### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Number: 737-53A1116**  Original Issue: July 21, 1988 Revision 4: September 30, 2013 ATA System: 5331 **SUBJECT:** FUSELAGE - Skin - Forward Galley Service Doorway Upper and Lower Corners - Inspection, Repair and Preventive Modification 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 © 1989 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 Unpublished Work.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: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 1 of 64 7.0Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 2 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**

BLANK PAGE**Table of Contents** Revision Transmittal Sheet............................................ 5 Summary...................................................... 7 1. PLANNING INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 A. Effectivity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 1. Airplanes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2. Spares Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 B. Concurrent Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 C. Reason. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 D. Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 F. Approval. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 G. Manpower. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 I. Electrical Load Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 J. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 1. Existing Data:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 2. Data Supplied with this Service Bulletin:. . . . . . . . . . . . . . . . . . . . . . . . . . . 44 3. Installation Drawings Used in the Preparation of this Service Bulletin:. . . . . . . . . . . 44 K. Publications Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 L. Interchangeability and Intermixability of Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . 44 M. Software Accomplishment Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 2. MATERIAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 B. Industry Support Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 C. Parts Necessary for Each Airplane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 1. Kits/Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 2. Parts and Materials Supplied by the Operator. . . . . . . . . . . . . . . . . . . . . . . . 45 3. Parts Modified and Reidentified. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 4. Parts Removed and Not Replaced. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 45 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 A. GENERAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 FIGURE 1: THIS FIGURE IS DELETED. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 FIGURE 2: THIS FIGURE IS DELETED. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 FIGURE 3: THIS FIGURE IS DELETED. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56 FIGURE 4: FORWARD GALLEY SERVICE DOORWAY - UPPER AFT CORNER INSPECTION . . . 57 FIGURE 5: FORWARD GALLEY SERVICE DOORWAY - UPPER FORWARD CORNER INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 FIGURE 6: FORWARD GALLEY SERVICE DOORWAY - LOWER AFT CORNER INSPECTION . . . 61 FIGURE 7: FORWARD GALLEY SERVICE DOORWAY - LOWER FORWARD CORNER INSPECTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 3 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 4 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Revision Transmittal Sheet**  **Number: 737-53A1116** Original Issue: July 21, 1988 Revision 4: September 30, 2013 ATA System: 5331 **SUBJECT:** FUSELAGE - Skin - Forward Galley Service Doorway Upper and Lower Corners - Inspection, Repair and Preventive Modification This revision includes all pages of the service bulletin. **COMPLIANCE INFORMATION RELATED TO THIS REVISION** Federal Aviation Administration (FAA) Airworthiness Directives AD 2008-08-23, AD 2008-09-13, AD 90-06-02 and AD 98-11-04 R1 are related to this service bulletin. More work is necessary on airplane(s) inspected or changed in accordance with the original issue, Revision 1, 2 or 3 of this service bulletin. Airplanes that have installed the preventive modification in accordance with original issue, Revision 1, 2 or 3 of this service bulletin, require follow-on inspection. Airplanes that have installed a repair at the upper forward corner in accordance with original issue, Revision 1, 2, or 3 require follow-on inspection. All airplanes require new inspections at the forward galley service doorway lower corners. Airplane line numbers 1561 thru 3132 were added to this service bulletin effectivity. **REASON FOR REVISION** This revision is sent to add airplane line numbers 1561 thru 3132 to the effectivity of this service bulletin and to revise the compliance information and the inspection instructions. The repairs and kits provided in the previous revisions are deleted and replaced with Structural Repair Manual (SRM) repairs. Terminology has been changed in the Work Instructions to agree with the terminology defined in Paragraph 3.A., General Information - Notes. The following sections are changed: 1. The service bulletin subject is updated. 2. The Summary Background is updated and a Summary Evaluation Table is added. 3. The Summary Action, Summary Effectivity, Summary Compliance, Summary Manpower, Summary Material Information and Summary Illustration are updated. 4. Paragraph 1.A.1., Airplanes - 737-300/-400 airplanes line numbers 1001 through 1560 are moved from Group 1 to Group 2. Airplane line numbers 1-291 are moved from group 1 to new Group 5. 737-300/-400/-500 airplanes line numbers 1561 through 3132 are added to new Group 3. 737-200 airplanes line numbers 1565 through 1585 are added to new Group 4.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 5 of 645. Paragraph 1.D., Description is updated and affected maintenance zones are added. 6. Paragraph 1.E., Compliance - Reference to FAA Airworthiness Directives AD 2008-08-23, AD 2008-09-13, AD 90-06-02 and AD 98-11-04 R1 is added and compliance information is updated. 7. Paragraph 1.F., Approval - Alternative Method of Compliance (AMOC) statements are added. 8. Paragraph 1.G., Manpower - Manpower information is updated. 9. Paragraph 1.H., Weight and Balance Changes - The Weight and Balance table is deleted. 10. Paragraph 1.J.1., Existing Data - References are updated. 11. Paragraph 1.J.2., Data Supplied with this Service Bulletin - The Drawings table is deleted. 12. Paragraph 1.K., Publications Affected - Reference to 737-500 SRM is added, reference 737-100/200 SRM is deleted and a Damage Tolerance Inspection (DTI) statement is added. 13. Paragraph 2.A., Material - Price and Availability - This information is deleted. 14. Paragraph 2.C.1., Kits/Parts - The kits are deleted. 15. Paragraph 2.C.2., Parts and Materials Supplied by the Operator - The parts and materials table is deleted. 16. Paragraph 2.E., Special Tooling - Price and Availability - The cold working tools information is deleted. 17. Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin - The cold working tools information is deleted. 18. Paragraph 1.M., Software Accomplishment Summary - Section is added. 19. Paragraph 3.A., General Information - Notes are added. 20. Paragraph 3.B., Work Instructions - Inspections instructions are added. 21. Figures 1, 2 and 3 are deleted and Figures 4 thru 7 are added. Vertical lines are put on the left edge of each page, except in Paragraph 1.A., Effectivity, to show the location of important changes. Pages with no vertical lines have no important changes. **REVISION HISTORY** July 21, 1988 Original Issue: September 07, 1989 Revision 1: September 30, 1993 Revision 2: July 20, 1995 Revision 3: September 30, 2013 Revision 4:

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 6 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**

### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Summary**  **Number: 737-53A1116** Original Issue: July 21, 1988 Revision 4: September 30, 2013 ATA System: 5331 **SUBJECT:** FUSELAGE - Skin - Forward Galley Service Doorway Upper and Lower Corners - Inspection, Repair and Preventive Modification 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** Based on a structural review of the 737 airplane, incorporation of the modification per this service bulletin is recommended on aging airplanes. This service bulletin gives instructions to inspect the skin and bearstrap in the forward galley service doorway upper and lower corners for cracking. If the work in this service bulletin is not done, undetected cracking in the forward galley service doorway corners could extend and result in rapid loss of cabin pressure and cause unscheduled maintenance. Six operators have found seventeen cracks in the skin and doublers at the upper corners of the forward galley service doorway on eight airplanes. There were eight cracks reported at the upper aft corner on three airplanes and nine cracks in the skin at the forward corner on five airplanes. The airplanes had accumulated from 29,000 to 47,300 flight hours and from 40,500 to 60,800 flight cycles. Cause of the cracking is attributed to fatigue from pressurization cycles. There have been nine reports of cracking at the upper forward and aft corner fastener locations of the forward galley service doorway in airplanes beyond the effectivity of Revision 3 of this service bulletin. A 0.5 inch long crack was reported on an airplane with 23,426 total flight cycles. Two cracks were reported common to the upper forward and aft corner radius fastener locations of the forward galley service doorway on airplanes that had incorporated the preventive modification in accordance with the original issue, Revision 1, 2 and 3 of this service bulletin. Multiple cracks were reported outside the inspection area of Revision 3 of this service bulletin common to the upper forward and aft door corners of the forward galley service doorway. A 6.5 inch long bearstrap crack was reported just below the upper forward corner inspection zone. The airplane had accumulated 59,804 total flight cycles.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 7 of 64Service bulletin 737-53-1074 provides inspection, preventive modification and repair instructions for the forward galley service doorway lower forward and aft corner areas for 737 airplane line numbers 1 thru 1014. Multiple cracks have been reported common to the skin and bearstrap at the lower forward and aft doorway corners in 737 airplane line numbers 1015 thru 3132 that are beyond the effectivity of service bulletin 737-53-1074. Several cracks ranging from 0.5 inch to 2 inches were reported in the skin and bearstrap at the lower forward doorway corner on airplanes that had accumulated between 44,796 and 73,109 total flight cycles. Multiple cracks ranging from 0.03 inch to 2.5 inches were reported in the skin and bearstrap at the lower aft doorway corner on airplanes that had accumulated between 28,040 and 70,456 total flight cycles. New inspections have been added to service bulletin 737-53A1116 for cracking of the forward galley service doorway lower forward and aft corners for all airplanes within this service bulletin's effectivity. After accomplishing the inspections in accordance with service bulletin 737-53A1116 Revision 4, operators do not need to accomplish service bulletin 737-53-1074 inspections for the forward service doorway lower corners. Boeing Service Related Problem (SRP) 737-SRP-53-0380 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 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 CrewOperations Manual and/or FAA Approved Airplane Flight Manual) Paragraph 2.C.1., Kits/Parts No Kits/Parts Required Paragraph 2.C.2., Parts and Materials Supplied by the Operator No Operator Supplied Material Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin No Special Tooling Required

