second Strike
H-40

HIGH CURRENT – COMPONENT B

IP = 5573 Amps

Iavg = 2252 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.260 Coulombs

PANEL: LS-6 Second Strike
H-41

HIGH CURRENT – COMPONENT C* Ip = 261 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 5.9 Coulombs

PANEL: LS-6 Second Strike
H-42

HIGH CURRENT – COMPONENT D Ip = 95.2 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 275000 A

2

-S

PANEL: LS-7
H-43

HIGH CURRENT – COMPONENT B

IP = 5493 Amps

Iavg = 2213 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.064 Coulombs

PANEL: LS-7
H-44

HIGH CURRENT – COMPONENT C* Ip = 303 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 5.6 Coulombs

PANEL: LS-7
H-45

HIGH CURRENT – COMPONENT D Ip = 94.8 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 270680 A

2

-S

PANEL: LS-8
H-46

HIGH CURRENT – COMPONENT B

IP = 5367 Amps

Iavg = 2189 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.947 Coulombs

PANEL: LS-8
H-47

HIGH CURRENT – COMPONENT C* Ip = 301 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 5.4 Coulombs

PANEL: LS-8
H-48

HIGH CURRENT – COMPONENT D Ip = 92.5 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 238070 A

2

-S

PANEL: LS-9
H-49

HIGH CURRENT – COMPONENT B

IP = 5427 Amps

Iavg = 2234 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.171 Coulombs

PANEL: LS-9
H-50

HIGH CURRENT – COMPONENT C* Ip = 288 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 5.1 Coulombs

PANEL: LS-9
H-51

HIGH CURRENT – COMPONENT D Ip = 95.7 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 276650 A

2

-S

PANEL: LS-10
H-52

HIGH CURRENT – COMPONENT B

IP = 5153 Amps

Iavg = 2082 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.408 Coulombs

PANEL: LS-10
H-53

HIGH CURRENT – COMPONENT C* Ip = 146 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 0.17 Coulombs

PANEL: LS-10
H-54

HIGH CURRENT – COMPONENT D Ip = 94.7 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 262030 A

2

-S

PANEL: LS-11
H-55

HIGH CURRENT – COMPONENT B

IP = 5000 Amps

Iavg = 2051 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.256 Coulombs

PANEL: LS-11
H-56

HIGH CURRENT – COMPONENT C* Ip = 242 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 3.7 Coulombs

PANEL: LS-11
H-57

HIGH CURRENT – COMPONENT D Ip = 95.0 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 269070 A

2

-S

PANEL: LS-12
H-58

HIGH CURRENT – COMPONENT B

IP = 5620 Amps

Iavg = 2266 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.329 Coulombs

PANEL: LS-12
H-59

HIGH CURRENT – COMPONENT C* Ip = 283 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 6.0 Coulombs

PANEL: LS-12
H-60

HIGH CURRENT – COMPONENT D Ip = 92.7 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 256770 A

2

-S

PANEL: LS-13
H-61

HIGH CURRENT – COMPONENT B

IP = 5073 Amps

Iavg = 2163 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.814 Coulombs

PANEL: LS-13
H-62

HIGH CURRENT – COMPONENT C* Ip = 365 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 12.3 Coulombs

PANEL: LS-13
H-63

HIGH CURRENT – COMPONENT D Ip = 95.0 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 273060 A

2

-S

PANEL: LS-14
H-64

HIGH CURRENT – COMPONENT B

IP = 5340 Amps

Iavg = 2174 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.872 Coulombs

PANEL: LS-14
H-65

HIGH CURRENT – COMPONENT C* Ip = 354 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 4.4 Coulombs

PANEL: LS-14
H-66

HIGH CURRENT – COMPONENT D Ip = 95.5 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 273200 A

2

-S

PANEL: LS-15
H-67

HIGH CURRENT – COMPONENT B

IP = 5613 Amps

Iavg = 2295 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.475 Coulombs

PANEL: LS-15
H-68

HIGH CURRENT – COMPONENT C* Ip = 358 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 4.3 Coulombs

PANEL: LS-15
H-69

HIGH CURRENT – COMPONENT D Ip = 95.2 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 271810 A

2

-S

PANEL: LS-16
H-70

HIGH CURRENT – COMPONENT B

IP = 5693 Amps

Iavg = 2343 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.713 Coulombs

PANEL: LS-16
H-71

HIGH CURRENT – COMPONENT C* Ip = 325 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 5.3 Coulombs

PANEL: LS-16
H-72

HIGH CURRENT – COMPONENT D Ip = 94.2 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 269380 A

2

-S

PANEL: LS-18
H-73

HIGH CURRENT – COMPONENT B

IP = 5287 Amps

Iavg = 2154 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.768 Coulombs

PANEL: LS-18
H-74

HIGH CURRENT – COMPONENT C* Ip = 225 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 5.4 Coulombs

PANEL: LS-18
H-75

HIGH CURRENT – COMPONENT D Ip = 95.2 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 270740 A

2

-S

PANEL: LS-19
H-76

HIGH CURRENT – COMPONENT B

IP = 5527 Amps

Iavg = 2246 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.228 Coulombs

PANEL: LS-19
H-77

HIGH CURRENT – COMPONENT C* Ip = 267 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 5.9 Coulombs

PANEL: LS-19
H-78

HIGH CURRENT – COMPONENT D Ip = 90.5 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 247740 A

2

-S

PANEL: LS-20
H-79

HIGH CURRENT – COMPONENT B

IP = 5367 Amps

Iavg = 2152 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.761 Coulombs

PANEL: LS-20
H-80

HIGH CURRENT – COMPONENT C* Ip = 297 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 16.6 Coulombs

PANEL: LS-20
H-81

HIGH CURRENT – COMPONENT D Ip = 99.7 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 297860 A

2

-S

PANEL: LS-20 Second Strike
H-82

HIGH CURRENT – COMPONENT B

IP = 4933 Amps

Iavg = 2014 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.068 Coulombs

PANEL: LS-20 Second Strike
H-83

HIGH CURRENT – COMPONENT C* Ip = 243 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 0.66 Coulombs

PANEL: LS-20 Second Strike
H-84

HIGH CURRENT – COMPONENT D Ip = 93.7 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 267580 A

2

-S

PANEL: LS-21
H-85

HIGH CURRENT – COMPONENT B

IP = 5353 Amps

Iavg = 2168 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.840 Coulombs

PANEL: LS-21
H-86

HIGH CURRENT – COMPONENT C* Ip = 367 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 4.3 Coulombs

PANEL: LS-21
H-87

HIGH CURRENT – COMPONENT D Ip = 94.5 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 270350 A

2

-S

PANEL: LS-22
H-88

HIGH CURRENT – COMPONENT B

IP = 5440 Amps

Iavg = 2220 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.099 Coulombs

PANEL: LS-22
H-89

HIGH CURRENT – COMPONENT C* Ip = 289 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 5.9 Coulombs

PANEL: LS-22
H-90

HIGH CURRENT – COMPONENT D Ip = 95.8 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 277130 A

2

-S

PANEL: LS-23
H-91

HIGH CURRENT – COMPONENT B

IP = 5707 Amps

Iavg = 2332 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.662 Coulombs

PANEL: LS-23
H-92

HIGH CURRENT – COMPONENT C* Ip = 230 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 3.2 Coulombs

PANEL: LS-23
H-93

HIGH CURRENT – COMPONENT D Ip = 95.2 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 275240 A

2

-S

PANEL: LS-24
H-94

HIGH CURRENT – COMPONENT B

IP = 5453 Amps

Iavg = 2235 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.174 Coulombs

PANEL: LS-24
H-95

HIGH CURRENT – COMPONENT C* Ip = 264 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 6.4 Coulombs

PANEL: LS-24
H-96

HIGH CURRENT – COMPONENT D Ip = 94.3 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 267390 A

2

-S

PANEL: LS-25
H-97

HIGH CURRENT – COMPONENT B

IP = 5340 Amps

Iavg = 2223 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.117 Coulombs

PANEL: LS-25
H-98

HIGH CURRENT – COMPONENT C* Ip = 317 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 4.3 Coulombs

PANEL: LS-25
H-99

HIGH CURRENT – COMPONENT D Ip = 95.5 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 275530 A

2

-S

PANEL: LS-26
H-100

HIGH CURRENT – COMPONENT B

IP = 5187 Amps

Iavg = 2091 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.454 Coulombs

PANEL: LS-26
H-101

HIGH CURRENT – COMPONENT C* Ip = 294 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 6.1 Coulombs

PANEL: LS-26
H-102

HIGH CURRENT – COMPONENT D Ip = 94.0 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 262530 A

2

-S

PANEL: LS-27
H-103

HIGH CURRENT – COMPONENT B

IP = 5147 Amps

Iavg = 2094 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.468 Coulombs

PANEL: LS-27
H-104

HIGH CURRENT – COMPONENT C* Ip = 270 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 6.5 Coulombs

PANEL: LS-27
H-105

HIGH CURRENT – COMPONENT D Ip = 93.0 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 259950 A

