### Commercial **Airplanes** 

# MD90 Service Bulletin **ALERT Number: MD90-55A014**  Original Issue: June 24, 2010 ATA System: 5531 **SUBJECT:** STABILIZERS - Vertical Stabilizer - Inspect/Repair Fixed Leading Edge Skin and Front Spar Cap at Station Zfs=52.267 Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15 CFR 730-774). An export license may be required before it is used for development, production or use by foreign persons from specific countries. The controller of this data has the individual responsibility to abide by all export laws. 9E991 ECCN: 

## BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2010 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter. Boeing also claims copyright in this document as a compilation and/or collective work. This document includes proprietary information owned by The Boeing Company and/or one or more third parties. Treatment of the document and the information it contains is governed by contract with Boeing. For more information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124. Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner, BBJ, DC-8, DC-9, DC-10, KC-10, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8A, Poseidon and the Boeing livery are all trademarks owned by The Boeing Company; and no trademark license is granted in connection with this document unless provided in writing by Boeing.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 1 of 53 2.0BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 2 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT**

BLANK PAGE**Table of Contents** Summary...................................................... 5 1. PLANNING INFORMATION ........................................ 9 A. Effectivity................................................ 9 1. Airplanes............................................. 9 2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 B. Concurrent Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 I. Electrical Load Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 J. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 1. Existing Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 2. Data supplied with this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3. Installation Drawings Used in the Preparation of this Service Bulletin. . . . . . . . . . . . 25 K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 L. Interchangeability and Intermixability of Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . 26 2. MATERIAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 C. Parts Necessary For Each Airplane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 1. Kits/Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 2. Parts and Materials Supplied by the Operator. . . . . . . . . . . . . . . . . . . . . . . . 27 3. Parts Modified and Reidentified. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 4. Parts Removed and Not Replaced. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 27 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 APPENDIX A: FLOWCHART - INITIAL INSPECTION AND REPETITIVE INSPECTION. . . . . . . . . . 41 APPENDIX B: INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267 . 44

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 3 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 4 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT**

BLANK PAGE

### Commercial **Airplanes** 

# MD90 Service Bulletin **ALERT Summary**  **Number: MD90-55A014** Original Issue: June 24, 2010 ATA System: 5531 **SUBJECT:** STABILIZERS - Vertical Stabilizer - Inspect/Repair Fixed Leading Edge Skin and Front Spar Cap at Station Zfs=52.267
THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH 1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OWNER. **CONCURRENT REQUIREMENTS**
None. **BACKGROUND** One operator reported finding elongated fastener holes at the leading edge of the vertical stabilizer at Station Zfs=52.267. The affected MD-90 airplane had accrued 15,555 flight-hours and 14,310 landing cycles when the elongated fastener holes were found during normal maintenance. Furthermore, two MD-80 operators reported finding a cracked vertical stabilizer skin at Station Zfs=52.267. Subsequent inspection on both affected MD-80 airplanes, revealed a severed front spar cap and a cracked front spar web. The affected MD-80 airplanes had accrued between 39,749 through 56,212 flight-hours and 32,176 through 44,001 landing cycles when the cracks/anomalies were found. Cracks were also found on several other MD-80 airplanes, in the vertical stabilizer front spar cap bolt holes. The MD-90 vertical stabilizer is similar in design and loading as that of the MD-80 vertical stabilizer. Based on service reports and findings, Boeing correlated fastener damage and/or elongated fastener holes at the leading edge of the vertical stabilizer with structural cracks. Boeing investigation determined that high loading occurrences, such as, but not limited to, in-flight turbulence can adversely impact the fasteners and loading at the leading edge of the vertical stabilizer. Inspection will determine condition of the vertical stabilizer skin. Incorporation of the leading edge repair will minimize the possibility of crack growth. If not corrected, cracks in the vertical stabilizer leading edge and front spar cap may result in the structure unable to support limit load, and may lead to the loss of the vertical stabilizer. **ACTION** Refer to Paragraph 1.D., Description. **EFFECTIVITY** MD-90-30 Airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes. **COMPLIANCE** Refer to Paragraph 1.E., Compliance.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 5 of 53**INDUSTRY SUPPORT INFORMATION** Boeing warranty remedies are not available for the inspection and/or repair procedures given in this service bulletin. **MANPOWER** Refer to Paragraph 1.G., Manpower. **MATERIAL INFORMATION** Operator Supplied Parts/Materials. Refer to Paragraph 2.A., Material - Price and Availability

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 6 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 7 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 8 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT**

BLANK PAGE

### Commercial **Airplanes** 

# MD90 Service Bulletin **ALERT Number: MD90-55A014**  Original Issue: June 24, 2010 ATA System: 5531 **SUBJECT:** STABILIZERS - Vertical Stabilizer - Inspect/Repair Fixed Leading Edge Skin and Front Spar Cap at Station Zfs=52.267
THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH 1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OWNER. **1. PLANNING INFORMATION A. Effectivity**  1. Airplanes This service bulletin is for the airplanes shown below.
**DESCRIPTION CONFIGURATION**  **GROUP** MD-90-30 Airplanes

- 1

Airplane Models: MD-90-30 **Group Fuselage Num-**  **ber** 1 2094 - 2100 1 2115 1 2117 1 2120 1 2122 - 2123 1 2125 - 2126 1 2129 1 2131

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 9 of 53**Group Fuselage Num-**  **ber** 1 2133 1 2136 1 2138 1 2140 - 2144 1 2146 - 2147 1 2149 - 2150 1 2153 - 2154 1 2156 - 2159 1 2161 - 2166 1 2169 - 2171 1 2173 1 2175 1 2177 1 2179 1 2181 1 2184 1 2186 1 2190 - 2191 1 2193 - 2195 1 2197 - 2198 1 2200 1 2202 - 2203 1 2205 1 2207 1 2209 - 2213 1 2215 - 2217 1 2219 - 2233 1 2235 - 2237 1 2240 1 2243 1 2245 1 2248

