### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Number: 737-27A1297**  Original Issue: April 16, 2010 Revision 1: August 02, 2010 ATA System: 2731 **SUBJECT:**FLIGHT CONTROLS - Elevator Tab Control Mechanism Detailed Inspection 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## BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2010 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter.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BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 1 of 68 5.0BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 2 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT**

BLANK PAGE**Table of Contents** Revision Transmittal Sheet............................................ 5 Summary...................................................... 7 1. PLANNING INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 A. Effectivity. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 1. Airplanes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2. Spares Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 B. Concurrent Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 C. Reason. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 D. Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 F. Approval. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 G. Manpower. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 I. Electrical Load Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 J. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 1. Existing Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 2. Data supplied with this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 3. Installation Drawings Used in the Preparation of this Service Bulletin. . . . . . . . . . . . 32 K. Publications Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 L. Interchangeability and Intermixability of Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . 32 2. MATERIAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 B. Industry Support Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 C. Parts Necessary For Each Airplane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 1. Kits/Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 2. Parts and Materials Supplied by the Operator. . . . . . . . . . . . . . . . . . . . . . . . 34 3. Parts Modified and Reidentified. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 4. Parts Removed and Not Replaced. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 34 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 A. GENERAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 FIGURE 1: ACCESS PANEL REMOVAL & INSTALLATION - LEFT SIDE. . . . . . . . . . . . . . . . 44 FIGURE 2: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - LEFT SIDE. . . . . . . 46 FIGURE 3: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - LEFT SIDE. . . . . . 51 FIGURE 4: ACCESS PANEL REMOVAL & INSTALLATION - RIGHT SIDE. . . . . . . . . . . . . . . 56 FIGURE 5: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - RIGHT SIDE. . . . . . 58 FIGURE 6: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - RIGHT SIDE. . . . . 63 FIGURE 7: DETERMINING IF REPLACEMENT MECHANISM IS NOT BOEING BUILT. . . . . . . . 68

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 3 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 4 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Revision Transmittal Sheet**  **Number: 737-27A1297** Original Issue: April 16, 2010 Revision 1: August 02, 2010 ATA System: 2731 **SUBJECT:**FLIGHT CONTROLS - Elevator Tab Control Mechanism Detailed Inspection This revision includes all pages of the service bulletin. **COMPLIANCE INFORMATION RELATED TO THIS REVISION** More work is necessary on airplanes inspected in accordance with the original issue of this service bulletin: Group 2 airplanes now require repeat inspections. Airplanes were added to new Group 3 of this service bulletin effectivity and airplanes were added to existing Group 2 of this service bulletin effectivity. Federal Aviation Administration (FAA) Airworthiness Directive AD 2010-09-05, is related to this service bulletin. **REASON FOR REVISION** This revision is sent to: add new Group 3 airplanes to the effectivity and add an inspection and compliance for Group 3 airplanes; add airplanes to existing Group 2 effectivity and change the compliance for Group 2 airplanes; remove the terminating action from the compliance; change the inspection method; delete Figure 7, "Determining if Replacement Mechanism is not Boeing Built" and all associated steps in the Work Instructions; provide manpower estimates; add warranty information; add convenience kit information. These sections were changed: 1. In paragraph 1.A., Effectivity, added Group 3 airplanes to the Group/Configuration table and to the effectivity. 2. In Paragraph 1.E., Compliance, changed the requirements for Group 2 airplanes, added Group 3 compliance, removed terminating action, 3. In Paragraph 1.G., Manpower, added manpower tables. 4. In Paragraph 2.B., Industry Support Information, added warranty remedies. 5. In Paragraph 2.C., Parts Necessary For Each Airplane, added convenience kit information. 6. In Figures 2, 3, 5, and 6, clarified feeler gage requirements and changed allowable depths. 7. Deleted Figure 7.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 5 of 68The data given in Information Notices 737-27A1297 IN 01, IN 02 and IN 03 is included in this revision, as applicable. 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** April 16, 2010 Original Issue: August 02, 2010 Revision 1:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 6 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT**

### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Summary**  **Number: 737-27A1297** Original Issue: April 16, 2010 Revision 1: August 02, 2010 ATA System: 2731 **SUBJECT:**FLIGHT CONTROLS - Elevator Tab Control Mechanism Detailed Inspection 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** An operator experienced a vibration event 21 days after performing inspections on the swage ring and spacer on the elevator tab control mechanism (mechanism) in accordance with Service Bulletin (SB) 737-27A1296. Investigation revealed that the vibration was most likely caused by the same conditions that Service Bulletin 737-27A1296 was meant to detect, but did not. For the most critical group of airplanes, this service bulletin does a more enhanced inspection than the inspection in SB 737-27A1296 and continues with repeat inspections. The more enhanced inspection includes using a feeler gage at specific locations to check for gaps. The inspections in this SB will detect a loose bearing in the aft attach lugs of the elevator tab control mechanism. A loose bearing in the aft attach lug of the elevator tab control mechanism could lead to unwanted elevator tab freeplay and then elevator tab vibration which could lead to structural failure of the elevator or the horizontal stabilizer. Since the initial release of this service bulletin, several operators have reported gaps in Boeing-built mechanisms, but no loose bearings. Also, additional analysis by Boeing has shown that non-Boeing built mechanisms built after Line Number 2708 may have bearings which will come loose. Because of this, the effectivity of this service bulletin is being increased to include airplanes beyond the effectivity of the initial release. Also, installing a Boeing-built mechanism is no longer terminating action to the repeat inspections. **ACTION** Remove the seal plate and lower hinge cover to gain access to the elevator tab control mechanism (mechanism) and do a detailed inspection of the aft attach lugs (lugs). Look for rotation of the spacer. Also, use a feeler gage to check for any gaps at certain locations. If there is a gap or a loose spacer, then replace the mechanism per the AMM and this SB. If there is no gap or a loose spacer, then return the airplane to a serviceable condition . Do repeat inspections of the mechanism at the times shown in paragraph 1.E., compliance.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 7 of 68**EFFECTIVITY** 737-600, -700, -700C, -800, -900, and -900ER Airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes. **COMPLIANCE** Refer to Paragraph 1.E., Compliance. Federal Aviation Administration (FAA) Airworthiness Directive AD 2010-09-05 is related to this service bulletin. **INDUSTRY SUPPORT INFORMATION** Boeing warranty remedies are available for 737 airplanes in warranty as of March 11, 2010. Please refer to Paragraph 2.B., Industry Support Information. **MANPOWER** Refer to Paragraph 1.G., Manpower. **MATERIAL INFORMATION** None.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 8 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 9 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 10 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Number: 737-27A1297**  Original Issue: April 16, 2010 Revision 1: August 02, 2010 ATA System: 2731 **SUBJECT:**FLIGHT CONTROLS - Elevator Tab Control Mechanism Detailed Inspection 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