2

-S

PANEL: LS-28
H-106

HIGH CURRENT – COMPONENT B

IP = 5440 Amps

Iavg = 2203 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.013 Coulombs

PANEL: LS-28
H-107

HIGH CURRENT – COMPONENT C* Ip = 327 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 5.3 Coulombs

PANEL: LS-28
H-108

HIGH CURRENT – COMPONENT D Ip = 94.0 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 271020 A

2

-S

PANEL: LS-29
H-109

HIGH CURRENT – COMPONENT B

IP = 5567 Amps

Iavg = 2287 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.437 Coulombs

PANEL: LS-29
H-110

HIGH CURRENT – COMPONENT C* Ip = 297 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 5.3 Coulombs

PANEL: LS-29
H-111

HIGH CURRENT – COMPONENT D Ip = 94.0 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 266340 A

2

-S

PANEL: LS-30
H-112

HIGH CURRENT – COMPONENT B

IP = 5513 Amps

Iavg = 2218 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.092 Coulombs

PANEL: LS-30
H-113

HIGH CURRENT – COMPONENT C* Ip = 330 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 5.1 Coulombs

PANEL: LS-30
H-114

HIGH CURRENT – COMPONENT D Ip = 91.8 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 251710 A

2

-S

PANEL: LS-32
H-115

HIGH CURRENT – COMPONENT B

IP = 5033 Amps

Iavg = 2133 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.666 Coulombs

PANEL: LS-32
H-116

HIGH CURRENT – COMPONENT C* Ip = 329 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 4.7 Coulombs

PANEL: LS-32
H-117

HIGH CURRENT – COMPONENT D Ip = 93.7 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 267780 A

2

-S

PANEL: LS-33
H-118

HIGH CURRENT – COMPONENT B

IP = 5453 Amps

Iavg = 2221 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.105 Coulombs

PANEL: LS-33
H-119

HIGH CURRENT – COMPONENT C* Ip = 258 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 6.7 Coulombs

PANEL: LS-33
H-120

HIGH CURRENT – COMPONENT D Ip = 91.3 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 249210 A

2

-S

PANEL: LS-34
H-121

HIGH CURRENT – COMPONENT B

IP = 5440 Amps

Iavg = 2224 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.120 Coulombs

PANEL: LS-34
H-122

HIGH CURRENT – COMPONENT C* Ip = 277Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 2.9 Coulombs

PANEL: LS-34
H-123

HIGH CURRENT – COMPONENT D Ip = 94.0 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 268530 A

2

-S

PANEL: LS-35
H-124

HIGH CURRENT – COMPONENT B

IP = 5153 Amps

Iavg = 2079 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.397 Coulombs

PANEL: LS-35
H-125

HIGH CURRENT – COMPONENT C* Ip = 299 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 6.1 Coulombs

PANEL: LS-35
H-126

HIGH CURRENT – COMPONENT D Ip = 94.0 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 267970 A

2

-S

PANEL: LS-36
H-127 

HIGH CURRENT – COMPONENT B

IP = 5300 Amps

Iavg = 2150 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.752 Coulombs

PANEL: LS-36
H-128

HIGH CURRENT – COMPONENT C* Ip = 305 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 5.6 Coulombs

PANEL: LS-36
H-129

HIGH CURRENT – COMPONENT D Ip = 93.3 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 253830 A

2

-S

PANEL: LS-37
H-130

HIGH CURRENT – COMPONENT B

IP = 5313 Amps

Iavg = 2178 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.890 Coulombs

PANEL: LS-37
H-131

HIGH CURRENT – COMPONENT C* Ip = 183 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 0.70 Coulombs

PANEL: LS-37
H-132

HIGH CURRENT – COMPONENT D Ip = 94.8 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 270310 A

2

-S

PANEL: LS-38
H-133

HIGH CURRENT – COMPONENT B

IP = 5340 Amps

Iavg = 2177 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.887 Coulombs

PANEL: LS-38
H-134

HIGH CURRENT – COMPONENT C* Ip = 343 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 4.9 Coulombs

PANEL: LS-38
H-118

HIGH CURRENT – COMPONENT D Ip = 92.2 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 251850 A

2

-S

PANEL: LS-39
H-119

HIGH CURRENT – COMPONENT B

IP = 5427 Amps

Iavg = 2257 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.283 Coulombs

PANEL: LS-39
H-120

HIGH CURRENT – COMPONENT C* Ip = 293 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 6.0 Coulombs

PANEL: LS-39
H-121

HIGH CURRENT – COMPONENT D Ip = 92.8 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 263700 A

2

-S

PANEL: LS-40
H-122

HIGH CURRENT – COMPONENT B

IP = 5307 Amps

Iavg = 2140 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.698 Coulombs

PANEL: LS-40
H-123

HIGH CURRENT – COMPONENT C* Ip = 253 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 1.3 Coulombs

PANEL: LS-40
H-124

HIGH CURRENT – COMPONENT D Ip = 93.7 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 260300 A

2

-S

PANEL: LS-41
H-125

HIGH CURRENT – COMPONENT B

IP = 5547 Amps

Iavg = 2285 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.426 Coulombs

PANEL: LS-41
H-126

HIGH CURRENT – COMPONENT C* Ip = 239 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 5.4 Coulombs

PANEL: LS-41
H-127

HIGH CURRENT – COMPONENT D Ip = 93.7 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 262790 A

2

-S

PANEL: LS-42
H-128

HIGH CURRENT – COMPONENT B

IP = 5547 Amps

Iavg = 2300 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.498 Coulombs

PANEL: LS-42
H-129

HIGH CURRENT – COMPONENT C* Ip = 296 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 5.8 Coulombs

PANEL: LS-42
H-130

HIGH CURRENT – COMPONENT D Ip = 94.2 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 262250 A

2

-S

PANEL: LS-43
H-131

HIGH CURRENT – COMPONENT B

IP = 5173 Amps

Iavg = 2136 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.681 Coulombs

PANEL: LS-43
H-132

HIGH CURRENT – COMPONENT C* Ip = 181 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 0.54 Coulombs

PANEL: LS-43
H-133

HIGH CURRENT – COMPONENT D Ip = 93.3 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 262610 A

2

-S

PANEL: LS-44
H-134

HIGH CURRENT – COMPONENT B

IP = 5293 Amps

Iavg = 2150 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.751 Coulombs

PANEL: LS-44
H-135

HIGH CURRENT – COMPONENT C* Ip = 317 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 5.0 Coulombs

PANEL: LS-44
H-136

HIGH CURRENT – COMPONENT D Ip = 90.8 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 253010 A

2

-S

PANEL: LS-45
H-137

HIGH CURRENT – COMPONENT B

IP = 4880 Amps

Iavg = 2046 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.230 Coulombs

PANEL: LS-45
H-138

HIGH CURRENT – COMPONENT C* Ip = 6 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 0.009 Coulombs

PANEL: LS-45
H-139

HIGH CURRENT – COMPONENT D Ip = 68.5 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 132140 A

2

-S

PANEL: LS-46
H-140

HIGH CURRENT – COMPONENT B

IP = 4240 Amps

Iavg = 2099 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.494 Coulombs

PANEL: LS-46
H-141

HIGH CURRENT – COMPONENT C* Ip = 0 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 0 Coulombs

PANEL: LS-46
H-142

HIGH CURRENT – COMPONENT D Ip = 70.7 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 140320 A

2

-S

PANEL: LS-47
H-143

HIGH CURRENT – COMPONENT B

IP = 4147 Amps

Iavg = 1829 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 9.146 Coulombs

PANEL: LS-47
H-144

HIGH CURRENT – COMPONENT C* Ip = 1.3 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 0.004 Coulombs

PANEL: LS-47
H-145

HIGH CURRENT – COMPONENT A Ip = 182.5 KA 100 uS / Div

COMPONENT A ACTION INTEGRAL AI = 1.4532E6 A

2

-S

PANEL: LS-34
H-146

HIGH CURRENT – COMPONENT B

IP = 6107 Amps

Iavg = 2328 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.642 Coulombs

PANEL: LS-34
H-147

HIGH CURRENT – COMPONENT C* Ip = 353 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 1.8 Coulombs

PANEL: LS-34
H-148

HIGH CURRENT – COMPONENT A Ip = 175.0 KA 100 uS / Div

COMPONENT A ACTION INTEGRAL AI = 1.4158E6 A

2

-S

PANEL: LS-39
H-149

HIGH CURRENT – COMPONENT B

IP = 6320 Amps

Iavg = 2150 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 10.750 Coulombs

PANEL: LS-39
H-150

HIGH CURRENT – COMPONENT C* Ip = 267 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 1.1 Coulombs

PANEL: LS-39
H-151

HIGH CURRENT – COMPONENT A Ip = 187.7 KA 100 uS / Div

COMPONENT A ACTION INTEGRAL AI = 1.8343E6 A

2

-S

PANEL: LS-40
H-152

HIGH CURRENT – COMPONENT B

IP = 6600 Amps

Iavg = 2267 Amps 1 mS / Div

COMPONENT B CHARGE TRANSFER 11.335 Coulombs

PANEL: LS-40
H-153

HIGH CURRENT – COMPONENT C* Ip = 342 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 5.5 Coulombs

