### Commercial **Airplanes** 

# 747 Service Bulletin **ALERT Number: 747-53A2854**  Original Issue: September 17, 2012 ATA System: 5331 **SUBJECT:** FUSELAGE - Skin - Skin Panel Chem-Milled Pocket Inspection and Repair at Locations Adjacent to Lap Splices Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15 CFR 300-774). 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 © 2012 Boeing. Unpublished Work. All Rights Reserved. Treatment of this document and its content is governed by contract with Boeing. Rights to use this document are licensed on a per aircraft basis and such rights may not be transferable. For more information, contact The Boeing Company. Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, DreamlinerTM, 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 Boeing liveries 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 is a trademark of Boeing Management Company.

Original Issue: September 17, 2012 747-53A2854 1 of 33 3.0Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 2 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT**

BLANK PAGE**Table of Contents** Summary...................................................... 5 1. PLANNING INFORMATION ........................................ 9 A. Effectivity................................................ 9 1. Airplanes............................................. 9 2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2. Data Supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 3. Installation Drawings Used in the Preparation of this Service Bulletin:. . . . . . . . . . . 14 K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 M. Software Accomplishment Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 C. Parts Necessary for Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 1. Kits/Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2. Parts and Materials Supplied by the Operator. . . . . . . . . . . . . . . . . . . . . . . . 15 3. Parts Modified and Reidentified. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 4. Parts Removed and Not Replaced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 15 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 FIGURE 1: SKIN INSPECTION IN SECTION 42, 44 AND 46 [Group 1]. . . . . . . . . . . . . . . . . 19 FIGURE 2: SKIN INSPECTION IN SECTION 42 [Group 2]. . . . . . . . . . . . . . . . . . . . . . . . 30

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 3 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 4 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 747 Service Bulletin **ALERT Summary**  **Number: 747-53A2854** Original Issue: September 17, 2012 ATA System: 5331 **SUBJECT:** FUSELAGE - Skin - Skin Panel Chem-Milled Pocket Inspection and Repair at Locations Adjacent to Lap Splices 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** This service bulletin gives instructions to do inspections of the fuselage skin for cracks just above certain lap splice locations. Skin cracks that are not found and repaired can become large and cause sudden loss of cabin pressure and loss of structural integrity.. Two operators of Boeing 757 airplanes have reported cracking, on two airplanes, that initiated at multiple locations on the inboard surface of the skin, along the edge of the chem-milled step just above the skin lap splice. No cracking of this kind has been reported on 747 airplanes, but analysis by Boeing indicates that the 747 fuselage skin in the areas shown in this service bulletin may be susceptible to similar cracking. The related Boeing 757 service bulletin is 757-53-0097, "FUSELAGE - Skin - Crown Skin Panel - Station 297 to Station 439, Chem-Milled Step Above Stringer 4 Left and Stringer 4 Right Lap Joint - Inspection". Accomplishment of the inspections in this service bulletin and installation of a repair will help prevent in-flight depressurization of the airplane and ensure the structural integrity of the fuselage skin at certain chem-milled skin locations. The skin at the edge of chem-milled steps above certain skin lap splices has been determined to be structure that is susceptible to Widespread Fatigue Damage (WFD). For more information about WFD, refer to 747-SL-53-088A. Boeing Service Related Problem (SRP) 747-SRP-53-0396 is related to this service bulletin. This table is provided to operators for planning purposes only. Refer to the applicable sections for more information.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 5 of 33**Reference Affected**  **Planning Data** Paragraph 1.A.2., Spares Affected No Spares Affected Paragraph 1.E., Compliance No AD Related Paragraph 1.H., Weight and Balance Changes No Weight and Balance Change Paragraph 1.I., Electrical Load Data No Electrical Load Changed Paragraph 1.K., Publications Affected No Publications Affected Paragraph 1.K., Publications Affected No Airplane Flight Operations Affected (Flight CrewOperations Manual and/or FAA Approved Airplane Flight Manual) Paragraph 2.C.1., Kits/Parts No Kits/Parts Required Paragraph 2.C.2., Parts and Materials Supplied by the Operator No Operator Supplied Material Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin No Special Tooling Required