**NOTE:**This service bulletin is for the airplanes identified below. The effectivity list shown below is complete for airplanes through line number 3554. At least one airplane after line number 3554 is also affected by this service bulletin, and these airplanes are in Group(s) 2. These airplanes will be added to the service bulletin's MyBoeingFleet.com (MBF) \"get effectivity\" result when they are added to the MBF Fleet Profile Page.
**DESCRIPTION CONFIGURATION**  **GROUP** Airplanes Line Number 2508 to 2707

- 1 Airplanes Line Number 2708 and on

- 2 Airplanes Line Number 1 to 2507

- 3

Airplane Models: 737-600, 737-700, 737-700C, 737-800, 737-900, 737-900ER **Group Variable Number** 3 YA001 - YA099 3 YA101 - YA199 3 YA201 - YA211

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 11 of 68**Group Variable Number** 3 YA221 3 YA231 - YA242 3 YA251 - YA256 3 YA271 - YA272 3 YA291 3 YA301 - YA302 3 YA311 - YA314 3 YA321 - YA323 3 YA336 - YA345 3 YA351 3 YA356 - YA357 3 YA366 - YA367 3 YA371 - YA377 3 YA501 - YA536 3 YA541 - YA552 3 YA571 - YA578 3 YA601 - YA615 3 YA621 - YA622 3 YA626 - YA631 3 YA635 - YA636 3 YA641 - YA642 3 YA645 - YA650 3 YA656 - YA659 3 YA666 - YA667 3 YA671 - YA672 3 YA681 - YA691 3 YA701 - YA710 3 YA721 - YA722 3 YA731 - YA734 3 YA751 - YA756 3 YA801 - YA803 3 YA809 3 YA811 - YA814

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 12 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT Group**  **Variable Number**3 YA831 - YA835 3 YA841 - YA862 3 YA881 - YA882 3 YA891 - YA892 3 YA961 - YA978 3 YB001 - YB006 3 YB101 - YB132 3 YB151 - YB153 3 YB156 - YB158 3 YB161 - YB164 3 YB171 - YB172 3 YB181 - YB184 3 YB201 - YB208 3 YB271 3 YB276 3 YB301 - YB310 3 YB371 - YB392 3 YB501 - YB502 3 YB521 - YB526 3 YB541 - YB544 3 YB551 3 YB561 - YB598 3 YB601 - YB632 2 YB633 - YB635 3 YB651 3 YB656 3 YB671 - YB672 3 YB851 - YB863 3 YB871 - YB874 3 YB881 - YB893 3 YB901 - YB903 3 YB911 3 YB961 - YB973

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 13 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT Group**  **Variable Number**1 YB974 2 YB975 2 YB981 1 YB986 - YB987 2 YB988 - YB996 3 YC001 - YC030 3 YC051 - YC084 3 YC091 - YC094 2 YC095 3 YC101 - YC104 3 YC111 - YC113 3 YC121 3 YC126 - YC127 3 YC136 - YC141 3 YC146 - YC147 3 YC151 - YC156 3 YC166 - YC171 3 YC176 - YC179 3 YC186 - YC190 3 YC201 - YC203 3 YC206 - YC207 3 YC301 - YC305 3 YC321 - YC387 3 YC391 - YC394 3 YC396 3 YC401 - YC417 3 YC421 - YC422 3 YC426 - YC428 3 YC436 - YC439 3 YC441 - YC448 3 YC451 - YC455 3 YC459 3 YC461 - YC467

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 14 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT Group**  **Variable Number**3 YC471 - YC499 3 YC501 - YC526 3 YC571 - YC583 3 YC587 - YC589 3 YC591 - YC593 3 YC601 - YC655 3 YC681 - YC696 3 YC701 - YC715 3 YC720 - YC725 3 YC727 - YC752 3 YC761 - YC770 3 YC781 - YC793 3 YC801 - YC892 3 YC901 - YC907 3 YC921 - YC922 3 YC931 - YC932 3 YC941 - YC951 3 YC971 - YC978 3 YC981 - YC983 3 YD001 - YD007 3 YD021 - YD025 3 YD041 - YD057 3 YD081 - YD084 3 YD101 - YD110 2 YD111 - YD113 3 YD121 - YD126 3 YD151 - YD159 3 YD171 - YD172 3 YD201 - YD203 3 YD206 - YD209 3 YD216 - YD219 3 YD251 - YD254 3 YD256 - YD257

