### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Number: 737-53A1329**  Original Issue: June 04, 2013 ATA System: 5330 **SUBJECT:** FUSELAGE - Skin - Forward Entry Doorway - Lower Corners - Inspection and Repair 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 © 2013 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 Unpublished Work.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, Dreamliner, BBJ, DC-8, DC-9, DC-10, KC-10, KC-46, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8, 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.

Original Issue: June 04, 2013 737-53A1329 1 of 29 6.0Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 2 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT**

BLANK PAGE**Table of Contents** Summary...................................................... 5 1. PLANNING INFORMATION ........................................ 9 A. Effectivity................................................ 9 1. Airplanes............................................. 9 2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 B. Concurrent Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 C. Reason. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 D. Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 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 M. Software Accomplishment Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 4. Parts Removed and Not Replaced. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 21 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 A. GENERAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 FIGURE 1: FUSELAGE - FORWARD ENTRY DOORWAY - SKIN ASSEMBLY AND BEAR STRAP AT THE LOWER CORNERS - INSPECTION [Group 2-3]. . . . . . . . . . . . . . . . . . . . . . . 26

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 3 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 4 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT**

BLANK PAGE

### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Summary**  **Number: 737-53A1329** Original Issue: June 04, 2013 ATA System: 5330 **SUBJECT:** FUSELAGE - Skin - Forward Entry Doorway - Lower Corners - Inspection and Repair 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 inspect the lower corners of the forward entry doorway for cracking on airplanes that do not have an airstair door cutout. If the work in this service bulletin is not done, continued crack progression can result in possible rapid decompression. Boeing has received five reports of cracking in the skin at the lower aft corner of the forward entry doorway on airplanes that do not have an airstair door cutout. The cracks ranged from 0.25 to 2.0 inches in length. The airplanes had accumulated between 34,813 and 73,083 total flight cycles. Cracks in the lower corners of the forward entry doorway are caused by fatigue loads in the skin and bear strap which are magnified by local stress concentrations due to the door cutout and edge margin effects at fastener locations near the corner radius. Additionally, cracks can be initiated from impact damage due to high usage rate of the forward entry door. Accomplishment of the work in this service bulletin will make sure that cracking at the lower corners of the forward entry doorway on airplanes that do not have an airstair door cutout is detected and a repair installed. Boeing Service Bulletin 737-53-1083 gives instructions for the inspection, modification and repair of the lower corners of the forward entry doorway on airplanes that have an airstair door cutout. Boeing Service Related Problem (SRP) 737-SRP-53-0381 is related to this service bulletin. Boeing Fleet Team Digest (FTD) 737 FTD 53-11003 is related to this service bulletin. This table is provided to operators for planning purposes only. Refer to the applicable sections for more information.
**Reference Affected**  **Planning Data** Paragraph 1.A.2., Spares Affected No Spares Affected

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 5 of 29**Reference Affected**  **Planning Data** Paragraph 1.E., Compliance and Paragraph 1.F., Approval Yes 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 Yes Publications Affected Paragraph 1.K., Publications Affected No Airplane Flight Operations Affected (Flight Crew Operations 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 Parts/Material Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin No Special Tooling Required

**ACTION Group 1:**  Contact Boeing to get instructions for the inspections and repairs for this service bulletin 737-53A1329 Original Issue and do the work instructed by Boeing. **Group 2-3:** Remove the scuff plates at the lower corners of the forward entry doorway. **Group 2:** At the lower corners of the forward entry doorway, do an internal detailed inspection of the skin assembly and bear strap, an internal High Frequency Eddy Current (HFEC) inspection of the bear strap and an external detailed and HFEC inspection of the skin assembly for any crack. If any crack is found in the skin assembly or bear strap, contact Boeing for repair instructions and do the work instructed by Boeing. If no cracking is found, do the repeat inspections at the intervals given in Paragraph 1.E., Compliance. **Group 3:** At the lower corners of the forward entry doorway, do an internal detailed inspection of the skin assembly and bear strap, an internal HFEC inspection of the bear strap and an external detailed and HFEC inspection of the skin assembly for any crack. If any crack is found in the skin assembly or bear strap at the lower aft corner, install a repair. If any crack is found in the skin assembly or bear strap at the lower forward corner, contact Boeing for repair instructions and do the work instructed by Boeing. If no cracking is found, do the repeat inspections at the intervals given in Paragraph 1.E., Compliance. **EFFECTIVITY** 737-200/-200C/-300/-400/-500 airplanes that do not have an airstair door cutout. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplane(s).

