### Commercial **Airplanes** 

# 737 Service Bulletin **SPECIAL ATTENTION Number: 737-53-1315**  Original Issue: July 29, 2011 ATA System: 5331 **SUBJECT:** FUSELAGE - Skin - Station 727 to 1016 - Aft Skin Inspection and Repair 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## BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2011 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter.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BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 1 of 46 4.0BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 2 of 46 **BOEING SERVICE BULLETIN 737-53-1315**

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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 1. Existing Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2. Data supplied with this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 3. Installation Drawings Used in the Preparation of this Service Bulletin. . . . . . . . . . . . 19 K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 2. MATERIAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 C. Parts Necessary For Each Airplane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 1. Kits/Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 2. Parts and Materials Supplied by the Operator. . . . . . . . . . . . . . . . . . . . . . . . 21 3. Parts Modified and Reidentified. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 4. Parts Removed and Not Replaced. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 22 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 FIGURE 1: INSPECTION ZONES - LEFT SIDE [Group 1]. . . . . . . . . . . . . . . . . . . . . . . . 29 FIGURE 2: INSPECTION ZONES - RIGHT SIDE [Group 1]. . . . . . . . . . . . . . . . . . . . . . . 32 FIGURE 3: INSPECTION ZONES - LEFT SIDE [Group 2]. . . . . . . . . . . . . . . . . . . . . . . . 35 FIGURE 4: INSPECTION ZONES - RIGHT SIDE [Group 2]. . . . . . . . . . . . . . . . . . . . . . . 37 FIGURE 5: EXTERNAL INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 FIGURE 6: INTERNAL INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 FIGURE 7: TIME LIMITED REPAIR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 3 of 46 **BOEING SERVICE BULLETIN 737-53-1315**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 4 of 46 **BOEING SERVICE BULLETIN 737-53-1315**

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### Commercial **Airplanes** 

# 737 Service Bulletin **SPECIAL ATTENTION Summary**  **Number: 737-53-1315** Original Issue: July 29, 2011 ATA System: 5331 **SUBJECT:** FUSELAGE - Skin - Station 727 to 1016 - Aft Skin Inspection and Repair
BOEING RECOMMENDS THAT EACH OPERATOR EXAMINE THIS SERVICE BULLETIN IMMEDIATELY. **CONCURRENT REQUIREMENTS** None. **BACKGROUND** This service bulletin is sent to make sure that fuselage skin cracks at specified locations are found and repaired. Continued operation with undetected skin cracks could cause unscheduled down time for repairs or possibly a decompression of the airplane. More than three hundred incidents of skin chem-mill cracks on twenty six airplanes have been reported from Body Station (STA) 727 to 1016 and Stringer S-14 to S-25 (left and right side) between 29,808 and 53,454 flight cycles. Most of the skin cracks were found aft of STA 747 on the left side. Several of the reported cracks occurred in multiple adjacent bays. On the existing skin panel assembly, the doubler is chem-milled to the skin. At these skin panel locations on the airplane, the loads could cause a condition where skin cracks could form along the longitudinal edges of the doubler. Boeing Service Related Problem (SRP) 737-SRP-53-0324 is related to this service bulletin. **ACTION** Do a detailed inspection and Non Destructive Inspection (NDI) in Zone 1, detailed inspection in Zone 2, and detailed inspection and NDI in Zone 3 in accordance with this service bulletin between STA 727 and STA 1016, between Stringers S-14 and S-25. If any cracks are found in the fuselage skin, install the time limited repair with blind fasteners in accordance with this service bulletin, or do a permanent repair in accordance with the Structural Repair Manual (SRM) 737-500 SRM 53-00-01, Repair 31, Figure 201. Do the repeat inspections in accordance with this service bulletin. **EFFECTIVITY** 737-500 airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 5 of 46**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. 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** 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: July 29, 2011 737-53-1315 6 of 46 **BOEING SERVICE BULLETIN 737-53-1315**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 7 of 46 **BOEING SERVICE BULLETIN 737-53-1315**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 8 of 46 **BOEING SERVICE BULLETIN 737-53-1315**

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### Commercial **Airplanes** 

# 737 Service Bulletin **SPECIAL ATTENTION Number: 737-53-1315**  Original Issue: July 29, 2011 ATA System: 5331 **SUBJECT:** FUSELAGE - Skin - Station 727 to 1016 - Aft Skin Inspection and Repair
BOEING RECOMMENDS THAT EACH OPERATOR EXAMINE THIS SERVICE BULLETIN IMMEDIATELY. **1. PLANNING INFORMATION A. Effectivity**  1. Airplanes Refer to Service Bulletin Index Document D6-19567 Part 3 for Airplane Variable Number, Line Number, and Serial Number data. This service bulletin is for the airplane(s) shown below.
**DESCRIPTION CONFIGURATION**  **GROUP** 737-500 Airplanes, Line Numbers 1718 to 2494

- 1 737-500 Airplanes, Line Numbers 2498 to 2553

- 2

Airplane Models:
737-500 **Group Variable Number**  1 PT001 - PT011 1 PT021 - PT027 2 PT028 1 PT041 - PT059 2 PT060 - PT064 1 PT101 - PT105 1 PT121 - PT125 1 PT146 - PT148

