### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Number: 737-52A1167**  Original Issue: December 01, 2011 ATA System: 5280 **SUBJECT:**DOORS - Landing Gear Doors - Inboard Main Landing Gear Door Hinge Fittings - Inspection and Replacement Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15 CFR 730-774). An export license may be required before it is used for development, production or use by foreign persons from specific countries. The controller of this data has the individual responsibility to abide by all export laws.9E991 ECCN: 

## BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2011 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter. Boeing also claims copyright in this document as a compilation and/or collective work. This document includes proprietary information owned by The Boeing Company and/or one or more third parties. Treatment of the document and the information it contains is governed by contract with Boeing. For more information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124. Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner, BBJ, DC-8, DC-9, DC-10, KC-10, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8A, Poseidon and the Boeing livery are all trademarks owned by The Boeing Company; and no trademark license is granted in connection with this document unless provided in writing by Boeing.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 1 of 59 4.0BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 2 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT**

BLANK PAGE**Table of Contents** Summary...................................................... 5 1. PLANNING INFORMATION........................................ 9 A. Effectivity................................................ 9 1. Airplanes............................................. 9 2. Spares Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 B. Concurrent Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 C. Reason. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 D. Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 F. Approval. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 G. Manpower. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 I. Electrical Load Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 J. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 1. Existing Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 2. Data supplied with this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 3. Installation Drawings Used in the Preparation of this Service Bulletin. . . . . . . . . . . . 26 K. Publications Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 L. Interchangeability and Intermixability of Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . 26 2. MATERIAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 B. Industry Support Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 C. Parts Necessary For Each Airplane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 1. Kits/Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 2. Parts and Materials Supplied by the Operator. . . . . . . . . . . . . . . . . . . . . . . . 29 3. Parts Modified and Reidentified. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 4. Parts Removed and Not Replaced. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 30 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 A. GENERAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 FIGURE 1: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - INSPECTION - LEFT SIDE. . . . 34 FIGURE 2: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - INSPECTION - RIGHT SIDE . . . 37 FIGURE 3: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - LEFT SIDE . . 40 FIGURE 4: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - RIGHT SIDE . 50

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 3 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 4 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Summary**  **Number: 737-52A1167** Original Issue: December 01, 2011 ATA System: 5280 **SUBJECT:**DOORS - Landing Gear Doors - Inboard Main Landing Gear Door Hinge Fittings - Inspection and Replacement THIS BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN IN PARAGRAPH 1.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OPERATOR. IF APPLICABLE SPARES HAVE BEEN SOLD, SEND THIS SERVICE BULLETIN TO THE NEW OWNER. **CONCURRENT REQUIREMENTS** None. **BACKGROUND** This service bulletin gives instructions to inspect the inboard main landing gear (MLG) door hinge fittings for any cracks. Undetected cracks in the inboard MLG door hinge fittings can lead to hinge fitting failures, which can cause departure of the inboard MLG door assemblies to occur. The inboard MLG door assembly departure may impact and damage control surfaces, which could lead to reduced controllability of the airplane. One operator reported an inboard MLG door assembly departure on a 737-700 airplane with 24,114 flight cycles. This was the first reported instance of inboard MLG door assembly departure that Boeing has received on this particular model. Boeing has conducted an analysis on the inboard MLG door assembly and found that the cracks in the inboard MLG door hinge fittings are caused by fatigue due to vibration when the landing gears are deployed. The analysis confirmed that the premature fatigue failure of the inboard MLG door hinge fittings resulted in the departure of the inboard MLG door assembly. A new and improved inboard MLG door hinge fitting has been designed to have a better durability. Production incorporation of the new and improved inboard MLG door hinge fitting affects airplanes line number 3829 and on. This service bulletin gives instructions to inspect the existing inboard MLG door hinge fittings for any cracks. Boeing Service Related Problem (SRP) 737NG-SRP-52-0097 is related to this service bulletin.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 5 of 59**ACTION (PRR 38275-176S)** Install safety equipment for the access of the MLG door. Do a detailed inspection or surface high frequency eddy current (HFEC) inspection of the inboard MLG door hinge fittings. If no crack is found, repeat the inspection or do the modification of the inboard MLG door hinge fitting assemblies as a preventative modification. If any crack is found, do the modification of the inboard MLG door hinge fitting assemblies. The modification installs new and improved inboard MLG door hinge fitting assemblies and terminates the repeat inspection requirements of this service bulletin. Put the airplane back to a serviceable condition. **EFFECTIVITY** 737-600/-700/-700C/-800/-900/-900ER airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes. **COMPLIANCE** The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. Refer to Paragraph 1.E., Compliance. **INDUSTRY SUPPORT INFORMATION** Boeing warranty remedies are available for 737 airplanes in warranty as of July 6, 2010. Please refer to Paragraph 2.B., Industry Support Information. **MANPOWER Elapsed Hours**  **Total Task Hours Airplanes**  6.50 12.00 All airplanes(a) (a) More time is needed if the MLG door adjustment is needed.
**MATERIAL INFORMATION** Boeing Supplied Kits/Parts. Operator Supplied Parts/Materials. Refer to Paragraph 2.A., Material - Price and Availability.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 6 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 7 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 8 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Number: 737-52A1167**  Original Issue: December 01, 2011 ATA System: 5280 **SUBJECT:**DOORS - Landing Gear Doors - Inboard Main Landing Gear Door Hinge Fittings - Inspection and Replacement 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

**DESCRIPTION CONFIGURATION**  **GROUP** 737-600/-700/-700C/-800/-900/-900ER airplanes line number 1 through 3828. - 1

Airplane Models: 737-600, 737-700, 737-700C, 737-800, 737-900, 737-900ER **Group Variable Number** 1 YA001 - YA099 1 YA101 - YA199 1 YA201 - YA211 1 YA221 1 YA231 - YA242 1 YA251 - YA256 1 YA271 - YA272 1 YA291 1 YA301 - YA302

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 9 of 59**Group Variable Number** 1 YA311 - YA314 1 YA321 - YA323 1 YA336 - YA345 1 YA351 1 YA356 - YA357 1 YA366 - YA367 1 YA371 - YA377 1 YA501 - YA536 1 YA541 - YA552 1 YA571 - YA578 1 YA601 - YA615 1 YA621 - YA622 1 YA626 - YA631 1 YA635 - YA636 1 YA641 - YA642 1 YA645 - YA650 1 YA656 - YA659 1 YA666 - YA667 1 YA671 - YA672 1 YA681 - YA691 1 YA701 - YA710 1 YA721 - YA722 1 YA731 - YA734 1 YA751 - YA756 1 YA801 - YA803 1 YA809 1 YA811 - YA814 1 YA831 - YA835 1 YA841 - YA862 1 YA881 - YA882 1 YA891 - YA892 1 YA961 - YA978 1 YB001 - YB006