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 6 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT 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. FAA AD 2008-09-13 is related to this service bulletin. Refer to Paragraph 1.E., Compliance. **INDUSTRY SUPPORT INFORMATION** Boeing warranty remedies are not available for the configuration changes, inspection and/or repair procedures given in this service bulletin. **MANPOWER Elapsed Hours**  **Total Task Hours Airplanes**  5.00 5.00 Group 2 5.00 5.00 Group 3
**MATERIAL INFORMATION** Operator Supplied Parts/Materials. Refer to Paragraph 2.A., Material - Price and Availability.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 7 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 8 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT**

### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Number: 737-53A1329**  Original Issue: June 04, 2013 ATA System: 5330 **SUBJECT:** FUSELAGE - Skin - Forward Entry Doorway - Lower Corners - Inspection and Repair 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 D6-19567 Part 3 for Airplane Variable Number, Line Number, and Serial Number data. This service bulletin is for the airplanes shown below.
**DESCRIPTION CONFIGURATION**  **GROUP** 737-200C airplanes, line numbers 72 thru 286 that do not have an airstair door cutout. - 1

737-200/-200C airplanes, line numbers 294 thru 1453 that do not have an airstair door cutout. - 2

737-300/-400/-500 airplanes, line numbers 1001 thru 3132 that do not have an airstair door cutout. - 3

Airplane Models: 737-200, 737-200C, 737-300, 737-400, 737-500 **Group Variable Number**  3 PJ301 - PJ302 3 PJ551 - PJ561 3 PJ601 - PJ615

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 9 of 29**Group Variable Number**  3 PJ811 2 PK041 - PK046 2 PK048 - PK050 2 PK052 - PK053 2 PK431 - PK433 2 PK911 - PK938 2 PK971 - PK974 2 PL101 - PL113 2 PL736 - PL747 2 PL758 2 PN401 - PN420 3 PP001 - PP054 3 PP102 - PP169 3 PP181 - PP199 3 PP231 - PP243 3 PP281 - PP286 3 PP301 - PP305 3 PP401 - PP440 3 PP471 - PP475 3 PP631 - PP634 3 PP671 - PP699 3 PP701 - PP733 3 PP771 - PP779 3 PP861 - PP877 3 PP961 - PP967 3 PP981 - PP991 3 PQ001 - PQ016 3 PQ026 - PQ041 3 PQ051 - PQ092 3 PQ101 - PQ199 3 PQ201 - PQ202 3 PQ231 - PQ237 3 PQ292 - PQ297

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 10 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT Group**  **Variable Number** 3 PQ299 3 PQ301 - PQ307 3 PQ331 - PQ332 3 PQ341 - PQ348 3 PQ431 - PQ438 3 PQ451 3 PQ454 3 PQ471 3 PQ479 - PQ481 3 PQ486 - PQ487 3 PQ491 - PQ493 3 PQ771 - PQ772 3 PQ791 - PQ793 3 PQ801 - PQ805 3 PQ931 - PQ935 3 PR031 - PR034 3 PR041 - PR045 3 PR061 - PR072 3 PR077 - PR080 3 PR181 3 PS643 - PS644 3 PS666 - PS669 3 PS691 - PS692 3 PS701 - PS706 3 PS751 - PS799 3 PS901 - PS941 3 PT001 - PT015 3 PT021 - PT031 3 PT101 - PT105 3 PT186 - PT188 3 PT301 - PT309 3 PT331 - PT360 3 PT381 - PT399