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 10 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT Group**  **Fuselage Num- ber**  1 2250 - 2251 1 2253 1 2255 - 2263 1 2288 - 2290 1 4001 - 4002 2. Spares Affected
None. **B. Concurrent Requirements**
None. **C. Reason** One operator reported finding elongated fastener holes at the leading edge of the vertical stabilizer at Station Zfs=52.267. The affected MD-90 airplane had accrued 15,555 flight-hours and 14,310 landing cycles when the elongated fastener holes were found during normal maintenance. Furthermore, two MD-80 operators reported finding a cracked vertical stabilizer skin at Station Zfs=52.267. Subsequent inspection on both affected MD-80 airplanes, revealed a severed front spar cap and a cracked front spar web. The affected MD-80 airplanes had accrued between 39,749 through 56,212 flight-hours and 32,176 through 44,001 landing cycles when the cracks/anomalies were found. Cracks were also found on several other MD-80 airplanes, in the vertical stabilizer front spar cap bolt holes. The MD-90 vertical stabilizer is similar in design and loading as that of the MD-80 vertical stabilizer. Based on service reports and findings, Boeing correlated fastener damage and/or elongated fastener holes at the leading edge of the vertical stabilizer with structural cracks. Boeing investigation determined that high loading occurrences, such as, but not limited to, in-flight turbulence can adversely impact the fasteners and loading at the leading edge of the vertical stabilizer. Inspection will determine condition of the vertical stabilizer skin. Incorporation of the leading edge repair will minimize the possibility of crack growth. If not corrected, cracks in the vertical stabilizer leading edge and front spar cap may result in the structure unable to support limit load, and may lead to the loss of the vertical stabilizer. **D. Description** This service bulletin provides instructions to do an initial inspection and repetitive inspections of the vertical stabilizer leading edge structure at the splice at Station Zfs=52.267, and the vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins, as follows: **NOTE:** Refer to APPENDIX A: FLOWCHART - INITIAL INSPECTION AND REPETITIVE INSPECTION, as a supplement to Paragraph 1.D., Description.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 11 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT PART A - INITIAL INSPECTION:**  1. Removes two rows of fasteners above the splice and two rows of fasteners below the splice at Station Zfs=52.267. 2. Does a detailed inspection for "distress" in, and "existing repairs" to, the vertical stabilizer leading edge structure at the splice at Station Zfs=52.267. **NOTE:** "Distress" is defined as deformed holes, elongated holes, oversized holes or cracks in the leading edge skin and splice. "Existing Repairs" are bushings, washers or reinforcing repairs to the leading edge. 3. Based on inspection results, does as follows:
**CONDITION 1 (Leading Edge is Not Distressed and No Existing Repair Found)** a. Does an inspection for cracking on the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267. b. Based on inspection results, does as follows: **CONDITION 1A (No Crack Found)** (1) Puts the airplane back to a serviceable condition. **CONDITION 1B (Any Crack Found)** (1) Does an evaluation/verification to confirm all crack indications. (2) Contacts Boeing for repair of all cracking and does the repair in accordance with Boeing's instructions. (3) Puts the airplane back to a serviceable condition. **CONDITION 2 (Leading Edge is Distressed)** a. Does an inspection for cracking on the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267. b. Based on inspection results, does as follows: **CONDITION 2A (No Crack Found)** (1) Does leading edge repair. (2) Puts the airplane back to a serviceable condition.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 12 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT CONDITION 2B (Any Crack Found)**  (1) Does leading edge repair. (2) Does an evaluation/verification to confirm all crack indications. (3) Contacts Boeing for repair of all cracking and does the repair in accordance with Boeing's instructions. (4) Puts the airplane back to a serviceable condition. **CONDITION 3 (Leading Edge Existing Repair Found)** a. Does an inspection for cracking on the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267. b. Based on inspection results, does as follows: **CONDITION 3A (No Crack Found)** (1) Puts the airplane back to a serviceable condition. **CONDITION 3B (Any Crack Found)** (1) Does an evaluation/verification to confirm all crack indications. (2) Contacts Boeing for repair of all cracking and does the repair in accordance with Boeing's instructions. (3) Puts the airplane back to a serviceable condition. **PART B - REPETITIVE INSPECTION:** 1. Inspection - Vertical Stabilizer Leading Edge:
a. Does a detailed inspection of the vertical stabilizer leading edge at the splice at Station Zfs=52.267 (fasteners not removed) for indications of loose fasteners and missing fasteners. b. Based on inspection results, does as follows: **CONDITION 4 (No Loose Leading Edge Fasteners and No Missing Leading Edge Fasteners)**  (1) Does repetitive detailed inspection of the vertical stabilizer leading edge at the splice at Station Zfs=52.267 (fasteners not removed) for indications of loose fasteners and missing fasteners.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 13 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT CONDITION 5 (Loose Leading Edge Fasteners or Missing Leading Edge Fasteners)**  (1) Does leading edge repair. (2) Does repetitive detailed inspection of the vertical stabilizer leading edge at the splice at Station Zfs=52.267 (fasteners not removed) for indications of loose fasteners and missing fasteners. 2. Inspection - Vertical Stabilizer Front Spar Cap Forward Flanges and either the Aft Flanges or Side Skins:
a. Does an inspection for cracking on the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267. b. Based on inspection results, does as follows: **CONDITION 6 (No Crack Found)** (1) Does repetitive inspection for cracks on the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267. **CONDITION 7 (Any Crack Found)** (1) Does an evaluation/verification to confirm all crack indications. (2) Contacts Boeing for repair of all cracking and does the repair in accordance with Boeing's instructions. 3. Puts the airplane back to a serviceable condition.
The work in this service bulletin is done in the maintenance zone(s) given below.
**Affected Maintenance Zones Zone**  **Model** 371, 373 MD-90-30 **E. Compliance** The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. **NOTE:** Refer to APPENDIX A: FLOWCHART - INITIAL INSPECTION AND REPETITIVE INSPECTION, as a supplement to Paragraph 1.E., Compliance. **NOTE:** "Distress" is defined as deformed holes, elongated holes, oversized holes or cracks in the leading edge skin and splice. "Existing Repairs" are bushings, washers or reinforcing repairs to the leading edge.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 14 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT Table 1: PART A - Initial Inspection: Fixed Leading Edge Skin and Front Spar Cap at Station Zfs=52.267**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- Within 4,100 flight cycles after the original issue dateon this service bulletin. Do a detailed inspection for "distress" in, and "existing repairs" to, the vertical stabilizer leading edge structure at the splice at Station Zfs=52.267 in accordance with Paragraph 3.B., Work Instructions. All Airplanes

- Before further flight. Do an inspection for cracking on the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267, using one of the options as follows: CONDITION 1 (Leading Edge is NotDistressed and No Existing Repair Found)

- - OPTION 1:Do an open hole Eddy Current, High Frequency (ETHF) inspection of the left and right vertical stabilizer front spar cap forward flanges in accordance with Paragraph 3.B., Work Instructions. AND Do a Radiographic Testing (RT) inspection of the left and right vertical stabilizer front spar cap aft flanges in accordance with Paragraph 3.B., Work Instructions. OR

- - OPTION 2: Do an open hole ETHF inspection of the left and right vertical stabilizer front spar capforward flanges in accordance with Paragraph 3.B., Work Instructions. AND Do an ETHF surface inspection of the left and right side skins at the vertical stabilizer front spar cap aft flanges in accordance with Paragraph 3.B., Work Instructions.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 15 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT Table 1: PART A - Initial Inspection: Fixed Leading Edge Skin and Front Spar Cap at Station Zfs=52.267**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- In Accordance With Table 2: PART B -Repetitive Inspection: Fixed LeadingEdge Skin at Station Zfs=52.267Do repetitive inspections of the vertical stabilizer leading edge structure at the splice at Station Zfs=52.267 in accordance with Paragraph 3.B., Work Instructions. CONDITION 1A(No Crack Found during either Option 1 or Option 2 Inspection)

AND

- In Accordance With Table 3: PART B -Repetitive Inspection: Front Spar Cap at Station Zfs=52.267 Do repetitive inspections of the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267 in accordance with Paragraph 3.B., Work Instructions.

- Before further flight. Do an evaluation/verification to confirm allcrack indications in accordance with Paragraph 3.B., Work Instructions. CONDITION 1B(Any Crack Found during either Option 1 or Option 2 Inspection)

- Before further flight. Contact Boeing for repair of all cracking and do the repair in accordance with Boeing's instructions. CONDITION 1B (Any confirmed crack indication)

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 16 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT Table 1: PART A - Initial Inspection: Fixed Leading Edge Skin and Front Spar Cap at Station Zfs=52.267**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- Before further flight. Do an inspection for cracking on the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267, using one of the options as follows: CONDITION 2(Leading Edge is Distressed)

- - OPTION 1: Do an open hole ETHF inspection of the left and right vertical stabilizer front spar capforward flanges in accordance with Paragraph 3.B., Work Instructions. AND Do an RT inspection of the left and right vertical stabilizer front spar cap aft flanges in accordance with Paragraph 3.B., Work Instructions. OR

- - OPTION 2: Do an open hole ETHF inspection of the left and right vertical stabilizer front spar capforward flanges in accordance with Paragraph 3.B., Work Instructions. AND Do an ETHF surface inspection of the left and right side skins at the vertical stabilizer front spar cap aft flanges in accordance with Paragraph 3.B., Work Instructions.