**ACTION** Get external access to the fuselage skin just above certain lap splice locations. Do external sliding probe eddy current inspections at the affected locations for cracks. If no crack indications are found, put the airplane back to a serviceable condition, and do the inspection again at the times given in this service bulletin. If crack indications are found, contact Boeing for repair data and do the repair. After repair, put the airplane back to a serviceable condition, and do the inspection again at the times given in this service bulletin. **EFFECTIVITY** 747-100B SUD, 747-300 and 747SP Airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes. **COMPLIANCE** Refer to Paragraph 1.E., Compliance. **INDUSTRY SUPPORT INFORMATION** Boeing warranty remedies are not available for the inspection and repair procedures given in this service bulletin. **MANPOWER Elapsed Hours**  **Total Task Hours Airplanes**  28.50 56.50 Group 1 5.25 10.00 Group 2 Refer to Paragraph 1.G., Manpower.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 6 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT MATERIAL INFORMATION**  None.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 7 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 8 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 747 Service Bulletin **ALERT Number: 747-53A2854**  Original Issue: September 17, 2012 ATA System: 5331 **SUBJECT:** FUSELAGE - Skin - Skin Panel Chem-Milled Pocket Inspection and Repair at Locations Adjacent to Lap Splices 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 Refer to Service Bulletin Index D6-30300 Part 3 for Airplane Variable Number, Line Number, and Serial Number data. This service bulletin is for the airplanes shown below.
**DESCRIPTION CONFIGURATION**  **GROUP** All 747SP airplanes.

- 1 747-100B SUD airplanes line number 636 and 655, and 747-300 airplanes line number 692 through 695. - 2

Airplane Models: 747-100B SUD, 747-300, 747SP **Group Variable Number**  1 RG001 - RG009 1 RG091 1 RG095 1 RG101 - RG104 1 RG121 - RG126

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 9 of 33**Group Variable Number**  1 RG141 - RG142 1 RG161 - RG164 1 RG171 - RG174 1 RG191 - RG193 1 RG211 - RG213 1 RG221 - RG222 1 RH101 - RH102 1 RH111 - RH112 1 RH121 - RH122 2 RS001 - RS002 2 RS265 - RS268 2. Spares Affected None. **B. Concurrent Requirements** None. **C. Reason** This service bulletin gives instructions to do inspections of the fuselage skin for cracks just above certain lap splice locations. Skin cracks that are not found and repaired can become large and cause sudden loss of cabin pressure and loss of structural integrity.. Two operators of Boeing 757 airplanes have reported cracking, on two airplanes, that initiated at multiple locations on the inboard surface of the skin, along the edge of the chem-milled step just above the skin lap splice. No cracking of this kind has been reported on 747 airplanes, but analysis by Boeing indicates that the 747 fuselage skin in the areas shown in this service bulletin may be susceptible to similar cracking. The related Boeing 757 service bulletin is 757-53-0097, "FUSELAGE - Skin - Crown Skin Panel - Station 297 to Station 439, Chem-Milled Step Above Stringer 4 Left and Stringer 4 Right Lap Joint - Inspection". Accomplishment of the inspections in this service bulletin and installation of a repair will help prevent in-flight depressurization of the airplane and ensure the structural integrity of the fuselage skin at certain chem-milled skin locations. The skin at the edge of chem-milled steps above certain skin lap splices has been determined to be structure that is susceptible to Widespread Fatigue Damage (WFD). For more information about WFD, refer to 747-SL-53-088A. Boeing Service Related Problem (SRP) 747-SRP-53-0396 is related to this service bulletin.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 10 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT D. Description**  Get external access to the fuselage skin just above certain lap splice locations. Do external sliding probe eddy current inspections at the affected locations for cracks. If no crack indications are found, put the airplane back to a serviceable condition, and do the inspection again at the times given in this service bulletin. If crack indications are found, contact Boeing for repair data and do the repair. After repair, put the airplane back to a serviceable condition, and do the inspection again at the times given in this service bulletin. The work in this service bulletin is done in the maintenance zone(s) given below. **Group 1:**
**Affected Maintenance Zones Zone**  **Model** 122, 147, 148, 241, 242 747SP **Group 2:**
**Affected Maintenance Zones Zone**  **Model** 225, 226 747-100B SUD, 747-300 **E. Compliance** Accomplish the required actions, based on the applicable conditions in Table 1, in accordance with Paragraph 3. Accomplishment Instructions. **Group 1: Table 1: Skin Inspection**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- Within 500 flight-cycles or one year afterthe original issue date of this service bulletin,whichever occurs later. Before 18,500total flight-cycles Do an external slidingprobe eddy current inspections for cracking inaccordance with Paragraph 3.B., Work Instructions. All airplanes