PANEL: LS-40
H-154
H-155

High Current Test – Panel LS-1 Setup

High Current Test – Panel LS-1 Pre-Strike
H-156

High Current Test – Panel LS-1 Components D, B, C*

High Current Test – Panel LS-1 Post-Strike Damage
H-157

High Current Test – Panel LS-2 Setup

High Current Test – Panel LS-2 Pre-Strike
H-158

High Current Test – Panel LS-2 Components D, B, C*

High Current Test – Panel LS-2 Post-Strike Damage
H-159

High Current Test – Panel LS-4 Setup

High Current Test – Panel LS-4 Pre-Strike
H-160

High Current Test – Panel LS-4 Components D, B, C*

High Current Test – Panel LS-4 Post-Strike Damage
H-161

High Current Test – Panel LS-5 Setup

High Current Test – Panel LS-5 Pre-Strike
H-162

High Current Test – Panel LS-5 Components D, B, C*

High Current Test – Panel LS-5 Post-Strike Damage
H-163

High Current Test – Panel LS-6 Setup

High Current Test – Panel LS-6 Pre-Strike
H-164

High Current Test – Panel LS-6 Components D, B, C*

High Current Test – Panel LS-6 Post-Strike Damage
H-165

High Current Test – Panel LS-6 Setup

High Current Test – Panel LS-6 Pre-Strike
H-166

High Current Test – Panel LS-6 Components D, B, C*

High Current Test – Panel LS-6 Post-Strike Damage
H-167

High Current Test – Panel LS-7 Setup

High Current Test – Panel LS-7 Pre-Strike
H-168

High Current Test – Panel LS-7 Components D, B, C*

High Current Test – Panel LS-7 Post-Strike Damage
H-169

High Current Test – Panel LS-8 Setup

High Current Test – Panel LS-8 Pre-Strike
H-170

High Current Test – Panel LS-8 Components D, B, C*

High Current Test – Panel LS-8 Post-Strike Damage
H-171

High Current Test – Panel LS-9 Setup

High Current Test – Panel LS-9 Pre-Strike
H-172

High Current Test – Panel LS-9 Components D, B, C*

High Current Test – Panel LS-9 Post-Strike Damage
H-173

High Current Test – Panel LS-10 Setup

High Current Test – Panel LS-10 Pre-Strike
H-174

High Current Test – Panel LS-10 Components D, B, C*

High Current Test – Panel LS-10 Post-Strike Damage
H-175

High Current Test – Panel LS-11 Setup

High Current Test – Panel LS-11 Pre-Strike
H-176

High Current Test – Panel LS-11 Components D, B, C*

High Current Test – Panel LS-11 Post-Strike Damage
H-177

High Current Test – Panel LS-12 Setup

High Current Test – Panel LS-12 Pre-Strike
H-178

High Current Test – Panel LS-12 Components D, B, C*

High Current Test – Panel LS-12 Post-Strike Damage
H-179

High Current Test – Panel LS-13 Setup

High Current Test – Panel LS-13 Pre-Strike
H-180

High Current Test – Panel LS-13 Components D, B, C*

High Current Test – Panel LS-13 Post-Strike Damage
H-181

High Current Test – Panel LS-14 Setup

High Current Test – Panel LS-14 Pre-Strike
H-182

High Current Test – Panel LS-14 Components D, B, C*

High Current Test – Panel LS-14 Post-Strike Damage
H-183

High Current Test – Panel LS-15 Setup

High Current Test – Panel LS-15 Pre-Strike
H-184

High Current Test – Panel LS-15 Components D, B, C*

High Current Test – Panel LS-15 Post-Strike Damage
H-185

High Current Test – Panel LS-16 Setup

High Current Test – Panel LS-16 Pre-Strike
H-186

High Current Test – Panel LS-16 Components D, B, C*

High Current Test – Panel LS-16 Post-Strike Damage
H-187

High Current Test – Panel LS-18 Setup

High Current Test – Panel LS-18 Pre-Strike
H-188

High Current Test – Panel LS-18 Components D, B, C*

High Current Test – Panel LS-18 Post-Strike Damage
H-189

High Current Test – Panel LS-19 Setup

High Current Test – Panel LS-19 Pre-Strike
H-190

High Current Test – Panel LS-19 Components D, B, C*

High Current Test – Panel LS-19 Post-Strike Damage
H-191

High Current Test – Panel LS-20 Setup

High Current Test – Panel LS-20 Pre-Strike
H-192

High Current Test – Panel LS-20 Components D, B, C*

High Current Test – Panel LS-20 Post-Strike Damage
H-193

High Current Test – Panel LS-20 Setup

High Current Test – Panel LS-20 Pre-Strike
H-194

High Current Test – Panel LS-20 Components D, B, C*

High Current Test – Panel LS-20 Post-Strike Damage
H-195

High Current Test – Panel LS-21 Setup

High Current Test – Panel LS-21 Pre-Strike
H-196

High Current Test – Panel LS-21 Components D, B, C*

High Current Test – Panel LS-21 Post-Strike Damage
H-197

High Current Test – Panel LS-22 Setup

High Current Test – Panel LS-22 Pre-Strike
H-198

High Current Test – Panel LS-22 Components D, B, C*

High Current Test – Panel LS-22 Post-Strike Damage
H-199

High Current Test – Panel LS-23 Setup

High Current Test – Panel LS-23 Pre-Strike
H-200

High Current Test – Panel LS-23 Components D, B, C*

High Current Test – Panel LS-23 Post-Strike Damage
H-201

High Current Test – Panel LS-24 Setup

High Current Test – Panel LS-24 Pre-Strike
H-202

High Current Test – Panel LS-24 Components D, B, C*

High Current Test – Panel LS-24 Post-Strike Damage
H-203

High Current Test – Panel LS-25 Setup

High Current Test – Panel LS-25 Pre-Strike
H-204

High Current Test – Panel LS-25 Components D, B, C*

High Current Test – Panel LS-25 Post-Strike Damage
H-205

High Current Test – Panel LS-26 Setup

High Current Test – Panel LS-26 Pre-Strike
H-206

High Current Test – Panel LS-26 Components D, B, C*

High Current Test – Panel LS-26 Post-Strike Damage
H-207

High Current Test – Panel LS-27 Setup

High Current Test – Panel LS-27 Pre-Strike
H-208

High Current Test – Panel LS-27 Components D, B, C*

High Current Test – Panel LS-27 Post-Strike Damage
H-209

High Current Test – Panel LS-28 Setup

High Current Test – Panel LS-28 Pre-Strike
H-210

High Current Test – Panel LS-28 Components D, B, C*

High Current Test – Panel LS-28 Post-Strike Damage
H-211

High Current Test – Panel LS-29 Setup

High Current Test – Panel LS-29 Pre-Strike
H-212

High Current Test – Panel LS-29 Components D, B, C*

High Current Test – Panel LS-29 Post-Strike Damage
H-213

High Current Test – Panel LS-30 Setup

High Current Test – Panel LS-30 Pre-Strike
H-214

High Current Test – Panel LS-30 Components D, B, C*

High Current Test – Panel LS-30 Post-Strike Damage
H-215

High Current Test – Panel LS-32 Setup

High Current Test – Panel LS-32 Pre-Strike
H-216

High Current Test – Panel LS-32 Components D, B, C*

High Current Test – Panel LS-32 Post-Strike Damage
H-217

High Current Test – Panel LS- 33Setup

High Current Test – Panel LS-33 Pre-Strike
H-218

High Current Test – Panel LS-33 Components D, B, C*

High Current Test – Panel LS-33 Post-Strike Damage
H-219

High Current Test – Panel LS-34 Setup

High Current Test – Panel LS-34 Pre-Strike
H-220

High Current Test – Panel LS-34 Components D, B, C*

High Current Test – Panel LS-34 Post-Strike Damage
H-221

High Current Test – Panel LS-35 Setup

High Current Test – Panel LS-35 Pre-Strike
H-222

High Current Test – Panel LS-35 Components D, B, C*

High Current Test – Panel LS-35 Post-Strike Damage
H-223

High Current Test – Panel LS-36 Setup

High Current Test – Panel LS-36 Pre-Strike
H-224

High Current Test – Panel LS-36 Components D, B, C*

High Current Test – Panel LS-36 Post-Strike Damage
H-225

High Current Test – Panel LS-37 Setup

High Current Test – Panel LS-37 Pre-Strike
H-226

High Current Test – Panel LS-37 Components D, B, C*

High Current Test – Panel LS-37 Post-Strike Damage