- Before further flight. Do leading edge repair in accordance with Paragraph 3.B., Work Instructions. CONDITION 2A(No Crack Found during either Option 1 or Option 2 Inspection) AND

- In Accordance With Table 2: PART B -Repetitive Inspection: Fixed LeadingEdge Skin at Station Zfs=52.267Do repetitive inspections of the vertical stabilizer leading edge structure at the splice at Station Zfs=52.267 in accordance with Paragraph 3.B., Work Instructions.

AND

- In Accordance With Table 3: PART B -Repetitive Inspection: Front Spar Cap at Station Zfs=52.267 Do repetitive inspections of the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267 in accordance with Paragraph 3.B., Work Instructions.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 17 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT Table 1: PART A - Initial Inspection: Fixed Leading Edge Skin and Front Spar Cap at Station Zfs=52.267**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- Before further flight. Do leading edge repair in accordance with Paragraph 3.B., Work Instructions. CONDITION 2B(Any Crack Found during either Option 1 or Option 2 Inspection) AND

- Before further flight. Do an evaluation/verification to confirm allcrack indications in accordance with Paragraph 3.B., Work Instructions. AND

- Before further flight. Contact Boeing for repair of all cracking and do the repair in accordance with Boeing's instructions. CONDITION 2B (Any confirmed crack indication)

- Before further flight. Do an inspection for cracking on the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267, using one of the options as follows: CONDITION 3 (Leading Edge Existing Repair Found)

- - OPTION 1: Do an open hole ETHF inspection of the left and right vertical stabilizer front spar capforward flanges in accordance with Paragraph 3.B., Work Instructions. AND Do an RT inspection of the left and right vertical stabilizer front spar cap aft flanges in accordance with Paragraph 3.B., Work Instructions. OR

- - OPTION 2: Do an open hole ETHF inspection of the left and right vertical stabilizer front spar capforward flanges in accordance with Paragraph 3.B., Work Instructions. AND Do an ETHF surface inspection of the left and right side skins at the vertical stabilizer front spar cap aft flanges in accordance with Paragraph 3.B., Work Instructions.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 18 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT Table 1: PART A - Initial Inspection: Fixed Leading Edge Skin and Front Spar Cap at Station Zfs=52.267**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- In Accordance With Table 2: PART B -Repetitive Inspection: Fixed LeadingEdge Skin at Station Zfs=52.267Do repetitive inspections of the vertical stabilizer leading edge structure at the splice at Station Zfs=52.267 in accordance with Paragraph 3.B., Work Instructions. CONDITION 3A(No Crack Found during either Option 1 or Option 2 Inspection)

AND

- In Accordance With Table 3: PART B -Repetitive Inspection: Front Spar Cap at Station Zfs=52.267 Do repetitive inspections of the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267 in accordance with Paragraph 3.B., Work Instructions.

- Before further flight. Do an evaluation/verification to confirm allcrack indications in accordance with Paragraph 3.B., Work Instructions. CONDITION 3B(Any Crack Found during either Option 1 or Option 2 Inspection)

- Before further flight. Contact Boeing for repair of all cracking and do the repair in accordance with Boeing's instructions. CONDITION 3B (Any confirmed crack indication) **Table 2: PART B - Repetitive Inspection: Fixed Leading Edge Skin at Station Zfs=52.267 Repeat Interval**  **(Not to Exceed) Compliance Time**  **Action Condition** 

- Within 4,400 flight cycles after doingthe initial inspection.Do a detailed inspection of the vertical stabilizer leading edge structure at the splice at Station Zfs=52.267 for indications of loosefasteners and missing fasteners in accordance with Paragraph 3.B., Work Instructions.Airplanes from CONDITION 1A or 2A or 3A ofTable 1: PART A - Initial Inspection on whichthe OPTION 1 inspections were done.

- Within 3,000 flight cycles after doingthe initial inspection.Do a detailed inspection of the vertical stabilizer leading edge structure at the splice at Station Zfs=52.267 for indications of loosefasteners and missing fasteners in accordance with Paragraph 3.B., Work Instructions.Airplanes from CONDITION 1A or 2A or 3A ofTable 1: PART A - Initial Inspection on whichthe OPTION 2 inspections were done.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 19 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT Table 2: PART B - Repetitive Inspection: Fixed Leading Edge Skin at Station Zfs=52.267**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition** 4,400 flight cycles (a) Within 4,400 flight cycles after doingthe detailed inspection.Do repetitive detailed inspection of the vertical stabilizer leading edge structure at the splice at Station Zfs=52.267 for indications of loose fasteners and missing fasteners inaccordance with Paragraph 3.B., Work Instructions. CONDITION 4 (No Loose Leading Edge Fasteners and No Missing Leading Edge Fasteners) for airplaneson which the prior inspection of the frontspar cap was done using OPTION 1. 3,000 flight cycles (a) Within 3,000 flight cycles after doingthe detailed inspection.Do repetitive detailed inspection of the vertical stabilizer leading edge structure at the splice at Station Zfs=52.267 for indications of loose fasteners and missing fasteners inaccordance with Paragraph 3.B., Work Instructions. CONDITION 4 (No Loose Leading Edge Fasteners and No Missing Leading Edge Fasteners) for airplaneson which the prior inspection of the frontspar cap was done using OPTION 2.

- Before further flight. Do leading edge repair in accordance with Paragraph 3.B., Work Instructions. CONDITION 5 (Loose Leading Edge Fasteners or MissingLeading Edge Fasteners) for airplanes onwhich the prior inspection of the front spar cap was done using OPTION 1. AND 4,400 flight cycles (a) Within 4,400 flight cycles after doingthe detailed inspection.Do repetitive detailed inspection of the vertical stabilizer leading edge structure at the splice at Station Zfs=52.267 for indications of loose fasteners and missing fasteners inaccordance with Paragraph 3.B., Work Instructions.

- Before further flight. Do leading edge repair in accordance with Paragraph 3.B., Work Instructions. CONDITION 5 (Loose Leading Edge Fasteners or MissingLeading Edge Fasteners) for airplanes onwhich the prior inspection of the front spar cap was done using OPTION 2. AND 3,000 flight cycles (a) Within 3,000 flight cycles after doingthe detailed inspection.Do repetitive detailed inspection of the vertical stabilizer leading edge structure at the splice at Station Zfs=52.267 for indications of loose fasteners and missing fasteners inaccordance with Paragraph 3.B., Work Instructions.(a) Changing from one inspection option to another option is acceptable, provided the repeat interval requirement is first complied with, before changing options.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 20 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT Table 3: PART B - Repetitive Inspection: Front Spar Cap at Station Zfs=52.267**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- Within 4,400 flight cycles after doingthe initial inspection. Do an inspection for cracking on the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267, using one of the options as follows:Airplanes from CONDITION 1A or 2A or 3A ofTable 1: PART A - Initial Inspection on whichthe OPTION 1 inspections were done.

- - OPTION 1: Do an open hole ETHF inspection of the left and right vertical stabilizer front spar capforward flanges in accordance with Paragraph 3.B., Work Instructions. AND Do an RT inspection of the left and right vertical stabilizer front spar cap aft flanges in accordance with Paragraph 3.B., Work Instructions. OR

- - OPTION 2: Do an open hole ETHF inspection of the left and right vertical stabilizer front spar capforward flanges in accordance with Paragraph 3.B., Work Instructions. AND Do an ETHF surface inspection of the left and right side skins at the vertical stabilizer front spar cap aft flanges in accordance with Paragraph 3.B., Work Instructions.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 21 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT Table 3: PART B - Repetitive Inspection: Front Spar Cap at Station Zfs=52.267**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- Within 3,000 flight cycles after doingthe initial inspection. Do an inspection for cracking on the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267, using one of the options as follows:Airplanes from CONDITION 1A or 2A or 3A ofTable 1: PART A - Initial Inspection on whichthe OPTION 2 inspections were done.