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 11 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT Group**  **Variable Number** 3 PT401 - PT438 3 PT561 - PT565 3 PT581 - PT586 3 PT611 - PT621 3 PT641 - PT644 3 PT651 - PT656 3 PT681 - PT685 3 PT701 - PT703 3 PT716 - PT717 3 PT801 - PT834 3 PT851 - PT854 3 PT901 - PT930 3 PT971 - PT973 3 PT981 - PT985 3 PU001 - PU025 3 PV001 - PV055 3 PV201 - PV209 3 PV226 - PV229 3 PV231 - PV237 3 PV271 - PV272 3 PV281 - PV287 3 PV351 3 PW062 - PW068 3 PW201 - PW252 3 PW401 - PW408 3 PW411 - PW418 3 PW421 - PW424 3 PW431 - PW435 3 PW441 - PW450 3 PW461 - PW467 3 PW511 - PW522 3 PW524 - PW550 3 PW561 - PW564

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 12 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT Group**  **Variable Number** 3 PW571 - PW576 3 PW611 - PW622 3 PW631 - PW637 3 PW681 - PW683 3 PW711 - PW717 3 PW761 3 PW771 1 PX701 1 PY001 - PY008 1 PY021 2 PY022 2 PY036 - PY037 2 PY046 - PY048 2 PY056 - PY057 2 PY111 - PY113 2 PY131 - PY135 2 PY141 - PY143 2 PY151 - PY154 2 PY156 - PY157 2 PY162 2 PY166 2 PY191 2 PY201 2 PY241 - PY244 2 PY270 - PY275 1 PY301 - PY304 2 PY401 2 PY409 - PY410 2 PY421 - PY422 2 PY451 2 PY461 - PY463 2 PY591 - PY595 2 PY671 - PY672

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 13 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT Group**  **Variable Number** 2 PY721 2. Spares Affected None. **B. Concurrent Requirements** None. **C. Reason** This service bulletin gives instructions to inspect the lower corners of the forward entry doorway for cracking on airplanes that do not have an airstair door cutout. If the work in this service bulletin is not done, continued crack progression can result in possible rapid decompression. Boeing has received five reports of cracking in the skin at the lower aft corner of the forward entry doorway on airplanes that do not have an airstair door cutout. The cracks ranged from 0.25 to 2.0 inches in length. The airplanes had accumulated between 34,813 and 73,083 total flight cycles. Cracks in the lower corners of the forward entry doorway are caused by fatigue loads in the skin and bear strap which are magnified by local stress concentrations due to the door cutout and edge margin effects at fastener locations near the corner radius. Additionally, cracks can be initiated from impact damage due to high usage rate of the forward entry door. Accomplishment of the work in this service bulletin will make sure that cracking at the lower corners of the forward entry doorway on airplanes that do not have an airstair door cutout is detected and a repair installed. Boeing Service Bulletin 737-53-1083 gives instructions for the inspection, modification and repair of the lower corners of the forward entry doorway on airplanes that have an airstair door cutout. Boeing Service Related Problem (SRP) 737-SRP-53-0381 is related to this service bulletin. Boeing Fleet Team Digest (FTD) 737 FTD 53-11003 is related to this service bulletin. **D. Description Group 1:**  Contact Boeing to get instructions for the inspections and repairs for this service bulletin 737-53A1329 Original Issue and do the work instructed by Boeing. **Group 2-3:** Remove the scuff plates at the lower corners of the forward entry doorway. **Group 2:** At the lower corners of the forward entry doorway, do an internal detailed inspection of the skin assembly and bear strap, an internal High Frequency Eddy Current (HFEC) inspection of the bear strap and an external detailed and HFEC inspection of the skin assembly for any crack. If any crack is found in the skin assembly or bear strap, contact Boeing for repair instructions and do the work instructed by Boeing. If no cracking is found, do the repeat inspections at the intervals given in Paragraph 1.E., Compliance.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 14 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT Group 3:**  At the lower corners of the forward entry doorway, do an internal detailed inspection of the skin assembly and bear strap, an internal HFEC inspection of the bear strap and an external detailed and HFEC inspection of the skin assembly for any crack. If any crack is found in the skin assembly or bear strap at the lower aft corner, install a repair. If any crack is found in the skin assembly or bear strap at the lower forward corner, contact Boeing for repair instructions and do the work instructed by Boeing. If no cracking is found, do the repeat inspections at the intervals given in Paragraph 1.E., Compliance. The work in this service bulletin is done in the maintenance zone(s) given below. **Group 1:**
**Affected Maintenance Zones Zone**  **Model** 1-5 737-200C **Group 2:**
**Affected Maintenance Zones Zone**  **Model** 1-5 737-200, 737-200C **Group 3:**
**Affected Maintenance Zones Zone**  **Model** 105 737-300, 737-400, 737-500 **E. Compliance** The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive (AD) related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. FAA AD 2008-09-13 is related to this service bulletin. **Group 1:** Contact Boeing to get instructions for the inspections and repairs for this service bulletin 737-53A1329 Original Issue and do the work instructed by Boeing within 120 days after the original issue date of this service bulletin.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 15 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT Group 2:**  **Table 1: Forward Entry Doorway - Lower Corners Inspection Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition** 4,500 flight cycles. Within 4,500flight cycles after the original issue date of this service bulletin. Before 27,000total flight cycles. At the forward entry doorway lower aft corner, do an internal detailed inspection of the skin assembly and bear strap, an internal High Frequency Eddy Current (HFEC) inspection of the bear strap andan external detailed and HFEC inspection of the skin assembly for any crack in accordance with Paragraph 3.B., Work Instructions, PART 2, step 1.a. All airplanes.