**ACTION** Get access to the interior surface of the forward galley service doorway. **Group 1:** At the upper and lower forward and aft corners of the forward galley service doorway, where no repair is installed that covers the corner radius fasteners, do an external Low Frequency Eddy Current (LFEC) inspection for cracking in the skin and bearstrap at the corner radius fasteners. Do an external detailed inspection for cracking in the skin and do an internal detailed inspection for cracking in the skin and bearstrap. If any crack is found in the skin or bearstrap at the upper aft corner, install a repair in accordance with this service bulletin or contact Boeing for repair instructions and do the work instructed by Boeing. If any crack is found in the skin or bearstrap

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 8 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**at the upper forward corner, lower aft corner or lower forward corner, contact Boeing for repair instructions and do the work instructed by Boeing. If no cracking is found, repeat the inspections at the intervals given in Paragraph 1.E., Compliance, or to terminate repeat inspections install the preventive modification in accordance with this service bulletin or contact Boeing for preventive modification instructions and do the work instructed by Boeing, as applicable. **Group 2-3:** At the upper and lower forward and aft corners of the forward galley service doorway where no Boeing approved repair is installed that covers the corner radius fasteners, do an external LFEC inspection for cracking in the skin and bearstrap at the corner radius fasteners. Do an external detailed inspection for cracking in the skin and do an internal detailed inspection for cracking in the skin and bearstrap. If any crack is found in the skin or bearstrap at the upper aft corner, lower aft corner or lower forward corner, install a Structural Repair Manual (SRM) repair or contact Boeing for repair instructions and do the work instructed by Boeing. If any crack is found in the skin or bearstrap at the upper forward corner, contact Boeing for repair instructions and do the work instructed by Boeing. If no cracking is found, repeat the inspections at the intervals given in Paragraph 1.E., Compliance, or to terminate repeat inspections install the preventive modification in accordance with this service bulletin or contact Boeing for preventive modification instructions and do the work instructed by Boeing, as applicable. **Group 4:** At the upper and lower forward and aft corners of the forward galley service doorway where no Boeing approved repair is installed that covers the corner radius fasteners, do an external LFEC inspection for cracking in the skin and bearstrap at the corner radius fasteners. Do an external detailed inspection for cracking in the skin and do an internal detailed inspection for cracking in the skin and bearstrap. If any crack is found contact Boeing for repair instructions and do the work instructed by Boeing. If no cracking is found, repeat the inspections at the intervals given in Paragraph 1.E., Compliance, or to terminate repeat inspections contact Boeing for preventive modification instructions and do the work instructed by Boeing. **Group 5:** Contact Boeing to get instructions for the inspections and repairs for this service bulletin 737-53A1116, Revision 4, and do the work instructed by Boeing. **EFFECTIVITY** 737-100, -200, -200C, -300, -400 and -500 Airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes. **COMPLIANCE** Federal Aviation Administration (FAA) Airworthiness Directives AD 2008-08-23, AD 2008-09-13, AD 90-06-02 and AD 98-11-04 R1 are related to this service bulletin. 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/or repair procedures given in this service bulletin.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 9 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT MANPOWER**  Refer to Paragraph 1.G., Manpower. **Elapsed Hours Total Task Hours**  **Airplanes** 13.85 18.30 Group 1-4

**MATERIAL INFORMATION** None.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 10 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 11 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 12 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Number: 737-53A1116**  Original Issue: July 21, 1988 Revision 4: September 30, 2013 ATA System: 5331 **SUBJECT:** FUSELAGE - Skin - Forward Galley Service Doorway Upper and Lower Corners - Inspection, Repair and Preventive Modification 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** 737-200/-200C airplanes line numbers 292 through 1560, excluding variable numbers PJ201 through PJ219. - 1

737-300/-400 airplanes line numbers 1001 through 1560. A repair exists in the Structural Repair Manual for these airplanes. - 2

737-300/-400/-500 airplanes line numbers 1561 through 3132. These airplanes have cold worked fastener holes at the forward galley service doorway upper corners and are added at Revision 4 of this service bulletin. A repair exists in the Structural Repair Manual for these airplanes. - 3

737-200 airplanes line numbers 1565 through 1585. These airplanes have cold worked fastener holes at the forward galley service doorway upper corners and are added at Revision 4 of this service bulletin. - 4

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 13 of 64**DESCRIPTION CONFIGURATION**  **GROUP** 737-100/-200/-200C airplanes line numbers 1 through 291. These airplanes have cold bonded skins. - 5

Airplane Models: 737-100, 737-200, 737-200C, 737-300, 737-400, 737-500 **Group Variable Number** 5 PA001 - PA022 5 PA099 5 PA231 - PA232 5 PC001 - PC005 5 PG001 - PG075 5 PG199 5 PG201 - PG230 5 PG251 - PG255 5 PG271 - PG279 5 PG301 - PG314 5 PG331 - PG332 5 PG351 - PG356 5 PG375 5 PG401 - PG403 5 PG431 - PG442 5 PG471 - PG475 5 PG501 - PG505 5 PG571 - PG583 1 PG584 - PG586 5 PG621 - PG630 5 PG651 - PG652 5 PG701 - PG705 1 PH001 1 PH011 - PH013 1 PH021 - PH024 5 PH701 - PH715

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 14 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group**  **Variable Number**5 PH731 - PH732 5 PH741 - PH742 1 PH743 5 PJ001 - PJ002 1 PJ003 - PJ009 5 PJ031 - PJ032 5 PJ071 - PJ072 5 PJ101 - PJ104 1 PJ105 - PJ119 3 PJ301 - PJ302 3 PJ551 - PJ561 3 PJ601 - PJ615 3 PJ811 3 PJ816 - PJ817 1 PK026 - PK029 1 PK041 - PK053 1 PK061 - PK070 1 PK081 - PK082 1 PK091 - PK099 1 PK101 - PK103 1 PK111 - PK120 1 PK141 - PK146 1 PK201 - PK204 1 PK211 - PK223 1 PK231 - PK241 1 PK251 - PK258 1 PK271 - PK274 1 PK281 - PK289 1 PK291 1 PK301 - PK318 1 PK341 1 PK351 - PK361 1 PK391

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 15 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group**  **Variable Number** 1 PK431 - PK433 1 PK451 - PK452 1 PK461 - PK469 1 PK495 1 PK501 - PK504 1 PK511 - PK515 1 PK519 1 PK521 - PK527 4 PK528 1 PK541 - PK565 1 PK581 1 PK591 - PK599 1 PK601 - PK617 1 PK621 - PK637 1 PK641 - PK642 1 PK661 - PK666 1 PK671 - PK681 1 PK691 - PK697 1 PK711 - PK716 1 PK731 - PK765 1 PK771 - PK779 1 PK801 - PK804 1 PK819 - PK827 1 PK830 1 PK861 - PK863 1 PK871 - PK874 1 PK881 - PK884 1 PK901 - PK938 1 PK971 - PK974 1 PL001 - PL028 1 PL061 1 PL081 1 PL101 - PL113