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 10 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT Group**  **Variable Number**1 YB101 - YB132 1 YB151 - YB153 1 YB156 - YB158 1 YB161 - YB164 1 YB171 - YB172 1 YB181 - YB184 1 YB201 - YB208 1 YB271 1 YB276 1 YB301 - YB310 1 YB371 - YB392 1 YB501 - YB502 1 YB521 - YB526 1 YB541 - YB544 1 YB551 1 YB561 - YB598 1 YB601 - YB635 1 YB651 1 YB656 1 YB671 - YB672 1 YB851 - YB863 1 YB871 - YB874 1 YB881 - YB893 1 YB901 - YB903 1 YB911 1 YB961 - YB975 1 YB981 1 YB986 - YB998 1 YC001 - YC030 1 YC051 - YC084 1 YC091 - YC095 1 YC101 - YC104 1 YC111 - YC113

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 11 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT Group**  **Variable Number**1 YC121 1 YC126 - YC127 1 YC136 - YC141 1 YC146 - YC147 1 YC151 - YC156 1 YC166 - YC171 1 YC176 - YC179 1 YC186 - YC190 1 YC201 - YC203 1 YC206 - YC207 1 YC301 - YC305 1 YC321 - YC387 1 YC391 - YC394 1 YC396 1 YC401 - YC417 1 YC421 - YC422 1 YC426 - YC428 1 YC436 - YC439 1 YC441 - YC448 1 YC451 - YC455 1 YC459 1 YC461 - YC467 1 YC471 - YC499 1 YC501 - YC526 1 YC571 - YC583 1 YC587 - YC589 1 YC591 - YC593 1 YC601 - YC655 1 YC681 - YC696 1 YC701 - YC715 1 YC720 - YC725 1 YC727 - YC752 1 YC761 - YC770

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 12 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT Group**  **Variable Number**1 YC781 - YC793 1 YC801 - YC892 1 YC901 - YC907 1 YC921 - YC922 1 YC931 - YC932 1 YC941 - YC951 1 YC971 - YC978 1 YC981 - YC983 1 YD001 - YD007 1 YD021 - YD025 1 YD041 - YD057 1 YD081 - YD084 1 YD101 - YD117 1 YD121 - YD126 1 YD151 - YD159 1 YD171 - YD172 1 YD201 - YD203 1 YD206 - YD209 1 YD216 - YD219 1 YD251 - YD254 1 YD256 - YD257 1 YD261 1 YD301 - YD334 1 YD391 1 YD401 - YD410 1 YD412 - YD417 1 YD481 - YD485 1 YD491 - YD499 1 YD501 - YD512 1 YD531 - YD535 1 YD541 - YD547 1 YD561 - YD564 1 YD571 - YD572

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 13 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT Group**  **Variable Number**1 YD591 - YD595 1 YD601 - YD612 1 YD651 - YD655 1 YE001 - YE020 1 YE051 1 YE101 - YE109 1 YE151 - YE157 1 YE171 - YE172 1 YE201 - YE206 1 YE301 - YE305 1 YE321 - YE326 1 YE371 - YE383 1 YF001 - YF011 1 YF021 - YF049 1 YF051 - YF067 1 YF086 - YF087 1 YF106 - YF107 1 YF111 - YF114 1 YF116 - YF119 1 YF121 - YF131 1 YF176 - YF178 1 YF191 - YF192 1 YF201 - YF276 1 YF401 - YF402 1 YF431 - YF432 1 YF436 - YF437 1 YF441 - YF442 1 YF451 - YF460 1 YF501 - YF599 1 YF601 - YF632 1 YF701 - YF707 1 YF801 - YF805 1 YF831 - YF832

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 14 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT Group**  **Variable Number**1 YF836 - YF838 1 YF901 - YF905 1 YF921 - YF928 1 YF951 - YF954 1 YG001 - YG044 1 YG061 - YG064 1 YG066 - YG089 1 YG091 - YG099 1 YG101 - YG104 1 YG111 - YG114 1 YG116 - YG133 1 YG201 - YG205 1 YG211 - YG214 1 YG221 - YG224 1 YG251 - YG252 1 YG501 - YG512 1 YG601 - YG602 1 YG701 1 YG711 1 YH001 - YH012 1 YH031 - YH055 1 YH071 - YH080 1 YH101 - YH132 1 YH201 - YH202 1 YH206 - YH207 1 YH301 - YH306 1 YH321 - YH322 1 YH501 - YH510 1 YH551 1 YH601 - YH602 1 YH611 - YH612 1 YH631 1 YJ001 - YJ013

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 15 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT Group**  **Variable Number**1 YJ021 1 YJ471 - YJ480 1 YJ501 - YJ517 1 YJ531 - YJ579 1 YJ591 - YJ599 1 YJ631 - YJ632 1 YJ671 - YJ694 1 YJ801 - YJ867 1 YJ871 - YJ880 1 YJ901 - YJ904 1 YJ908 - YJ929 1 YJ931 - YJ937 1 YJ941 - YJ956 1 YJ961 1 YJ976 - YJ977 1 YK001 - YK007 1 YK101 - YK104 1 YK111 - YK112 1 YK121 - YK122 1 YK131 - YK133 1 YK136 - YK139 1 YK141 - YK142 1 YK146 - YK148 1 YK151 - YK154 1 YK161 - YK167 1 YK171 1 YK176 - YK177 1 YK186 1 YK191 1 YK196 1 YK201 - YK202 1 YK301 - YK314 1 YK321 - YK340

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 16 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT Group**  **Variable Number**1 YK361 - YK378 1 YK401 - YK406 1 YK426 - YK427 1 YK431 - YK450 1 YK456 - YK467 1 YK471 - YK473 1 YK476 1 YK480 - YK487 1 YK491 - YK492 1 YK495 - YK498 1 YK511 - YK516 1 YK521 - YK530 1 YK551 - YK571 1 YK576 - YK577 1 YK580 - YK585 1 YK601 - YK602 1 YK606 - YK607 1 YK611 - YK616 1 YK621 - YK634 1 YK641 - YK644 1 YK651 - YK665 1 YK671 - YK672 1 YK676 - YK677 1 YK681 - YK686 1 YK691 1 YK701 - YK713 1 YK716 - YK719 1 YK721 - YK741 1 YK751 - YK770 1 YK776 - YK778 1 YK781 - YK785 1 YK791 - YK792 1 YK796 - YK797