- - OPTION 1: Do an open hole ETHF inspection of the left and right vertical stabilizer front spar capforward flanges in accordance with Paragraph 3.B., Work Instructions. AND Do an RT inspection of the left and right vertical stabilizer front spar cap aft flanges in accordance with Paragraph 3.B., Work Instructions. OR

- - OPTION 2: Do an open hole ETHF inspection of the left and right vertical stabilizer front spar capforward flanges in accordance with Paragraph 3.B., Work Instructions. AND Do an ETHF surface inspection of the left and right side skins at the vertical stabilizer front spar cap aft flanges in accordance with Paragraph 3.B., Work Instructions. 4,400 flight cycles (a) Within 4,400 flight cycles after doing the inspection. Do repetitive inspections of the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267 in accordance with Paragraph 3.B., Work Instructions. CONDITION 6 (No Crack Found) for airplanes on which the prior inspection of the front spar cap was done using OPTION 1. 3,000 flight cycles (a) Within 3,000 flight cycles after doing the inspection. Do repetitive inspections of the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267 in accordance with Paragraph 3.B., Work Instructions. CONDITION 6 (No Crack Found) for airplanes on which the prior inspection of the front spar cap was done using OPTION 2.

- Before further flight. Do an evaluation/verification to confirm allcrack indications in accordance with Paragraph 3.B., Work Instructions. CONDITION 7(Any Crack Found during either Option 1 or Option 2 Inspection)

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 22 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT Table 3: PART B - Repetitive Inspection: Front Spar Cap at Station Zfs=52.267**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- Before further flight. Contact Boeing for repair of all cracking and do the repair in accordance with Boeing's instructions. CONDITION 7 (Any confirmed crack indication)(a) Changing from one inspection option to another option is acceptable, provided the repeat interval requirement is first complied with, before changing options.

**F. Approval** This service bulletin was examined by the Federal Aviation Administration (FAA). The changes specified in this service bulletin comply with the applicable regulations and are FAA approved, as well as European Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved airplanes listed in the service bulletin effectivity. This service bulletin and its approval were based on the airplane in its original Boeing delivery configuration or as modified by other approved Boeing changes. If an airplane has a non-Boeing modification or repair that affects a component or system also affected by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval before incorporating this service bulletin. **G. Manpower** The table below shows an estimate of the task hours necessary to do the inspection/change/repair for each airplane. This estimate is for direct labor only, done by an experienced crew. Adjust the estimate with operator task hour data if necessary. The estimate does not include lost time. These are some examples of lost time: • Time to adjust to the workplace • Time to schedule the work • Time to inspect the work • Time to cure the materials • Time to make the parts • Time to find the tools. **Table 1: PART A - Initial Inspection: Fixed Leading Edge Skin and Front Spar Cap at Station Zfs=52.267**  **Elapsed Hours Task Hours**  **Number of Persons Task**  1.5 1.5 1 Remove Fasteners - Fixed Leading Edge 1.0 1.0 1 Inspect - Fixed Lead- ing Edge 1.0 1.0 1 Remove Fasteners -Front Spar Cap Forward Flange

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 23 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT Table 1: PART A - Initial Inspection: Fixed Leading Edge Skin and Front Spar Cap at Station**  **Zfs=52.267 Elapsed Hours**  **Task Hours Number of Persons**  **Task** 1.0 1.0 1 Inspect - Front Spar Cap Forward Flange 1.5 1.5 1 Install Fasteners -Front Spar Cap Forward Flange 2.0 2.0 1 Inspect - Front Spar Cap Aft Flange 2.0 2.0 1 Install Fasteners - Fixed Leading Edge 10.0 10.0 TOTAL FOR EACH AIRPLANE (a) (b) (a) Inspection hours given are for each airplane. (b) Task hours required for repairs are not included and are to be determined by the operator based on inspection results. **Table 2: PART B - Repetitive Inspection: Fixed Leading Edge Skin and Front Spar Cap at Station Zfs=52.267**  **Elapsed Hours Task Hours**  **Number of Persons Task**  1.0 1.0 1 Inspect - Fixed Lead- ing Edge 1.0 1.0 1 Remove Fasteners -Front Spar Cap Forward Flange 1.0 1.0 1 Inspect - Front Spar Cap Forward Flange 1.5 1.5 1 Install Fasteners -Front Spar Cap Forward Flange 2.0 2.0 1 Inspect - Front Spar Cap Aft Flange 6.5 6.5 TOTAL FOR EACH AIRPLANE (a) (b) (a) Inspection hours given are for each airplane. (b) Task hours required for repairs are not included and are to be determined by the operator based on inspection results.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 24 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT H. Weight and Balance Changes**  Weight and balance changes affected by incorporation of this service bulletin are contingent upon the changes to each particular airplane. Weight data is to be computed by the operator by weighing parts removed and parts installed during this change. Necessary revisions should be made to the appropriate airplane weight and balance report. **I. Electrical Load Data** Not changed. **J. References** 1. Existing Data a. Non-Destructive Test Standard Practices Manual (NDTSPM), 02-00-07, 06-00-07, 06-10-01.001, 06-10-01.003, Part 01-00-03, Part 02-00-03, Part 02-00-04, Part 06-00-03, Part 06-00-04. b. MD90 Structural Repair Manual (SRM) 55-30-05. 2. Data supplied with this Service Bulletin
None. 3. Installation Drawings Used in the Preparation of this Service Bulletin **Change Title**  **Document Number** A REPAIR-FIXED LEADING EDGESKIN, ZFS=52.267, VERTICAL STABILIZER SG09550004

DA STRUCTURE ASSY-VERT STAB 5912123 Y LEADING EDGE INSTL-VERTICAL STABILIZER 5930609

F CAP-VERT STAB FRONT SPAR 5911394 AD SPAR ASSY-VERT STAB, FRONT 9911833 These drawings were used to prepare this service bulletin. These drawings are not necessary to make the specified changes, and are not supplied with this service bulletin. These drawings may not be applicable to all airplane configurations or operators. **K. Publications Affected**
1. Publications:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 25 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT Chapter-Section**  **Publication** MD90 SRM 55-30-05 Structural Repair Manual 2. Damage Tolerance Based Structural Inspections: Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the Maintenance Program. This service bulletin affects FCS. DTI requirements for the structure affected are contained in Paragraph 1.E., Compliance of this service bulletin. **L. Interchangeability and Intermixability of Parts** Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 26 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT 2. MATERIAL INFORMATION**  **A. Material - Price and Availability**
None. **B. Industry Support Information** Boeing warranty remedies are not available for the inspection and/or repair procedures given in this service bulletin. **C. Parts Necessary For Each Airplane** 1. Kits/Parts Based on inspection results, refer to Service General Repair Drawing SG09550004, for repair parts necessary for each airplane. 2. Parts and Materials Supplied by the Operator Based on inspection results, refer to Service General Repair Drawing SG09550004, for operator supplied parts and materials necessary to do the required repairs. 3. Parts Modified and Reidentified
None. 4. Parts Removed and Not Replaced None. **D. Parts Necessary to Change Spares**
None. **E. Special Tooling - Price and Availability** Inspection equipment required to accomplish this service bulletin are listed in APPENDIX B and in the Non-Destructive Test Standard Practices Manual ( NDTSPM ) and are to be procured from operator’s stock or sources indicated. **F. Special Tooling Necessary to do this Service Bulletin** No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 27 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 28 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT**