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 16 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group**  **Variable Number** 1 PL151 1 PL171 - PL172 1 PL201 - PL203 1 PL221 1 PL401 - PL417 1 PL421 1 PL441 1 PL451 - PL456 1 PL471 1 PL491 1 PL501 - PL506 1 PL551 - PL562 1 PL581 1 PL601 - PL603 1 PL611 1 PL621 - PL626 1 PL631 - PL632 5 PL711 - PL712 5 PL716 1 PL717 - PL747 1 PL756 1 PL758 1 PL761 - PL770 1 PL781 - PL788 1 PL793 5 PL801 - PL803 1 PM001 - PM006 1 PM016 - PM017 1 PM021 - PM023 1 PM051 - PM066 1 PM101 - PM119 1 PM141 - PM142 1 PM171

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 17 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group**  **Variable Number** 1 PM181 1 PM251 - PM255 1 PM281 - PM283 3 PM381 - PM399 3 PM401 - PM417 3 PM541 - PM564 1 PN001 - PN002 1 PN021 - PN043 1 PN081 - PN086 1 PN101 - PN117 1 PN131 - PN163 1 PN401 - PN420 1 PN431 - PN433 1 PN451 - PN456 1 PN471 - PN472 4 PN473 - PN474 1 PN481 1 PN491 - PN493 1 PN501 - PN502 1 PN511 4 PN512 4 PN521 2 PP001 - PP045 3 PP046 - PP054 2 PP101 - PP135 3 PP136 - PP160 2 PP161 - PP169 2 PP181 - PP192 3 PP193 - PP199 2 PP201 - PP205 2 PP221 2 PP231 - PP243 2 PP281 - PP286

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 18 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group**  **Variable Number**2 PP301 - PP305 2 PP351 - PP353 2 PP376 - PP384 2 PP391 - PP392 3 PP393 2 PP401 - PP436 3 PP437 - PP440 2 PP471 - PP475 2 PP501 - PP504 3 PP505 - PP520 2 PP521 - PP522 2 PP631 - PP634 2 PP651 - PP652 2 PP671 - PP699 2 PP701 - PP733 2 PP771 - PP779 2 PP801 - PP804 3 PP805 - PP808 2 PP821 - PP827 2 PP831 - PP842 3 PP843 - PP845 2 PP846 - PP848 2 PP851 - PP852 2 PP861 - PP870 3 PP871 - PP877 2 PP891 - PP899 2 PP901 - PP910 3 PP911 - PP930 2 PP931 - PP936 2 PP946 - PP948 2 PP951 - PP952 2 PP961 - PP965 3 PP966 - PP967

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 19 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group**  **Variable Number**2 PP981 - PP982 3 PP983 - PP990 2 PP991 3 PP993 2 PQ001 - PQ012 3 PQ013 - PQ016 2 PQ026 - PQ037 3 PQ038 - PQ041 2 PQ051 - PQ065 3 PQ066 - PQ085 2 PQ086 - PQ090 3 PQ091 - PQ092 2 PQ101 - PQ123 3 PQ124 - PQ199 3 PQ201 - PQ202 3 PQ221 - PQ230 2 PQ231 - PQ233 3 PQ234 - PQ237 2 PQ241 - PQ242 3 PQ243 3 PQ251 - PQ267 3 PQ281 - PQ299 3 PQ301 - PQ307 3 PQ331 - PQ332 3 PQ341 - PQ348 3 PQ361 - PQ373 3 PQ391 - PQ395 3 PQ401 - PQ418 3 PQ421 3 PQ431 - PQ438 3 PQ447 - PQ448 3 PQ451 3 PQ454

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 20 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group**  **Variable Number** 3 PQ471 - PQ475 3 PQ479 - PQ481 3 PQ486 - PQ487 3 PQ491 - PQ493 3 PQ771 - PQ772 3 PQ791 - PQ793 3 PQ801 - PQ805 3 PQ931 - PQ935 3 PQ951 3 PQ971 - PQ997 3 PR001 - PR017 3 PR021 - PR034 3 PR041 - PR045 3 PR061 - PR072 3 PR077 - PR082 3 PR091 - PR092 3 PR096 3 PR101 3 PR121 - PR122 3 PR131 - PR132 3 PR141 - PR143 3 PR161 - PR172 3 PR181 3 PS601 - PS631 3 PS636 - PS638 3 PS641 - PS644 3 PS651 - PS657 3 PS666 - PS669 3 PS691 - PS692 3 PS701 - PS706 3 PS751 - PS799 3 PS811 3 PS836 - PS837

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 21 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group**  **Variable Number** 3 PS841 - PS846 3 PS851 - PS852 3 PS856 3 PS861 - PS863 3 PS866 - PS868 3 PS871 - PS874 3 PS896 - PS897 3 PS901 - PS941 3 PS956 - PS957 3 PS961 - PS963 3 PS971 - PS978 3 PT001 - PT015 3 PT021 - PT031 3 PT041 - PT064 3 PT101 - PT105 3 PT121 - PT138 3 PT146 - PT148 3 PT161 - PT170 3 PT181 - PT188 3 PT211 - PT220 3 PT295 3 PT301 - PT309 3 PT331 - PT360 3 PT381 - PT399 3 PT401 - PT438 3 PT501 - PT517 3 PT561 - PT565 3 PT581 - PT586 3 PT611 - PT621 3 PT641 - PT644 3 PT651 - PT656 3 PT671 - PT672 3 PT681 - PT685

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 22 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group**  **Variable Number** 3 PT701 - PT703 3 PT716 - PT717 3 PT721 - PT725 3 PT801 - PT834 3 PT851 - PT854 3 PT871 - PT886 3 PT901 - PT930 3 PT971 - PT973 3 PT981 - PT985 3 PT996 3 PU001 - PU025 3 PU301 3 PU311 - PU313 2 PV001 - PV004 3 PV005 - PV055 3 PV201 - PV209 3 PV226 - PV229 3 PV231 - PV237 3 PV271 - PV272 3 PV281 - PV287 3 PV296 3 PV301 - PV302 3 PV351 3 PV356 - PV357 3 PW001 - PW054 3 PW061 - PW068 3 PW072 3 PW086 - PW088 3 PW091 - PW094 3 PW101 - PW102 3 PW106 3 PW111 - PW120 3 PW156 - PW157

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 23 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group**  **Variable Number** 3 PW161 - PW171 3 PW201 - PW252 3 PW261 - PW268 3 PW271 - PW276 3 PW278 3 PW281 - PW293 3 PW296 3 PW301 - PW327 3 PW401 - PW408 3 PW411 - PW418 3 PW421 - PW424 3 PW431 - PW435 3 PW441 - PW450 3 PW461 - PW467 3 PW501 - PW504 3 PW511 - PW522 3 PW524 - PW550 3 PW556 - PW557 3 PW561 - PW564 3 PW571 - PW576 3 PW591 - PW596 3 PW611 - PW622 3 PW631 - PW637 3 PW661 - PW662 3 PW681 - PW683 3 PW701 - PW702 3 PW711 - PW717 3 PW741 - PW742 3 PW761 3 PW771 3 PW831 3 PW851 - PW856 5 PX071

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 24 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group**  **Variable Number**5 PX701 5 PY001 - PY008 5 PY021 1 PY022 5 PY031 1 PY036 - PY037 1 PY046 - PY048 1 PY051 - PY053 1 PY056 - PY057 1 PY101 - PY103 1 PY111 - PY113 1 PY131 - PY135 1 PY141 - PY143 1 PY151 - PY154 1 PY156 - PY157 1 PY161 - PY162 1 PY166 1 PY191 1 PY201 1 PY221 - PY222 1 PY231 1 PY241 - PY244 1 PY270 - PY275 1 PY281 1 PY286 5 PY301 - PY304 5 PY321 - PY323 5 PY341 - PY346 5 PY361 - PY362 5 PY381 1 PY401 1 PY409 - PY411 1 PY421 - PY422