H-227

High Current Test – Panel LS-38 Setup

High Current Test – Panel LS-38 Pre-Strike
H-228

High Current Test – Panel LS-38 Components D, B, C*

High Current Test – Panel LS-38 Post-Strike Damage
H-229

High Current Test – Panel LS-39 Setup

High Current Test – Panel LS-39 Pre-Strike
H-230

High Current Test – Panel LS-39 Components D, B, C*

High Current Test – Panel LS-39 Post-Strike Damage
H-231

High Current Test – Panel LS-40 Setup

High Current Test – Panel LS-40 Pre-Strike
H-232

High Current Test – Panel LS-40 Components D, B, C*

High Current Test – Panel LS-40 Post-Strike Damage
H-233

High Current Test – Panel LS-41 Setup

High Current Test – Panel LS-41 Pre-Strike
H-234

High Current Test – Panel LS-41 Components D, B, C*

High Current Test – Panel LS-41 Post-Strike Damage
H-235

High Current Test – Panel LS-42 Setup

High Current Test – Panel LS-42 Pre-Strike
H-236

High Current Test – Panel LS-42 Components D, B, C*

High Current Test – Panel LS-42 Post-Strike Damage
H-237

High Current Test – Panel LS-43 Setup

High Current Test – Panel LS-43 Pre-Strike
H-238

High Current Test – Panel LS-43 Components D, B, C*

High Current Test – Panel LS-43 Post-Strike Damage
H-239

High Current Test – Panel LS-44 Setup

High Current Test – Panel LS-44 Pre-Strike
H-240

High Current Test – Panel LS-44 Components D, B, C*

High Current Test – Panel LS-44 Post-Strike Damage
H-241

High Current Test – Panel LS-45 Setup

High Current Test – Panel LS-45 Pre-Strike
H-242

High Current Test – Panel LS-45 Components D, B, C*

High Current Test – Panel LS-45 Post-Strike Damage
H-243

High Current Test – Panel LS-46 Side 1Setup

High Current Test – Panel LS-46 Side 1 Pre-Strike
H-244

High Current Test – Panel LS-46 Side 1 Components D, B, C*

High Current Test – Panel LS-46 Post-Strike Damage
H-245

High Current Test – Panel LS-47 Setup

High Current Test – Panel LS-47 Pre-Strike
H-246

High Current Test – Panel LS-47 Components D, B, C*

High Current Test – Panel LS-47 Post-Strike Damage
H-247

High Current Test – Panel LS-34 Setup

High Current Test – Panel LS-34 Pre-Strike
H-248

High Current Test – Panel LS-34 Components A, B, C*

High Current Test – Panel LS-34 Post-Strike Damage
H-249

High Current Test – Panel LS-39 Setup

High Current Test – Panel LS-39 Pre-Strike
H-250

High Current Test – Panel LS-39 Components A, B, C*

High Current Test – Panel LS-39 Post-Strike Damage
H-251

High Current Test – Panel LS-40 Setup

High Current Test – Panel LS-40 Pre-Strike
H-252

High Current Test – Panel LS-40 Components A, B, C*

High Current Test – Panel LS-40 Post-Strike Damage
H-253

High Current Test – Calibration Panel Setup

High Current Test – Calibration Panel Pre-Strike
H-254

High Current Test – Calibration Panel Components D, B, C*

High Current Test – Calibration Panel Post-Strike Damage
END OF REPORT

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I-1 

Appendix I 

First-Generation Direct Effects Pictures (Cessna) 
I-2 

Figure I-1: Capacitor bank at DNB for DEL testing. 
I-3 

Figure I-2: Capacitor bank at DNB for DEL testing. 
I-4 

Figure I-3: Capacitor bank at DNB for DEL testing. 

Figure I-4: Inductor at DNB for DEL testing. 
I-5 

Figure I-5: Capacitor bank at DNB for DEL testing. 

Figure I-6: DEL panel setup at DNB 
I-6 

Figure I-7: DEL panel LS-20 setup at DNB 

Figure I-8: DEL panel LS-8 (rear) setup at DNB 
I-7 

Figure I-9: DEL panel (rear) setup at DNB. 

Figure I-10: DEL panel (rear) setup at DNB. 
I-8 

Figure I-11: DEL panel setup at DNB. 

Figure I-12: DEL panel (top view) setup at DNB. 
I-9 

Figure I-13: DEL panel (top view) setup at DNB. 

Figure I-14: DEL panel setup at DNB. 
I-10

Figure I-15: DEL panel setup (rear) at DNB. 

Figure I-16: DEL panel setup (rear) at DNB. 
I-11

Figure I-17: DEL panel after strike at DNB. 

Figure I-18: Panel LS-1 after strike. 
I-12

Figure I-19: Panel LS-2 after strike. 

Figure I-20: Panel LS-4 after strike. 
I-13

Figure I-21: Panel LS-5 after strike. 

Figure I-22: Panel LS-6 after strike. 
I-14

Figure I-23: Panel LS-7 after strike. 

Figure I-24: Panel LS-8 after strike. 
I-15

Figure I-25: Panel LS-9 after strike. 

Figure I-26: Panel LS-10 after strike. 
I-16

Figure I-27: Panel LS-11 after strike. 

Figure I-28: Panel LS-12 after strike. 
I-17

Figure I-29: Panel LS-13 after strike. 

Figure I-30: Panel LS-14 after strike. 
I-18

Figure I-31: Panel LS-15 after strike. 

Figure I-32: Panel LS-16 after strike. 
I-19

Figure I-33: Panel LS-18 after strike. 

Figure I-34: Panel LS-19 after strike. 
I-20

Figure I-35: Panel LS-20 after first strike. 

Figure I-36: Side view of panel LS-20 after first strike. 
I-21

Figure I-37: Panel LS-20 after second strike. 

Figure I-38: Panel LS-22 after strike. 
I-22

Figure I-39: Panel LS-23 after strike. 

Figure I-40: Panel LS-24 after strike. 
I-23 

Figure I-41: Panel LS-25 after strike. 

Figure I-42: Panel LS-26 after strike. 
I-24

Figure I-43: Panel LS-27 after strike. 

Figure I-44: Panel LS-28 after strike. 
I-25

Figure I-45: Panel LS-29 after strike. 

Figure I-46: Panel LS-30 after strike. 
I-26

Figure I-47: Panel LS-32 after strike. 

Figure I-48: Panel LS-33 after strike. 
I-27

Figure I-49: Panel LS-34 after first strike. 

Figure I-50: Panel LS-34 after second strike ( 100 kAmps and 200 kAmp). 
I-28

Figure I-51: Panel LS-35 after strike. 

Figure I-52: Panel LS- 36 after strike. 
I-29

Figure I-53: Panel LS-37 after strike. 

Figure I-54: Panel LS-38 after strike. 
I-30

Figure I-55: Panel LS-39 after first strike. 

Figure I-56: Panel LS-39 after second strike. 
I-31

Figure I-57: Panel LS-39 after second strike ( 100 kAmps and 200 kAmps). 

Figure I-58: Panel LS-40 after strike. 
I-32

Figure I-59: Panel LS-41 after strike. 

Figure I-60: Panel LS-42 after strike. 
I-33

Figure I-61: Panel LS-43 after strike. 

Figure I-62: Panel LS-43 after strike. 
I-34

Figure I-63: Panel LS-44 after strike. 

Figure I-64: Panel LS-45 after strike. 
J-1 

Appendix J 

Second-Generation Thermography Report 
J-2 

 

 

REPORT TITLE: NDI of NASA STAR-C

2 Test Article CFRP Panels (Phase Two)

Report #: 13-359-004 Date: January 8, 2013

To: Vicki Johnson From: Michael Daehling

cc: S. Brown I. Nelson

Approved by: Jay Amos

Subject Information 

P/N: NASA PANEL 1 and 2

NASA STAR-C^2 Test Articles

S/N: See table I

Part description: 5 plies Uni 45/90 12k-145-UNI 

Outer plies 3k-193-PW

(~.043” CPT): Oven-cured 

Per SX512110

Material: CMAC004

Model: NA

Inspector M. Daehling, J. Amos Charge #: E-NNC10CA36C

Inspector Level Trainee & 3

Material Type NCT321-G150/NAS-S-12K-UNI

Type of Inspection Pulse Echo & Thermography (IRT)

Infrared Thermography (Flash method) was performed on the panels with a modified 4 lamp flash hood and graded per 

CSTI009. 
J-3 

Table I 

Test Panel NDI Results 

* Voids in protective skin adhesive appear smaller & changed position, possibly due to heat generated during 

strike test. 

Panel Initial 

Passing 

Level

Pre-test 

Condition

Post-test 

Delamination 

(sq.in.)

Panel Initial 

Passing 

Level

Pre-test 

Condition

Post-test 

Delamination 

(sq.in.)