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 15 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT Group**  **Variable Number**3 YD261 3 YD301 - YD334 3 YD391 3 YD401 - YD410 3 YD412 - YD414 1 YD415 2 YD416 - YD417 3 YD481 - YD485 3 YD491 - YD499 3 YD501 - YD512 3 YD531 - YD535 3 YD541 - YD547 3 YD561 - YD564 3 YD571 - YD572 3 YD591 - YD595 3 YD601 - YD612 3 YD651 - YD655 3 YE001 - YE020 3 YE051 3 YE101 - YE109 3 YE151 - YE157 3 YE171 - YE172 3 YE201 - YE206 3 YE301 - YE305 3 YE321 - YE326 3 YE371 - YE383 1 YF001 2 YF002 - YF011 1 YF021 - YF026 2 YF027 - YF049 1 YF051 - YF052 2 YF053 - YF065 1 YF086

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 16 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT Group**  **Variable Number**2 YF087 3 YF106 - YF107 3 YF111 2 YF112 - YF114 2 YF116 - YF119 2 YF121 - YF128 1 YF176 - YF178 2 YF191 - YF192 2 YF201 - YF276 2 YF401 - YF402 2 YF431 - YF432 2 YF441 - YF442 2 YF451 - YF460 2 YF501 - YF599 2 YF601 - YF605 2 YF701 - YF707 2 YF801 - YF803 2 YF831 - YF832 2 YF836 - YF838 2 YF901 - YF905 2 YF921 - YF927 2 YF951 3 YG001 - YG044 3 YG061 - YG064 3 YG066 - YG089 3 YG091 - YG099 3 YG101 - YG103 2 YG104 3 YG111 - YG114 3 YG116 - YG119 1 YG120 2 YG121 - YG128 3 YG201 - YG205

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 17 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT Group**  **Variable Number**3 YG211 - YG214 2 YG221 - YG224 3 YG251 - YG252 3 YG501 - YG509 2 YG510 - YG511 3 YG601 - YG602 3 YG701 1 YG711 3 YH001 - YH010 1 YH011 - YH012 2 YH031 - YH050 3 YH051 - YH052 1 YH053 - YH054 2 YH055 2 YH071 - YH078 3 YH101 - YH102 1 YH103 - YH115 2 YH116 - YH132 1 YH201 - YH202 1 YH206 - YH207 1 YH301 2 YH302 - YH306 2 YH321 - YH322 3 YJ001 - YJ008 1 YJ009 - YJ010 3 YJ011 - YJ013 3 YJ021 3 YJ471 - YJ480 3 YJ501 - YJ517 3 YJ531 - YJ559 1 YJ560 - YJ566 2 YJ567 - YJ579 3 YJ591 - YJ596

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 18 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT Group**  **Variable Number**1 YJ597 2 YJ598 - YJ599 3 YJ631 - YJ632 3 YJ671 - YJ694 3 YJ801 - YJ867 3 YJ871 - YJ873 1 YJ874 - YJ875 2 YJ876 - YJ880 3 YJ901 - YJ903 1 YJ904 1 YJ908 2 YJ909 - YJ910 3 YJ911 - YJ929 3 YJ931 - YJ937 3 YJ941 - YJ956 2 YJ961 3 YJ976 - YJ977 3 YK001 - YK007 3 YK101 - YK104 3 YK111 - YK112 3 YK121 - YK122 3 YK131 - YK132 1 YK133 3 YK136 - YK139 3 YK141 - YK142 3 YK146 - YK148 3 YK151 - YK154 3 YK161 - YK166 1 YK167 3 YK171 1 YK176 2 YK177 2 YK186

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 19 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT Group**  **Variable Number**2 YK191 2 YK196 2 YK201 - YK202 3 YK301 - YK308 1 YK309 2 YK310 - YK314 3 YK321 - YK336 1 YK337 - YK338 2 YK339 - YK340 3 YK361 - YK372 1 YK373 - YK375 2 YK376 - YK378 3 YK401 - YK406 3 YK426 - YK427 3 YK431 - YK450 3 YK456 - YK460 2 YK461 - YK467 2 YK471 - YK473 3 YK476 3 YK480 - YK485 2 YK486 - YK487 2 YK491 1 YK495 2 YK496 - YK498 3 YK511 - YK516 1 YK521 - YK523 2 YK524 - YK530 3 YK551 - YK565 1 YK566 - YK569 2 YK570 3 YK571 3 YK576 - YK577 3 YK580 - YK585

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 20 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT Group**  **Variable Number**3 YK601 - YK602 3 YK606 - YK607 3 YK611 - YK614 1 YK615 - YK616 3 YK621 - YK625 1 YK626 - YK627 2 YK628 - YK630 3 YK631 - YK634 3 YK641 - YK644 3 YK651 - YK660 1 YK661 2 YK662 - YK665 1 YK671 2 YK672 2 YK676 - YK677 2 YK681 - YK686 2 YK691 3 YK701 - YK709 1 YK710 - YK712 2 YK713 3 YK716 - YK719 3 YK721 - YK741 3 YK751 - YK756 1 YK757 - YK760 2 YK761 - YK770 2 YK776 - YK778 2 YK781 - YK785 3 YK791 - YK792 3 YK796 - YK797 3 YK801 - YK870 1 YK871 - YK887 2 YK888 - YK899 3 YK901 - YK910

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 21 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT Group**  **Variable Number**1 YK911 2 YK912 3 YK918 2 YK919 3 YK921 - YK923 1 YK924 - YK927 2 YK928 3 YK941 - YK950 1 YK951 - YK952 2 YK953 - YK959 3 YK961 - YK971 2 YK972 - YK980 3 YK981 - YK984 1 YK985 2 YK986 - YK996 3 YL001 - YL005 3 YL011 - YL016 3 YL021 - YL024 3 YL051 - YL052 3 YL056 - YL057 3 YL061 3 YL066 - YL069 3 YL076 - YL077 3 YL101 - YL109 1 YL110 - YL116 2 YL117 - YL136 3 YL201 - YL205 1 YL206 - YL209 2 YL210 - YL226 3 YL271 - YL272 3 YL281 - YL282 2 YL283 - YL284 3 YL301 - YL303