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 25 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group**  **Variable Number** 1 PY441 1 PY451 1 PY461 - PY463 1 PY591 - PY595 1 PY611 - PY612 1 PY621 1 PY631 1 PY651 1 PY671 - PY672 1 PY721 1 PY741 2. Spares Affected None. **B. Concurrent Requirements** None. **C. Reason** As a result of the FAA-sponsored Aging Fleet Conference, a 737 Structures Task Group with Airline and Boeing members and FAA observers was formed to review structural service bulletin modifications and recommend selected bulletins for incorporation on aging airplanes. This service bulletin modification has been recommended for incorporation on aging 737 airplanes. This service bulletin gives instructions to inspect the skin and bearstrap in the forward galley service doorway upper and lower corners for cracking. If the work in this service bulletin is not done, undetected cracking in the forward galley service doorway corners could extend and result in rapid loss of cabin pressure and cause unscheduled maintenance. Inspection of the upper corners of the forward galley service doorway will detect cracking that could result in pressurization difficulties. Repair of cracks or accomplishment of preventive modification on uncracked structure is terminating action for inspection per this service bulletin. Cause of the cracking is attributed to fatigue from pressurization cycles. Six operators have reported cracks in the upper corner of the forward galley service doorways on a total of eight airplanes. Three airplanes had a total of eight cracks in the upper aft corner, with crack lengths of up to 2 inches in the skin, and a 2 inch long crack in the bearstrap doubler on one airplane. Five airplanes had a total of nine cracks from 0.1 inch to 1.5 inches in length in the upper forward corner skin. The airplanes had accumulated from 29,000 to 47,300 flight hours, and from 40,500 to 60,800 flight cycles.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 26 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**There have been nine reports of cracking at the upper forward and aft corner fastener locations of the forward galley service doorway in airplanes beyond the effectivity of Revision 3 of this service bulletin. A 0.5 inch long crack was reported on an airplane with 23,426 total flight cycles. Two cracks were reported common to the upper forward and aft corner radius fastener locations of the forward galley service doorway on airplanes that had incorporated the preventive modification in accordance with the original issue, Revision 1, 2 and 3 of this service bulletin. Multiple cracks were reported outside the inspection area of Revision 3 of this service bulletin common to the upper forward and aft door corners of the forward galley service doorway. A 6.5 inch long bearstrap crack was reported just below the upper forward corner inspection zone. The airplane had accumulated 59,804 total flight cycles. Service bulletin 737-53-1074 provides inspection, preventive modification and repair instructions for the forward galley service doorway lower forward and aft corner areas for 737 airplane line numbers 1 thru 1014. Multiple cracks have been reported common to the skin and bearstrap at the lower forward and aft doorway corners in 737 airplane line numbers 1015 thru 3132 that are beyond the effectivity of service bulletin 737-53-1074. Several cracks ranging from 0.5 inch to 2 inches were reported in the skin and bearstrap at the lower forward doorway corner on airplanes that had accumulated between 44,796 and 73,109 total flight cycles. Multiple cracks ranging from 0.03 inch to 2.5 inches were reported in the skin and bearstrap at the lower aft doorway corner on airplanes that had accumulated between 28,040 and 70,456 total flight cycles. New inspections have been added to service bulletin 737-53A1116 for cracking of the forward galley service doorway lower forward and aft corners for all airplanes within this service bulletin's effectivity. After accomplishing the inspections in accordance with service bulletin 737-53A1116 Revision 4, operators do not need to accomplish service bulletin 737-53-1074 inspections for the forward service doorway lower corners. Boeing Service Related Problem (SRP) 737-SRP-53-0380 is related to this service bulletin. Boeing Fleet Team Digest (FTD) 737 FTD 53-11003 is related to this service bulletin. Revision 1 of this service bulletin was issued to provide the recommendations of the Aging Fleet 737 Structures Working Group and to change the forward galley service doorway upper forward corner repair doubler installation. The installation change eliminates one fastener and moves one fastener to make the repair compatible with the service bulletin 737-53-1074 modification. Revision 2 was sent to provide a list of reference service bulletins applicable to 737 door corners and hinge cutouts. Also, the crack location and limits that can be repaired with instructions in this bulletin were defined in this revision. Revision 3 was sent to: – Add the contents of the preventive modification and repair kits to Paragraph 2.C., Parts Necessary for Each Airplane. This data was inadvertently omitted in Revision 2. – Add structural repair manual subject numbers to stop drill 737-300 and 737-400 airplanes in accordance with Figure 2. – Add structural repair manual subject numbers to coldwork 737-300 and 737-400 airplanes in accordance with Figure 3. – Add reference to the Maintenance Planning Document item number that is related to the inspections in this service bulletin. – Add reference to the structural repair manual subject numbers changed by the repairs and modifications shown in this service bulletin. Revision 4 is sent to add airplane line numbers 1561 thru 3132 to the effectivity of this service bulletin and to revise the compliance information and the inspection instructions. The repairs and kits provided in the previous revisions are deleted and replaced with Structural Repair Manual (SRM) repairs.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 27 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**The forward galley door upper forward corner repair installed in accordance with this service bulletin overlaps the preventive modification for the upper hinge cutout installed in accordance with service bulletin 737-53-1074. Service bulletin 737-53-1074 has similar access requirements as this service bulletin. **D. Description** Get access to the interior surface of the forward galley service doorway. **Group 1:** At the upper and lower forward and aft corners of the forward galley service doorway, where no repair is installed that covers the corner radius fasteners, do an external Low Frequency Eddy Current (LFEC) inspection for cracking in the skin and bearstrap at the corner radius fasteners. Do an external detailed inspection for cracking in the skin and do an internal detailed inspection for cracking in the skin and bearstrap. If any crack is found in the skin or bearstrap at the upper aft corner, install a repair in accordance with this service bulletin or contact Boeing for repair instructions and do the work instructed by Boeing. If any crack is found in the skin or bearstrap at the upper forward corner, lower aft corner or lower forward corner, contact Boeing for repair instructions and do the work instructed by Boeing. If no cracking is found, repeat the inspections at the intervals given in Paragraph 1.E., Compliance, or to terminate repeat inspections install the preventive modification in accordance with this service bulletin or contact Boeing for preventive modification instructions and do the work instructed by Boeing, as applicable. **Group 2-3:** At the upper and lower forward and aft corners of the forward galley service doorway where no Boeing approved repair is installed that covers the corner radius fasteners, do an external LFEC inspection for cracking in the skin and bearstrap at the corner radius fasteners. Do an external detailed inspection for cracking in the skin and do an internal detailed inspection for cracking in the skin and bearstrap. If any crack is found in the skin or bearstrap at the upper aft corner, lower aft corner or lower forward corner, install a Structural Repair Manual (SRM) repair or contact Boeing for repair instructions and do the work instructed by Boeing. If any crack is found in the skin or bearstrap at the upper forward corner, contact Boeing for repair instructions and do the work instructed by Boeing. If no cracking is found, repeat the inspections at the intervals given in Paragraph 1.E., Compliance, or to terminate repeat inspections install the preventive modification in accordance with this service bulletin or contact Boeing for preventive modification instructions and do the work instructed by Boeing, as applicable. **Group 4:** At the upper and lower forward and aft corners of the forward galley service doorway where no Boeing approved repair is installed that covers the corner radius fasteners, do an external LFEC inspection for cracking in the skin and bearstrap at the corner radius fasteners. Do an external detailed inspection for cracking in the skin and do an internal detailed inspection for cracking in the skin and bearstrap. If any crack is found contact Boeing for repair instructions and do the work instructed by Boeing. If no cracking is found, repeat the inspections at the intervals given in Paragraph 1.E., Compliance, or to terminate repeat inspections contact Boeing for preventive modification instructions and do the work instructed by Boeing. **Group 5:** Contact Boeing to get instructions for the inspections and repairs for this service bulletin 737-53A1116, Revision 4, and do the work instructed by Boeing.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 28 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**Revision 4 - More work is necessary on airplane(s) inspected or changed in accordance with the original issue, Revision 1, 2 or 3 of this service bulletin. Airplanes that have installed the preventive modification in accordance with original issue, Revision 1, 2 or 3 of this service bulletin, require follow-on inspection. Airplanes that have installed a repair at the upper forward corner in accordance with original issue, Revision 1, 2, or 3 require follow-on inspection. All airplanes require new inspections at the forward galley service doorway lower corners. **NOTE:**This service bulletin is listed in Boeing Document D6-38505. The work in this service bulletin is done in the maintenance zone(s) given below. **Group 1:**

**Affected Maintenance Zones Zone**  **Model** 1-6 737-200, 737-200C **Group 2:**

**Affected Maintenance Zones Zone**  **Model** 106 737-300, 737-400 **Group 3:**

**Affected Maintenance Zones Zone**  **Model** 106 737-300, 737-400, 737-500 **Group 4:**

**Affected Maintenance Zones Zone**  **Model** 1-6 737-200 **Group 5:**

**Affected Maintenance Zones Zone**  **Model** 1-6 737-100, 737-200, 737-200C **E. Compliance** Federal Aviation Administration (FAA) Airworthiness Directives AD 2008-08-23, AD 2008-09-13, AD 90-06-02 and AD 98-11-04 R1 are related to this service bulletin.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 29 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**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. **Group 5:** Contact Boeing to get instructions for the inspections and repairs for this service bulletin 737-53A1116, Revision 4, and do the work instructed by Boeing within 120 days of the issue date of this service bulletin. **Group 1: Table 1: Forward Galley Service Doorway Upper Aft Corner Inspection**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition (a)**  4,500 flight cycles. Within 4,500flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles.Do an external Low Frequency Eddy Current (LFEC) inspection of the skin and bearstrap for any crack in accordance with Paragraph 3.B., Work Instructions, step 2.a.(1).Airplanes that have not accomplished the preventive modification or the repair in accordance with the original issue, Revision 1,2 or 3 of this service bulletin.