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 17 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT Group**  **Variable Number**1 YK801 - YK899 1 YK901 - YK912 1 YK918 - YK919 1 YK921 - YK929 1 YK941 - YK998 1 YL001 - YL005 1 YL011 - YL016 1 YL021 - YL024 1 YL051 - YL052 1 YL056 - YL057 1 YL061 1 YL066 - YL069 1 YL076 - YL077 1 YL101 - YL137 1 YL201 - YL230 1 YL241 - YL242 1 YL271 - YL272 1 YL281 - YL284 1 YL301 - YL303 1 YL311 - YL314 1 YL316 - YL321 1 YL351 - YL353 1 YL371 - YL374 1 YL401 1 YL421 - YL429 1 YL431 - YL444 1 YL461 - YL478 1 YL501 - YL509 1 YL531 - YL534 1 YL541 - YL551 1 YL561 - YL579 1 YL591 - YL598 1 YL601 - YL606

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 18 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT Group**  **Variable Number**1 YL611 - YL612 1 YL616 - YL617 1 YL621 1 YL626 1 YL631 - YL634 1 YL636 - YL637 1 YL661 - YL664 1 YL676 - YL691 1 YL696 - YL697 1 YL701 - YL707 1 YL731 1 YL751 - YL752 1 YL756 - YL757 1 YL761 - YL780 1 YL796 - YL797 1 YL801 - YL815 1 YL901 - YL910 1 YL921 - YL940 1 YL951 - YL968 1 YM101 - YM1031 YM201 - YM2441 YM251 - YM2991 YM301 - YM3991 YM401 - YM4131 YM471 1 YM481 - YM4841 YM501 - YM5151 YM521 - YM522 1 YM541 1 YM551 - YM5531 YM571 - YM572 1 YM581 - YM582 1 YM591 - YM599

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 19 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT Group**  **Variable Number**1 YM631 - YM6341 YM641 - YM652 1 YM671 - YM6741 YM691 - YM6991 YM701 - YM7101 YM761 - YM7651 YM771 - YM7791 YN001 - YN016 1 YN021 - YN024 1 YN061 1 YN071 - YN082 1 YN091 - YN092 1 YN101 - YN112 1 YN121 1 YN201 - YN202 1 YN211 - YN219 1 YN231 - YN236 1 YN261 1 YN501 1 YN531 - YN534 1 YN551 1 YN601 1 YN701 - YN702 1 YQ001 - YQ003 1 YQ011 - YQ019 1 YQ026 - YQ029 1 YQ036 - YQ044 1 YQ201 - YQ202 1 YQ231 1 YQ241 - YQ251 1 YQ281 1 YQ291 - YQ296 1 YQ301 - YQ302

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 20 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT Group**  **Variable Number**1 YQ401 - YQ403 1 YQ451 - YQ454 1 YR001 - YR013 1 YR051 - YR056 1 YR101 - YR102 1 YR111 - YR116 1 YR126 - YR129 1 YR141 - YR142 1 YR166 - YR172 1 YR201 - YR204 1 YR231 - YR245 1 YR271 - YR278 1 YR286 1 YR291 - YR294 1 YR296 - YR297 1 YR301 - YR311 1 YR361 - YR362 1 YR381 1 YR401 - YR405 1 YR421 - YR422 1 YR431 1 YR451 - YR453 1 YR501 - YR503 1 YR511 - YR512 1 YR516 - YR518 1 YR526 1 YR601 - YR605 1 YR616 - YR617 1 YR651 - YR652 1 YR656 1 YR701 - YR712 1 YR801 - YR805 1 YR851 - YR853

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 21 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT Group**  **Variable Number**1 YR951 1 YS001 1 YS051 - YS052 2. Spares Affected None. **B. Concurrent Requirements** None. **C. Reason** This service bulletin gives instructions to inspect the inboard main landing gear (MLG) door hinge fittings for any cracks. Undetected cracks in the inboard MLG door hinge fittings can lead to hinge fitting failures, which can cause departure of the inboard MLG door assemblies to occur. The inboard MLG door assembly departure may impact and damage control surfaces, which could lead to reduced controllability of the airplane. One operator reported an inboard MLG door assembly departure on a 737-700 airplane with 24,114 flight cycles. This was the first reported instance of inboard MLG door assembly departure that Boeing has received on this particular model. Boeing has conducted an analysis on the inboard MLG door assembly and found that the cracks in the inboard MLG door hinge fittings are caused by fatigue due to vibration when the landing gears are deployed. The analysis confirmed that the premature fatigue failure of the inboard MLG door hinge fittings resulted in the departure of the inboard MLG door assembly. A new and improved inboard MLG door hinge fitting has been designed to have a better durability. Production incorporation of the new and improved inboard MLG door hinge fitting affects airplanes line number 3829 and on. This service bulletin gives instructions to inspect the existing inboard MLG door hinge fittings for any cracks. Boeing Service Related Problem (SRP) 737NG-SRP-52-0097 is related to this service bulletin. **D. Description** Install safety equipment for the access of the MLG door. Do a detailed inspection or surface high frequency eddy current (HFEC) inspection of the inboard MLG door hinge fittings. If no crack is found, repeat the inspection or do the modification of the inboard MLG door hinge fitting assemblies as a preventative modification. If any crack is found, do the modification of the inboard MLG door hinge fitting assemblies. The modification installs new and improved inboard MLG door hinge fitting assemblies and terminates the repeat inspection requirements of this service bulletin. Put the airplane back to a serviceable condition. The work in this service bulletin is done in the maintenance zone(s) given below.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 22 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT Affected Maintenance Zones** **Zone Model**  732, 733, 742, 743 737-600, 737-700, 737-700C, 737-800, 737-900, 737-900ER **E. Compliance** The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. For airplanes which have incorporated Boeing Business Jet (BBJ) Lower Cabin Altitude Supplemental Type Certificate (STC) ST01697SE (6500 feet maximum cabin altitude in lieu of 8000 feet) as referenced in Boeing Service Bulletin 737-21-1149, the airplane parts addressed in this service bulletin are not affected by those increased cabin pressures. **Table 1: Inboard MLG Door Hinge Fitting Inspection and Replacement Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition**

- Within 600 flight cycles after the original issuedate of this service bulletin. Before 10,000total flight cycles. Do a detailed inspection of the inboard MLG door hinge fittings for cracks in accordance with Part 2 inParagraph 3.B., Work Instructions, (a)Airplanes that have not replaced the inboard MLGdoor hinge fitting assemblies with part numbers 113A8341-1 and/or -2.ORDo a surface HFEC inspection of the inboard MLG door hinge fittings for cracks in accordance with Part 2 in Paragraph 3.B., Work Instructions. (a)