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 9 of 46**Group Variable Number**  1 PT161 - PT170 1 PT181 - PT187 1 PT211 - PT220 1 PT295 1 PT301 - PT303 2 PT304 - PT306 1 PT331 - PT360 1 PT381 - PT399 1 PT401 - PT435 2 PT436 - PT438 1 PT501 - PT512 1 PT561 - PT565 1 PT581 - PT584 1 PT611 - PT621 1 PT641 - PT642 1 PT651 - PT655 1 PT671 - PT672 1 PT701 - PT703 1 PU001 - PU025 2. Spares Affected None. **B. Concurrent Requirements** None. **C. Reason** This service bulletin is sent to make sure that fuselage skin cracks at specified locations are found and repaired. Continued operation with undetected skin cracks could cause unscheduled down time for repairs or possibly a decompression of the airplane. More than three hundred incidents of skin chem-mill cracks on twenty six airplanes have been reported from Body Station (STA) 727 to 1016 and Stringer S-14 to S-25 (left and right side) between 29,808 and 53,454 flight cycles. Most of the skin cracks were found aft of STA 747 on the left side. Several of the reported cracks occurred in multiple adjacent bays.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 10 of 46 **BOEING SERVICE BULLETIN 737-53-1315**On the existing skin panel assembly, the doubler is chem-milled to the skin. At these skin panel locations on the airplane, the loads could cause a condition where skin cracks could form along the longitudinal edges of the doubler. Boeing Service Related Problem (SRP) 737-SRP-53-0324 is related to this service bulletin. **D. Description** Do a detailed inspection and Non Destructive Inspection (NDI) in Zone 1, detailed inspection in Zone 2, and detailed inspection and NDI in Zone 3 in accordance with this service bulletin between STA 727 and STA 1016, between Stringers S-14 and S-25. If any cracks are found in the fuselage skin, install the time limited repair with blind fasteners in accordance with this service bulletin, or do a permanent repair in accordance with the Structural Repair Manual (SRM) 737-500 SRM 53-00-01, Repair 31, Figure 201. Do the repeat inspections in accordance with this service bulletin. The work in this service bulletin is done in the maintenance zone(s) given below.
**Affected Maintenance Zones Zone**  **Model** 218, 220 737-500 **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:** The following inspection tables give the minimum inspections required for safety. Operators may wish to accomplish the actions given below earlier for economic reasons. Its likely some cracks could be found between inspections.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 11 of 46 **BOEING SERVICE BULLETIN 737-53-1315 Group 1:**  **Table 1: Inspection of Aft Skins Between STA 727 and STA 1016, Stringer S-14 to S-25 Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition** 4,500 flight cycles. (c) Within 4,500 flight cycles from the original issue date ofthis service bulletin. Before 22,000total flight cycles. Zone 1 Do an external detailedinspection and an external subsurface eddy current, Magneto Optic Imager (MOI) or C-scan inspection for cracks in the fuselage skin at thechem-mill steps in accordance with Paragraph 3.B. Work Instructions, Part 1. All Airplanes

(b) (d) 4,500 flight cycles. (c) Within 4,500 flight cycles from the original issue date ofthis service bulletin. Before 22,000total flight cycles. Zone 2 Do an external detailed inspection to inspect for cracks in the fuselage skin at the chem-mill steps in accordance withParagraph 3.B. Work Instructions, Part 1. (a) (b) 3,700 flight cycles. (c) Within 4,500 flight cycles from the original issue date ofthis service bulletin. Before 22,000total flight cycles. Zone 3 Do an external detailedinspection and an external subsurface eddy current, MOI or C-scan inspection for cracks in the fuselage skin at thechem-mill steps in accordance with Paragraph 3.B. Work Instructions, Part 1. (b)

- - Before further flight. Do a Time Limited Repairin accordance with Paragraph 3.B. Work Instructions, Part 2, step 1.c. Any crack found in the skin.

OR

- - Before further flight. Do a permanent repair inaccordance with Paragraph 3.B. Work Instructions Part 2, step 1.b.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 12 of 46 **BOEING SERVICE BULLETIN 737-53-1315 Group 1:**  **Table 1: Inspection of Aft Skins Between STA 727 and STA 1016, Stringer S-14 to S-25 Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition**

- - Within 3,000 flight cycles ofthe repair installation.Do a general visual inspection for loose ormissing fasteners in accordance with Paragraph 3.B. Work Instructions Part 2, step 1.c.(2). Airplanes with Time Limited Repairs

- - Within 4,500 flight cycles ofthe repair installation. Do an internal detailedinspection and High Frequency Eddy Current inspection of the bonded doubler for disbonding and cracks in accordance with Paragraph 3.B. Work Instructions Part 2, step 1.c.(3).

- - Within 6,000 flight cycles ofthe repair installation.Make the time limited repair permanent in accordance with Paragraph 3.B. Work Instructions Part 2, step 1.c.(4).

- - Before further flight. Replace the fastener inaccordance with Paragraph 3.B. Work Instructions Part 2, step 1.c.(2)(a). If any fastener is loose or missing.

- - Before further flight. Contact Boeing for repair instructions and do thework instructed by Boeing. If any disbonding or crack is found.