Do an external detailed inspection of the skin for any crack in accordance with Paragraph 3.B., Work Instructions, step 2.a.(1). 18,000 flight cycles. Within 4,500flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles. Do an internal detailed inspection of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 2.a.(1).

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 30 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group 1:**  **Table 1: Forward Galley Service Doorway Upper Aft Corner Inspection Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition (a)** 4,500 flight cycles. Within 4,500flight cycles after the Revision 4 date of this service bulletin. Within 35,000flight cycles after the installation of the preventive modification.Do an external LFEC inspection of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 2.a.(1).Airplanes that have accomplished the preventive modification in accordancewith the original issue, Revision 1, 2 or 3 of this service bulletin. Do an external detailed inspection of the skin for any crack in accordance with Paragraph 3.B., Work Instructions, step 2.a.(1) 18,000 flight cycles. Within 9,000flight cycles after the Revision 4 date of this service bulletin. Within 35,000flight cycles after the installation of the preventive modification. Do an internal detailed inspection of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 2.a.(1).

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

(a) Accomplishment of a repair in accordance with the original issue or Revision 1, 2 or 3 of this service bulletin terminates the requirement for repeat inspections as given in Table 1 for the repaired doorway corner. Post repair inspections are provided in Table 11.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 31 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group 2:**  **Table 2: Forward Galley Service Doorway Upper Aft Corner Inspection Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition (b)** 4,500 flight cycles. (a) Within 4,500flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles.Do an external LFEC inspection of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 2.b.(1).Airplanes that have not accomplished the preventive modification or the repair in accordance with the original issue, Revision 1,2 or 3 of this service bulletin. Do an external detailed inspection of the skin for any crack in accordance with Paragraph 3.B., Work Instructions, step 2.b.(1). 18,000 flight cycles. (a) Within 4,500flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles. Do an internal detailed inspection of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 2.b.(1).

- Before further flight. Do the repair in accor- dance with Paragraph 3.B., Work Instructions, step 2.b.(1)(a). If any crack is found in the skin or bearstrap.

(a) 4,500 flight cycles. Within 4,500flight cycles after the Revision 4 date of this service bulletin. Within 35,000flight cycles after the installation of the preventive modification.Do an external LFEC inspection of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 2.b.(2).Airplanes that have accomplished the preventive modification in accordancewith the original issue, Revision 1, 2 or 3 of this service bulletin. Do an external detailed inspection of the skin for any crack in accordance with Paragraph 3.B., Work Instructions, step 2.b.(2). 18,000 flight cycles. Within 9,000flight cycles after the Revision 4 date of this service bulletin. Within 35,000flight cycles after the installation of the preventive modification. Do an internal detailed inspection of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 2.b.(2).

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 32 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group 2:**  **Table 2: Forward Galley Service Doorway Upper Aft Corner Inspection Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition (b)**

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

(a) Accomplishment of a repair or preventive modification in accordance with Revision 4 of this service bulletin terminates the requirement for repeat inspections as given in Table 2 for the repaired or preventive modified doorway corner. Post repair and post preventive modification inspections are provided in the applicable SRM. (b) Accomplishment of a repair in accordance with the original issue or Revision 1, 2 or 3 of this service bulletin terminates the requirement for repeat inspections as given in Table 2 for the repaired doorway corner. Post repair inspections are provided in Table 11. **Group 3: Table 3: Forward Galley Service Doorway Upper Aft Corner Inspection**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition**  4,500 flight cycles. (a) Within 4,500flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles.Do an external LFEC inspection of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 2.c.(1). All airplanes

Do an external detailed inspection of the skin for any crack in accordance with Paragraph 3.B., Work Instructions, step 2.c.(1). 18,000 flight cycles. (a) Within 4,500flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles. Do an internal detailed inspection of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 2.c.(1).

- Before further flight. Do the repair in accor- dance with Paragraph 3.B., Work Instructions, step 2.c.(1)(a). If any crack is found in the skin or bearstrap.

(a)

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 33 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group 3:**  **Table 3: Forward Galley Service Doorway Upper Aft Corner Inspection Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition** (a) Accomplishment of a repair or preventive modification in accordance with Revision 4 of this service bulletin terminates the requirement for repeat inspections as given in Table 3 for the repaired or preventive modified doorway corner. Post repair and post preventive modification inspections are provided in the applicable SRM. **Group 4: Table 4: Forward Galley Service Doorway Upper Aft Corner Inspection**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition**  4,500 flight cycles. Within 4,500flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles.Do an external LFEC inspection of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 2.d.(1). All airplanes

Do an external detailed inspection of the skin for any crack in accordance with Paragraph 3.B., Work Instructions, step 2.d.(1). 18,000 flight cycles. Within 4,500flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles. Do an internal detailed inspection of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 2.d.(1).

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

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 34 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group 1-2:**  **Table 5: Forward Galley Service Doorway Upper Forward Corner Inspection Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition** 4,500 flight cycles. Within 4,500flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles.Do an external LFEC inspection of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 3.a.Airplanes that have not accomplished the preventive modification or installed a repair at the upper forward corner in accordance with original issue, Revision 1,2 or 3 of this service bulletin. Do an external detailed inspection of the skin for any crack in accordance with Paragraph 3.B., Work Instructions, step 3.a. 18,000 flight cycles. Within 4,500flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles. Do an internal detailed inspection of all visible surfaces of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 3.b. 4,500 flight cycles. Within 4,500flight cycles after the Revision 4 date of this service bulletin. Within 35,000flight cycles after the installation of the preventive modification.Do an external LFEC inspection of the skin and bearstrap in accordance with Paragraph 3.B., Work Instructions, step 3.a.Airplanes that have accomplished the preventive modification in accordancewith original issue, Revision 1, 2 or 3 of this service bulletin. Do an external detailed inspection of the skin for any crack in accordance with Paragraph 3.B., Work Instructions, step 3.a. 18,000 flight cycles. Within 9,000flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles. Do an internal detailed inspection of all visible surfaces of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 3.b.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 35 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group 1-2:**  **Table 5: Forward Galley Service Doorway Upper Forward Corner Inspection Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition**

No further action is required per this service bulletin in the repaired area.Airplanes with a repair installed that meets the requirements of the Accomplishment Instructions, Paragraph 3.A.14. of this service bulletin. 18,000 flight cycles. Within 9,000flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles. Do an internal detailed inspection of all visible surfaces of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 3.b.Airplanes with a Boeing repair approved by FAA 8100-9 form installed at the upper forward corner thatdoes not meet the requirements as given in the Accomplishment Instructions Paragraph 3.A.14. (a)

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

(a) In addition, post repair inspections are provided in the D6-38669 Repair Assessment Guidelines document.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 36 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group 3-4:**  **Table 6: Forward Galley Service Doorway Upper Forward Corner Inspection Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition** 4,500 flight cycles. Within 4,500flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles.Do an external LFEC inspection of the skin and bearstrap in accordance with Paragraph 3.B., Work Instructions, step 3.a.Airplanes that have not installed a repair at the upper forward corner.