- Within 600 flight cycles after the original issuedate of this service bulletin. Within 10,000flight cycles after the replacement. Do a detailed inspection of the inboard MLG door hinge fittings for cracks in accordance with Part 2 inParagraph 3.B., Work Instructions, (a)Airplanes that have replaced the inboard MLGdoor hinge fitting assemblies with new fittings with part numbers 113A8341-1 and/or -2. ORDo a surface HFEC inspection of the inboard MLG door hinge fittings for cracks in accordance with Part 2 in Paragraph 3.B., Work Instructions. (a)

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 23 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT Table 1: Inboard MLG Door Hinge Fitting Inspection and Replacement**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition**  - 600 flight cyclesafter previous detailed inspection. (a) Within 600 flight cycles after the previous inspection. Do a detailed inspection of the inboard MLG door hinge fittings for cracks in accordance with Part 2 inParagraph 3.B., Work Instructions, (a) No crack is found after a detailed inspection.
- 5,500 flight cyclesafter previous surface HFEC inspection. (a) ORDo a surface HFEC inspection of the inboard MLG door hinge fittings for cracks in accordance with Part 2 in Paragraph 3.B., Work Instructions. (a) - 600 flight cyclesafter previous detailed inspection. (a) Within 5,500 flight cycles after the previous inspection. Do a detailed inspection of the inboard MLG door hinge fittings for cracks in accordance with Part 2 inParagraph 3.B., Work Instructions, (a) No crack is found after a surface HFEC inspection.
- 5,500 flight cyclesafter previous surface HFEC inspection. (a) ORDo a surface HFEC inspection of the inboard MLG door hinge fittings for cracks in accordance with Part 2 in Paragraph 3.B., Work Instructions. (a)

- Before further flight. Do the modification of the inboard MLG door hingefitting assemblies in accordance with Part 3 inParagraph 3.B., Work Instructions. (a) Any crack is found.

(a) Modification of the inboard MLG door hinge fitting assemblies in accordance with Part 3 in Paragraph 3.B., Work Instructions, terminates the inspection requirements of this service bulletin. The modification installs new and improved MLG door hinge fitting assemblies. **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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 24 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT**If an airplane has a non-Boeing modification or repair that affects a component or system also affected by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval before incorporating this service bulletin. **G. Manpower Elapsed Hours**  **Task Hours Number of Persons**  **Task** 1.00 2.00 2 Access 0.50 0.50 1 FIGURE 1 0.50 0.50 1 FIGURE 2 1.75 3.50 2 FIGURE 3 1.75 3.50 2 FIGURE 4 1.00 2.00 2 Restoration - Close Access 6.50 12.00 TOTAL FOR EACH AIRPLANE(a) (a) More time is needed if the MLG door adjustment is needed. **H. Weight and Balance Changes** None. **I. Electrical Load Data** Not changed. **J. References** 1. Existing Data a. Engineering Change Memo PRR 38275-176S b. Boeing Service Related Problem (SRP) 737NG-SRP-52-0097 c. Standard Overhaul Practices Manual (SOPM) 20-00-00, 20-41-02, 20-43-03, 20-50-11, 20-50-19 d. 737 Non-Destructive Testing (NDT) Manual Part 6, 51-00-00, Figure 4 or 23 e. 737-600/700/800/900 Aircraft Maintenance Manual (AMM) 32-00-01, 32-13-11 f. 737-600 Structural Repair Manual (SRM) 51-40-05 g. 737-700 Structural Repair Manual (SRM) 51-40-05 h. 737-700CONV Structural Repair Manual (SRM) 51-40-05 i. 737-700IGW (BBJ) Structural Repair Manual (SRM) 51-40-05

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 25 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT**j. 737-800 Structural Repair Manual (SRM) 51-40-05 k. 737-900 Structural Repair Manual (SRM) 51-40-05 l. 737-900ER Structural Repair Manual (SRM) 51-40-05 m. Airplane Flight Manual (D631A001), Appendix Configuration Deviation List (CDL) 2. Data supplied with this Service Bulletin None. 3. Installation Drawings Used in the Preparation of this Service Bulletin
**Title Drawing Number** MLG Inboard Door Assembly 113A8331 MLG Inboard Door Assembly 113A8335 Inboard MLG Door Hing Fitting Assembly 113A8341 The table above lists applicable drawings used to prepare this service bulletin. The drawings are not necessary to make the specified changes, and are not supplied with this service bulletin. The drawings may not be applicable to all airplane configurations or operators. **K. Publications Affected** 1. Publications: **Chapter-Section Publication**  32-13 737 Illustrated Parts Catalog 32-13-23 Component Maintenance 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 does not affect FCS, therefore DTIs are not necessary. **L. Interchangeability and Intermixability of Parts** Refer to Paragraph 2.C., Parts Necessary for Each Airplane, for interchangeability and intermixability information.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 26 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT 2. MATERIAL INFORMATION**  **A. Material - Price and Availability** Boeing can supply the kits shown in Paragraph 2.C., Parts Necessary for Each Airplane. Operators are encouraged to share schedule requirements with Boeing for incorporation of the service bulletin. The kits are subject to the terms and conditions of the Boeing standard purchase order acknowledgment. Prices are in United States Dollars. Terms: Net 30 days. Reference this service bulletin and submit your purchase order by one of these methods: 1. Order on-line via ATA Spec 2000 or The Boeing PART Page 2. Fax to (206) 662-7145 **REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION** 
**Unit Price as of the original issue** **date of this Ser vice Bulletin (US**  **Dollars) ROLT as of the**  **original issue date of this Ser** **vice Bulletin (Cal endar Days)**  **QTY Date**  **Name Kit Number** 