(a) External or internal subsurface eddy current, MOI or C-scan inspections can be used in place of the external detailed inspections. (b) It is not required to inspect areas under external repair doublers, provided either: (1) The doubler extends a minimum of 3 rows of fasteners beyond the chem-mill step and the repair was approved by the FAA or a Boeing company authorized representative who was authorized by the FAA to make such findings, or (2) The doubler extends a minimum of 2 rows beyond the chem-mill step and was accomplished in accordance with 737-500 SRM 53-00-01, Repair 31, Figure 201. (c) Accomplishment of the permanent repair in accordance with Paragraph 3.B. Work Instructions Part 2, step 1.b. is terminating action for the repeat inspection in the area of the repair only. (d) If it is not possible to inspect an area due to interference with external support structure for the fairing, then do an internal eddy current inspection in accordance with 737 NDT Part 6, 53-30-20 in place of the external inspections. The internal inspection is only applicable locally where the external inspections are not possible.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 13 of 46 **BOEING SERVICE BULLETIN 737-53-1315 Group 2:**  **Table 2: Inspection of Aft Skins Between STA 907 and STA 1016, Stringer S-14 to S-25 Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition** 4,500 flight cycles. (c) Within 4,500 flight cycles from the original issue date ofthis service bulletin. Before 22,000total flight cycles. Zone 2 Do an external detailed inspection to inspect for cracks in the fuselage skin at the chem-mill steps in accordance withParagraph 3.B. Work Instructions, Part 1. All Airplanes

(a) (b) 3,700 flight cycles. (c) Within 4,500 flight cycles from the original issue date ofthis service bulletin. Before 22,000total flight cycles. Zone 3 Do an external detailedinspection and an external subsurface eddy current, Magneto Optic Imager (MOI) or C-scan inspection for cracks in the fuselage skin at thechem-mill steps in accordance with Paragraph 3.B. Work Instructions, Part 1. (b)

- - Before further flight. Do a Time Limited Repairin accordance with Paragraph 3.B. Work Instructions, Part 2, step 1.c. Any crack found in the skin.

OR

- - Before further flight. Do a permanent repair inaccordance with Paragraph 3.B. Work Instructions, Part 2, step 1.b.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 14 of 46 **BOEING SERVICE BULLETIN 737-53-1315 Group 2:**  **Table 2: Inspection of Aft Skins Between STA 907 and STA 1016, Stringer S-14 to S-25 Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition**

- - Within 3,000 flight cycles ofthe repair installation.Do a general visual inspection for loose ormissing fasteners in accordance with Paragraph 3.B. Work Instructions, Part 2, step 1.c.(2). Airplanes with Time Limited Repairs

- - Within 4,500 flight cycles ofthe repair installation. Do an internal detailedinspection and High Frequency Eddy Current inspection of the bonded doubler for disbonding and cracks in accordance with Paragraph 3.B. Work Instructions, Part 2, step 1.c.(3).

- - Within 6,000 flight cycles ofthe repair installation.Make the time limited repair permanent in accordance with Paragraph 3.B. Work Instructions, Part 2, step 1.c.(4).

- - Before further flight. Replace the fastener inaccordance with Paragraph 3.B. Work Instructions Part 2 step 1.c.(2)(a). If any fastener is loose or missing

- - Before further flight. Contact Boeing for repair instructions and do thework instructed by Boeing. If any disbonding or crack is found.

(a) External or internal subsurface eddy current, MOI or C-scan inspections can be used in place of the external detailed inspections. (b) It is not required to inspect areas under external repair doublers, provided either: (1) The doubler extends a minimum of 3 rows of fasteners beyond the chem-mill step and the repair was approved by the FAA or a Boeing company authorized representative who was authorized by the FAA to make such findings, or (2) The doubler extends a minimum of 2 rows beyond the chem-mill step and was accomplished in accordance with 737-500 SRM 53-00-01, Repair 31, Figure 201. (c) Accomplishment of the permanent repair in accordance with Paragraph 3.B. Work Instructions Part 2, step 1.b. is terminating action for the repeat inspection in the area of the repair only.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 15 of 46 **BOEING SERVICE BULLETIN 737-53-1315 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 this inspection and 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. **Group 1: Table 1 - Skin Panel Inspection and Repair.**  **Elapsed Hours Task Hours**  **Number of Persons Task**  5.75 23.00 4 FIGURE 5 1.50 (a) 1.50 (a) 1 FIGURE 6 3.50 (b) 7.00 (b) 2 FIGURE 7 5.75 23.00 TOTAL FOR EACH AIRPLANE(a) The estimate shown is for a typical internal bonded doubler inspection not including access and is not included in the total shown. The operator must multiply the number of internal inspections required by the estimate given and add to the total shown to arrive at the revised total. (b) The estimate shown is for one typical repair and is not included in the totalshown. The operator must multiply the number of repairs required by the estimate given and add to the total shown to arrive at the revised total. **Group 2: Table 2 - Skin Panel Inspection and Repair.**  **Elapsed Hours Task Hours**  **Number of Persons Task**  3.00 6.00 2 FIGURE 5