4,500 flight cycles. Within 4,500flight cycles after the original issue date of this service bulletin. Before 27,000total flight cycles. At the forward entry doorway lowerforward corner, do an internal detailed inspection of the skin assembly and bear strap, an internal HFEC inspection of the bear strap and an external detailed andHFEC inspection of the skin assembly for any crack in accordancewith Paragraph 3.B., Work Instructions, PART 2, step 1.b.

- Before further flight. Contact Boeing for repair instruc- tions and do the work instructed by Boeing. If any crack is found in the skin assembly or bear strap. **Group 3: Table 2: Forward Entry Doorway - Lower Corners Inspection**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition**  4,500 flight cycles. Within 4,500flight cycles after the original issue date of this service bulletin. Before 27,000total flight cycles. At the forward entry doorway lower aft corner, do an internal detailed inspection of the skin assembly and bear strap, an internal HFEC inspection of the bear strap andan external detailed and HFEC inspection of the skin assembly for any crack in accordance with Paragraph 3.B., Work Instructions, PART 2, step 2.a. All airplanes. (a)

- Before further flight. Install the repair in accordancewith Paragraph 3.B., Work Instructions, PART 2, step 2.a.(1). If any crack is found in the skin assembly or bear strap at the lower aft corner. (a)

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 16 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT Group 3:**  **Table 2: Forward Entry Doorway - Lower Corners Inspection Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition** 4,500 flight cycles. Within 4,500flight cycles after the original issue date of this service bulletin. Before 27,000total flight cycles. At the forward entry doorway lowerforward corner, do an internal detailed inspection of the skin assembly and bear strap, an internal HFEC inspection of the bear strap and an external detailed andHFEC inspection of the skin assembly for any crack in accordancewith Paragraph 3.B., Work Instructions, PART 2, step 2.b. All airplanes.