Do an external detailed inspection of the skin for any crack in accordance with Paragraph 3.B., Work Instructions, step 3.a. 18,000 flight cycles. Within 4,500flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles. Do an internal detailed inspection of all visible surfaces of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 3.b.No further action is required per this service bulletin in the repaired area.Airplanes with a repair installed that meets the requirements of the Accomplishment Instructions, Paragraph 3.A.14. of this service bulletin. 18,000 flight cycles. Within 9,000flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles. Do an internal detailed inspection of all visible surfaces of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 3.b.Airplanes with a Boeing repair approved by FAA 8100-9 form installed at the upper forward corner thatdoes not meet the requirements as given in the Accomplishment Instructions Paragraph 3.A.14. (a)

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

(a) In addition, post repair inspections are provided in the D6-38669 Repair Assessment Guidelines document.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 37 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group 1, 4:**  **Table 7: Forward Galley Service Doorway Lower Aft Corner Inspection Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition** 4,500 flight cycles. Within 4,500flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles.Do an external LFEC inspection for cracking in the skin and bearstrap inaccordance with Paragraph 3.B., Work Instructions, step 4.a.(1). All airplanes

Do an external detailed inspection of the skin for any crack in accordance with Paragraph 3.B., Work Instructions, step 4.a.(1). 18,000 flight cycles. Within 4,500flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles. Do an internal detailed inspection of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 4.a.(1).

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

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 38 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group 2-3:**  **Table 8: Forward Galley Service Doorway Lower Aft Corner Inspection Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition** 4,500 flight cycles. (a) Within 4,500flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles.Do an external LFEC inspection of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 4.b.(1). All airplanes

Do an external detailed inspection of the skin for any crack in accordance with Paragraph 3.B., Work Instructions, step 4.b.(1). 18,000 flight cycles. (a) Within 4,500flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles. Do an internal detailed inspection of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 4.b.(1).

- Before further flight. Do the repair in accor- dance with Paragraph 3.B., Work Instructions, step .4.b.(1)(a) If any crack is found in the skin or bearstrap.

(a) (a) Accomplishment of a repair or preventive modification in accordance with Revision 4 of this service bulletin terminates the requirement for repeat inspections as given in Table 8 for the repaired or preventive modified doorway corner. Post repair and post preventive modification inspections are provided in the applicable SRM.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 39 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group 1, 4:**  **Table 9: Forward Galley Service Doorway Lower Forward Corner Inspection Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition** 4,500 flight cycles. Within 4,500flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles.Do an external LFEC inspection of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 5.a.(1). All airplanes.

Do an external detailed inspection of the skin for any crack in accordance with Paragraph 3.B., Work Instructions, step 5.a.(1). 18,000 flight cycles. Within 4,500flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles. Do an internal detailed inspection of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 5.a.(1).

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

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 40 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT Group 2-3:**  **Table 10: Forward Galley Service Doorway Lower Forward Corner Inspection Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition** 4,500 flight cycles. (a) Within 4,500flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles.Do an external LFEC inspection of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 5.b.(1). All airplanes.

Do an external detailed inspection of the skin for any crack in accordance with Paragraph 3.B., Work Instructions, step 5.b.(1). 18,000 flight cycles. (a) Within 4,500flight cycles after the Revision 4 date of this service bulletin. Before 35,000total flight cycles. Do an internal detailed inspection of the skin and bearstrap for any crack inaccordance with Paragraph 3.B., Work Instructions, step 5.b.(1).

- Before further flight. Do the repair in accor- dance with Paragraph 3.B., Work Instructions, step 5.b.(1)(a). If any crack is found in the skin or bearstrap.

(a) (a) Accomplishment of a repair or preventive modification in accordance with Revision 4 of this service bulletin terminates the requirement for repeat inspections as given in Table 10 for the repaired or preventive modified doorway corner. Post repair and post preventive modification inspections are provided in the applicable SRM. **Group 1-2: Table 11: Inspection of Fuselage Skin Assembly and Bearstrap for Airplanes With a Boeing Drawing**  **65C33800 Repair Installed in Accordance With the Original Issue or Revision 1, 2 or 3 of This Service Bulletin.**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition**  Repeat the inspection at interval in accordance with the RAG. Within 12,000flight cycles after the repair was installed. Before 60,000total flight cycles.Do the inspection in accordance with the Repair Assessment Guidelines (RAG) D6-38669.Airplanes that have installed a Boeing drawing65C33800 repair in accordance with the Original Issue or Revision 1, 2 or 3 of this Service Bulletin.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 41 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT 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. The Manager of the FAA Seattle Aircraft Certification Office (ACO) approves accomplishment of the applicable inspections, repairs, and modifications, with the corresponding compliance times, provided in Section 1.E, Compliance, of this service bulletin, Revision 4, as an alternative method of compliance (AMOC) to the requirements of paragraph A of Airworthiness Directive (AD) 90-06-02. The modification in accordance with SB 737-53A1116, Figure 3 is no longer required. This AMOC applies only to the modification specified in Boeing document D6-38505 for SB 737-53A1116. All provisions of AD 90-06-02 that are not specifically referenced above remain fully applicable and must be complied with accordingly. For Boeing Model 737-100/200 series airplanes, the Manager of the FAA Seattle ACO approves the supplemental inspection methods, thresholds and repeat intervals as given in the Repair Assessment Guidelines D6-38669 for the repair defined in the applicable tables of Paragraph 1.E., Compliance, of this Service Bulletin, Revision 4 as an method of compliance (MOC) to the inspections of Structurally Significant Item (SSI) F-15A required by paragraph (g), of AD 98-11-04 R1. This approval applies to this SSI and only for the portions of the bear strap and skin that have been repaired in accordance with this SB. If operators choose this MOC, then they must revise their FAA-approved maintenance or inspection program to incorporate these alternative inspections. All provisions of AD 98-11-04 R1 that are not specifically referenced above remain fully applicable and must be complied with accordingly. In addition, for Boeing Model 737-200C series airplanes, the Manager of the FAA Seattle ACO approves the inspection methods, thresholds, repeat intervals, as given in the Repair Assessment Guidelines D6-38669 for the repairs defined in the applicable tables of Paragraph 1.E., Compliance, of Boeing Alert Service Bulletin 737-53A1116, Revision 4 as an AMOC to the inspections of SSI F-15A required by paragraphs (g) and (h) of AD 2008-08-23. This approval applies to this SSI and only for the portions of the bearstrap and skin that have been repaired in accordance with this service bulletin. If operators choose this AMOC, then they must revise their FAA-approved maintenance or inspection program to incorporate these alternative inspections. All provisions of AD 2008-08-23 that are not specifically referenced above remain fully applicable and must be complied with accordingly. In addition, for Boeing Model 737-300/-400/-500 series airplanes, the Manager of the FAA Seattle ACO approves the inspection methods, thresholds, repeat intervals as given in the Repair Assessment Guidelines D6-38669 for the repairs defined in the applicable tables of Paragraph 1.E., Compliance, of Boeing Alert Service Bulletin 737-53A11116, Revision 4 as an AMOC to the inspections of SSI F-15A as required by paragraphs (g) and (h) of AD 2008-09-13. This approval applies to this SSI and only for the portions of the bearstrap and frame chord that have been repaired in accordance with this service bulletin. If operators choose this AMOC, then they must revise their FAA-approved maintenance or inspection program to incorporate these alternative inspections. All provisions of AD 2008-09-13 that are not specifically referenced above remain fully applicable and must be complied with accordingly.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 42 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT 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: • 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**  1.00 1.00 1 Open Access 2.20 4.40 2 FIGURE 4 2.25 4.50 2 FIGURE 5 3.70 3.70 1 FIGURE 6 3.70 3.70 1 FIGURE 7 1.00 1.00 1 Close Access 13.85 18.30 TOTAL FOR EACH AIRPLANE **H. Weight and Balance Changes** None. **I. Electrical Load Data** Not changed. **J. References** 1. Existing Data: a. Boeing Service Bulletin 737-53-1074 b. Boeing Service Letter 737-SL-51-042 c. Boeing Service Related Problem (SRP) 737-SRP-53-0380 d. Federal Aviation Administration (FAA) Airworthiness Directive (AD) 2008-08-23, 2008-09-13, 2008-11-04, 90-06-02, 98-11-04 R1 e. Service Bulletin Index D6-19567 f. 737 Fleet Team Digest (FTD) 53-11003