18129 Porosity 2.3, 1.5, 1.3

2.5, 2.5, 2.0

2.6. 1.7, 1.4

18141 1 18170 2 Porosity 

center splices

No delams poststrike

18154 2 Porosity along 

splices

18171 2 Porosity 

center splices

18155 1 18172 1

18156 1 18186 2 Porosity 

center splice

18157 2 Porosity 

center splices

18187 2 Porosity 

center splices

18158 2 Porosity 

center splices

18188 2 Porosity 

center splices

18159 2 Porosity on 

SW splice

18189 2 Porosity 

center splices

18160 2 Porosity 

center splices

18190 2 Porosity 

along splices

18161 1 Porosity 

center splices

No delams 

post-strike

18191 2 Porosity 

along splices

18162 3 Voids -

Porosity along 

splices

No delams or 

change in preexisting voids*

18200 1

0.2, 0.7

18163 3 Porosity along 

splices

No delams 

post-strike

18201 2 1 Void 0.24, 1.26, 2.8;

no change in 

pre-existing void

18164 1 18202 3 2 Voids 0.07, 0.38;

no change in 

pre-existing void

18165 2 Porosity 

center splices

18829 1 0.35, 0.48, 0.15, 

0.12, 1.68, 0.56, 

0.12 

18166 1 18830 1 0.32, 0.32, 0.18, 

0.27, 0.24, 0.27, 

1.44, 0.32, 0.28

18167 1 18831 2 1 Void 0.61, 0.61, 0.61, 

0.61, 0.74, 0.38, 

0.38 

18168 2 Porosity along 

splices

No delams 

post-strike

18169 2 Porosity along 

splices

1.05
J-4 

SN 18129 1d 0.42s SN 18129 1d 1.0s porosity SN 18129 2d PA 

SN 18129 1d 0.42s Post Impact SN 18129 1d 1.0s voids Post Impact SN 18129 2d PA Post Impact 

Porosity
J-5 

SN 18141 1d 0.42s SN 18141 1d 1.0s SN 18141 2d PA 

SN 18154 1d 0.42s SN 18154 1d 1.0s SN 18154 2d PA 
J-6 

SN 18155 1d 0.42s SN 18155 1d 1.0s SN 18155 2d PA 

SN 18156 1d 0.42s SN 18156 1d 1.0s SN 18156 2d PA 
J-7 

SN 18157 1d 0.42s SN 18157 1d 1.0s SN 18157 2d PA 

SN 18158 1d 0.42s SN 18158 1d 1.0s SN 18158 2d PA 
J-8 

SN 18159 1d 0.42s SN 18159 1d 1.0s SN 18159 2d PA 

SN 18160 1d 0.42s SN 18160 1d 1.0s SN18160 2d PA 
J-9 

Sn18161 1d 0.42s bag side Sn18161 1d 1.0s bag side Sn18161 2d PA bag side 

SN 18161 1d 0.42s Post strike SN 18161 1d 1.0s post strike SN 18161 2d PA Post strike 

Light artifacts from backside 

adhesive bond variation
J-10

SN 18162 1d 0.3s assembled SN 18162 1d 0.18s assembled SN 18162 1d 1.72s assembled 

SN 18162 1d 0.42s Post strike SN 18162 1d 1.0s post strike SN 18162 2d PA Post strike 

Light artifacts from backside 

adhesive bond variation
J-11

SN 18163 1d 0.3s bag side assembled SN 18163 1d 0.42s bag side assembled SN 18163 1d 1.0s bag side assembled 

SN 18163 2d PA bag side assembled 

Light artifacts from backside 

adhesive bond variation
J-12

SN 18163 1d 0.16s post strike SN 18163 1d 0.42s post strike SN 18163 1d 1.0s post strike 

SN 18163 2d PA post strike 
J-13

SN 18164 1d 0.42s SN 18164 1d 1.0s SN 18164 2d PA 

SN 18165 1d 0.42s SN 18165 1d 1.0s SN 18165 2d PA 
J-14

 SN 18165 1d 0.3s void 0.38 in 

SN 18166 1d 0.42s SN 18166 1d 1.0s SN 18166 2d PA 
J-15

SN 18167 1d 0.42s SN 18167 1d 1.0s SN 18167 2d PA 

SN18168 1d 0.42s assembled SN18168 1d 1.0s assembled SN18168 2d PA assembled 
J-16

SN 18168 1d 0.42s post strike SN 18168 1d 1.0s post strike SN 18168 2d PA post strike 

SN18169 1d 0.3s assembled SN18169 1d 1.0s assembled SN18169 2d PA assembled 
J-17

SN 18169 1d 0.42s post strike SN 18169 1d 1.0s voids post strike SN 18169 2d PA post strike 

SN 18170 1d 0.42s SN 18170 1d 1.0s SN 18170 2d PA 
J-18

SN 18170 1d 0.42s post strike SN 18170 1d 1.0s post strike SN 18170 2d PA post strike 

 SN18171 1d 0.42s SN 18171 1d 1.0s SN 18171 2d PA 
J-19

SN 18172 1d 0.42s SN 18172 1d 1.0s SN 18172 2d PA 

SN 18186 1d 0.42s SN 18186 1d 1.0s SN 18186 2d PA 
J-20

SN18187 1d 0.42s SN18187 1d 1.0s SN18187 2d PA 

 

SN18188 1d 0.42s SN 18188 1d 1.0s SN18188 2d PA 

 
J-21

SN18189 1d 0.42s SN18189 1d 1.0s SN18189 2d PA 

SN 18190 1d 0.42s SN18190 1d 1.0s SN18190 2D PA 

Panel standoffs

(Typical)
J-22

SN18191 1d 0.42s SN18191 1d 1.0s SN18191 2d PA 

SN18191 1d 0.42s single shot 48x48 in. 
J-23

SN 18200 1d 0.3s SN 18200 1d 1.0s SN 18200 2d PA 

SN 18200 1d 0.42s Post impact SN 18200 1d 1.0s voids post impact SN 18200 2d PA post impact 
J-24

SN 18201 1d 0.3s SN 18201 1d 1.0s void SN 18201 2d PA

SN 18201 1d 0.42s post impact SN 18201 1d 1.0s voids post impact SN 18201 2d PA post impact 
J-25

SN 18202 1d 0.3s SN 18202 1d 1.0s voids SN 18202 2d PA 

SN 18202 1d 0.08s post impact SN 18202 1d 0.42s post impact SN 18202 1d 1.0s voids post impact 
J-26

SN 18202 2d PA post impact 

SN18829 1d 0.42s SN18829 1d 1.0s SN18829 2d PA 
J-27

SN18829 1d 0.08s post impact SN18829 1d 0.42s post impact SN18829 1d 1.0s voids post impact 

SN18829 2d PA Post impact 
J-28

SN18830 1d 0.42s SN18830 1d 1.0s SN18830 2d PA 

SN18830 1d 0.1s post impact SN18830 1d 0.42s post impact SN18830 1d 1.0s voids post impact 
J-29

SN18830 2d PA post impact 

SN18831 1d 0.42s SN18831 1d 1.0s SN18831 2d PA 
J-30

SN18831 1d 0.12s post impact SN18831 1d 0.42s post impact SN18831 1d 1.0s voids post impact 

SN18831 1d 1.0s post impact SN18831 2d PA post impact 
K-1 

Appendix K 

Second-Generation Indirect Effects Test Data 
K-2 

Figure K-1: Current calibration oscillogram input waveform with 616 A. 

Figure K-2: Voltage calibration oscillogram waveform with 800 V. 
K-3 

Figure K-3: Current calibration oscillogram with 629 A. 

Figure K-4: Voltage calibration oscillogram with 816 V. 
K-4 

Figure K-5: Panel FLS-1 with voltage -20 V and current -458 A. 

Figure K-6: Panel FLS-1 with voltage 20 V and current 462 A. 
K-5 

Figure K-7: Panel FLS 2 with voltage -18 V and current -412 A. 

Figure K-8: Panel FLS-2 with voltage 22 V and current 429 A. 
K-6 

Figure K-9: Panel FLS-3 with voltage -19 V and current -429 A. 

Figure K-10: Panel FLS-3 with voltage 20 V and current 458 A. 
K-7 

Figure K-11: Panel FLS-4 with voltage -21 V and current -466 A. 

Figure K-12: Panel FLS-4 with voltage 21 V and current 462 A. 
K-8 

Figure K-13: Panel FLS-5 with voltage -19 V and current -420 A. 

Figure K-14: Panel FLS-5 with voltage 19 V and current 420 A. 
K-9 

Figure K-15: Panel FLS-6 with voltage -22 V and current -470 A. 

Figure K-16: Panel FLS-6 with voltage 20 V and current 462 A. 
K-10

Figure K-17: Panel CFC with voltage -14 V and current -245 A. 

Figure K-18: Panel CFC with voltage 22 V and current 250 A. 
L-1 

Appendix L 

Second-Generation Direct Effects Test Data and Pictures (DNB Engineering Report) 
L-2 
DNB ENGINEERING, INC. 3535 W. COMMONWEALTH AVE. FULLERTON, CA 92833 (714) 870-7781 FAX (714) 870-5081www.dnbenginc.com
DNB ENGINEERING, INC. 3535 W. COMMONWEALTH AVE. FULLERTON, CA 92833 (714) 870-7781 FAX (714) 870-5081www.dnbenginc.com
DNB ENGINEERING, INC. 3535 W. COMMONWEALTH AVE. FULLERTON, CA 92833 (714) 870-7781 FAX (714) 870-5081www.dnbenginc.com
DNB ENGINEERING, INC. 3535 W. COMMONWEALTH AVE. FULLERTON, CA 92833 (714) 870-7781 FAX (714) 870-5081www.dnbenginc.com

1.0 INTRODUCTION

Lightning Direct Effect tests for Category 2A were performed on six Composite Panels, manufactured by Cessna Aircraft

Corporation. Testing began on 1-25-13 and was completed on 1-25-13. The purpose of this test was to demonstrate

compliance with the applicable sections of SAE ARP5416. All test results have been summarized herein, and all data 

sheets have been incorporated in Appendix D.

2.0 TEST REQUIREMENTS

The test requirements for the tests performed as outlined in this document are defined by the applicable sections of

SAE ARP5416.