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 16 of 46 **BOEING SERVICE BULLETIN 737-53-1315 Group 2:**  **Table 2 - Skin Panel Inspection and Repair. Elapsed Hours**  **Task Hours Number of Persons**  **Task** 1.50 (a) 1.50 (a) 1 FIGURE 6 3.50 (b) 7.00 (b) 2 FIGURE 7 3.00 6.00 TOTAL FOR EACH AIRPLANE(a) The estimate shown is for a typical internal bonded doubler inspection not including access and is not included in the total shown. The operator must multiply the number of internal inspections required by the estimate given and add to the total shown to arrive at the revised total. (b) The estimate shown is for one typical repair and is not included in the totalshown. The operator must multiply the number of repairs required by the estimate given and add to the total shown to arrive at the revised total. **H. Weight and Balance Changes** All airplanes: 1. Calculate the change in weight for each time limited repair done in accordance with FIGURE 7 as follows: a. Calculate the gross area of each repair doubler in square inches (Length x Width). Example for FIGURE 7: Length = approximately 16 inches and Width = approximately 10 inches. Area = 160 square inches. (It is acceptable to ignore the curvature of the fuselage, holes and rounding of corners). b. Record the thickness for each repair doubler (see FIGURE 7, Table 1) and calculate the change in weight for each different thickness using the following formulas: (1) To calculate the weight for each 0.040 inch thick repair doubler installed, including fasteners, paint and sealant, multiply the repair doubler area (from step 1.a.) by 0.005 lb per sq in. Example for FIGURE 7: Change in weight = 160 x 0.005 = 0.8 pounds rounded to the nearest 1/10th pound. (2) To calculate the weight for each 0.050 inch thick repair doubler installed, including fasteners, paint and sealant, multiply the repair doubler area (from step 1.a.) by 0.006 lb per sq in. Example for FIGURE 7: Change in weight = 160 x 0.006 = 1.0 pounds rounded to the nearest 1/10th pound. (3) For change in weight calculations for repair doubler thicknesses different to those specified in step 1.b.(1) and 1.b.(2) contact Boeing for further instructions.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 17 of 46 **BOEING SERVICE BULLETIN 737-53-1315 NOTE:**  If the total weight of all the repair doublers is less than 20 pounds per airplane, where the repair doubler thickness is uncertain, use 0.006 lb per sq in. to calculate the weight. 2. Calculate the change in moment for each time limited repair done in accordance with FIGURE 7 as follows: a. Record the station of the geometric center of the repair doubler. For example, if a repair doubler is between stations 907 and 917, the geometric center is station 912. Refer to 737-500 SRM 53-00-00, Figure 1, Fuselage Station Diagram, if necessary, to locate the geometric centre of the of the repair doubler. b. To calculate the change in moment for each repair doubler, use the formula applicable for the station of the geometric center of the repair doubler locations as follows: (1) From station 727 to 747: change in weight from step 1.b. x (station from step 2.a. + 30) = Change in Moment. Example for FIGURE 7: 1.0 x (737 + 30) = 770 Pound-Inches rounded to nearest 10 pound-inches. (2) From station 747 to 1016: change in weight from step 1.b. x (station from step 2.a. + 60) = Change in Moment. Example for FIGURE 7: 1.0 x (912 + 60) = 970 Pound-Inches rounded to nearest 10 pound-inches. 3. If multiple time limited repairs are installed in accordance with FIGURE 7, treat each one individually and then sum the weights and moments. **I. Electrical Load Data** Not changed. **J. References** 1. Existing Data a. Boeing Service Letter 737-SL-51-042 b. Boeing Service Related Problem (SRP) 737-SRP-53-0324 c. Standard Overhaul Practices Manual (SOPM) 20-30-03, 20-43-03 d. 737 Non-Destructive Testing (NDT) Manual Part 6, 51-00-00, Part 6, 53-30-09, Part 6, 53-30-18, Part 6, 53-30-19, Part 6, 53-30-20, Part 6, 53-30-25 e. 737-300/400/500 Aircraft Maintenance Manual (AMM) 25-21-39, 25-21-46, 25-22-00, 25-27-15, 25-52-73 f. 737-500 Structural Repair Manual (SRM) 51-40-08, 53-00-00, 53-00-01

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 18 of 46 **BOEING SERVICE BULLETIN 737-53-1315**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 - S-14L to S-25L, STA 727 to STA 908. 65-45774 Skin Panel Instl - S-4L to S-25L, STA 908 to STA 1016. 65-52988 Skin Panel Instl - S-14R to S-25R, STA 727 to STA 908. 65-45775 Skin Panel Instl - Aft Galley Door, STA 908 - STA 1016, S-4R to S-25R. 65-45778

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: 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. DTI requirements for the structure affected are contained in 737-500 SRM 53-00-01, Repair 31, Figure 201 for the permanent repair and for the time limited repair after it has been made permanent. The time limited repair is considered a category "C" repair that must be modified within the compliance time given in Paragraph 1.E., Compliance. **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: July 29, 2011 737-53-1315 19 of 46 **BOEING SERVICE BULLETIN 737-53-1315**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 20 of 46 **BOEING SERVICE BULLETIN 737-53-1315**

BLANK PAGE**2. MATERIAL INFORMATION A. Material - Price and Availability**  The operator can supply the parts and materials shown in Paragraph 2.C., Parts Necessary for Each Airplane. As an alternative, operators can purchase the parts from Boeing Spares. This service bulletin does not show the Boeing price and supply data. **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
**Notes Name**  **QTY**