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 43 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**g. 737 Non-Destructive Testing (NDT) Manual Part 6, 51-00-26 h. 737-300 Structural Repair Manual (SRM) 53-10-01 i. 737-400 Structural Repair Manual (SRM) 53-10-01 j. 737-500 Structural Repair Manual (SRM) 53-10-01 k. Boeing Document D6-38505, "Aging Airplane Service Bulletin Structural Modification and Inspection Program - Model 737-100/-200/-200C" 2. Data Supplied with this Service Bulletin: None. 3. Installation Drawings Used in the Preparation of this Service Bulletin: None. **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: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 44 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT 2. MATERIAL INFORMATION**  **A. Material - Price and Availability** None. **B. Industry Support Information** Boeing warranty remedies are not available for the inspection, and/or repair procedures given in this service bulletin. **C. Parts Necessary for Each Airplane** 1. Kits/Parts 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: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 45 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 46 of 64 **BOEING SERVICE BULLETIN 737-53A1116 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. 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.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 47 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**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. 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. 11. 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. 12. 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. 13. If a Boeing external doubler corner repair approved by FAA 8100-9 form is installed common to the door corner radius fasteners of the upper aft corner, lower aft corner or lower forward corner, then the inspections given in this service bulletin are not required for the repaired area. Post repair inspections are provided in the FAA 8100-9 form approving the repair. 14. If a Boeing repair approved by FAA 8100-9 form is installed at the upper forward doorway corner, inspections as given in this service bulletin for the upper forward corner are not required in the repair area if the repair meets the following requirements: – The repair doubler covers the doorway upper forward corner and the upper hinge cutout. – The repair has been approved as an Alternative Method of Compliance (AMOC) to AD 2008-11-04. Post repair inspections are provided in the FAA 8100-9 form approving the repair. 15. If the external detailed inspection area is hidden by an existing non-corner Boeing repair approved by FAA 8100-9 form, the external detailed inspection of the skin is not required common to the hidden area. External detailed inspection is still required in the area not hidden by the repair. **B. WORK INSTRUCTIONS Group 5:**  Contact Boeing to get instructions for the inspections and repairs for this service bulletin 737-53A1116, Revision 4, and do the work instructed by Boeing.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 48 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**1. Part 1: Access a. Open the forward galley door for access to interior surface of door cutout to accomplish inspection and rework of doorway upper and lower corners.

2.**Group 1-4:** Part 2: Forward Galley Service Doorway Upper Aft Corner Inspection

a.**Group 1:** (1) Do an external LFEC inspection, an internal detailed inspection of the skin and bearstrap and an external detailed inspection of the skin for any crack at the upper aft corner of the forward galley service doorway in accordance with FIGURE 4. (a) If any crack is found, contact Boeing for repair instructions and do the work instructed by Boeing. (b) If no cracking is found, do the repeat inspections at the interval given in Paragraph 1.E., Compliance. b.**Group 2:** (1) Airplanes that have not accomplished the preventive modification or the repair in accordance with the original issue, Revision 1, 2 or 3 of this service bulletin, do an external LFEC inspection, an internal detailed inspection of the skin and bearstrap and an external detailed inspection of the skin for any crack at the upper aft corner of the forward galley service doorway in accordance with FIGURE 4. (a) If any crack is found in the skin or bearstrap, do the repair in accordance with applicable 737-300 SRM 53-10-01 Repair 16 or 737-400 SRM 53-10-01 Repair 16. **NOTE:**1. Installation of 737-300 SRM 53-10-01 Repair 16 or 737-400 SRM 53-10-01 Repair 16 terminates repeat inspection requirements of this service bulletin for the upper aft corner. 2. Post repair inspections are provided in the applicable SRM. (b) If no cracking is found, do the repeat inspections at the interval given in Paragraph 1.E., Compliance or do the preventive modification in accordance with applicable 737-300 SRM 53-10-01 Repair 16 or 737-400 SRM 53-10-01 Repair 16. **NOTE:**1. Installation of the preventive modification in accordance with 737-300 SRM 53-10-01 Repair 16 or 737-400 SRM 53-10-01 Repair 16 terminates repeat inspection requirements of this service bulletin for the upper aft corner. 2. Post preventive modification inspections are provided in the applicable SRM.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 49 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**(2) Airplanes that have accomplished the preventive modification in accordance with the original issue, Revision 1, 2 or 3 of this service bulletin, do an external LFEC inspection, an internal detailed inspection of the skin and bearstrap and an external detailed inspection of the skin for any crack at the upper aft corner of the forward galley service doorway in accordance with FIGURE 4. (a) If any crack is found contact Boeing for repair instructions and do the work instructed by Boeing. (b) If no cracking is found, do the repeat inspections at the interval given in Paragraph 1.E., Compliance.

c.**Group 3:** (1) Do an external LFEC inspection, an internal detailed inspection of the skin and bearstrap and an external detailed inspection of the skin for any crack at the upper aft corner of the forward galley service doorway in accordance with FIGURE 4. (a) If any crack is found in the skin or bearstrap, do the repair in accordance with applicable 737-300 SRM 53-10-01 Repair 16, 737-400 SRM 53-10-01 Repair 16 or 737-500 SRM 53-10-01 Repair 16. **NOTE:**1. Installation of 737-300 SRM 53-10-01 Repair 16, 737-400 SRM 53-10-01 Repair 16 or 737-500 SRM 53-10-01 Repair 16 terminates repeat inspection requirements of this service bulletin for the upper aft corner. 2. Post repair inspections are provided in the applicable SRM. (b) If no cracking is found, do the repeat inspections at the interval given in Paragraph 1.E., Compliance or do the preventive modification in accordance with applicable 737-300 SRM 53-10-01 Repair 16, 737-400 SRM 53-10-01 Repair 16 or 737-500 SRM 53-10-01 Repair 16. **NOTE:**1. Installation of the preventive modification in accordance with 737-300 SRM 53-10-01 Repair 16, 737-400 SRM 53-10-01 Repair 16 or 737-500 SRM 53-10-01 Repair 16 terminates repeat inspection requirements of this service bulletin for the upper aft corner. 2. Post preventive modification inspections are provided in the applicable SRM. d.**Group 4:** (1) Do an external LFEC inspection, an internal detailed inspection of the skin and bearstrap and an external detailed inspection of the skin for any crack at the upper aft corner of the forward galley service doorway in accordance with FIGURE 4. (a) If any crack is found in the skin or bearstrap, contact Boeing for repair instructions and do the work instructed by Boeing.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 50 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**(b) If no cracking is found, do the repeat inspections at the interval given in Paragraph 1.E., Compliance.
3.**Group 1-4:** Part 3: Forward Galley Service Doorway Upper Forward Corner Inspection a. Do an external LFEC inspection of the skin and bearstrap and an external detailed inspection of the skin for any crack at the upper forward corner of the forward galley service doorway in accordance with FIGURE 5. (1) If any crack is found in the skin or bearstrap, contact Boeing for repair instructions and do the work instructed by Boeing. (2) If no cracking is found, do the repeat inspections at the interval given in Paragraph 1.E., Compliance. b. Do an internal detailed inspection of all visible surfaces of the skin and bearstrap for any crack at the upper forward corner of the forward galley service doorway in accordance with FIGURE 5. (1) If any crack is found in the skin or bearstrap, contact Boeing for repair instructions and do the work instructed by Boeing. (2) If no cracking is found, do the repeat inspections at the interval given in Paragraph 1.E., Compliance.

4.**Group 1-4:** Part 4: Forward Galley Service Doorway Lower Aft Corner Inspection

a.**Group 1, 4:** (1) Do an external LFEC inspection, an internal detailed inspection of the skin and bearstrap and an external detailed inspection of the skin for any crack at the lower aft corner of the forward galley service doorway in accordance with FIGURE 6. (a) If any crack is found in the skin or bearstrap, contact Boeing for repair instructions and do the work instructed by Boeing. (b) If no cracking is found, do the repeat inspections at the interval given in Paragraph 1.E., Compliance. b.**Group 2-3:** (1) Do an external LFEC inspection, an internal detailed inspection of the skin and bearstrap and an external detailed inspection of the skin for any crack at the lower aft corner of the forward galley service doorway in accordance with FIGURE 6. (a) If any crack is found in the skin or bearstrap, do the repair in accordance with applicable 737-300 SRM 53-10-01 Repair 19, Repair 20, 737-400 SRM 53-10-01 Repair 19, Repair 20, 737-500 SRM 53-10-01 Repair 19, Repair 20.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 51 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT NOTE:** 1. For aircraft line numbers 1001 thru 1922, Boeing recommends installing applicable 737-300 SRM 53-10-01 Repair 20, 737-400 SRM 53-10-01 Repair 20 or 737-500 SRM 53-10-01 Repair 20 if existing repairs do not prevent the installation of this SRM repair. 2. Installation of the 737-300 SRM 53-10-01 Repair 19, 737-400 SRM 53-10-01 Repair 19, or 737-500 SRM 53-10-01 Repair 19 terminates repeat inspection requirements of this service bulletin for the lower aft corner. 3. Installation of the 737-300 SRM 53-10-01 Repair 20, 737-400 SRM 53-10-01 Repair 20 or 737-500 SRM 53-10-01 Repair 20 terminates repeat inspection requirements of this service bulletin for the lower aft and forward corner. 4. Post repair inspections are provided in the applicable SRM. (b) If no cracking is found, do the repeat inspections at the interval given in Paragraph 1.E., Compliance or do the preventive modification in accordance with applicable 737-300 SRM 53-10-01 Repair 19, Repair 20, 737-400 SRM 53-10-01 Repair 19, Repair 20, or 737-500 SRM 53-10-01 Repair 19, Repair 20. **NOTE:**1. Installation of the preventive modification in accordance with 737-300 SRM 53-10-01 Repair 19, 737-400 SRM 53-10-01 Repair 19, or 737-500 SRM 53-10-01 Repair 19 terminates repeat inspection requirements of this service bulletin for the lower aft corner. 2. Installation of the preventive modification in accordance with 737-300 SRM 53-10-01 Repair 20, 737-400 SRM 53-10-01 Repair 20 or 737-500 SRM 53-10-01 Repair 20 terminates repeat inspection requirements of this service bulletin for the lower aft and forward corner. 3. Post preventive modification inspections are provided in the applicable SRM.