3.0 TEST EQUIPMENT

The test equipment log in Appendix B lists information on test equipment used, along with current calibration status.

DNB’s calibration service providers use procedures provided by the manufacturers and by other widely recognized

bodies (for example, GIDEP). Standards used during calibration are traceable to NIST.

SUMMARY OF TEST RESULTS

Lightning Direct Effects, SAE ARP5416 Introduction

Direct Effect Lightning tests for Category 2A were performed on the six Composite Panels which included High 

Current tests.

High Current Test

High Current calibration and tests were performed with the high current generator configured for negative polarity. The

electrode was placed 50 mm above the Composite Panel. A leader wire was connected to the electrode and

positioned just above the Composite Panel. An aluminum panel was used for the calibration. High current

components D, B, and C* were then applied. This was done for the aluminum panel and the forty four Composite

Panels. The following waveforms were applied to the Composite Panels:

Component D: IP = 100 KA +/-10%; Action Integral = 2.5E5 A2-S +/-20%

Component B: Iavg=2000 Amps +/-10%; Charge Transfer@5 mS=10 Coulombs +/-20% Component C*: Iavg = 400 Amps +/-

10%; Charge Transfer = 18 Coulombs +/-20% Component A: IP = 200 KA +/-10%; Action Integral = 2.0E6 A2-S +/-20%

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4.1 Lightning Direct Effects (Continued)

High Current Test

A metal strip was placed on the back side of the Composite Panel to simulate a wiring bundle or fuel line. This is done

as a worst case setup to try and induce a puncture. The metal strip was connected to ground with a 30 awg fuse wire.

After each strike, the wire was checked to see if there was enough current coupled to the metal strip to open the fuse

wire. After the completion of the six panels, two panels were selected for a Zone 1A strike and were tested with 

Components A, B, and C*.

Pre and Post Functional Test Data

If applicable, the Composite Panels were checked for proper functionality prior to the direct effects lightning tests.

After completion of the direct effects lightning tests, the Composite Panels were again checked for proper

functionality. Any available pre and post functionality data is provided in a separate Cessna Aircraft Corporation

document.

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4.1 Lightning Direct Effects (Continued)

Test Results

The Composite Panels showed varying degrees of damage. None of the Composite Panels showed any signs of 

puncture. None of the strikes caused the fuse wire to open.

Test Log

The Test Log is provided in Appendix A. Test Equipment

A list of the test equipment used to perform all testing complete with calibration dates is provided in Appendix B.

Test Data

Test Data are provided in Appendix D. Test Photographs

Test photographs are provided in Appendix E. Disposition of Test Samples

Following testing, the Composite Panels were returned to Cessna Aircraft Corporation for further evaluation.

Bonding Measurements

Bonding measurements were not performed during these tests.

5.0 TEST DESCRIPTION

The test method and description, including details of the test set-up and test figures are described in SAE Arp5416

for each of the lightning tests. A list of the test equipment used in the performance of each of these tests, along with

current calibration information is included in Appendix B. Photographs of each test setup were taken and are included in

Appendix E.

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6.0 CONCLUSIONS

The Composite Panels completed the direct effects lightning tests in accordance with SAE ARP5416. Upon the

completion of testing, the test sample and all applicable Cessna Aircraft Corporation support equipment were

returned to representatives of Cessna Aircraft Corporation.

The results listed in this report relate only to the items tested as listed on the Test Completion Record on sheet 

4 herein.

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APPENDIX A

Test Log

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LIGHTNING TEST LOG 

CUSTOMER:CESSNA TEST SAMPLE: JET DIVERTING ELECTRODE STUDY

TEST ENGINEER: STEVE COOK CUSTOMER REPRESENTATIVE: VANDANA PENDSE

DATE TIME TEST DESCRIPTION

1-25-13 8:00 Setting up for high current test.

10:00 Panel FLS-3 – first strike

10:20 Panel FLS-3 – second strike

11:00 Panel FLS-4 – first strike

11:20 Panel FLS-4 – second strike

11:50 Panel FLS-5 – first strike

12:15 Panel FLS-5 – second strike

1:35 Panel FLS-6 – first strike

2:00 Panel FLS-6 – second strike

2:25 Panel FLS-1 – first strike

2:45 Panel FLS-1 – second strike

3:15 Panel FLS-2 – first strike

3:40 Panel FLS-2 – second strike

4:15 Panel FLS-6 Zone 1A

4:50 Panel FLS-1 Zone 1A

5:00 Testing completed.

PAGE A2
DNB ENGINEERING, INC. 3535 W. COMMONWEALTH AVE. FULLERTON, CA 92833 (714) 870-7781 FAX (714) 870-5081www.dnbenginc.com

APPENDIX B

Test Equipment Log

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MANUFACTURER DESCRIPTION MODEL NO. SERIAL NO. CAL DUE

DNB COMPONENT A/D GENERATOR 100KV200KA 001 CPT

DNB COMPONENT B GENERATOR 15KV2160 001 CPT

DNB COMPONENT C GENERATOR 72900VDC 001 CPT

PEARSON CURRENT PROBE – A/D 1423 2343 11-30-13

PEARSON CURRENT PROBE – B 301X 1212 10-14-13

DNB CURRENT PROBE – C HMHB100 12364 12-14-13

YOKOGAWA SCOPECORDER DL750 12B07030H 1-16-14

BIRD 20 dB ATTENUATOR 150-SA-FFN-20 162467 8-25-13

BIRD 20 dB ATTENUATOR 150-SA-FFN-20 0219 8-25-13

TEST EQUIPMENT LOG 

DIRECT EFFECT LIGHTNING 

CPT – Calibration performed prior to test. 
APPENDIX C

Transducer Factors

N/A

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APPENDIX D

Test Data

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DIRECT EFFECT LIGHTNING TEST SUMMARY 

Test

Comp. D IP

(KA)

Comp. D AI

(

Comp. B IAvg

(Amps)

Comp. B CT

(C)

Comp. C* IP

(Amps)

Comp. C* CT

(C)

Cal 96.0 299040 2320 11.598 491 18.5

FLS1 94.0 271700 2266 11.331 267 4.0

FLS1 93.0 264240 2242 11.211 138 0.25

FLS2 94.7 276410 2169 10.847 425 20.0

FLS2 93.7 270370 2174 10.869 416 21.4

FLS3 94.8 278350 2229 11.145 348 4.2

FLS3 93.7 268330 2249 11.247 217 1.1

FLS4 93.3 268460 2222 11.112 177 0.007

FLS4 91.5 251490 2268 11.339 291 1.1

FLS5 94.2 274060 2226 11.130 417 21.1

FLS5 94.2 275950 2177 10.886 421 21.2

FLS6 92.3 248950 2244 11.218 146 0.55

FLS6 90.2 256950 2099 10.496 100 0.41

FLS1 185.0 1.9259E6 2473 12.366 508 20.0

FLS6 186.2 2.0085E6 2438 12.189 498 18.2

D2
D3

HIGH CURRENT – COMPONENT D IP = 96.0 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 299040 A

2

- S

CALIBRATION
D4

HIGH CURRENT – COMPONENT B IP = 5320 Amps

Iavg = 2320 Amps

1 mS / Div

COMPONENT B CHARGE TRANSFER 11.598 Coulombs

CALIBRATION
HIGH CURRENT – COMPONENT C* IP = 491 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 18.5 Coulombs

CALIBRATION

D5
D6

HIGH CURRENT – COMPONENT D IP = 94.0 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 271700 A

2

-S

Panel: FLS1 – First Strike
D7

HIGH CURRENT – COMPONENT B IP = 5147 Amps

Iavg = 2266 Amps

1 mS / Div

COMPONENT B CHARGE TRANSFER 11.331 Coulombs

Panel: FLS1 – First Strike
HIGH CURRENT – COMPONENT C* IP = 267 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 4.0 Coulombs

Panel: FLS1 – First Strike

D8
D9

HIGH CURRENT – COMPONENT D IP = 93.0 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 264240 A

2

-S

Panel: FLS1 – Second Strike
D10

HIGH CURRENT – COMPONENT B IP = 5040 Amps

Iavg = 2242 Amps

1 mS / Div

COMPONENT B CHARGE TRANSFER 11.211 Coulombs

Panel: FLS1 – Second Strike
HIGH CURRENT – COMPONENT C* IP = 138 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 0.25 Coulombs

Panel: FLS1 – Second Strike

D11 
D12

HIGH CURRENT – COMPONENT D IP = 94.7 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 276410 A

2

-S

Panel: FLS2 – First Strike
D13

HIGH CURRENT – COMPONENT B IP = 4893 Amps

Iavg = 2169 Amps

1 mS / Div

COMPONENT B CHARGE TRANSFER 10.847 Coulombs

Panel: FLS2 – First Strike
HIGH CURRENT – COMPONENT C* IP = 425 Amps 20 mS / Div

COMPONENT C* CHARGE TRANSFER 20.0 Coulombs

Panel: FLS2 – First Strike

D14 
D15

HIGH CURRENT – COMPONENT D IP = 93.7 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 270370 A