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 22 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT Group**  **Variable Number**3 YL311 - YL312 2 YL313 - YL314 1 YL316 - YL319 2 YL320 - YL321 2 YL351 - YL353 1 YL371 - YL373 2 YL374 2 YL401 3 YL421 - YL425 1 YL426 2 YL427 - YL429 3 YL431 - YL437 2 YL438 - YL444 3 YL461 - YL471 1 YL472 - YL473 2 YL474 - YL478 3 YL501 - YL503 1 YL504 - YL505 2 YL506 - YL509 3 YL531 1 YL532 - YL533 2 YL534 2 YL541 - YL544 3 YL561 1 YL562 - YL565 2 YL566 - YL569 1 YL591 - YL592 2 YL593 - YL598 3 YL601 - YL604 1 YL605 - YL606 1 YL611 2 YL612 1 YL616

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 23 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT Group**  **Variable Number**2 YL617 1 YL621 2 YL626 2 YL631 - YL634 2 YL636 - YL637 1 YL661 - YL664 2 YL676 - YL681 2 YL691 2 YL696 - YL697 2 YL701 - YL706 2 YL731 2 YL751 - YL752 2 YL756 - YL757 2 YL761 - YL779 2 YL796 - YL797 2 YL801 - YL815 3 YL901 - YL903 1 YL904 - YL907 2 YL908 - YL910 2 YL921 - YL930 3 YL931 - YL932 2 YL933 - YL940 1 YL951 - YL952 2 YL953 - YL968 3 YM101 - YM103 3 YM201 - YM231 1 YM232 - YM238 2 YM239 - YM242 3 YM251 - YM299 3 YM301 - YM353 1 YM354 - YM374 2 YM375 - YM398 3 YM471

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 24 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT Group**  **Variable Number**3 YM481 - YM484 3 YM501 - YM515 3 YM521 - YM522 3 YM541 3 YM551 - YM553 3 YM571 - YM572 3 YM581 - YM582 3 YM591 - YM593 2 YM594 - YM599 3 YM631 - YM634 3 YM641 - YM646 1 YM647 - YM651 2 YM652 3 YM671 - YM672 2 YM673 - YM674 1 YM691 - YM692 2 YM693 - YM698 1 YM701 - YM702 2 YM703 - YM710 2 YM761 - YM765 3 YN001 - YN014 1 YN015 - YN016 3 YN021 - YN023 1 YN024 3 YN061 3 YN071 - YN079 2 YN080 - YN082 3 YN091 - YN092 3 YN101 - YN112 3 YN121 3 YN201 2 YN202 3 YN211 - YN214

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 25 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT Group**  **Variable Number**1 YN215 - YN216 2 YN217 - YN219 3 YN231 1 YN232 2 YN233 - YN236 2 YN261 2 YQ001 - YQ003 2 YQ011 - YQ018 2 YQ026 - YQ027 2 YQ036 - YQ042 2 YQ201 2 YQ231 2 YQ241 - YQ242 2 YQ291 - YQ295 2 YQ401 - YQ403 2 YR001 - YR005 2 YR051 - YR053 2 YR101 2 YR111 - YR113 2 YR126 2 YR166 2 YR201 - YR203 2 YR231 - YR233 2. Spares Affected None. **B. Concurrent Requirements** None. **C. Reason** An operator experienced a vibration event 21 days after performing inspections on the swage ring and spacer on the elevator tab control mechanism (mechanism) in accordance with Service Bulletin (SB) 737-27A1296. Investigation revealed that the vibration was most likely caused by the same conditions that Service Bulletin 737-27A1296 was meant to detect, but did not. For the most critical group of airplanes, this service bulletin does a more enhanced inspection than the inspection in SB 737-27A1296

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 26 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT**and continues with repeat inspections. The more enhanced inspection includes using a feeler gage at specific locations to check for gaps. The inspections in this SB will detect a loose bearing in the aft attach lugs of the elevator tab control mechanism. A loose bearing in the aft attach lug of the elevator tab control mechanism could lead to unwanted elevator tab freeplay and then elevator tab vibration which could lead to structural failure of the elevator or the horizontal stabilizer. Since the initial release of this service bulletin, several operators have reported gaps in Boeing-built mechanisms, but no loose bearings. Also, additional analysis by Boeing has shown that non-Boeing built mechanisms built after Line Number 2708 may have bearings which will come loose. Because of this, the effectivity of this service bulletin is being increased to include airplanes beyond the effectivity of the initial release. Also, installing a Boeing-built mechanism is no longer terminating action to the repeat inspections. This revision is sent to: add new Group 3 airplanes to the effectivity and add an inspection and compliance for Group 3 airplanes; add airplanes to existing Group 2 effectivity and change the compliance for Group 2 airplanes; remove the terminating action from the compliance; change the inspection method; delete Figure 7, "Determining if Replacement Mechanism is not Boeing Built" and all associated steps in the Work Instructions; provide manpower estimates; add warranty information; add convenience kit information. The data given in Information Notices 737-27A1297 IN 01, IN 02 and IN 03 is included in this revision, as applicable. **D. Description** Remove the seal plate and lower hinge cover to gain access to the elevator tab control mechanism (mechanism) and do a detailed inspection of the aft attach lugs (lugs). Look for rotation of the spacer. Also, use a feeler gage to check for any gaps at certain locations. If there is a gap or a loose spacer, then replace the mechanism per the AMM and this SB. If there is no gap or a loose spacer, then return the airplane to a serviceable condition . Do repeat inspections of the mechanism at the times shown in paragraph 1.E., compliance. The work in this service bulletin is done in the maintenance zone(s) given below. **Group 1-2:**
**Affected Maintenance Zones Zone**  **Model** 333, 334, 343, 344 737-700, 737-700C, 737-800, 737-900ER **Group 3:**
**Affected Maintenance Zones Zone**  **Model** 333, 334, 343, 344 737-600, 737-700, 737-700C, 737-800, 737-900, 737-900ER