**(e) Part Number /**  **Specification** (a) 2024-T3 Clad Sheet x0.040 inch thick 40 inches

x 30 inches AMS QQ-A-250/5

(a) 2024-T3 Clad Sheet x0.050 inch thick 40 inches

x 30 inches AMS QQ-A-250/5

(b) Blind Rivet 120 BACR15FR5E5R (b) Blind Rivet 120 BACR15FR5E6R (b) Blind Rivet 120 BACR15FR6E6R (b) Blind Rivet 120 BACR15FR6E7R (b) Solid Rivet 120 BACR15BB6AD6C (b) Solid Rivet 120 BACR15BB6AD7C (b) Solid Rivet 120 BACR15BB7AD7C (b) Solid Rivet 120 BACR15BB7AD8C (c) Chemical Conversion Coating 2 Ounces TYPE 2, Class A (d) Primer 3 Ounces BMS 10-11, Type 1 (d) Sealant 6 Ounces BMS 5-95, Class B-1/2, B-2

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 21 of 46 **BOEING SERVICE BULLETIN 737-53-1315 Notes**  **Name QTY** 

**(e) Part Number /**  **Specification** (a) Use to make external doubler in accordance with FIGURE 7 Table 1. (b) Refer to 737 Structural Repair Manual Chapter 51 for alternate fasteners. (c) Refer to SOPM 20-43-03 for material sources. (d) Refer to the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data. (e) Quantities shown are for a single typical repair as shown in FIGURE 7. Not all rivets are required.
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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 22 of 46 **BOEING SERVICE BULLETIN 737-53-1315 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 – Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch – Angular tolerance is plus or minus 2 degrees – Hole dimensions for standard solid rivets and fasteners are in Structural Repair Manual (SRM) Chapter 51 – Torque limits to tighten nuts and bolts are in SRM Chapter 51 4. Use the approved fastener and process material substitutions in accordance with SRM Chapter 51. 5. If the length of any fastener specified in this service bulletin does not meet installation standards given in SRM Chapter 51, then a fastener of the same specification, or an approved substitute, with a length which meets the installation standards given in SRM Chapter 51 may be used. In addition, washers may be installed for fastener grip length in accordance with SRM Chapter 51. 6. 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. 7. A General Visual Inspection is defined as: A visual examination of an interior or exterior area, installation or assembly to detect obvious damage, failure or irregularity. This level of inspection is made from within touching distance unless otherwise specified. A mirror may be necessary to enhance visual access to all exposed surfaces in the inspection area. This level of inspection is made under normally available lighting conditions such as daylight, hangar lighting, flashlight or drop-light and may require removal or opening of access panels or doors. Stands, ladders or platforms may be required to gain proximity to the area being checked.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 23 of 46 **BOEING SERVICE BULLETIN 737-53-1315**8. 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. 9. Boeing Service Letter 737-SL-51-042, 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. 10. 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 PART 1 - EXTERNAL INSPECTION** 
1. **Group 1:** Determine the skin inspection zones for the left side in accordance with FIGURE 1.
2. **Group 1:** Determine the skin inspection zones for the right side in accordance with FIGURE 2.
3. **Group 2:** Determine the skin inspection zones for the left side in accordance with FIGURE 3.
4. **Group 2:** Determine the skin inspection zones for the right side in accordance with FIGURE 4. 5. Do an external detailed inspection and an external subsurface eddy current, Magneto Optic Imager (MOI) or C-scan inspection for cracking in the skin at the zone 1 locations in accordance with FIGURE 5. If it is not possible to inspect an area due to interference with external support structure for the fairing, then do an internal eddy current inspection in accordance with 737 NDT Part 6, 53-30-20 in place of the external inspections. The internal inspection is only applicable locally where the external inspections are not possible. **NOTE:** It is not required to inspect areas under external repair doublers, provided either: 1. The doubler extends a minimum of 3 rows of fasteners beyond the chem-mill step and the repair was approved by the FAA or a Boeing company authorized representative who was authorized by the FAA to make such findings, or 2. The doubler extends a minimum of 2 rows beyond the chem-mill step and was accomplished in accordance with 737-500 SRM 53-00-01, Repair 31, Figure 201. **NOTE:** Zone 1 areas are areas under the fairing that may or may not have had a history of cracking. a. If any crack is found, repair in accordance with Part 2.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 24 of 46 **BOEING SERVICE BULLETIN 737-53-1315**6. Do an external detailed inspection for cracking in the skin at the zone 2 locations in accordance with FIGURE 5. **NOTE:** It is not required to inspect areas under external repair doublers, provided either: 1. The doubler extends a minimum of 3 rows of fasteners beyond the chem-mill step and the repair was approved by the FAA or a Boeing company authorized representative who was authorized by the FAA to make such findings, or 2. The doubler extends a minimum of 2 rows beyond the chem-mill step and was accomplished in accordance with 737-500 SRM 53-00-01, Repair 31, Figure 201. **NOTE:** It is optional to do external subsurface eddy current, Magneto Optic Imager (MOI) or C-scan inspections in accordance with FIGURE 5, or internal subsurface eddy current in accordance with 737 NDT Part 6, 53-30-20 in place of the external detailed inspections. **NOTE:** Zone 2 areas are areas outside of the fairing that have similar loading and structural configuration as Zones 1 and 3, but no history of cracks. Boeing request that any cracking in zone 2 is reported. Please send the following details to the Boeing Airline Support Group: 1. Airplane Identification Number. 2. Flight Cycles. 3. Flight Hours. 4. Size, location of the crack and is the crack visible. 5. Detection method. a. If any crack is found, repair in accordance with Part 2. 