BLANK PAGE**3. ACCOMPLISHMENT INSTRUCTIONS A. GENERAL INFORMATION**  **WARNING:** IF ELECTRICAL POWER IS APPLIED TO THE AIRPLANE, MAKE SURE YOU OBEY ALL PRECAUTIONS WHILE YOU DO WORK. IF YOU DO NOT OBEY THE PRECAUTIONS, DEATH OR INJURY TO PERSONS, AND DAMAGE TO THE AIRPLANE CAN OCCUR. **CAUTION:** ELECTRICALLY GROUND THE AIRPLANE. THIS WILL HELP TO PREVENT DAMAGE TO THE AIRPLANE OR EQUIPMENT. **CAUTION:** KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL, METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR OTHER ELECTRICAL DAMAGE. **NOTE:** 1. The instructions identified in Paragraph 3.B., Work Instructions, and the Figure(s) give the recommended sequence of steps. The sequence of steps to do this service bulletin can be changed. 2. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 3. Equivalent parts are listed in the AEPL, Drawing 7595071. 4. Use the approved fastener substitutions and process material substitutions, in accordance with MD90 SRM 51. 5. Obey all of the warnings and cautions given in the specified manual sections. 6. The inspection area of the vertical stabilizer leading edge structure is two rows of fasteners above the splice and two rows of fasteners below the splice at Station Zfs=52.267. 7. "Distress" in the vertical stabilizer leading edge structure at the splice at Station Zfs=52.267 is defined as deformed holes, elongated holes, oversized holes or cracks in the leading edge skin and splice. 8. "Existing Repairs" to the vertical stabilizer leading edge structure at the splice at Station Zfs=52.267 are bushings, washers or reinforcing repairs to the leading edge. 9. "Breakaway torque" is defined as the torque required to overcome static friction when 100 percent of the locking feature is engaged and the fastener is unseated. Breakaway torque can be prefixed with a "maximum" or "minimum", and can be measured in either a loosening or tightening direction. Check for proper minimum breakaway torque. The minimum breakaway torque value for 1/4 inch diameter fasteners is 5.0 inch-pounds. The minimum breakaway torque value for 5/16 inch diameter fasteners is 7.0 inch-pounds.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 29 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT**10. The inspection area of the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins is defined as 12.50 inches +/- 0.25 inch above the leading edge skin splice and 12.50 inches +/- 0.25 inch below the leading edge skin splice at Station Zfs=52.267. 11. Where the work instructions include installation of a kept part, a new or serviceable part with the same part number can be installed as an alternative to the same part. The removed part can be discarded if a new part or serviceable part is installed. 12. Refer to APPENDIX A: FLOWCHART - INITIAL INSPECTION AND REPETITIVE INSPECTION which describes the initial inspection and repetitive inspection requirements and can be used as a supplement to Paragraph 3.B., Work Instructions. 13. Refer to APPENDIX B: INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267, for the inspection procedures and requirements in accordance with Paragraph 3.B., Work Instructions. 14. A Detailed Inspection is defined as: An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirrors, magnifying lenses, etc. may be necessary. Surface cleaning and elaborate procedures may be required. 15. These work instructions refer to procedures included in other Boeing documents. When the words "refer to" are used and the operator has an accepted alternative procedure, the accepted alternative procedure can be used. When the words "in accordance with" are included in the instruction, the procedure in the Boeing document must be used. **B. WORK INSTRUCTIONS PART A - INITIAL INSPECTION:**  1. Do an initial inspection of the vertical stabilizer leading edge structure at the splice at Station Zfs=52.267 as follows:

a. Remove and keep two rows of fasteners above the splice and two rows of fasteners below the splice at Station Zfs=52.267. **NOTE:** Remove fasteners one row at a time. b. Do a detailed inspection for "distress" in, and "existing repairs" to, the vertical stabilizer leading edge structure at the splice at Station Zfs=52.267. **NOTE:** "Distress" is defined as deformed holes, elongated holes, oversized holes or cracks in the leading edge skin and splice. "Existing Repairs" are bushings, washers or reinforcing repairs to the leading edge. 2. Based on inspection results, do as follows:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 30 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT CONDITION 1 (Leading Edge is Not Distressed and No Existing Repair Found)**  a. Do an inspection for cracking on the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267 in accordance with APPENDIX B, using one of the options as follows: **NOTE:** The inspection area is defined as 12.50 inches +/- 0.25 inch above the leading edge skin splice and 12.50 inches +/- 0.25 inch below the leading edge skin splice at Station Zfs=52.267. **OPTION 1:** (1) Do an Eddy Current, High Frequency (ETHF) inspection of the left and right vertical stabilizer front spar cap forward flanges as follows: (a) Remove and keep fasteners common to the left and right vertical stabilizer front spar cap forward flanges, above and below the leading edge skin splice at Station Zfs=52.267. (b) Do an open hole ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges at the fastener holes above and below the leading edge skin splice at Station Zfs=52.267 in accordance with the inspection procedure in APPENDIX B, Inspection Sequence 1. (2) Do a Radiographic Testing (RT) inspection of the left and right vertical stabilizer front spar cap aft flanges in accordance with the inspection procedure in APPENDIX B, Inspection Sequence 2 - Option 1. **OPTION 2:** (1) Do an ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges as follows: (a) Remove and keep fasteners common to the left and right vertical stabilizer front spar cap forward flanges, above and below the leading edge skin splice at Station Zfs=52.267. (b) Do an open hole ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges at the fastener holes above and below the leading edge skin splice at Station Zfs=52.267 in accordance with the inspection procedure in APPENDIX B, Inspection Sequence 1. (2) Do an ETHF surface inspection of the side skin at the left and right vertical stabilizer front spar cap aft flanges in accordance with the inspection procedure in APPENDIX B, Inspection Sequence 2 - Option 2. b. Based on inspection results, do as follows:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 31 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT CONDITION 1A (No Crack Found during either Option 1 or Option 2 Inspection)**  (1) Install kept fasteners common to the left and right vertical stabilizer front spar cap forward flanges. (2) Install kept leading edge fasteners. **CONDITION 1B (Any Crack Found during either Option 1 or Option 2 Inspection)** (1) Crack Found on the Vertical Stabilizer Front Spar Cap Forward Flange (a) Remove and keep nut plate gang channel on the vertical stabilizer front spar cap forward flange where the crack indication was found. (b) Do an evaluation/verification to confirm any crack indication found on the vertical stabilizer front spar cap forward flange. Refer to NDTSPM 06-00-07 for applicable Crack/Defect Evaluation/Verification. 1) Crack Indication Not Confirmed a) Install kept nut plate gang channel on the vertical stabilizer front spar cap forward flange. b) Install kept fasteners common to the left and right vertical stabilizer front spar cap forward flanges. 2) Crack Indication Confirmed a) Contact Boeing for repair of the vertical stabilizer front spar cap forward flange and do the repair in accordance with Boeing's instructions. (2) Crack Found on the Vertical Stabilizer Side Skin or Front Spar Cap Aft Flange (a) Do an evaluation/verification to confirm any crack indication found on the vertical stabilizer side skins. Refer to NDTSPM 06-00-07 for applicable Crack/Defect Evaluation/Verification. 1) Crack Indication Not Confirmed a) Install kept leading edge fasteners. 2) Crack Indication Confirmed a) Contact Boeing for repair of the vertical stabilizer side skins and do the repair in accordance with Boeing's instructions. (b) Do an evaluation/verification to confirm any crack indication found on the front spar cap aft flange. Refer to NDTSPM 02-00-07 for applicable Crack/Defect Evaluation/Verification. 1) Crack Indication Not Confirmed