- Before further flight. Contact Boeing for repair instruc- tions and do the work instructed by Boeing. If any crack is found in the skin assembly or bear strap at thelower forward corner. (a) Accomplishment of the repair in accordance with this service bulletin terminates the repeat inspections required by this service bulletin in the area common to the repair. Supplemental inspections are provided in the applicable Structural Repair Manual (SRM). **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. For 737-300/-400/-500 airplanes as required by paragraph (i) of AD 2008-09-13, the repair identified in this service bulletin has been evaluated to determine if it affects the Boeing Supplemental Structural Inspection Document D6-82669, Revision New Inspections as required by paragraph (g) and (h) of the AD. The SRM repair identified in Paragraph 3.B, Work Instructions, Part 2, Step 2.a(1) of this bulletin may affect certain areas of Significant Structural Item F-13A inspections. Supplemental inspections are provided in the noted SRM repair. **G. Manpower** The table below shows an estimate of the task hours necessary to do this service bulletin 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:

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 17 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT**• 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. **Elapsed Hours Task Hours**  **Number of Persons Task**  1.50 1.50 1 Open Access 2.00 2.00 1 FIGURE 1 1.50 1.50 1 Close Access 5.00 5.00 TOTAL FOR EACH AIRPLANE (a) (a) No manpower information is given for the repair. **H. Weight and Balance Changes** None. **I. Electrical Load Data** Not changed. **J. References** 1. Existing Data: a. Boeing Service Bulletin 737-53-1083 b. Boeing Service Letter 737-SL-51-042 c. Boeing Service Related Problem (SRP) 737-SRP-53-0381 d. Federal Aviation Administration (FAA) Airworthiness Directive (AD) 2008-09-13 e. Service Bulletin Index D6-19567 f. 737 Fleet Team Digest (FTD) 53-11003 g. 737 Non-Destructive Testing (NDT) Manual Part 6, 51-00-00 h. 737-100/200 Aircraft Maintenance Manual (AMM) 52-11-00 i. 737-300/400/500 Aircraft Maintenance Manual (AMM) 52-11-00, 53-13-01 j. 737-300 Structural Repair Manual (SRM) 53-10-01 k. 737-400 Structural Repair Manual (SRM) 53-10-01 l. 737-500 Structural Repair Manual (SRM) 53-10-01

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 18 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT**2. Data Supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin:
**Title Drawing Number**  SKIN AND STRINGER INSTALLATION - SECTION 41 65-45800 SKIN AND STRINGER INSTALLATION - FORWARD ENTRY AND GALLEY DOORS 65C34778

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: **Chapter-Section Publication**  53-10 737-300 Structural Repair Manual 53-10 737-400 Structural Repair Manual 53-10 737-500 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. **M. Software Accomplishment Summary** Not affected.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 19 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 20 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT**