7. Do an external detailed inspection and an external subsurface eddy current, MOI or C-scan inspection for cracking in the skin at the zone 3 locations in accordance with FIGURE 5. **NOTE:** It is not required to inspect areas under external repair doublers, provided either: 1. The doubler extends a minimum of 3 rows of fasteners beyond the chem-mill step and the repair was approved by the FAA or a Boeing company authorized representative who was authorized by the FAA to make such findings, or 2. The doubler extends a minimum of 2 rows beyond the chem-mill step and was accomplished in accordance with 737-500 SRM 53-00-01, Repair 31, Figure 201. **NOTE:** Zone 3 areas are areas outside the fairing which have had a history of cracking. a. If any crack is found, repair in accordance with Part 2. 8. Repeat inspections in accordance with paragraph Paragraph 1.E., Compliance.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 25 of 46 **BOEING SERVICE BULLETIN 737-53-1315 PART 2 - FUSELAGE SKIN REPAIR**  1. Repair all skin cracks using a permanent repair or a time limited repair as follows: a. Get internal access to the repair area as follows: **NOTE:** Access is not necessary to accomplish the Time Limited Repair. – Remove the passenger seats as necessary. Refer to 737-300/400/500 AMM 25-22-00 as an accepted procedure. – Remove the passenger carpets as necessary. Refer to 737-300/400/500 AMM 25-27-15 as an accepted procedure. – Remove the passenger cabin sidewall panels as necessary. Refer to 737-300/400/500 AMM 25-21-46 as an accepted procedure. – Remove the passenger cabin sidewall insulation blankets as necessary. Refer to 737-300/400/500 AMM 25-21-39 as an accepted procedure. – Remove the aft cargo compartment sidewall panels and insulation blankets as necessary. Refer to 737-300/400/500 AMM 25-52-73 as an accepted procedure. b. Permanent repair: **NOTE:** Accomplishment of the permanent repair is terminating action for the repeat inspection in the area of the repair only. (1) Do an internal inspection of the bonded doubler for cracks and disbond in accordance with FIGURE 6. **NOTE:** This inspection is not required along the horizontal edge of the bonded doubler if the stringer does not make it possible to place the eddy current probe at the required location for inspection (a) If a shear-tie does not make it possible to place the eddy current probe at the required location for this inspection, then remove the two end fasteners from the shear-tie and inspect the open holes in accordance with 737 NDT Part 6, 51-00-00, Figure 16. 1) If no cracks are found in the open hole, and the hole will be common to the repair doubler, then install fasteners in accordance with the SRM repair instructions that follow. 2) If no cracks are found in the open hole and the hole will not be common to the repair doubler, then install the same type and size fastener as specified in production. (b) If any crack or disbonding in the bonded doubler is found, contact Boeing for further instructions and do the work instructed by Boeing. (2) Repair the skin crack(s) in accordance with 737-500 SRM 53-00-01, Repair 31, Figure 201. c. Time Limited Repair:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 26 of 46 **BOEING SERVICE BULLETIN 737-53-1315 NOTE:**  This repair cannot be used if the rivets that exist are larger than 3/16 inch diameter. 1.
2. This repair cannot be used in areas where hi-locks, lockbolts, or bolts were installed in production. If these fasteners are installed in the area of a crack, do the permanent repair. 3. Do not use this repair common to fuselage cut-outs, lap joints or butt joints. **CAUTION:** USE CAUTION WHEN LOCATING BLIND FASTENERS RELATIVE TO HIDDEN INTERNAL STRUCTURE. DRILLING INTO HIDDEN INTERNAL STRUCTURE OR EQUIPMENT MAY RESULT IN DOWNTIME FOR EXPENSIVE REPAIR. (1) For typical cracks found in the skin at the chem-mill step, except at the lap splice, repair in accordance with FIGURE 7. (a) If any corrosion or disbonded doubler is found contact Boeing for repair instructions and do the work instructed by Boeing. (b) If the crack cut-out edge is 0.5 inches or less from the end of the visible crack then do the Permanent repair in accordance with Part 2. (2) Do an external general visual inspection for loose or missing fasteners in the repaired area at the time given in Paragraph 1.E., Compliance. **NOTE:** Installation of the permanent repair terminates the requirement for this inspection. (a) If any loose or missing fastener is found replace the loose or missing fastener in accordance with FIGURE 7. (3) Do an internal detailed inspection and High Frequency Eddy Current (HFEC) inspection of the bonded doubler for disbonding and cracks in accordance with FIGURE 6 at the time given in Paragraph 1.E., Compliance. (a) If any disbonding or crack is found contact Boeing for repair instructions and do the work instructed by Boeing. **NOTE:** Installation of the permanent repair terminates the requirement for this inspection. (4) In accordance with the compliance time given in Paragraph 1.E., Compliance, for the Time Limited Repair, make the repair permanent as follows: (a) Accomplish a repair in accordance with 737-500 SRM 53-00-01, Repair 31, Figure 201 except at existing blind rivet locations, install permanent fasteners in accordance with FIGURE 7 Table 3. d. Install the furnishings that were removed for access as follows:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 27 of 46 **BOEING SERVICE BULLETIN 737-53-1315**– Install the aft cargo compartment sidewall panels and insulation blankets. Refer to 737-300/400/500 AMM 25-52-73 as an accepted procedure. – Install the passenger cabin sidewall insulation blankets. Refer to 737-300/400/500 AMM 25-21-39 as an accepted procedure. – Install the passenger cabin sidewall panels. Refer to 737-300/400/500 AMM 25-21-46 as an accepted procedure. – Install the passenger carpets. Refer to 737-300/400/500 AMM 25-27-15 as an accepted procedure. – Install the passenger seats. Refer to 737-300/400/500 AMM 25-22-00 as an accepted procedure. 2. Put the airplane back to a serviceable condition.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 28 of 46 **BOEING SERVICE BULLETIN 737-53-1315 This Figure applies only to: Group 1.** 