- Before further flight Contact Boeing for repair data and do the repair. Any cracking found

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 11 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT Group 1:**  **Table 1: Skin Inspection Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition** 500 flight-cycles Within 500 flight-cycles after the previous inspection. Do external sliding probe eddy current inspections for cracking in unrepaired areas in accordance withParagraph 3.B., Work Instructions. No cracking found

**Group 2: Table 2: Skin Inspection**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- Within 800 flight-cycles or one year afterthe original issue date of this service bulletin,whichever occurs later. Before 18,500total flight-cycles Do an external slidingprobe eddy current inspections for cracking inaccordance with Paragraph 3.B., Work Instructions. All airplanes

- Before further flight Contact Boeing for repair data and do the repair. Any cracking found 800 flight-cycles Within 800 flight-cycles after the previous inspection. Do external sliding probe eddy current inspections for cracking in unrepaired areas in accordance withParagraph 3.B., Work Instructions. No cracking found

**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.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 12 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT G. Manpower**  The table below shows an estimate of the task hours necessary to do this inspection 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. **Group 1: Table 1 - Skin Inspection in Section 42, 44 and 46**  **Elapsed Hours Task Hours**  **Number of Persons Task**  0.50 0.50 1 Prepare 28.00 56.00 2 Inspect (Figure 1) 28.50 56.50 TOTAL FOR EACH AIRPLANE **Group 2: Table 2 - Skin Inspection in Section 42**  **Elapsed Hours Task Hours**  **Number of Persons Task**  0.50 0.50 1 Prepare 4.75 9.50 2 Inspect (Figure 2) 5.25 10.00 TOTAL FOR EACH AIRPLANE
**NOTE:** More time will be required for repairs if cracks are found. **H. Weight and Balance Changes** None. **I. Electrical Load Data** Not applicable. **J. References** 1. Existing Data: a. Boeing Service Bulletin 757-53-0097 b. Boeing Service Letter 747-SL-51-048, 747-SL-53-088A

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 13 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT**c. Boeing Service Related Problem (SRP) 747-SRP-53-0396 d. Service Bulletin Index D6-30300 e. 747 Non-Destructive Testing (NDT) Manual Part 6, 53-30-25 2. Data Supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin:
**Title Drawing Number**  Skin Panel Instl - STA 741.1 to STA 1000.0 Stgr 6 to Stgr 12 65B04112 Skin Panel Instl - STA 520 to STA 1000 S-23R to S-34R 65B18625 Skin Panel Instl - STA 1000 to STA 1200.0, Stgr 6 to Stgr 12 65B18631 The table above lists applicable drawings used to prepare this service bulletin. The drawings are not necessary to make the specified changes, and are not supplied with this service bulletin. The drawings may not be applicable to all airplane configurations or operators. **K. Publications Affected** 1. Publications: None. 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 but no new DTIs are necessary. **L. Interchangeability and Intermixability of Parts** Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts. **M. Software Accomplishment Summary** Not affected.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 14 of 33 **BOEING SERVICE BULLETIN 747-53A2854 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 repair procedures given in this service bulletin. **C. Parts Necessary for Each Airplane** 1. Kits/Parts None. 2. Parts and Materials Supplied by the Operator None. 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** None. **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.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 15 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 16 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT**