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 27 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT E. Compliance**  Federal Aviation Administration (FAA) Airworthiness Directive AD 2010-09-05 is related to this service bulletin. **Table 1: ELEVATOR TAB CONTROL MECHANISM INSPECTION - LEFT SIDE Repeat Interval**  **(Not to Exceed) Compliance Time (Whichever**  **Occurs Later) Action**  **Condition** 300 flight hours

- Within 30 daysafter the Revision 1 date ofthis service bulletin or within 300 flight hoursfrom the previous repeat inspection performed in accordance with the original issue ofthe service bulletin, whichever occurs later. Do a detailed inspectionof the mechanism in accordance with Step 2 ofparagraph 3.B., Work Instructions. (a) Group 1

300 flight hours Within 14 daysafter the Revision 1 date ofthis service bulletin.Within 2,000 Total Flight Cycles or 4,000 Total Flight Hours,whichever occurs first. Do a detailed inspection of the elevator tab controlmechanism in accordance with Step 2 ofparagraph 3.B., Work Instructions Group 2

1,800 flight hours.

- Within 180 days or 1,800 flight hours after the Revision 1 date of this service bulletin,whichever occurs first. Do a detailed inspection of the elevator tab controlmechanism in accordance with Step 2 ofparagraph 3.B., Work Instructions Group 3 300 flight hours ifmechanism is replaced due to afinding of a discrepant mechanism.

- Before further flight Replace the elevator tab control mechanism and do detailed inspection before and after installing it, in accordance with Step 7 of paragraph 3.B., Work Instructions All:Elevator tab control mechanism is found to be discrepant OR Replacement elevator tab control mechanism is found to be discrepant. (a) For Group 1 airplanes doing repeat inspection in accordance with the original issue of this service bulletin: It is acceptable to do the initial inspection using the inspection in the original issue of this service bulletin. However, the first repeat inspection and all following repeat inspections must use the Revision 1 inspection.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 28 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT Table 2: ELEVATOR TAB CONTROL MECHANISM INSPECTION - RIGHT SIDE**  **Repeat Interval (Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition**  300 flight hours

- Within 30 daysafter the Revision 1 date ofthis service bulletin or within 300 flight hoursfrom the previous repeat inspection performed in accordance with the original issue ofthe service bulletin, whichever occurs later. Do a detailed inspectionof the mechanism in accordance with Step 5 ofparagraph 3.B., Work Instructions. (a) Group 1

300 flight hours Within 14 daysafter the Revision 1 date ofthis service bulletin.Within 2,000 Total Flight Cycles or 4,000 Total Flight Hours,whichever occurs first. Do a detailed inspection of the elevator tab controlmechanism in accordance with Step 5 ofparagraph 3.B., Work Instructions Group 2

1,800 flight hours.

- Within 180 days or 1,800 flight hours after the Revision 1 date of this service bulletin,whichever occurs first. Do a detailed inspection of the elevator tab controlmechanism in accordance with Step 5 ofparagraph 3.B., Work Instructions Group 3 300 flight hours ifmechanism is replaced due to afinding of a discrepant mechanism.

- Before further flight Replace the elevator tab control mechanism and do detailed inspection before and after installing it, in accordance with Step 8 of paragraph 3.B., Work Instructions All:Elevator tab control mechanism is found to be discrepant OR Replacement elevator tab control mechanism is found to be discrepant. (a) For Group 1 airplanes doing repeat inspection in accordance with the original issue of this service bulletin: It is acceptable to do the initial inspection using the inspection in the original issue of this service bulletin. However, the first repeat inspection and all following repeat inspections must use the Revision 1 inspection.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 29 of 68 **BOEING SERVICE BULLETIN 737-27A1297 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. In addition, the Manager of the FAA Seattle Aircraft Certification Office approves the action (i.e. inspection or modification) defined in this service bulletin as an alternative method of compliance to the requirements of paragraph (g), (h), (m), (n), (o), (p), and (q) of AD 2010-09-05. All provisions of AD 2010-09-05 that are not specifically referenced in the above statement remain fully applicable and must be complied with. **G. Manpower** The table below shows an estimate of the task hours necessary to do this inspection for each airplane. This estimate is for direct labor only, done by an experienced crew. Adjust the estimate with operator task hour data if necessary. The estimate does not include lost time. These are some examples of lost time: • Time to adjust to the workplace • Time to schedule the work • Time to inspect the work • Time to cure the materials • Time to make the parts • Time to find the tools. **INSPECT LEFT SIDE Elapsed Hours**  **Task Hours Number of Persons**  **Task** 0.50 0.50 1 Open Access 1.00 1.00 1 Figure 1 0.75 0.75 1 Figure 2 0.75 0.75 1 Figure 3 0.50 0.50 1 Close Access 3.50 3.50 TOTAL FOR EACH AIR- PLANE
**INSPECT RIGHT SIDE Elapsed Hours**  **Task Hours Number of Persons**  **Task** 0.50 0.50 1 Open Access

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 30 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT INSPECT RIGHT SIDE**  **Elapsed Hours Task Hours**  **Number of Persons Task**  1.00 1.00 1 Figure 4 0.75 0.75 1 Figure 5 0.75 0.75 1 Figure 6 0.50 0.50 1 Close Access 3.50 3.50 TOTAL FOR EACH AIR- PLANE
**REPLACE MECHANISM LEFT SIDE** Elapsed Hours Task Hours Number of Persons Task 1.50 1.50 1 Remove Mechanism 0.75 0.75 1 Figure 2 0.75 0.75 1 Figure 3 1.50 1.50 1 Install Mechanism 1.50 1.50 1 Inspect 0.25 0.25 1 Part Mark 1.00 2.00 2 Functional Test (a) (a) 2 Flight Test 7.25 8.25 TOTAL FOR EACH AIR- PLANE (a) Flight test hours not included in estimate.
**REPLACE MECHANISM RIGHT SIDE** Elapsed Hours Task Hours Number of Persons Task 1.50 1.50 1 Remove Mechanism 0.75 0.75 1 Figure 5 0.75 0.75 1 Figure 6 1.50 1.50 1 Install Mechanism 1.50 1.50 1 Inspect 0.25 0.25 1 Part Mark 1.00 2.00 2 Functional Test (a) (a) 2 Flight Test 7.25 8.25 TOTAL FOR EACH AIR- PLANE