**FIGURE 1: INSPECTION ZONES - LEFT SIDE (SHEET 1 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 29 of 46 **BOEING SERVICE BULLETIN 737-53-1315 FIGURE 1: INSPECTION ZONES - LEFT SIDE**  **(SHEET 2 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 30 of 46 **BOEING SERVICE BULLETIN 737-53-1315 FIGURE 1: INSPECTION ZONES - LEFT SIDE**  **(SHEET 3 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 31 of 46 **BOEING SERVICE BULLETIN 737-53-1315 This Figure applies only to: Group 1.** 

**FIGURE 2: INSPECTION ZONES - RIGHT SIDE (SHEET 1 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 32 of 46 **BOEING SERVICE BULLETIN 737-53-1315 FIGURE 2: INSPECTION ZONES - RIGHT SIDE**  **(SHEET 2 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 33 of 46 **BOEING SERVICE BULLETIN 737-53-1315 FIGURE 2: INSPECTION ZONES - RIGHT SIDE**  **(SHEET 3 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 34 of 46 **BOEING SERVICE BULLETIN 737-53-1315 This Figure applies only to: Group 2.** 

**FIGURE 3: INSPECTION ZONES - LEFT SIDE (SHEET 1 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 35 of 46 **BOEING SERVICE BULLETIN 737-53-1315 FIGURE 3: INSPECTION ZONES - LEFT SIDE**  **(SHEET 2 OF 2)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 36 of 46 **BOEING SERVICE BULLETIN 737-53-1315 This Figure applies only to: Group 2.** 

**FIGURE 4: INSPECTION ZONES - RIGHT SIDE (SHEET 1 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 37 of 46 **BOEING SERVICE BULLETIN 737-53-1315 FIGURE 4: INSPECTION ZONES - RIGHT SIDE**  **(SHEET 2 OF 2)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 38 of 46 **BOEING SERVICE BULLETIN 737-53-1315 FIGURE 5: EXTERNAL INSPECTION**  **(SHEET 1 OF 2)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 39 of 46 **BOEING SERVICE BULLETIN 737-53-1315**The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  (a)

- - Fuselage Skin Inspect 1 (b)

- - Fuselage Skin Inspect 2 (a) Do a detailed inspection on the surface of the skin panels (b) Do a subsurface eddy current, Magneto Optic Imager (MOI) or C-scan inspection on the skin for subsurface cracks along the edge of the bonded doubler in accordance with one of the following procedures; 737 NDT Part 6, 53-30-09, 737 NDT Part 6, 53-30-18, 737 NDT Part 6, 53-30-19, or 737 NDT Part 6, 53-30- 25.

**FIGURE 5: EXTERNAL INSPECTION (SHEET 2 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 40 of 46 **BOEING SERVICE BULLETIN 737-53-1315 FIGURE 6: INTERNAL INSPECTION**  **(SHEET 1 OF 2)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 41 of 46 **BOEING SERVICE BULLETIN 737-53-1315**The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  (a)

- - Bonded Doubler Inspect 1 (b)

- - Bonded Doubler Inspect 2 (a) Do a detailed inspection of the bonded doubler for disbonding adjacent to the area detailed in Step 2. (b) Do a High Frequency Eddy Current (HFEC) inspection for cracks in the bonded doubler within 0.25 inch of the doubler edge in the area shown in accordance with 737 NDT Part 6, 51-00-00, Figure 4 or Figure 23. Place the HFEC probe on the doubler and scan the probe parallel to the edge of the doubler.