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 32 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT**a) Install kept leading edge fasteners. 2) Crack Indication Confirmed a) Contact Boeing for repair of the vertical stabilizer front spar cap aft flange and do the repair in accordance with Boeing's instructions. **CONDITION 2 (Leading Edge is Distressed)** a. Do an inspection for cracking on the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267 in accordance with APPENDIX B, using one of the options as follows: **NOTE:** The inspection area is defined as 12.50 inches +/- 0.25 inch above the leading edge skin splice and 12.50 inches +/- 0.25 inch below the leading edge skin splice at Station Zfs=52.267. **OPTION 1:** (1) Do an ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges as follows: (a) Remove and keep fasteners common to the left and right vertical stabilizer front spar cap forward flanges, above and below the leading edge skin splice at Station Zfs=52.267. (b) Do an open hole ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges at the fastener holes above and below the leading edge skin splice at Station Zfs=52.267 in accordance with the inspection procedure in APPENDIX B, Inspection Sequence 1. (2) Do an RT inspection of the left and right vertical stabilizer front spar cap aft flanges in accordance with the inspection procedure in APPENDIX B, Inspection Sequence 2 - Option 1. **OPTION 2:** (1) Do an ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges as follows:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 33 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT**(a) Remove and keep fasteners common to the left and right vertical stabilizer front spar cap forward flanges, above and below the leading edge skin splice at Station Zfs=52.267. (b) Do an open hole ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges at the fastener holes above and below the leading edge skin splice at Station Zfs=52.267 in accordance with the inspection procedure in APPENDIX B, Inspection Sequence 1. (2) Do an ETHF surface inspection of the side skin at the left and right vertical stabilizer front spar cap aft flanges in accordance with the inspection procedure in APPENDIX B, Inspection Sequence 2 - Option 2. b. Based on inspection results, do as follows: **CONDITION 2A (No Crack Found during either Option 1 or Option 2 Inspection)** (1) Do leading edge repair in accordance with Service General Repair Drawing SG09550004. **NOTE:** At operator's discretion, replace 9911813-503 vertical stabilizer leading edge splice band or repair in accordance with Service General Repair Drawing SG09550004. (2) Install kept fasteners common to the left and right vertical stabilizer front spar cap forward flanges. (3) Install kept leading edge fasteners. **CONDITION 2B (Any Crack Found during either Option 1 or Option 2 Inspection)** (1) Do leading edge repair in accordance with Service General Repair Drawing SG09550004. **NOTE:** At operator's discretion, replace 9911813-503 vertical stabilizer leading edge splice band or repair in accordance with Service General Repair Drawing SG09550004. (2) Crack Found on the Vertical Stabilizer Front Spar Cap Forward Flange (a) Remove and keep nut plate gang channel on the vertical stabilizer front spar cap forward flange where the crack indication was found. (b) Do an evaluation/verification to confirm any crack indication found on the vertical stabilizer front spar cap forward flange. Refer to NDTSPM 06-00-07 for applicable Crack/Defect Evaluation/Verification. 1) Crack Indication Not Confirmed

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 34 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT**a) Install kept nut plate gang channel on the vertical stabilizer front spar cap forward flange. b) Install kept fasteners common to the left and right vertical stabilizer front spar cap forward flanges. 2) Crack Indication Confirmed a) Contact Boeing for repair of the vertical stabilizer front spar cap forward flange and do the repair in accordance with Boeing's instructions. (3) Crack Found on the Vertical Stabilizer Side Skin or Front Spar Cap Aft Flange (a) Do an evaluation/verification to confirm any crack indication found on the vertical stabilizer side skins. Refer to NDTSPM 06-00-07 for applicable Crack/Defect Evaluation/Verification. 1) Crack Indication Not Confirmed a) Install kept leading edge fasteners. 2) Crack Indication Confirmed a) Contact Boeing for repair of the vertical stabilizer side skins and do the repair in accordance with Boeing's instructions. (b) Do an evaluation/verification to confirm any crack indication found on the front spar cap aft flange. Refer to NDTSPM 02-00-07 for applicable Crack/Defect Evaluation/Verification. 1) Crack Indication Not Confirmed a) Install kept leading edge fasteners. 2) Crack Indication Confirmed a) Contact Boeing for repair of the vertical stabilizer front spar cap aft flange and do the repair in accordance with Boeing's instructions. **CONDITION 3 (Leading Edge Existing Repair Found)** a. Do an inspection for cracking on the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267 in accordance with APPENDIX B, using one of the options as follows: **NOTE:** The inspection area is defined as 12.50 inches +/- 0.25 inch above the leading edge skin splice and 12.50 inches +/- 0.25 inch below the leading edge skin splice at Station Zfs=52.267. **OPTION 1:** (1) Do an ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges as follows:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 35 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT**(a) Remove and keep fasteners common to the left and right vertical stabilizer front spar cap forward flanges, above and below the leading edge skin splice at Station Zfs=52.267. (b) Do an open hole ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges at the fastener holes above and below the leading edge skin splice at Station Zfs=52.267 in accordance with the inspection procedure in APPENDIX B, Inspection Sequence 1. (2) Do an RT inspection of the left and right vertical stabilizer front spar cap aft flanges in accordance with the inspection procedure in APPENDIX B, Inspection Sequence 2 - Option 1. **OPTION 2:** (1) Do an ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges as follows: (a) Remove and keep fasteners common to the left and right vertical stabilizer front spar cap forward flanges, above and below the leading edge skin splice at Station Zfs=52.267. (b) Do an open hole ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges at the fastener holes above and below the leading edge skin splice at Station Zfs=52.267 in accordance with the inspection procedure in APPENDIX B, Inspection Sequence 1. (2) Do an ETHF surface inspection of the side skin at the left and right vertical stabilizer front spar cap aft flanges in accordance with the inspection procedure in APPENDIX B, Inspection Sequence 2 - Option 2. b. Based on inspection results, do as follows: **CONDITION 3A (No Crack Found during either Option 1 or Option 2 Inspection)** (1) Install kept fasteners common to the left and right vertical stabilizer front spar cap forward flanges. (2) Install kept leading edge fasteners. **CONDITION 3B (Any Crack Found during either Option 1 or Option 2 Inspection)** (1) Crack Found on the Vertical Stabilizer Front Spar Cap Forward Flange (a) Remove and keep nut plate gang channel on the vertical stabilizer front spar cap forward flange where the crack indication was found. (b) Do an evaluation/verification to confirm any crack indication found on the vertical stabilizer front spar cap forward flange. Refer to NDTSPM 06-00-07 for applicable Crack/Defect Evaluation/Verification. 1) Crack Indication Not Confirmed