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 31 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT REPLACE MECHANISM RIGHT SIDE**  (a) Flight test hours not included in estimate. **H. Weight and Balance Changes** None. **I. Electrical Load Data** Not changed. **J. References** 1. Existing Data a. Boeing Service Bulletin 737-27A1296 b. Federal Aviation Administration (FAA) Airworthiness Directive 2010-09-05 c. Standard Overhaul Practices Manual (SOPM) 20-50-10 d. 737-600/700/800/900 Aircraft Maintenance Manual (AMM) 27-31-00, 27-31-34 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: None. 2. Damage Tolerance Based Structural Inspections: Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the Maintenance Program. This service bulletin 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: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 32 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT 2. MATERIAL INFORMATION**  **A. Material - Price and Availability** No kit is necessary to do this service bulletin. However, a convenience topkit is available from Boeing that contains the hardware required to install an elevator tab control mechanism on the left and right side of the airplane. Refer to paragraph 2.C., Parts Necessary For Each Airplane. The Boeing price data shown below is given for planning purposes. Supply data can be given if requested.
**Unit Price thru 31- Jul-2011**  **Name Kit Number**  $7,285.00 Kit - Elevator Tab Mechanism 002A0001-100 The kit is 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 **B. Industry Support Information** Boeing warranty remedies are available for 737 NG airplanes in warranty as of March 11, 2010. For inspection labor hours reimbursement for airplanes in warranty as of that date, send a warranty claim to Boeing Product Assurance Contracts. If the condition described in this service bulletin is found during the inspection for airplanes in warranty as of that date, send parts to Boeing in accordance with the Service Bulletin and associated FAA AD. If needed, exchange units are available for purchase through Boeing Spares. Please send claims for airplanes in warranty as of March 11, 2010, to Boeing Warranty & Product Assurance Contracts. **C. Parts Necessary For Each Airplane** 1. Kits/Parts None, however a convenience topkit is available from Boeing that contains the hardware required to install an elevator tab control mechanism on the left and right side of the airplane:
002A0001-100 KIT - ELEVATOR TAB MECHANISM QTY KIT - ELEVATOR TAB MECHANISM - HANGAR JOINT 002A0001-101 2 KIT - ELEVATOR TAB MECHANISM - LUG ATTACH JOINT 002A0001-102 2 KIT - ELEVATOR TAB MECHANISM - FWD TAB ROD ATTACH JOINT 002A0001-103 2

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 33 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT**KIT - ELEVATOR TAB MECHANISM - AFT TAB ROD ATTACH JOINT 002A0001-104 2

2. Parts and Materials Supplied by the Operator
**Notes Existing Part Number**  **Name QTY**  **Part Number / Specification** 

- 251A2430-15 or -17 Elevator Tab Control Mechanism - Left 1 251A2430-15 or - 17

- 251A2430-16 or -18 Elevator Tab Control Mechanism - Right 1 251A2430-16 or - 18
3. Parts Modified and Reidentified None. 4. Parts Removed and Not Replaced None. **D. Parts Necessary to Change Spares** None. **E. Special Tooling - Price and Availability** None. **F. Special Tooling Necessary to do this Service Bulletin** No special tools or equipment are necessary to do the change in this service bulletin. But, maintenance and overhaul tools in the manuals given in Paragraph 1.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available.