$6,550.00 175 (a) 7/27/2011 thru 10/06/2011 TOP KIT - MLG DOORINBOARD HINGE FITTING ASSEMBLY 002A0003-147 $6,550.00 175 (b) 9/28/2011 thru 11/26/2013 (a) A quantity of 15 per every two weeks is available for the dates specified. (b) A quantity of 32 per month is available for the dates specified. The operator can supply the parts and materials shown in Paragraph 2.C., Parts Necessary for Each Airplane if needed. As an alternative, operators can purchase the parts from Boeing Spares. This service bulletin does not show the Boeing price and supply data. **B. Industry Support Information** Boeing warranty remedies are available for 737 airplanes in warranty as of July 6, 2010. For task hour reimbursement for airplanes in warranty as of that date, send a warranty claim to Boeing Warranty & Product Assurance Contracts. The kits/parts for airplanes in warranty as of that date will be supplied at no charge. Send a purchase order for the kits/parts to Boeing Spares. Please refer to this service bulletin number and reference the airplane variable number(s) in your purchase order. **C. Parts Necessary For Each Airplane** 1. Kits/Parts To get the kits/parts shown below, refer to Paragraph 2.A., Material - Price and Availability.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 27 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT NOTE:** One top kit and the items shown in Paragraph 2.C.2., Parts and Materials Supplied by the Operator, are necessary for each airplane. The Top Kit is divided into Figure kits for each installation figure shown in the table below. **Figure Kit 4**  **3 Top Kit**  1 1 002A0003-147
**ALL**
**KIT 002A0003-147**

**NOTES Existing Part**  **Number Name**  **Figure**

**New Part Number 4**  **3 QTY**  (a) (b) 113A8341-2 HINGE FITTING ASSY 1 1 113A8341-10 (a) (b) 113A8341-1 HINGE FITTING ASSY 1 1 113A8341-9 (c) HEX DRIVE BOLT 2 2 BACB30NX8K10 (c) BOLT, PROTRUD- ING HD 2 2 BACB30NX8K12 (c) BOLT, PROTRUD- ING HD 1 1 BACB30NX8K22 (c) BOLT, PROTRUD- ING HD 1 1 BACB30NX8K23 (c) BOLT 2 2 BACB30NX8K27

- COLLAR 8 8 BACC30BH8

- WASHER 8 8 BACW10BP4DP (a) Discard the existing part. (b) You can use the existing part to replace the new or changed part. If you use the existing, you cancel the effect of the change given in this service bulletin. (c) If grip length shown is not available at Boeing, fasteners supplied in kits may be one grip length longer than indicated. Also, if any fasteners part numbers listed are not available or have been superseded, substitute fasteners may be supplied in kits.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 28 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT**2. Parts and Materials Supplied by the Operator
**Notes Name**  **QTY Part Number /**  **Specification** This is an optional part. Install this part as necessary. BOLT, PROTRUDING HD 4 BACB30NX8K10X This is an optional part. Install this part as necessary. BOLT, PROTRUDING HD 4 BACB30NX8K12X This is an optional part. Install this part as necessary. BOLT, PROTRUDING HD 2 BACB30NX8K22X This is an optional part. Install this part as necessary. BOLT, PROTRUDING HD 2 BACB30NX8K23X This is an optional part. Install this part as necessary. BOLT, PROTRUDING HD 2 BACB30NX8K24X This is an optional part. Install this part as necessary. BOLT, PROTRUDING HD 4 BACB30NX8K27X This is an optional part. Install this part as necessary. BOLT, PROTRUDING HD 4 BACB30NX8K28X This is an optional part. Install this part as necessary. BOLT, PROTRUDING HD 2 BACB30NX8K24 This is an optional part. Install this part as necessary. BOLT, PROTRUDING HD 4 BACB30NX8K28 This is an optional part. Install this part as necessary. WASHER, PLAIN 22 BACW10BP41DP This is an optional part. Install this part as necessary. WASHER, PLAIN 6 BACW10BP4DP (a) CHEMICAL CONVERSION COAT- ING 2 Oz ALODINE (b) PRIMER 2 Oz BMS 10-11, TYPE I (b) SEALANT 4 Oz BMS 5-95 (a) Refer to SOPM 20-43-03 for material alternatives and SOPM 20-00-00 for supplier data. (b) Refer to the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data.
3. Parts Modified and Reidentified None. 4. Parts Removed and Not Replaced None.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 29 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT D. Parts Necessary to Change Spares**  None. **E. Special Tooling - Price and Availability** None. **F. Special Tooling Necessary to do this Service Bulletin** No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 30 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT 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. 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. 8. 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. 9. 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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 31 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT**10. The use of an inspection putty on the pushrods on the inboard main landing gear (MLG) doors is recommended to make sure that there are no adjustments made to the pushrods during the removal and installation of the inboard MLG doors. **B. WORK INSTRUCTIONS Part 1 - Access**  1. Install MLG downlock pins. Refer to 737-600/700/800/900 AMM 32-00-01 as an accepted procedure. 2. Do Part 2 - Inspection. **Part 2 - Inspection** 1. Do a detailed inspection or surface high frequency eddy current (HFEC) inspection of the left side inboard MLG door hinge fittings for cracks in accordance with FIGURE 1. 2. Do a detailed inspection or surface HFEC inspection of the right side inboard MLG door hinge fittings for cracks in accordance with FIGURE 2. 3. If no crack is found, repeat the inspections at the time given in Paragraph 1.E., Compliance. **NOTE:**As an alternative, it is acceptable to do Part 3 - Modification of Inboard MLG Door Hinge Fitting Assemblies as a preventative modification. The modification of the inboard MLG door hinge fitting assemblies terminates the inspection requirements of this service bulletin. The modification installs new and improved inboard MLG door hinge fitting assemblies. 4. If any crack is found, do Part 3 - Modification of Inboard MLG Door Hinge Fitting Assemblies. **Part 3 - Modification of Inboard MLG Door Hinge Fitting Assemblies CAUTION:** BE CAREFUL NOT TO DAMAGE THE LOCKWIRES ON THE PUSHRODS OF THE INBOARD MLG DOORS. DAMAGE TO THE LOCKWIRE MAY CAUSE AN ADJUSTMENT OF THE PUSHRODS. 1. Remove the inboard MLG doors. Refer to 737-600/700/800/900 AMM 32-13-11 as an accepted procedure. **NOTE:**MLG door adjustment is necessary if the pushrods need a replacement or any adjustment is made on the existing pushrods. 2. Modify the inboard MLG door hinge fitting assemblies in accordance with FIGURE 3 and FIGURE 4. **NOTE:**The modification of the inboard MLG door hinge fitting assemblies terminates the inspection requirements of this service bulletin. The modification installs new and improved inboard MLG door hinge fitting assemblies. 3. Install the inboard MLG doors. Refer to 737-600/700/800/900 AMM 32-13-11 as an accepted procedure. 4. If no adjustment was made on the existing pushrods, MLG door adjustment is not necessary.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 32 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT**5. If any adjustment was made on the existing pushrods or the pushrods need a replacement, do the MLG door adjustment. Refer to 737-600/700/800/900 AMM 32-13-11 as an accepted procedure. **Part 4 - Restoration** 1. Remove the MLG downlock pins. Refer to 737-600/700/800/900 AMM 32-00-01 as an accepted procedure. 2. Put the airplane back to a serviceable condition.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 33 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT FIGURE 1: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - INSPECTION - LEFT SIDE**  **(SHEET 1 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 34 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT FIGURE 1: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - INSPECTION - LEFT SIDE**  **(SHEET 2 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 35 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for this figure.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  (a) (b) (c) 1 113A8341-1 HINGE FITTING AS- SEMBLY Inspect 1 (a) (b) (c) 1 113A8341-2 HINGE FITTING AS- SEMBLY Inspect 2 (a) Do a detailed inspection or surface HFEC inspection in accordance with 737 NDT Part 6, 51-00-00, Figure 4 or 23, of the inboard MLG door hinge fittings for a crack. (b) Inboard MLG door hinge fitting assembly includes inboard MLG door hinge fitting and bushings. Only the Inspection of the inboard MLG door hinge fitting is necessary. (c) Inspect the visible and accessible areas of the inboard MLG door hinge fitting. Removal of the part is not necessary.