BLANK PAGE**2. MATERIAL INFORMATION A. Material - Price and Availability**  None. **B. Industry Support Information** Boeing warranty remedies are not available for the configuration changes, inspection and/or 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: June 04, 2013 737-53A1329 21 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 22 of 29 **BOEING SERVICE BULLETIN 737-53A1329 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 – 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. 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. 6. 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. 7. 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. 8. 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.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 23 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT**9. 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. 10. 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 kept part. **B. WORK INSTRUCTIONS Group 1:**  1. Contact Boeing to get instructions for the inspections and repairs for this service bulletin 737-53A1329 Original Issue and do the work instructed by Boeing. **Group 2-3: PART 1 - ACCESS**  1. Open the forward entry door. Refer to 737-300/400/500 AMM 52-11-00 or 737-100/200 AMM 52-11-00 as an accepted procedure. 2. Remove the forward entry doorway scuff plates and their support structures at the forward entry doorway. Refer to 737-300/400/500 AMM 53-13-01 as an accepted procedure. **Group 2-3: PART 2 - INSPECTION** 
1. **Group 2:** a. At the forward entry doorway lower aft corner, do an internal detailed inspection of the skin assembly and bear strap, an internal High Frequency Eddy Current (HFEC) inspection of the bear strap and an external detailed and HFEC inspection of the skin assembly for any crack in accordance with FIGURE 1. (1) If any crack is found in the skin assembly or bear strap, contact Boeing for repair instructions and do the work instructed by Boeing. (2) If no cracking is found, do the repeat inspections at the intervals given in Paragraph 1.E., Compliance. b. At the forward entry doorway lower forward corner, do an internal detailed inspection of the skin assembly and bear strap, an internal HFEC inspection of the bear strap and an external detailed and HFEC inspection of the skin assembly for any crack in accordance with FIGURE 1. (1) If any crack is found in the skin assembly or bear strap, contact Boeing for repair instructions and do the work instructed by Boeing. (2) If no cracking is found, do the repeat inspections at the intervals given in Paragraph 1.E., Compliance.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 24 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT**2. **Group 3:** a. At the forward entry doorway lower aft corner, do an internal detailed inspection of the skin assembly and bear strap, an internal HFEC inspection of the bear strap and an external detailed and HFEC inspection of the skin assembly for any crack in accordance with FIGURE 1. (1) If any crack is found in the skin assembly or bear strap, do the following: (a) Install a repair in accordance with applicable 737-300 SRM 53-10-01 Repair 12 or 737-400 SRM 53-10-01 Repair 12 or 737-500 SRM 53-10-01 Repair 12. **NOTE:** Installation of the SRM repair terminates the repeat inspection requirements of this Service Bulletin for the area common to the repair. Supplemental inspections are provided in the applicable Structural Repair Manual (SRM). (2) If no cracking is found, do the repeat inspections at the intervals given in Paragraph 1.E., Compliance. b. At the forward entry doorway lower forward corner, do an internal detailed inspection of the skin assembly and bear strap, an internal HFEC inspection of the bear strap and an external detailed and HFEC inspection of the skin assembly for any crack in accordance with FIGURE 1. (1) If any crack is found in the skin assembly or bear strap, contact Boeing for repair instructions and do the work instructed by Boeing. (2) If no cracking is found, do the repeat inspections at the intervals given in Paragraph 1.E., Compliance. **Group 2-3: PART 3 - CLOSE ACCESS**  1. Install the forward entry doorway scuff plates and their support structures at the forward entry doorway. Refer to 737-300/400/500 AMM 53-13-01 as an accepted procedure. 2. Close the forward entry door. Refer to 737-300/400/500 AMM 52-11-00 or 737-100/200 AMM 52-11-00 as an accepted procedure. 3. Put the airplane back to a serviceable condition.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 25 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT This Figure applies only to: Group 2-3.** 

**FIGURE 1: FUSELAGE - FORWARD ENTRY DOORWAY - SKIN ASSEMBLY AND BEAR STRAP AT THE LOWER CORNERS - INSPECTION**  **(SHEET 1 OF 4)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 26 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT FIGURE 1: FUSELAGE - FORWARD ENTRY DOORWAY - SKIN ASSEMBLY AND BEAR STRAP AT THE**  **LOWER CORNERS - INSPECTION (SHEET 2 OF 4)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 27 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

**FIGURE 1: FUSELAGE - FORWARD ENTRY DOORWAY - SKIN ASSEMBLY AND BEAR STRAP AT THE LOWER CORNERS - INSPECTION**  **(SHEET 3 OF 4)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 28 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT More Data**  **Qty Identification**  **Name Task**  **Step** (a)

- - Bear Strap Inspect 1 (b)

- - Skin Assembly Inspect 2 (c)

- - Skin Assembly Inspect 3 (d)

- - Bear Strap and Skin Assembly Inspect 4 (a) Do an internal High Frequency Eddy Current (HFEC) inspection of the bear strap for any crack around the fasteners shown in accordance with 737 NDT Manual Part 6, 51-00-00, Figure 4 or Figure 23. (b) Do an external detailed inspection of the skin assembly for any crack.(c) Do an external HFEC inspection of the skin assembly for any crack around the fasteners shown in accordance with 737 NDT Manual Part 6, 51-00-00, Figure 4 or Figure 23. (d) Do an internal detailed inspection of all the visible surfaces of the bear strap and skin assembly for any crack.

**FIGURE 1: FUSELAGE - FORWARD ENTRY DOORWAY - SKIN ASSEMBLY AND BEAR STRAP AT THE LOWER CORNERS - INSPECTION**  **(SHEET 4 OF 4)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: June 04, 2013 737-53A1329 29 of 29 **BOEING SERVICE BULLETIN 737-53A1329 ALERT**  **ALERT**