.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 34 of 68 **BOEING SERVICE BULLETIN 737-27A1297 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. The instructions identified in Paragraph 3.B., Work Instructions, and the Figure(s) give the recommended sequence of steps. The sequence of steps to do this service bulletin can be changed. 2. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 3. Obey all of the warnings and cautions given in the specified manual sections. 4. Use the approved fastener and process material substitutions in accordance with 737 SRM 51. Alternate fasteners are listed in 737 SRM 51 and Boeing Drawing 65-88700. 5. If the length of any fastener specified in this service bulletin does not meet the installation standards in 737 SRM 51, then a fastener of the same specification, or an approved substitute, with a length which meets the installation standards in 737 SRM 51 may be used. 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 access 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. 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. **B. WORK INSTRUCTIONS** 1. OPEN ACCESS - LEFT SIDE:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 35 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT**a. Remove pressure from the elevator hydraulic systems A and B. Refer to 737-600/700/800/900 AMM 27-31-00 as an accepted procedure. b. Gain access by removing the seal plate and hinge lower cover in accordance with Figure 1. c. Put the horizontal stabilizer in a neutral position: (1) Supply electrical power. Refer to 737-600/700/800/900 AMM 24-22-00 as an accepted procedure. (2) Make sure that these circuit breakers are closed: **F/O Electrical System Panel, P6-2**
**Name Number**  **Col Row**  FLIGHT CONTROL STAB TRIM CONT C00207 10 B FLIGHT CONTROL STAB TRIM ACTUATOR C00840 10 D (3) Make sure that the main cutout switch, S272 is in the NORMAL position. (4) Make sure that the STAB TRIM switch on the stab trim and cabin door panel, P8-47 is in the NORMAL position. (5) Make sure that the flaps are in the full up position. (6) Move the stabilizer to 4 units +/- .5 d. Put the elevator into a neutral position: (1) Using hand pressure, move the elevator until it is within 2 inches of the index mark mounted on the side of the tailcone. 2. DETAILED INSPECTION - LEFT SIDE: a. For the inboard aft attach lug of the elevator tab control mechanism (mechanism), use a feeler gage and finger pressure to do a detailed inspection in accordance with Figure 2 and determine if the elevator tab control mechanism is discrepant. While doing the inspection, apply inboard and outboard hand pressure to the elevator tab control mechanism in accordance with Figure 2. For the outboard aft attach lug of the elevator tab control mechanism, use a feeler gage and finger pressure to do a detailed inspection in accordance with Figure 3 and determine if the elevator tab control mechanism is discrepant. While doing the inspection, apply inboard and outboard hand pressure to the elevator tab control mechanism in accordance with Figure 3.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 36 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT**(1) Spacer: If the spacer moves or rotates, then the mechanism is discrepant (2) Swage Ring to Lug interface: Make sure that there is no gap between the swage ring and the outer face of the aft attach lug such that a 0.005 inch feeler gage can be inserted more than 0.025 inch. If there is such a gap, then then the elevator tab control mechanism is discrepant. (3) Lug to Lug interface: Make sure that there is no gap between the two nested lugs such that a 0.005 inch feeler gage can be inserted more than 0.16 inch. If there is such a gap, then the elevator tab control mechanism is discrepant. (4) Lug to Spacer interface: Make sure that there is no gap between the inner face of the aft attach lug and the spacer such that a 0.005 inch feeler gage can be inserted more than 0.16 inch. If there is such a gap, then the elevator tab control mechanism is discrepant. b. If the elevator tab control mechanism is discrepant, then replace it in accordance with Step 3.B.7. 3. CLOSE ACCESS - LEFT SIDE: a. Reinstall the hinge lower cover and the seal plate in accordance with Figure 1. b. Restore pressure to the elevator hydraulic systems A and B. Refer to 737-600/700/800/900 AMM 27-31-00 as an accepted procedure. If continuing with inspection of the right side, this step can be skipped. 4. OPEN ACCESS - RIGHT SIDE a. If not already done, remove pressure from the elevator hydraulic systems A and B. Refer to 737-600/700/800/900 AMM 27-31-00 as an accepted procedure. b. Gain access by removing the seal plate and hinge lower cover in accordance with Figure 4. c. If not already done, put the horizontal stabilizer in a neutral position: (1) Supply electrical power. Refer to 737-600/700/800/900 AMM 24-22-00 as an accepted procedure. (2) Make sure that these circuit breakers are closed: **F/O Electrical System Panel, P6-2**
**Name Number**  **Col Row**  FLIGHT CONTROL STAB TRIM CONT C00207 10 B FLIGHT CONTROL STAB TRIM ACTUATOR C00840 10 D (3) Make sure that the main cutout switch, S272 is in the NORMAL position.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 37 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT**(4) Make sure that the STAB TRIM switch on the stab trim and cabin door panel, P8-47 is in the NORMAL position. (5) Make sure that the flaps are in the full up position. (6) Move the stabilizer to 4 units +/- 0 .5 d. If not already done, put the elevator in a neutral position: (1) Using hand pressure, move the elevator until it is within 2 inches of the index mark mounted on the side of the tailcone. 5. DETAILED INSPECTION - RIGHT SIDE: a. For the inboard aft attach lug of the elevator tab control mechanism (mechanism), use a feeler gage and finger pressure to do a detailed inspection in accordance with Figure 5 and determine if the elevator tab control mechanism is discrepant. While doing the inspection, apply inboard and outboard hand pressure to the elevator tab control mechanism in accordance with Figure 5. For the outboard aft attach lug of the elevator tab control mechanism, use a feeler gage and finger pressure to do a detailed inspection in accordance with Figure 6 and determine if the elevator tab control mechanism is discrepant. While doing the inspection, apply inboard and outboard hand pressure to the elevator tab control mechanism in accordance with Figure 6. (1) Spacer: If the spacer moves or rotates, then the mechanism is discrepant (2) Swage Ring to Lug interface: Make sure that there is no gap between the swage ring and the outer face of the aft attach lug such that a 0.005 inch feeler gage can be inserted more than 0.025 inch. If there is such a gap, then then the elevator tab control mechanism is discrepant. (3) Lug to Lug interface: Make sure that there is no gap between the two nested lugs such that a 0.005 inch feeler gage can be inserted more than 0.16 inch. If there is such a gap, then the elevator tab control mechanism is discrepant. (4) Lug to Spacer interface: Make sure that there is no gap between the inner face of the aft attach lug and the spacer such that a 0.005 inch feeler gage can be inserted more than 0.16 inch. If there is such a gap, then the elevator tab control mechanism is discrepant. b. If the elevator tab control mechanism is discrepant, then replace it in accordance with Step 3.B.8. 6. CLOSE ACCESS - RIGHT SIDE a. Reinstall the hinge lower cover and the seal plate in accordance with Figure 4. b. Restore pressure to the elevator hydraulic systems A and B. Refer to 737-600/700/800/900 AMM 27-31-00 as an accepted procedure. 7. REPLACEMENT OF A MECHANISM- LEFT SIDE