5.**Group 1-4:** Part 5: Forward Galley Service Doorway Lower Forward Corner Inspection

a.**Group 1, 4:** (1) Do an external LFEC inspection, an internal detailed inspection of the skin and bearstrap and an external detailed inspection of the skin for any crack at the lower forward corner of the forward galley service doorway in accordance with FIGURE 7. (a) If any crack is found in the skin or bearstrap, contact Boeing for repair instructions and do the work instructed by Boeing. (b) If no cracking is found, do the repeat inspections at the interval given in Paragraph 1.E., Compliance.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 52 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**b.**Group 2-3:** (1) Do an external LFEC inspection, an internal detailed inspection of the skin and bearstrap and an external detailed inspection of the skin for any crack at the lower forward corner of the forward galley service doorway in accordance with FIGURE 7. (a) If any crack is found in the skin or bearstrap, do the repair in accordance with applicable 737-300 SRM 53-10-01 Repair 18, Repair 20, 737-400 SRM 53-10-01 Repair 18, Repair 20, 737-500 SRM 53-10-01 Repair 18, Repair 20. **NOTE:**1. For aircraft line numbers 1001 thru 1922, Boeing recommends installing applicable 737-300 SRM 53-10-01 Repair 20, 737-400 SRM 53-10-01 Repair 20 or 737-500 SRM 53-10-01 Repair 20 if existing repairs do not prevent the installation of this SRM repair. 2. Installation of the 737-300 SRM 53-10-01 Repair 18, 737-400 SRM 53-10-01 Repair 18, or 737-500 SRM 53-10-01 Repair 18 terminates repeat inspection requirements of this service bulletin for the lower forward corner. 3. Installation of the 737-300 SRM 53-10-01 Repair 20, 737-400 SRM 53-10-01 Repair 20 or 737-500 SRM 53-10-01 Repair 20 terminates repeat inspection requirements of this service bulletin for the lower aft and forward corner. 4. Post repair inspections are provided in the applicable SRM. (b) If no cracking is found, do the repeat inspections at the interval given in Paragraph 1.E., Compliance or do the preventive modification in accordance with applicable 737-300 SRM 53-10-01 Repair 18, Repair 20, 737-400 SRM 53-10-01 Repair 18, Repair 20, or 737-500 SRM 53-10-01 Repair 18, Repair 20. **NOTE:**1. Installation of the preventive modification in accordance with 737-300 SRM 53-10-01 Repair 18, 737-400 SRM 53-10-01 Repair 18, or 737-500 SRM 53-10-01 Repair 18 terminates repeat inspection requirements of this service bulletin for the lower forward corner. 2. Installation of the preventive modification in accordance with 737-300 SRM 53-10-01 Repair 20, 737-400 SRM 53-10-01 Repair 20 or 737-500 SRM 53-10-01 Repair 20 terminates repeat inspection requirements of this service bulletin for the lower aft and forward corner. 3. Post preventive modification inspections are provided in the applicable SRM. 6. Part 6: Close Access a. Refinish the rework area around doorway as required, and put the airplane back to a serviceable condition.

Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4: September 30, 2013 53 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT FIGURE 1: THIS FIGURE IS DELETED**  **(SHEET 1 OF 1)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4 September 30, 2013 54 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT FIGURE 2: THIS FIGURE IS DELETED**  **(SHEET 1 OF 1)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4 September 30, 2013 55 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT FIGURE 3: THIS FIGURE IS DELETED**  **(SHEET 1 OF 1)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4 September 30, 2013 56 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT FIGURE 4: FORWARD GALLEY SERVICE DOORWAY - UPPER AFT CORNER INSPECTION**  **(SHEET 1 OF 2)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4 September 30, 2013 57 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**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)

- - Skin and Bearstrap Inspect 1 (b)

- - Skin Inspect 2 (c)

- - Skin and Bearstrap Inspect 3 (a) Do an external Low Frequency Eddy Current (LFEC) inspection for any crack in the skin and bearstrap around the corner fasteners in accordance with 737 NDT Manual Part 6, 51-00-26. (b) Do an external detailed inspection for any crack in the skin. (c) Do an internal detailed inspection for any crack in the skin and bearstrap.

**FIGURE 4: FORWARD GALLEY SERVICE DOORWAY - UPPER AFT CORNER INSPECTION (SHEET 2 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4 September 30, 2013 58 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT FIGURE 5: FORWARD GALLEY SERVICE DOORWAY - UPPER FORWARD CORNER INSPECTION**  **(SHEET 1 OF 2)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4 September 30, 2013 59 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**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)

- - Skin and Bearstrap Inspect 1 (b)

- - Skin Inspect 2 (c)

- - Skin and Bearstrap Inspect 3 (a) Do an external Low Frequency Eddy Current (LFEC) inspection for any crack in the skin and bearstrap around the corner fasteners in accordance with 737 NDT Manual Part 6, 51-00-26. (b) Do an external detailed inspection for any crack in the skin. (c) Do an internal detailed inspection for any crack in the skin and bearstrap.

**FIGURE 5: FORWARD GALLEY SERVICE DOORWAY - UPPER FORWARD CORNER INSPECTION (SHEET 2 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4 September 30, 2013 60 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT FIGURE 6: FORWARD GALLEY SERVICE DOORWAY - LOWER AFT CORNER INSPECTION**  **(SHEET 1 OF 2)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4 September 30, 2013 61 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**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)

- - Skin and Bearstrap Inspect 1 (b)

- - Skin Inspect 2 (c)

- - Skin and Bearstrap Inspect 3 (a) Do an external Low Frequency Eddy Current (LFEC) inspection for any crack in the skin and bearstrap around the corner fasteners in accordance with 737 NDT Manual Part 6, 51-00-26. (b) Do an external detailed inspection for any crack in the skin. (c) Do an internal detailed inspection for any crack in the skin and bearstrap.

**FIGURE 6: FORWARD GALLEY SERVICE DOORWAY - LOWER AFT CORNER INSPECTION (SHEET 2 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4 September 30, 2013 62 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT FIGURE 7: FORWARD GALLEY SERVICE DOORWAY - LOWER FORWARD CORNER INSPECTION**  **(SHEET 1 OF 2)**
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4 September 30, 2013 63 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**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)

- - Skin and Bearstrap Inspect 1 (b)

- - Skin Inspect 2 (c)

- - Skin and Bearstrap Inspect 3 (a) Do an external Low Frequency Eddy Current (LFEC) inspection for any crack in the skin and bearstrap around the corner fasteners in accordance with 737 NDT Manual Part 6, 51-00-26. (b) Do an external detailed inspection for any crack in the skin. (c) Do an internal detailed inspection for any crack in the skin and bearstrap.

**FIGURE 7: FORWARD GALLEY SERVICE DOORWAY - LOWER FORWARD CORNER INSPECTION (SHEET 2 OF 2)** 
Export Controlled ECCN: 9E991 - BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: July 21, 1988 737-53A1116 Revision 4 September 30, 2013 64 of 64 **BOEING SERVICE BULLETIN 737-53A1116 ALERT**  **ALERT**