**FIGURE 1: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - INSPECTION - LEFT SIDE (SHEET 3 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 36 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT FIGURE 2: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - INSPECTION - RIGHT SIDE**  **(SHEET 1 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 37 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT FIGURE 2: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - INSPECTION - RIGHT SIDE**  **(SHEET 2 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 38 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for this figure.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  (a) (b) (c) 1 113A8341-1 HINGE FITTING AS- SEMBLY Inspect 1 (a) (b) (c) 1 113A8341-2 HINGE FITTING AS- SEMBLY Inspect 2 (a) Do a detailed inspection or surface HFEC inspection in accordance with 737 NDT Part 6, 51-00-00, Figure 4 or 23, of the inboard MLG door hinge fittings for a crack. (b) Inboard MLG door hinge fitting assembly includes inboard MLG door hinge fitting and bushings. Only the Inspection of the inboard MLG door hinge fitting is necessary. (c) Inspect the visible and accessible areas of the inboard MLG door hinge fitting. Removal of the part is not necessary.

**FIGURE 2: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - INSPECTION - RIGHT SIDE (SHEET 3 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 39 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT FIGURE 3: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - LEFT SIDE**  **(SHEET 1 OF 10)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 40 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT FIGURE 3: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - LEFT SIDE**  **(SHEET 2 OF 10)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 41 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT FIGURE 3: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - LEFT SIDE**  **(SHEET 3 OF 10)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 42 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for this figure.
**More Data Qty**  **Identification Name**  **Task Step**  Locate the positionof the part by making an outline of the part on the inboard MLG door. The new part will be installed by aligning the partagainst the outline.(a) 1 113A8341-1 HINGE FITTING AS- SEMBLY Locate 1

Locate the positionof the part by making an outline of the part on the inboard MLG door. The new part will be installed by aligning the partagainst the outline.(a) 1 113A8341-2 HINGE FITTING AS- SEMBLY Locate

- 8
- FASTENERS Remove 2

- 1 113A8341-1 HINGE FITTING AS- SEMBLY Remove

- 1 113A8341-2 HINGE FITTING AS- SEMBLY Remove Clean any sealant on the door where the inboard MLGdoor hinge fitting assembly was removed. 1
- INBOARD MLG DOOR Clean 3

Align the new part within +/- 0.01 inch against the marked outline of the old part. 1 113A8341-9 HINGE FITTING ASSY Align 4

Use a clamping device to hold the part in place. 1 113A8341-9 HINGE FITTING ASSY Put / Hold

**FIGURE 3: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - LEFT SIDE (SHEET 4 OF 10)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 43 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT More Data**  **Qty Identification**  **Name Task**  **Step** Align the new part within +/- 0.01 inch against the marked outline of the old part. 1 113A8341-10 HINGE FITTING ASSY Align 5

Use a clamping device to hold the part in place. 1 113A8341-10 HINGE FITTING ASSY Put / Hold

Backdrill to existingdiameter at the existing fastener hole locations on the inboard MLG door. It is recommended to install temporaryfasteners as fasteners holes are drilledto avoid any movement of the part.(b) 8
- FASTENER HOLES Drill / Ream 6

- 1 113A8341-9 HINGE FITTING ASSY Remove / Keep 7

- 1 113A8341-10 HINGE FITTING ASSY Remove / Keep

- 1 113A8341-9 HINGE FITTING ASSY Clean/Deburr 8

- 1 113A8341-10 HINGE FITTING ASSY Clean/Deburr

- 1
- INBOARD MLG DOOR Clean/Deburr Apply chemical conversion coating to bare aluminum on the inboard MLGdoor hinge fitting assemblies and inboard MLG door as necessary. Refer to SOPM 20-43-03 asan accepted procedure. - ALODINE CHEMICAL CONVER- SION COATING Apply 9

Refer to SOPM 20-41-02 as an accepted procedure. - BMS 10-11, TYPE I PRIMER Apply

**FIGURE 3: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - LEFT SIDE (SHEET 5 OF 10)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 44 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT More Data**  **Qty Identification**  **Name Task**  **Step** Apply faying surface sealant between the inboard MLG doorhinge fitting assemblies and inboard MLG door. Refer to SOPM 20-50-19 asan accepted procedure. - BMS 5-95 SEALANT Apply 10

(c) 1 113A8341-9 HINGE FITTING ASSY Install (New) 11 (c) 1 113A8341-10 HINGE FITTING ASSY Install (New) 12 Apply sealant to fill the counterbores and aerodynamicallyfair to the outer surface of the inboard MLG door. Refer to SOPM 20-50-11 asan accepted procedure. - BMS 5-95 SEALANT Apply 13

(a) Making an outline of the part can be done by, but not limited to, installing temporary brackets or having a trace around the inboard MLG door hinge fitting assemblies. (b) Make sure the existing fastener hole surface meets the requirements in accordance with 737-600 SRM 51-40-05, 737-700 SRM 51-40-05, 737-700CONV SRM 51-40-05, 737-700IGW (BBJ) SRM 51-40-05, 737-800 SRM 51-40-05, 737-900 SRM 51-40-05, or 737-900ER SRM 51-40-05. If the fastener hole surface does not meet the requirements of the SRM, drill to the full size fastener holes as shown in the optional fastener table.(c) Install the part with standard diameter size fasteners or optional over size fasteners as shown in the fastener tables.