2

-S

Panel: FLS2 – Second Strike
D16

HIGH CURRENT – COMPONENT B IP = 5000 Amps

Iavg = 2174 Amps

1 mS / Div

COMPONENT B CHARGE TRANSFER 10.869 Coulombs

Panel: FLS2 – Second Strike
HIGH CURRENT – COMPONENT C* IP = 416 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 21.4 Coulombs

Panel: FLS2 – Second Strike

D17 
D18

HIGH CURRENT – COMPONENT D IP = 94.8 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 278350 A

2

-S

Panel: FLS3 – First Strike
D19

HIGH CURRENT – COMPONENT B IP = 5147 Amps

Iavg = 2229 Amps

1 mS / Div

COMPONENT B CHARGE TRANSFER 11.145 Coulombs

Panel: FLS3 – First Strike
HIGH CURRENT – COMPONENT C* IP = 348 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 4.2 Coulombs

Panel: FLS3 – First Strike

D20 
D21

HIGH CURRENT – COMPONENT D IP = 93.7 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 268330 A

2

-S

Panel: FLS3 – Second Strike
D22

HIGH CURRENT – COMPONENT B IP = 5027 Amps

Iavg = 2249 Amps

1 mS / Div

COMPONENT B CHARGE TRANSFER 11.247 Coulombs

Panel: FLS3 – Second Strike
HIGH CURRENT – COMPONENT C* IP = 217 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 1.1 Coulombs

Panel: FLS3 – Second Strike

D23 
D24

HIGH CURRENT – COMPONENT D IP = 93.3 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 268460 A

2

-S

Panel: FLS4 – First Strike
D25

HIGH CURRENT – COMPONENT B IP = 5100 Amps

Iavg = 2222 Amps

1 mS / Div

COMPONENT B CHARGE TRANSFER 11.112 Coulombs

Panel: FLS4 – First Strike
HIGH CURRENT – COMPONENT C* IP = 177 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 0.007 Coulombs

Panel: FLS4 – First Strike

D26 
D27

HIGH CURRENT – COMPONENT D IP = 91.5 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 251490 A

2

-S

Panel: FLS4 – Second Strike
D28

HIGH CURRENT – COMPONENT B IP = 5193 Amps

Iavg = 2268 Amps

1 mS / Div

COMPONENT B CHARGE TRANSFER 11.339 Coulombs

Panel: FLS4 – Second Strike
HIGH CURRENT – COMPONENT C* IP = 291 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 1.1 Coulombs

Panel: FLS4 – Second Strike

D29 
D30

HIGH CURRENT – COMPONENT D IP = 94.2 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 274060 A

2

-S

Panel: FLS5 – First Strike
D31

HIGH CURRENT – COMPONENT B IP = 5013 Amps

Iavg = 2226 Amps

1 mS / Div

COMPONENT B CHARGE TRANSFER 11.130 Coulombs

Panel: FLS5 – First Strike
HIGH CURRENT – COMPONENT C* IP = 417 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 21.1 Coulombs

Panel: FLS5 – First Strike

D32 
D33

HIGH CURRENT – COMPONENT D IP = 94.2 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 275950 A

2

-S

Panel: FLS5 – Second Strike
D34

HIGH CURRENT – COMPONENT B IP = 4927 Amps

Iavg = 2177 Amps

1 mS / Div

COMPONENT B CHARGE TRANSFER 10.886 Coulombs

Panel: FLS5 – Second Strike
HIGH CURRENT – COMPONENT C* IP = 421 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 21.2 Coulombs

Panel: FLS5 – Second Strike

D35 
D36

HIGH CURRENT – COMPONENT D IP = 92.3 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 248950 A

2

-S

Panel: FLS6 – First Strike
D37

HIGH CURRENT – COMPONENT B IP = 5020 Amps

Iavg = 2244 Amps

1 mS / Div

COMPONENT B CHARGE TRANSFER 11.218 Coulombs

Panel: FLS6 – First Strike
HIGH CURRENT – COMPONENT C* IP = 146 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 0.55 Coulombs

Panel: FLS6 – First Strike

D38 
D39

HIGH CURRENT – COMPONENT D IP = 90.2 KA 100 uS / Div

COMPONENT D ACTION INTEGRAL AI = 256950 A

2

-S

Panel: FLS6 – Second Strike
D40

HIGH CURRENT – COMPONENT B IP = 4833 Amps

Iavg = 2099 Amps

1 mS / Div

COMPONENT B CHARGE TRANSFER 10.496 Coulombs

Panel: FLS6 – Second Strike
HIGH CURRENT – COMPONENT C* IP = 100 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 0.41 Coulombs

Panel: FLS6 – Second Strike

D41 
D42

HIGH CURRENT – COMPONENT A IP = 185.0 KA 100 uS / Div

COMPONENT A ACTION INTEGRAL AI = 1.9259E6 A

2

-S

Panel: FLS1 – Third Strike (Zone 1A)
D43

HIGH CURRENT – COMPONENT B IP = 6553 Amps

Iavg = 2473 Amps

1 mS / Div

COMPONENT B CHARGE TRANSFER 12.366 Coulombs

Panel: FLS1 – Third Strike (Zone 1A)
HIGH CURRENT – COMPONENT C* IP = 508 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 20.0 Coulombs

Panel: FLS1 – Third Strike (Zone 1A)

D44 
D45

HIGH CURRENT – COMPONENT A IP = 186.2 KA 100 uS / Div

COMPONENT A ACTION INTEGRAL AI = 2.0085E6 A

2

-S

Panel: FLS6 – Third Strike (Zone 1A)
D46

HIGH CURRENT – COMPONENT B IP = 6467 Amps

Iavg = 2438 Amps

1 mS / Div

COMPONENT B CHARGE TRANSFER 12.189 Coulombs

Panel: FLS6 – Third Strike (Zone 1A)
HIGH CURRENT – COMPONENT C* IP = 498 Amps 50 mS / Div

COMPONENT C* CHARGE TRANSFER 18.2 Coulombs

Panel: FLS6 – Third Strike (Zone 1A)

D47 
APPENDIX E

Photographs

SIZE

A

CAGE CODE

63242

DRAWING NO.

TR057111

SCALE: NONE REV LTR - SHEET E1

DNB ENGINEERING, INC. 3535 W. COMMONWEALTH AVE. FULLERTON, CA 92833 (714) 870-7781 FAX (714) 870-5081 www.dnbenginc.com
E2

High Current Test – FSL1 – Pre-Strike

High Current Test – FSL1 – Components D, B, C*
E3

High Current Test – FSL1 – Post-Strike Damage

High Current Test – FSL1 – Pre-Strike
E4

High Current Test – FSL1 – Components D, B, C*

High Current Test – FSL1 – Post-Strike Damage
E5

High Current Test – FSL2 – Pre-Strike
E6

High Current Test – FSL2 – Components D, B, C*
E7

High Current Test – FSL2 – Post-Strike Damage
E8

High Current Test – FSL2 – Pre-Strike
E9

High Current Test – FSL2 – Components D, B, C*

High Current Test – FSL2 – Post-Strike Damage
E10

High Current Test – FSL3 – Pre-Strike
E11

High Current Test – FSL3 – Components D, B, C*
E12

High Current Test – FSL3 – Post-Strike Damage

High Current Test – FSL3 – Pre-Strike
E13

High Current Test – FSL3 – Components D, B, C*

High Current Test – FSL3 – Post-Strike Damage
E14

High Current Test – FSL4 – Pre-Strike

High Current Test – FSL4 – Components D, B, C*
E15

High Current Test – FSL4 – Post-Strike Damage

High Current Test – FSL4 – Pre-Strike
E16

High Current Test – FSL4 – Components D, B, C*

High Current Test – FSL4 – Post-Strike Damage
E17

High Current Test – FSL5 – Pre-Strike
E18

High Current Test – FSL5 – Components D, B, C*
E19

High Current Test – FSL5 – Post-Strike Damage
E20

High Current Test – FSL5 – Pre-Strike
E21

High Current Test – FSL5 – Components D, B, C*
E22

High Current Test – FSL5 – Post-Strike Damage
E23

High Current Test – FSL6 – Pre-Strike

High Current Test – FSL6 – Components D, B, C*
E24

High Current Test – FSL6 – Post-Strike Damage

High Current Test – FSL6 – Pre-Strike
E25

High Current Test – FSL6 – Components D, B, C*

High Current Test – FSL6 – Post-Strike Damage
E26

High Current Test – FSL1 – Pre-Strike (Zone 1A)

High Current Test – FSL1 – Components A, B, C*
E27

High Current Test – FSL1 – Post-Strike Damage
E28

High Current Test – FSL6 – Pre-Strike (Zone 1A)
E29

High Current Test – FSL6 – Components A, B, C*

No Photo

High Current Test – FSL6 – Post-Strike Damage

M-1 

Appendix M 

Acoustic Test Data Uncertainty 
M-2 

Table M-1 - TL Uncertainty (1 of 3) 

1/3 Octave FAC-6a FAC-6b FAC-6c FAC-6d

 Frequency

 (Hz) (+/- dB) Notes (+/- dB) Notes (+/- dB) Notes (+/- dB) Notes

50 [c][f] [c][f] [d][f] [c][f]

63 [d][f] [d][f] [d][f] [d][f]