BLANK PAGE**3. ACCOMPLISHMENT INSTRUCTIONS A. GENERAL INFORMATION**  **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. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 2. Obey all of the warnings and cautions given in the specified manual sections. 3. Unless shown differently, these dimensions and tolerances are used: – Linear dimensions are in inches – Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus or minus 0.03 inch 4. 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. 5. Boeing Service Letter 747-SL-51-048, Damage Reporting and Repair Plan/Design Guidelines, is an acceptable procedure to request information from Boeing for additional structural repair instructions. The Service Letter describes what information must be provided to Boeing before a structural repair can be provided. 6. The instructions in Paragraph 3.B., Work Instructions and the figures can include operation of tools or test equipment. Boeing Engineering Tool Drawings, the Illustrated Tool and Equipment Manual, and the Special Tool and Ground Handling Drawing Index contain data on versions of the tools or test equipment that you can use. It is permitted to use replaced tools. It is not permitted to use superseded tools. 7. If it is necessary to remove more parts for access, you can remove those parts. If you can get access without removing identified parts, it is not necessary to remove all of the identified parts. Jacking and shoring limitations must be observed. **B. WORK INSTRUCTIONS Group 1:**  **SKIN INSPECTION** 1. Get external access and do external sliding probe eddy current inspections for cracking in accordance with FIGURE 1. **NOTE:** If any part of the inspection area is covered by an external doubler, contact Boeing for inspection instructions.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 17 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT**2. If any cracking is found, contact Boeing for repair data and do the repair. 3. Put the airplane back in a serviceable condition. Do the external sliding probe eddy current inspections again in all affected unrepaired areas at the time given in Paragraph 1.E., Compliance, Table 1. **Group 2: SKIN INSPECTION**  1. Get external access and do external sliding probe eddy current inspections for cracking in accordance with FIGURE 2. **NOTE:** If any part of the inspection area is covered by an external doubler, contact Boeing for inspection instructions. 2. If any cracking is found, contact Boeing for repair data and do the repair. 3. Put the airplane back in a serviceable condition. Do the external sliding probe eddy current inspections again in all affected unrepaired areas at the time given in Paragraph 1.E., Compliance, Table 2.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 18 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT This Figure applies only to: Group 1.** 

**FIGURE 1: SKIN INSPECTION IN SECTION 42, 44 AND 46 (SHEET 1 OF 11)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 19 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT FIGURE 1: SKIN INSPECTION IN SECTION 42, 44 AND 46**  **(SHEET 2 OF 11)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 20 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT FIGURE 1: SKIN INSPECTION IN SECTION 42, 44 AND 46**  **(SHEET 3 OF 11)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 21 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT FIGURE 1: SKIN INSPECTION IN SECTION 42, 44 AND 46**  **(SHEET 4 OF 11)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 22 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT FIGURE 1: SKIN INSPECTION IN SECTION 42, 44 AND 46**  **(SHEET 5 OF 11)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 23 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT FIGURE 1: SKIN INSPECTION IN SECTION 42, 44 AND 46**  **(SHEET 6 OF 11)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 24 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT FIGURE 1: SKIN INSPECTION IN SECTION 42, 44 AND 46**  **(SHEET 7 OF 11)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 25 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT FIGURE 1: SKIN INSPECTION IN SECTION 42, 44 AND 46**  **(SHEET 8 OF 11)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 26 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT FIGURE 1: SKIN INSPECTION IN SECTION 42, 44 AND 46**  **(SHEET 9 OF 11)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 27 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT FIGURE 1: SKIN INSPECTION IN SECTION 42, 44 AND 46**  **(SHEET 10 OF 11)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 28 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT**The step number shown below agrees with the number shown in the circle symbols in the figure.
**More Data Qty**  **Identification Name**  **Task Step**  Do external sliding probe eddy current inspections of the skin for cracks just above the upper row of fasteners in the affected lap joint in accordance with 747 NDT Part 6, 53-30- 25. - - Skin Inspect 1

**FIGURE 1: SKIN INSPECTION IN SECTION 42, 44 AND 46 (SHEET 11 OF 11)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 29 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT This Figure applies only to: Group 2.** 

**FIGURE 2: SKIN INSPECTION IN SECTION 42 (SHEET 1 OF 4)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 30 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT FIGURE 2: SKIN INSPECTION IN SECTION 42**  **(SHEET 2 OF 4)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 31 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT FIGURE 2: SKIN INSPECTION IN SECTION 42**  **(SHEET 3 OF 4)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 32 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT**The step number shown below agrees with the number shown in the circle symbols in the figure.
**More Data Qty**  **Identification Name**  **Task Step**  Do external sliding probe eddy current inspections of the skin for cracks just above the upper row of fasteners in the affected lap joint in accordance with 747 NDT Part 6, 53-30- 25. - - Skin Inspect 1

**FIGURE 2: SKIN INSPECTION IN SECTION 42 (SHEET 4 OF 4)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: September 17, 2012 747-53A2854 33 of 33 **BOEING SERVICE BULLETIN 747-53A2854 ALERT**  **ALERT**