**FIGURE 3: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - LEFT SIDE (SHEET 6 OF 10)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 45 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT**The codes shown below agree with the letter shown in the upper left corner of the fastener symbols in the figure. A number in the lower right corner gives the grip length of the fastener. The QTY numbers shown below are the number of fasteners necessary for this figure.
**More Data Hole Dia**  **Qty Identification**  **Name Code**  Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.247 - 0.250 2 BACB30NX8K10 HEX DRIVE BOLT A

Install the part under the collar. - 2 BACW10BP4DP WASHER

- - 2 BACC30BH8 COLLAR Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.247 - 0.250 2 BACB30NX8K12 BOLT, PROTRUDING HD B

Install the part under the collar. - 2 BACW10BP4DP WASHER

- - 2 BACC30BH8 COLLAR Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.247 - 0.250 1 BACB30NX8K22 BOLT, PROTRUDING HD C

Install the part under the collar. - 1 BACW10BP4DP WASHER

- - 1 BACC30BH8 COLLAR

**FIGURE 3: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - LEFT SIDE (SHEET 7 OF 10)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 46 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT More Data**  **Hole Dia Qty**  **Identification Name**  **Code** Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.247 - 0.250 1 BACB30NX8K23 BOLT, PROTRUDING HD D

Install the part under the collar. - 1 BACW10BP4DP WASHER

- - 1 BACC30BH8 COLLAR Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.247 - 0.250 2 BACB30NX8K27 BOLT E

Install the part under the collar. - 2 BACW10BP4DP WASHER

- - 2 BACC30BH8 COLLAR The codes shown below are optional fasteners for each fastener symbols in the figure. The QTY numbers shown below are the number of optional fasteners necessary for this figure. It is not necessary to install all of the optional fasteners as shown in this figure.
**More Data Hole Dia**  **Qty Identification**  **Name Code**  Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.263 - 0.266 2 BACB30NX8K10X HEX DRIVE BOLT A (Op- tion 1)

Install the part under the collar. - 2 BACW10BP41DP WASHER

- - 2 BACC30BH8 COLLAR Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.263 - 0.266 2 BACB30NX8K12X BOLT, PROTRUDING HDB (Option 1)

Install the part under the collar. - 2 BACW10BP41DP WASHER

- - 2 BACC30BH8 COLLAR

**FIGURE 3: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - LEFT SIDE (SHEET 8 OF 10)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 47 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT More Data**  **Hole Dia Qty**  **Identification Name**  **Code** Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.263 - 0.266 1 BACB30NX8K22X BOLT, PROTRUDING HDC (Option 1)

Install the part under the collar. - 1 BACW10BP41DP WASHER

- - 1 BACC30BH8 COLLAR Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.263 - 0.266 1 BACB30NX8K23X BOLT, PROTRUDING HDD (Option 1)

Install the part under the collar. - 1 BACW10BP41DP WASHER

- - 1 BACC30BH8 COLLAR Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.263 - 0.266 1 BACB30NX8K24X BOLT, PROTRUDING HDD (Option 2)

Install the part under the collar. Adjust the quantity, no more than 2, for the grip length. - 2 BACW10BP41DP WASHER

- - 1 BACC30BH8 COLLAR Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.247 - 0.250 1 BACB30NX8K24 BOLT, PROTRUDING HDD (Option 3)

Install the part under the collar. Adjust the quantity, no more than 2, for the grip length. - 2 BACW10BP4DP WASHER

- - 1 BACC30BH8 COLLAR Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.263 - 0.266 2 BACB30NX8K27X BOLT E (Op- tion 1)

Install the part under the collar. - 2 BACW10BP41DP WASHER

- - 2 BACC30BH8 COLLAR

**FIGURE 3: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - LEFT SIDE (SHEET 9 OF 10)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 48 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT More Data**  **Hole Dia Qty**  **Identification Name**  **Code** Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.263 - 0.266 2 BACB30NX8K28X BOLT E (Op- tion 2)

Install the part under the collar. Adjust the quantity, no more than 2, for the grip length. - 4 BACW10BP41DP WASHER

- - 2 BACC30BH8 COLLAR Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.247 - 0.250 2 BACB30NX8K28 BOLT E (Op- tion 3)

Install the part under the collar. Adjust the quantity, no more than 2, for the grip length. - 4 BACW10BP4DP WASHER

- - 2 BACC30BH8 COLLAR

**FIGURE 3: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - LEFT SIDE (SHEET 10 OF 10)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 49 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT FIGURE 4: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - RIGHT SIDE**  **(SHEET 1 OF 10)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 50 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT FIGURE 4: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - RIGHT SIDE**  **(SHEET 2 OF 10)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 51 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT FIGURE 4: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - RIGHT SIDE**  **(SHEET 3 OF 10)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 52 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for this figure.
**More Data Qty**  **Identification Name**  **Task Step**  Locate the positionof the part by making an outline of the part on the inboard MLG door. The new part will be installed by aligning the partagainst the outline.(a) 1 113A8341-1 HINGE FITTING AS- SEMBLY Locate 1

Locate the positionof the part by making an outline of the part on the inboard MLG door. The new part will be installed by aligning the partagainst the outline.(a) 1 113A8341-2 HINGE FITTING AS- SEMBLY Locate

- 8
- FASTENERS Remove 2

- 1 113A8341-1 HINGE FITTING AS- SEMBLY Remove

- 1 113A8341-2 HINGE FITTING AS- SEMBLY Remove Clean any sealant on the door where the inboard MLGdoor hinge fitting assembly was removed. 1
- INBOARD MLG DOOR Clean 3

Align the new part within +/- 0.01 inch against the marked outline of the old part. 1 113A8341-9 HINGE FITTING ASSY Align 4

Use a clamping device to hold the part in place. 1 113A8341-9 HINGE FITTING ASSY Put / Hold

**FIGURE 4: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - RIGHT SIDE (SHEET 4 OF 10)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 53 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT More Data**  **Qty Identification**  **Name Task**  **Step** Align the new part within +/- 0.01 inch against the marked outline of the old part. 1 113A8341-10 HINGE FITTING ASSY Align 5

Use a clamping device to hold the part in place. 1 113A8341-10 HINGE FITTING ASSY Put / Hold

Backdrill to existingdiameter at the existing fastener hole locations on the inboard MLG door. It is recommended to install temporaryfasteners as fasteners holes are drilledto avoid any movement of the part.(b) 8
- FASTENER HOLES Drill / Ream 6

- 1 113A8341-9 HINGE FITTING ASSY Remove / Keep 7

- 1 113A8341-10 HINGE FITTING ASSY Remove / Keep

- 1 113A8341-9 HINGE FITTING ASSY Clean/Deburr 8

- 1 113A8341-10 HINGE FITTING ASSY Clean/Deburr

- 1
- INBOARD MLG DOOR Clean/Deburr Apply chemical conversion coating to bare aluminum on the inboard MLGdoor hinge fitting assemblies and inboard MLG door as necessary. Refer to SOPM 20-43-03 asan accepted procedure. - ALODINE CHEMICAL CONVER- SION COATING Apply 9