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 36 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT**a) Install kept nut plate gang channel on the vertical stabilizer front spar cap forward flange. b) Install kept fasteners common to the left and right vertical stabilizer front spar cap forward flanges. 2) Crack Indication Confirmed a) Contact Boeing for repair of the vertical stabilizer front spar cap forward flange and do the repair in accordance with Boeing's instructions. (2) Crack Found on the Vertical Stabilizer Side Skin or Front Spar Cap Aft Flange (a) Do an evaluation/verification to confirm any crack indication found on the vertical stabilizer side skins. Refer to NDTSPM 06-00-07 for applicable Crack/Defect Evaluation/Verification. 1) Crack Indication Not Confirmed a) Install kept leading edge fasteners. 2) Crack Indication Confirmed a) Contact Boeing for repair of the vertical stabilizer side skins and do the repair in accordance with Boeing's instructions. (b) Do an evaluation/verification to confirm any crack indication found on the front spar cap aft flange. Refer to NDTSPM 02-00-07 for applicable Crack/Defect Evaluation/Verification. 1) Crack Indication Not Confirmed a) Install kept leading edge fasteners. 2) Crack Indication Confirmed a) Contact Boeing for repair of the vertical stabilizer front spar cap aft flange and do the repair in accordance with Boeing's instructions. 3. Put the airplane back to a serviceable condition. 4. Do repetitive inspections of the vertical stabilizer leading edge structure at the splice at Station Zfs=52.267, and the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267, at intervals specified in Paragraph 1.E., Compliance. **PART B - REPETITIVE INSPECTION:** 1. Inspection - Vertical Stabilizer Leading Edge:
a. Do a detailed inspection of the vertical stabilizer leading edge at the splice at Station Zfs=52.267 (fasteners not removed) for indications of loose fasteners and missing fasteners.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 37 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT NOTE:**  The inspection area is two rows of fasteners above the splice and two rows of fasteners below the splice at Station Zfs=52.267. b. Based on inspection results, do as follows: **CONDITION 4 (No Loose Leading Edge Fasteners and No Missing Leading Edge Fasteners)**  (1) Do repetitive detailed inspection of the vertical stabilizer leading edge at the splice at Station Zfs=52.267 (fasteners not removed) for indications of loose fasteners and missing fasteners at intervals specified in Paragraph 1.E., Compliance. **CONDITION 5 (Loose Leading Edge Fasteners or Missing Leading Edge Fasteners)** (1) Do leading edge repair in accordance with Service General Repair Drawing SG09550004. **NOTE:** At operator's discretion, replace 9911813-503 vertical stabilizer leading edge splice band or repair in accordance with Service General Repair Drawing SG09550004. (2) Do repetitive detailed inspection of the vertical stabilizer leading edge at the splice at Station Zfs=52.267 (fasteners not removed) for indications of loose fasteners and missing fasteners at intervals specified in Paragraph 1.E., Compliance. 2. Inspection - Vertical Stabilizer Front Spar Cap Forward Flanges and either the Aft Flanges or Side Skins:
a. Do an inspection for cracking on the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267 in accordance with APPENDIX B, using one of the options as follows: **NOTE:** The inspection area is defined as 12.50 inches +/- 0.25 inch above the leading edge skin splice and 12.50 inches +/- 0.25 inch below the leading edge skin splice at Station Zfs=52.267. **OPTION 1:** (1) Do an ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges as follows: (a) Remove and keep fasteners common to the left and right vertical stabilizer front spar cap forward flanges, above and below the leading edge skin splice at Station Zfs=52.267. (b) Do an open hole ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges at the fastener holes above and below the leading edge skin splice at Station Zfs=52.267 in accordance with the inspection procedure in APPENDIX B, Inspection Sequence 1. (2) Do an RT inspection of the left and right vertical stabilizer front spar cap aft flanges in accordance with the inspection procedure in APPENDIX B, Inspection Sequence 2 - Option 1.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 38 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT OPTION 2:**  (1) Do an ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges as follows: (a) Remove and keep fasteners common to the left and right vertical stabilizer front spar cap forward flanges, above and below the leading edge skin splice at Station Zfs=52.267. (b) Do an open hole ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges at the fastener holes above and below the leading edge skin splice at Station Zfs=52.267 in accordance with the inspection procedure in APPENDIX B, Inspection Sequence 1. (2) Do an ETHF surface inspection of the side skin at the left and right vertical stabilizer front spar cap aft flanges in accordance with the inspection procedure in APPENDIX B, Inspection Sequence 2 - Option 2. b. Based on inspection results, do as follows: **CONDITION 6 (No Crack Found during either Option 1 or Option 2 Inspection)** (1) Install kept fasteners common to the left and right vertical stabilizer front spar cap forward flanges. (2) Install kept leading edge fasteners. **CONDITION 7 (Any Crack Found during either Option 1 or Option 2 Inspection)** (1) Crack Found on the Vertical Stabilizer Front Spar Cap Forward Flange (a) Remove and keep nut plate gang channel on the vertical stabilizer front spar cap forward flange where the crack indication was found. (b) Do an evaluation/verification to confirm any crack indication found on the vertical stabilizer front spar cap forward flange. Refer to NDTSPM 06-00-07 for applicable Crack/Defect Evaluation/Verification. 1) Crack Indication Not Confirmed a) Install kept nut plate gang channel on the vertical stabilizer front spar cap forward flange. b) Install kept fasteners common to the left and right vertical stabilizer front spar cap forward flanges. 2) Crack Indication Confirmed a) Contact Boeing for repair of the vertical stabilizer front spar cap forward flange and do the repair in accordance with Boeing's instructions. (2) Crack Found on the Vertical Stabilizer Side Skin or Front Spar Cap Aft Flange

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 39 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT**(a) Do an evaluation/verification to confirm any crack indication found on the vertical stabilizer side skins. Refer to NDTSPM 06-00-07 for applicable Crack/Defect Evaluation/Verification. 1) Crack Indication Not Confirmed a) Install kept leading edge fasteners. 2) Crack Indication Confirmed a) Contact Boeing for repair of the vertical stabilizer side skins and do the repair in accordance with Boeing's instructions. (b) Do an evaluation/verification to confirm any crack indication found on the front spar cap aft flange. Refer to NDTSPM 02-00-07 for applicable Crack/Defect Evaluation/Verification. 1) Crack Indication Not Confirmed a) Install kept leading edge fasteners. 2) Crack Indication Confirmed a) Contact Boeing for repair of the vertical stabilizer front spar cap aft flange and do the repair in accordance with Boeing's instructions. 3. Put the airplane back to a serviceable condition. 4. Do repetitive detailed inspection of the vertical stabilizer leading edge at the splice at Station Zfs=52.267 (fasteners not removed) for indications of loose fasteners and missing fasteners at intervals specified in Paragraph 1.E., Compliance. 5. Do repetitive inspection of the left and right vertical stabilizer front spar cap forward flanges and either the aft flanges or side skins at Station Zfs=52.267 at intervals specified in Paragraph 1.E., Compliance.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 40 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT APPENDIX A: FLOWCHART - INITIAL INSPECTION AND REPETITIVE INSPECTION**  1. This flowchart describes the initial inspection and repetitive inspection requirements and can be used as a supplement to Paragraph 1.D., Description, Paragraph 1.E., Compliance, and Paragraph 3.B., Work Instructions.

**APPENDIX A: FLOWCHART - INITIAL INSPECTION AND REPETITIVE INSPECTION (SHEET 1 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 41 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT APPENDIX A: FLOWCHART - INITIAL INSPECTION AND REPETITIVE INSPECTION**  **(SHEET 2 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 42 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT APPENDIX A: FLOWCHART - INITIAL INSPECTION AND REPETITIVE INSPECTION**  **(SHEET 3 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 43 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT APPENDIX B: INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267**  1. Model Affected: MD-90 2. Drawing Reference: 5912123, 5930609, 5911394, 9911833 **Description:** 1. The inspection area consists of the vertical stabilizer front spar caps at Station Zfs=52.267. The purpose of Inspection Sequence 1 is to inspect the fastener holes common to the left and right front spar cap forward flanges and leading edge panels in accordance with Figure 1. The purpose of Inspection Sequence 2 is to detect fatigue cracks initiating at the fastener holes common to the left and right spar cap aft flanges and/or side skins in accordance with Figure 2 or Figure 3. The fatigue cracks will travel in the forward and aft directions from the fastener holes. **NOTE:** Two inspection methods are acceptable for Inspection Sequence 2 as follows: Option 1 - Radiographic Testing (RT) Option 2 - Eddy Current, High Frequency (ETHF)
**Inspection Sequence 1:** 1. Eddy Current, High Frequency (ETHF) **Inspection Sequence 2:** 1. Radiographic Testing (RT) or Eddy Current, High Frequency (ETHF)

**Preparation for Inspection** 1. Remove all dirt, grease, and loose paint from the inspection area. 2. Thoroughly clean the inspection area with an approved cleaning agent.