80 4.6 [c] 4.6 [c] 4.6 [c] 4.6 [c]

100 2.1 2.1 2.1 2.1

125 1.9 1.8 1.9 1.8

160 2.0 2.0 2.0 2.0

200 0.9 0.9 0.9 1.0

250 0.4 0.5 0.5 0.5

315 0.6 0.4 0.4 0.5

400 0.3 0.3 0.3 0.3

500 0.4 0.4 0.4 0.4

630 0.3 0.3 0.3 0.3

800 0.3 0.3 0.3 [c] 0.3

1000 0.2 0.2 0.2 [c] 0.2

1250 0.2 0.2 0.2 [c] 0.2

1600 0.2 0.2 0.2 [c] 0.2 [c]

2000 0.2 0.2 [c] 0.2 [d] 0.2 [d]

2500 0.2 [c] 0.2 [d] 0.2 [d] 0.2 [d]

3150 0.2 [c] 0.2 [d] 0.2 [d] 0.2 [d]

4000 0.2 [d] 0.2 [d] 0.2 [d] 0.2 [d]

5000 0.2 [d] 0.2 [d] 0.2 [d] 0.3 [d]

6300 0.3 [d] 0.3 [d] 0.2 [d] 0.3 [d]

8000 0.4 [d] 0.3 [d] 0.3 [d] 0.3 [d]

10000 0.5 [d] 0.5 [d] 0.5 [d] 0.5 [d]
M-3 

Table M-2 - TL Uncertainty (2 of 3) 

1/3 Octave FAC-1 FAC-2 FAC-3 FAC-4 FAC-5 FAC-7 FAC-8

 Frequency

 (Hz) (+/- dB) Notes (+/- dB) Notes (+/- dB) Notes (+/- dB) Notes (+/- dB) Notes (+/- dB) Notes (+/- dB) Notes

50 [d][f] [d][f] [c][f] [d][f] [c][f] [c][f] [c][f]

63 [b][d][f] [b][d][f] [d][f] [b][d][f] [b][d][f] [c][f] [d][f]

80 4.6 [c] 4.6 [c] 4.6 [c] 4.6 [c] 4.6 [c] 4.6 [c] 4.6 [c]

100 2.1 2.1 2.1 2.1 2.1 2.1 2.1

125 1.9 1.9 1.8 1.9 1.8 1.9 1.9

160 2.0 2.0 2.0 2.0 2.0 2.0 2.0

200 0.9 0.9 0.9 0.8 0.9 0.8 0.9

250 0.5 0.4 0.5 0.4 0.4 0.6 0.4

315 0.5 0.4 0.5 0.4 0.4 0.5 0.4

400 0.3 0.3 0.3 0.3 0.3 0.4 0.3

500 0.3 0.4 0.4 0.4 0.4 0.4 0.3

630 0.3 0.3 0.3 0.3 0.3 0.3 0.3

800 0.3 0.3 0.3 0.3 0.3 0.3 0.3

1000 0.2 0.2 0.2 0.2 0.3 0.2 0.2

1250 0.2 0.2 0.2 0.2 0.2 0.2 0.2

1600 0.2 [c] 0.2 [c] 0.2 [c] 0.2 [c] 0.2 0.2 0.2

2000 0.2 [c] 0.2 [c] 0.2 [c] 0.2 [c] 0.3 [c] 0.2 0.2

2500 0.2 [c] 0.2 [c] 0.2 [c] 0.2 [c] 0.2 [c] 0.3 0.2

3150 0.2 [c] 0.2 [c] 0.2 [c] 0.2 [c] 0.2 [c] 0.2 0.2

4000 0.2 [c] 0.2 [c] 0.2 [c] 0.2 0.2 [c] 0.2 0.2

5000 0.2 [c] 0.2 [c] 0.2 [c] 0.2 [c] 0.2 [c] 0.2 0.2

6300 0.2 [c] 0.2 [c] 0.2 [c] 0.3 [c] 0.2 [c] 0.3 [c] 0.3 [c]

8000 0.3 [d] 0.3 [d] 0.3 [d] 0.3 [d] 0.3 [d] 0.4 [c] 0.3 [c]

10000 0.5 [d] 0.5 [d] 0.5 [d] 0.5 [d] 0.5 [d] 0.5 [c] 0.5 [c]
M-4 

Table M-3 - TL Uncertainty (3 of 3) 

Table M-1 Notes: 

 [b]: Specimen TL within 10 dB of facility flanking limits. No correction applied. Value represents lower bound 

for specimen TL in this band; 

[c]: Specimen TL corrected for sound transmission through laboratory filler wall per requirements of ASTM E90-09 

Annex A3; 

[d]: Specimen TL too close to laboratory filler wall. Value represents lower bound for specimen TL in this band; 

[f] Insufficient number of independent microphone samples to determine test uncertainty. 

1/3 Octave FAC-9a FAC-9b FAC-9d FAC-9e FAC-9f FAC-9g FAC-9h

 Frequency

 (Hz) (+/- dB) Notes (+/- dB) Notes (+/- dB) Notes (+/- dB) Notes (+/- dB) Notes (+/- dB) Notes (+/- dB) Notes

50 [c][f] [c][f] [c][f] [d][f] [d][f] [d][f] [b][d][f]

63 [c][f] [d][f] [b][d][f] [b][d][f] [b][d][f] [b][d][f] [b][d][f]

80 4.6 4.6 [c] 4.6 [c] 4.6 [c] 4.6 [c] 4.6 [c] 4.6 [c]

100 2.1 2.1 2.1 2.1 2.1 2.0 2.1

125 1.8 1.8 1.8 1.8 1.9 1.8 1.8

160 2.0 2.0 2.0 2.0 2.0 2.0 2.0

200 0.8 0.9 0.8 0.9 0.8 0.9 0.8

250 0.5 0.4 0.4 0.4 0.5 0.4 0.4

315 0.4 0.5 0.5 0.4 0.5 0.5 0.4

400 0.3 0.4 0.3 0.3 0.4 0.4 0.3

500 0.3 0.3 0.4 0.4 0.4 0.4 0.4 [c]

630 0.3 0.3 0.3 0.3 [c] 0.3 [c] 0.3 [c] 0.3 [c]

800 0.3 0.3 0.3 0.3 [c] 0.3 [c] 0.3 [c] 0.3 [c]

1000 0.2 0.2 0.3 0.2 [c] 0.2 [c] 0.3 [c] 0.3 [c]

1250 0.2 0.2 0.2 0.2 [c] 0.2 [c] 0.2 [c] 0.2 [c]

1600 0.2 0.2 0.2 [c] 0.2 [c] 0.2 [c] 0.2 [d] 0.2 [d]

2000 0.2 0.2 0.2 [c] 0.2 [d] 0.2 [d] 0.2 [d] 0.2 [d]

2500 0.2 0.2 [c] 0.2 [c] 0.2 [d] 0.2 [d] 0.2 [d] 0.2 [d]

3150 0.2 0.2 [c] 0.2 [c] 0.2 [d] 0.2 [d] 0.2 [d] 0.2 [d]

4000 0.2 0.2 0.2 [c] 0.2 [d] 0.2 [d] 0.2 [d] 0.2 [d]

5000 0.2 0.2 [c] 0.2 [c] 0.2 [d] 0.2 [d] 0.2 [d] 0.2 [d]

6300 0.2 0.3 [c] 0.2 [d] 0.2 [d] 0.2 [d] 0.2 [d] 0.3 [d]

8000 0.3 0.3 [d] 0.3 [d] 0.3 [d] 0.3 [d] 0.3 [d] 0.3 [d]

10000 0.5 0.5 [d] 0.5 [d] 0.5 [d] 0.5 [d] 0.5 [d] 0.5 [d]
REPORT DOCUMENTATION PAGE Form Approved

OMB No. 0704-0188

2. REPORT TYPE 

Contractor Report

 4. TITLE AND SUBTITLE

Protective Skins for Composite Airliners Final Report 

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NNC10CA36C

 6. AUTHOR(S)

Johnson, Vicki; Boone, Richard L.; Jones, Shannon; Pendse, Vandana;

Hayward, Greg

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NASA Langley Research Center 

Hampton, Virginia 23681 

 

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Traditional composite aircraft structures are designed for load bearing and then overdesigned for impact damage and hot humid environments. Seeking 

revolutionary improvement in the performance and weight of composite structures, Cessna Aircraft Company, with sponsorship from the NASA Fundamental 

Aeronautics Program/Subsonic Fixed Wing Project, has developed and tested a protective skin concept which would allow the primary composite structure to 

carry only load and would meet the impact, hot and humid, and other requirements through protective skins. A key requirement for the protective skins is to 

make any impact damage requiring repair visible. Testing from the first generation of skins helped identify the most promising materials which were used in a 

second generation of test articles. This report summarizes lessons learned from the first generation of protective skins, the design and construction of the 

second-generation test articles, test results from the second generation for impact, electromagnetic effects, aesthetics and smoothing, thermal, and acoustic (for 

the first time), and an assessment of the feasibility of the protective skin concept. 

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Acoustic properties; Composite aircraft; Impact properties; N+3 Aircraft concepts; Protective skin; Thermal properties

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