Refer to SOPM 20-41-02 as an accepted procedure. - BMS 10-11, TYPE I PRIMER Apply

**FIGURE 4: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - RIGHT SIDE (SHEET 5 OF 10)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 54 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT More Data**  **Qty Identification**  **Name Task**  **Step** Apply faying surface sealant between the inboard MLG doorhinge fitting assemblies and inboard MLG door. Refer to SOPM 20-50-19 asan accepted procedure. - BMS 5-95 SEALANT Apply 10

(c) 1 113A8341-9 HINGE FITTING ASSY Install (New) 11 (c) 1 113A8341-10 HINGE FITTING ASSY Install (New) 12 Apply sealant to fill the counterbores and aerodynamicallyfair to the outer surface of the inboard MLG door. Refer to SOPM 20-50-11 asan accepted procedure. - BMS 5-95 SEALANT Apply 13

(a) Making an outline of the part can be done by, but not limited to, installing temporary brackets or having a trace around the inboard MLG door hinge fitting assemblies. (b) Make sure the existing fastener hole surface meets the requirements in accordance with 737-600 SRM 51-40-05, 737-700 SRM 51-40-05, 737-700CONV SRM 51-40-05, 737-700IGW (BBJ) SRM 51-40-05, 737-800 SRM 51-40-05, 737-900 SRM 51-40-05, or 737-900ER SRM 51-40-05. If the fastener hole surface does not meet the requirements of the SRM, drill to the full size fastener holes as shown in the optional fastener table.(c) Install the part with standard diameter size fasteners or optional over size fasteners as shown in the fastener tables.

**FIGURE 4: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - RIGHT SIDE (SHEET 6 OF 10)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 55 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT**The codes shown below agree with the letter shown in the upper left corner of the fastener symbols in the figure. A number in the lower right corner gives the grip length of the fastener. The QTY numbers shown below are the number of fasteners necessary for this figure.
**More Data Hole Dia**  **Qty Identification**  **Name Code**  Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.247 - 0.250 2 BACB30NX8K10 HEX DRIVE BOLT A

Install the part under the collar. - 2 BACW10BP4DP WASHER

- - 2 BACC30BH8 COLLAR Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.247 - 0.250 2 BACB30NX8K12 BOLT, PROTRUDING HD B

Install the part under the collar. - 2 BACW10BP4DP WASHER

- - 2 BACC30BH8 COLLAR Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.247 - 0.250 1 BACB30NX8K22 BOLT, PROTRUDING HD C

Install the part under the collar. - 1 BACW10BP4DP WASHER

- - 1 BACC30BH8 COLLAR

**FIGURE 4: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - RIGHT SIDE (SHEET 7 OF 10)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 56 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT More Data**  **Hole Dia Qty**  **Identification Name**  **Code** Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.247 - 0.250 1 BACB30NX8K23 BOLT, PROTRUDING HD D

Install the part under the collar. - 1 BACW10BP4DP WASHER

- - 1 BACC30BH8 COLLAR Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.247 - 0.250 2 BACB30NX8K27 BOLT E

Install the part under the collar. - 2 BACW10BP4DP WASHER

- - 2 BACC30BH8 COLLAR The codes shown below are optional fasteners for each fastener symbols in the figure. The QTY numbers shown below are the number of optional fasteners necessary for this figure. It is not necessary to install all of the optional fasteners as shown in this figure.
**More Data Hole Dia**  **Qty Identification**  **Name Code**  Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.263 - 0.266 2 BACB30NX8K10X HEX DRIVE BOLT A (Op- tion 1)

Install the part under the collar. - 2 BACW10BP41DP WASHER

- - 2 BACC30BH8 COLLAR Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.263 - 0.266 2 BACB30NX8K12X BOLT, PROTRUDING HDB (Option 1)

Install the part under the collar. - 2 BACW10BP41DP WASHER

- - 2 BACC30BH8 COLLAR

**FIGURE 4: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - RIGHT SIDE (SHEET 8 OF 10)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 57 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT More Data**  **Hole Dia Qty**  **Identification Name**  **Code** Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.263 - 0.266 1 BACB30NX8K22X BOLT, PROTRUDING HDC (Option 1)

Install the part under the collar. - 1 BACW10BP41DP WASHER

- - 1 BACC30BH8 COLLAR Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.263 - 0.266 1 BACB30NX8K23X BOLT, PROTRUDING HDD (Option 1)

Install the part under the collar. - 1 BACW10BP41DP WASHER

- - 1 BACC30BH8 COLLAR Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.263 - 0.266 1 BACB30NX8K24X BOLT, PROTRUDING HDD (Option 2)

Install the part under the collar. Adjust the quantity, no more than 2, for the grip length. - 2 BACW10BP41DP WASHER

- - 1 BACC30BH8 COLLAR Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.247 - 0.250 1 BACB30NX8K24 BOLT, PROTRUDING HDD (Option 3)

Install the part under the collar. Adjust the quantity, no more than 2, for the grip length. - 2 BACW10BP4DP WASHER

- - 1 BACC30BH8 COLLAR Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.263 - 0.266 2 BACB30NX8K27X BOLT E (Op- tion 1)

Install the part under the collar. - 2 BACW10BP41DP WASHER

- - 2 BACC30BH8 COLLAR

**FIGURE 4: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - RIGHT SIDE (SHEET 9 OF 10)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 58 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT More Data**  **Hole Dia Qty**  **Identification Name**  **Code** Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.263 - 0.266 2 BACB30NX8K28X BOLT E (Op- tion 2)

Install the part under the collar. Adjust the quantity, no more than 2, for the grip length. - 4 BACW10BP41DP WASHER

- - 2 BACC30BH8 COLLAR Wet install with BMS 5-95 sealant. Refer to SOPM 20-50-19 as an accepted procedure. 0.247 - 0.250 2 BACB30NX8K28 BOLT E (Op- tion 3)

Install the part under the collar. Adjust the quantity, no more than 2, for the grip length. - 4 BACW10BP4DP WASHER

- - 2 BACC30BH8 COLLAR

**FIGURE 4: INBOARD MLG DOOR HINGE FITTING ASSEMBLY - MODIFICATION - RIGHT SIDE (SHEET 10 OF 10)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: December 01, 2011 737-52A1167 59 of 59 **BOEING SERVICE BULLETIN 737-52A1167 ALERT**  **ALERT**