**FIGURE 6: INTERNAL INSPECTION (SHEET 2 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 42 of 46 **BOEING SERVICE BULLETIN 737-53-1315 FIGURE 7: TIME LIMITED REPAIR**  **(SHEET 1 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 43 of 46 **BOEING SERVICE BULLETIN 737-53-1315**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for each typical repair. **NOTE:** In the typical repair shown in this figure, the left side tear strap location shows a typical shear tie fastener pattern. The right side tear strap location shows a typical non-shear tied fastener pattern. The detail may be different, depending on the specific repair location. Use this figure as a guide, maintaining the same number and pattern of fasteners around the cut-out, and common to the tear straps or shear ties.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  (a)

- - Fuselage Skin Inspect 1 Common to the repair. - - Existing Fasteners Remove 2 (b) (c)

- - Fuselage Skin Cut 3 (d)

- - Chemical Conversion Coating Apply 4 (d)

- BMS 10-11, TYPE 1 Primer Apply For required Repair Doubler thickness. - - Upper Skin Thickness Measure 5
See Table 1 for Repair Doubler thickness. (e) (f) 1 2024-T3 CLAD SHEET Repair Doubler Make

To the Repair Doubler. - - Chemical Conversion Coating Apply 6
One coat to the Repair Doubler. - BMS 10-11, TYPE 1 Primer Apply (g) (h) (i) (j) 1

- Repair Doubler Install (New) 7

- BMS 5-95, CLASS B- 1/2, B-2 Fillet Seal Apply 8

- - Finish Apply 9 (a) Do a detailed inspection of the fuselage skin in the area of the crack(s) for corrosion or disbonded doublers. Look for bulging, white powder or a thin black line. (b) Cut the skin as shown, regardless of the crack length, provided the crack is contained within the cut-out area. Make sure a minimum 2D edge margin is maintained when cutting. The cut-out must be as shown to eliminate undetected cracks. The cut-out must be a minimum of 0.5 inches beyond the visible end of the crack. (c) The cut line cannot enter the radius of the bonded doubler at the tear straps. Maintain a 63 micro-inch or better surface finish on the cut-out edge. (d) Apply a Chemical Conversion coating to the cut edges in the fuselage skin. Refer to SOPM 20-43-03 as an accepted procedure. Then apply one coat of Primer BMS 10-11, Type 1.

**FIGURE 7: TIME LIMITED REPAIR (SHEET 2 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 44 of 46 **BOEING SERVICE BULLETIN 737-53-1315 MORE DATA**  **QTY IDENTIFICATION**  **NAME TASK**  **STEP** (e) Size the repair doubler to maintain a minimum edge distance of two times the fastener diameter at all fastener locations. Maintain a minimum corner radius of 0.5 inch. (f) Pre-form the repair doubler to match the contour of the fuselage. (g) Shim all gaps from 0.01 - 0.04 inch prior to fastener installation. Do not install shims between the skin and the doubler. (h) Clean the faying surfaces of the fuselage skin and repair doubler. Refer to SOPM 20-30-03 as an accepted procedure. (i) Install the repair doubler with BMS 5-95, Class B-1/2, B-2 sealant. (j) See fastener table 2 for rivets to be used. **Table 1 - Repair Doubler Thickness. Repair Doubler Thickness (Inches)**  **Existing Skin Thickness (Inches)** 0.040 0.032 or 0.036 0.050 0.040 Contact Boeing for further instructions. 0.050

**Table 2 - Blind Rivet Installation.**
**MORE DATA HOLE DIA**  **QTY IDENTIFICATION**  **NAME CODE**  (a) (b) (e) (f) (g) 0.176 - 0.180

- BACR15FR5E( )R, (NAS1738E5-( ) optional) Blind Rivet A

(a) (c) (d) 0.205 - 0.209

- BACR15FR6E( )R, (NAS1738E6-( ) optional) Blind Rivet B

(a) Install with repair washers in accordance with 737-500 SRM 51-40-08 at existing countersink locations. (b) Use this rivet at existing rivet positions, where the original rivet size was 5/32 inch diameter and at all new rivet positions. If any existing hole is damaged, increase the damaged hole size and install a Code B rivet. (c) Use this rivet at existing rivet positions, where the original rivet size was 3/16 inch diameter. (d) Maintain a minimum edge margin at the shear tie, of 1.5 times the rivet diameter. Maintain a minimum edge margin of 1.7 times the rivet diameter from the edge of the tear strap. (e) Maintain a minimum edge margin of 2 times the rivet diameter for new rivet locations and 1.7 times the rivet diameter for rivet locations that exist. (f) Install the rivets using the rivet pattern shown as a guide in the forward and aft direction. Use this figure to determine rivet pitch in the circumferential direction. Make the distance between the rivets 0.93 to 1.10 inches.

**FIGURE 7: TIME LIMITED REPAIR (SHEET 3 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 45 of 46 **BOEING SERVICE BULLETIN 737-53-1315 Table 2 - Blind Rivet Installation.** 
**MORE DATA HOLE DIA**  **QTY IDENTIFICATION**  **NAME CODE**  (g) At new rivet positions common to tear strap maintain minimum pitch of 0.75 inch. **Table 3 - Replacement of Blind Rivets With Solid Rivets.**
**MORE DATA HOLE DIA**  **QTY IDENTIFICATION**  **NAME CODE**  (a) (c) 0.190 - 0.196

- BACR15BB6AD( )C Solid Rivet C (b) (c) 0.225 - 0.231

- BACR15BB7AD( )C Solid Rivet D (a) Replace existing 5/32 inch blind rivets with Code C rivets. (b) Replace existing 3/16 inch blind rivets with Code D rivets. (c) The minimum diameter of the driven head of the rivet is 1.4 times the rivet diameter.

**FIGURE 7: TIME LIMITED REPAIR (SHEET 4 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 29, 2011 737-53-1315 46 of 46 **BOEING SERVICE BULLETIN 737-53-1315**