**Table 1 - Equipment/Materials Supplier**  **CAGE QTY**  **Type Test Equipment**  Staveley Instruments 0M421 1 Sperry SPX 160 Portable X-ray machine (1.5 mm projected focal spot). 1329 East Kemper Road Cincinnati, Ohio 45246

**APPENDIX B: INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267 (SHEET 1 OF 10)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 44 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT Table 1 - Equipment/Materials**  **Supplier CAGE**  **QTY Type**  **Test Equipment** Eastman Kodak Company 19139 10 Kodak M X-ray film 343 State Street (Refer to Table 2 for sizes) Rochester, New York 14650 19139 4 Kodak AA X-ray film (Refer to Table 2 for sizes) Source Optional

- - For radiographic identifica- tion. Lead numbers Source Optional

- - - Masking Tape Source Optional

- In conformance with envi- ronmental regulations andharmless to surfaces contacted. Cleaning Agent

**NOTE:** The equipment/materials listed above were used to develop this procedure. Refer to NDTSPM Part 02-00-04 and NDTSPM Part 06-00-04 for supplier/vendor information. 1.
2. Equipment/material substitutions producing results equivalent to those defined by this document may also be used. Refer to NDTSPM Part 01-00-03, NDTSPM Part 02-00-03, and NDTSPM Part 06-00-03 for equipment/material information.

**Inspection Procedure:** 1. Inspection Sequence 1 (Front Spar Cap Forward Flange Area) **Inspection Method 01 (Eddy Current, High Frequency)** a. Perform an open hole ETHF inspection of the left and right vertical stabilizer front spar cap forward flanges above and below the leading edge skin splice at Station Zfs=52.267 within the specified dimensions in accordance with Figure 1. Scan the circumference of the holes following the instructions found in the Nondestructive Testing Standard Practice Manual NDTSPM 06-10-01.003 (ETHF - Procedure 3). **NOTE:** Scoring of the fastener hole bore caused by the removal of fasteners may cause crack-like indications. Removal of nut plate may be necessary for proper clean up of the hole. Refer to NDTSPM 06-10-01.003 "Access" and "Preparation and Cleaning" for further information. The nut plate may also interfere with the probe scan with some open hole eddy current probe designs.

**APPENDIX B: INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267 (SHEET 2 OF 10)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 45 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT APPENDIX B: INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267**  **(SHEET 3 OF 10)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 46 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT**2. Inspection Sequence 2 (Front Spar Cap Aft Flange Area) **OPTION 1: Inspection Method 01 (Radiographic Testing)** a. Inspection for cracks of the vertical stabilizer front spar cap aft flange at Station Zfs=52.267 in accordance with Figure 2. **NOTE:** The following steps must be done to both left and right sides of the vertical stabilizer. **EXPOSURE 1:** (1) Prepare Exposure 1 radiographic identification tag with the data as follows, using operator's shop practice: – Service Bulletin number – Exposure number and left or right side – Aircraft I.D. – Date (2) Attach Exposure 1 identification tag to film pack for each exposure using operator's shop practice. (3) Use masking tape to attach film to inspection element for Exposure 1 in accordance with Figure 2. (4) Expose film in accordance with x-ray parameters in Table 2 and Figure 2. **EXPOSURE 2:** (1) Prepare Exposure 2 radiographic identification tag with the data as follows, using operator's shop practice: – Service Bulletin number – Exposure number and left or right side – Aircraft I.D. – Date (2) Attach Exposure 2 identification tag to film pack for each exposure using operator's shop practice. (3) Use masking tape to attach film to inspection element for Exposure 2 in accordance with Figure 2. (4) Expose film in accordance with x-ray parameters in Table 2 and Figure 2. **EXPOSURE 3:** (1) Prepare Exposure 3 radiographic identification tag with the data as follows, using operator's shop practice:

**APPENDIX B: INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267 (SHEET 4 OF 10)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 47 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT**– Service Bulletin number – Exposure number and left or right side – Aircraft I.D. – Date (2) Attach Exposure 3 identification tag to film pack for each exposure using operator's shop practice. (3) Use masking tape to attach film to inspection element for Exposure 3 in accordance with Figure 2. (4) Expose film in accordance with x-ray parameters in Table 2 and Figure 2. **EXPOSURE 4:** (1) Prepare Exposure 4 radiographic identification tag with the data as follows, using operator's shop practice: – Service Bulletin number – Exposure number and left or right side – Aircraft I.D. – Date (2) Attach Exposure 4 identification tag to film pack for each exposure using operator's shop practice. (3) Use masking tape to attach film to inspection element for Exposure 4 in accordance with Figure 2. (4) Expose film in accordance with x-ray parameters in Table 2 and Figure 2. **EXPOSURE 5:** (1) Prepare Exposure 5 radiographic identification tag with the data as follows, using operator's shop practice: – Service Bulletin number – Exposure number and left or right side – Aircraft I.D. – Date (2) Attach Exposure 5 identification tag to film pack for each exposure using operator's shop practice. (3) Use masking tape to attach film to inspection element for Exposure 5 in accordance with Figure 2. (4) Expose film in accordance with x-ray parameters in Table 2 and Figure 2.

**APPENDIX B: INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267 (SHEET 5 OF 10)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 48 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT APPENDIX B: INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267**  **(SHEET 6 OF 10)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 49 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT APPENDIX B: INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267**  **(SHEET 7 OF 10)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 50 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT Table 2: Radiographic Exposure Data for Vertical Stabilizer Front Spar Cap Aft Flange at Station**  **Zfs=52.267**
**REMARKS FILM**  **DIM "A" (Inch)**  **mas (a)**  **kV EXPOSURE**  **NUMBER SIZE**  **(Inch) QTY**  **ASTM TYPE**

5 X 7 2 1 (b) 36 +/- 0.5 600 84 1 5 X 7 2 1 and 2 (c) 36 +/- 0.5 600 84 2 5 X 7 2 1 and 2 (c) 36 +/- 0.5 600 84 3 5 X 7 2 1 (b) 36 +/- 0.5 600 84 4 5 X 7 2 1 (b) 36 +/- 0.5 600 84 5 (a) May adjust mas as necessary to achieve a 1.7 to 3.5 H & D Density in the area of interest. (b) Kodak M or equivalent type with similar speed. (c) Kodak M and AA or equivalent type with similar speed (double load film pack). **OPTION 2: Inspection Method 01 (Eddy Current, High Frequency)** a. Perform an ETHF surface inspection of the vertical stabilizer side skins at those fasteners common to the left and right vertical stabilizer front spar cap aft flanges within the specified dimensions in accordance with Figure 3. Scan around the fasteners looking for cracks in the forward and aft direction. Scan around fasteners following the instructions found in the Nondestructive Testing Standard Practice Manual NDTSPM 06-10-01.001 (ETHF - Procedure 1). Use Calibration Method "P" and Scan Method "47".

**APPENDIX B: INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267 (SHEET 8 OF 10)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 51 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT APPENDIX B: INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267**  **(SHEET 9 OF 10)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 52 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT Inspection Results**  1. Any indication is considered a crack which exhibits the same relative phase angle and an amplitude of 50 percent or greater than the indication obtained from the calibration notch in the reference standard. 2. Crack indications found during ETHF inspection shall be confirmed. Refer to NDTSPM 06-00-07 for applicable Crack/Defect Evaluation/Verification sections(s). 3. Crack indications found during RT inspection shall be confirmed. Refer to NDTSPM 02-00-07 for applicable Crack/Defect Evaluation/Verification section(s). **Post Inspection Procedure** 1. Remove and secure all test equipment and materials from the area.

**APPENDIX B: INSPECTION OF VERTICAL STABILIZER FRONT SPAR CAP AT STATION ZFS=52.267 (SHEET 10 OF 10)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 24, 2010 MD90-55A014 53 of 53 **BOEING SERVICE BULLETIN MD90-55A014 ALERT**  **ALERT**