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 38 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT WARNING:** WHEN INSTALLING THE PINS TO CONNECT THE ELEVATOR TAB CONTROL MECHANISM TO THE ELEVATOR, MAKE SURE YOU DON'T DAMAGE THE LUGS OR THE BEARINGS. IF A LUG OR BEARING IS DAMAGED, THEN IT COULD LEAD TO UNWANTED ELEVATOR TAB FREEPLAY AND THEN ELEVATOR TAB VIBRATION WHICH COULD LEAD TO STRUCTURAL FAILURE OF THE ELEVATOR OR THE HORIZONTAL STABILIZER. a. Gain access as required and remove the elevator tab control mechanism (mechanism). Refer to 737-600/700/800/900 AMM 27-31-34 as an accepted procedure. b. Replace the elevator tab control mechanism as follows: (1) Before you install the replacement mechanism, do the following inspection: (a) For the inboard attach lug of the elevator tab control mechanism, use a feeler gage and finger pressure to do a detailed inspection in accordance with Figure 2, except as noted below, and determine if the replacement mechanism is discrepant. For the outboard attach lug of the elevator tab control mechanism, use a feeler gage and finger pressure to do a detailed inspection in accordance with Figure 3, except as noted below, and determine if the replacement mechanism is discrepant.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 39 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT NOTE:** Figures 2 and 3 show the detailed inspection being done on an elevator tab control mechanism that is installed. If a replacement mechanism is being inspected before it is installed, then: – Do not apply force as shown in the figures or as discussed in the figure notes, – These figures will not show what the mechanic will see when doing the inspection, but this is OK. 1) Spacer: If the spacer moves or rotates, then the replacement mechanism is discrepant 2) Swage Ring to Lug interface: Make sure that there is no gap between the swage ring and the outer face of the aft attach lug such that a 0.005 inch feeler gage can be inserted more than 0.025 inch. If there is such a gap, then then the replacement mechanism is discrepant. 3) Lug to Lug interface: Make sure that there is no gap between the two nested lugs such that a 0.005 inch feeler gage can be inserted more than 0.16 inch. If there is such a gap, then the replacement mechanism is discrepant. 4) Lug to Spacer interface: Make sure that there is no gap between the inner face of the aft attach lug and the spacer such that a 0.005 inch feeler gage can be inserted more than 0.16 inch. If there is such a gap, then the replacement mechanism is discrepant. (b) If the replacement mechanism is discrepant, then it cannot be installed. (2) Install the replacement mechanism. Refer to 737-600/700/800/900 AMM 27-31-34 as an accepted procedure. (3) After you install the replacement mechanism, do a detailed inspection of the elevator tab control mechanism in accordance with Step 3.B.2. c. Close access as required. Refer to 737-600/700/800/900 AMM 27-31-34 as an accepted procedure. d. Functional tests and a manual reversion flight test of the airplane are required when an elevator tab control mechanism is replaced. Refer to 737-600/700/800/900 AMM 27-31-00 and 737-600/700/800/900 AMM 27-31-34 as an accepted procedure. 8. REPLACEMENT OF A MECHANISM - RIGHT SIDE

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 40 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT WARNING:** WHEN INSTALLING THE PINS TO CONNECT THE ELEVATOR TAB CONTROL MECHANISM TO THE ELEVATOR, MAKE SURE YOU DON'T DAMAGE THE LUGS OR THE BEARINGS. IF A LUG OR BEARING IS DAMAGED, THEN IT COULD LEAD TO UNWANTED ELEVATOR TAB FREEPLAY AND THEN ELEVATOR TAB VIBRATION WHICH COULD LEAD TO STRUCTURAL FAILURE OF THE ELEVATOR OR THE HORIZONTAL STABILIZER. a. Gain access as required and remove the elevator tab control mechanism (mechanism). Refer to 737-600/700/800/900 AMM 27-31-34 as an accepted procedure. b. Replace the elevator tab control mechanism as follows: (1) Before you install the replacement mechanism, do the following inspection: (a) For the inboard attach lug of the elevator tab control mechanism, use a feeler gage and finger pressure to do a detailed inspection in accordance with Figure 5, except as noted below, and determine if the replacement mechanism is discrepant. For the outboard attach lug of the elevator tab control mechanism, use a feeler gage and finger pressure to do a detailed inspection in accordance with Figure 6, except as noted below, and determine if the replacement mechanism is discrepant.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 41 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT NOTE:** Figures 5 and 6 show the detailed inspection being done on an elevator tab control mechanism that is installed. If a replacement mechanism is being inspected before it is installed, then: – Do not apply force as shown in the figures or as discussed in the figure notes, – These figures will not show what the mechanic will see when doing the inspection, but this is OK. 1) Spacer: If the spacer moves or rotates, then the replacement mechanism is discrepant 2) Swage Ring to Lug interface: Make sure that there is no gap between the swage ring and the outer face of the aft attach lug such that a 0.005 inch feeler gage can be inserted more than 0.025 inch. If there is such a gap, then then the replacement mechanism is discrepant. 3) Lug to Lug interface: Make sure that there is no gap between the two nested lugs such that a 0.005 inch feeler gage can be inserted more than 0.16 inch. If there is such a gap, then the replacement mechanism is discrepant. 4) Lug to Spacer interface: Make sure that there is no gap between the inner face of the aft attach lug and the spacer such that a 0.005 inch feeler gage can be inserted more than 0.16 inch. If there is such a gap, then the replacement mechanism is discrepant. (b) If the replacement mechanism is discrepant, then it cannot be installed. (2) Install the replacement mechanism. Refer to 737-600/700/800/900 AMM 27-31-34 as an accepted procedure. (3) After you install the replacement mechanism, do a detailed inspection of the elevator tab control mechanism in accordance with Step 3.B.5. c. Close access as required. Refer to 737-600/700/800/900 AMM 27-31-34 as an accepted procedure. d. Functional tests and a manual reversion flight test of the airplane are required when an elevator tab control mechanism is replaced. Refer to 737-600/700/800/900 AMM 27-31-00 and 737-600/700/800/900 AMM 27-31-34 as an accepted procedure. 9. Report all initial inspection findings to Boeing and report all discrepant mechanism findings from a repeat inspection to Boeing. Identify the airplane and give the total flight hours and flight cycles of the airplane. If there is damage, give the extent of the damage. Send your report to: BOEING COMMERCIAL AIRPLANES GROUP ATTENTION: MANAGER, AIRLINE SUPPORT Email: rse.boecom@boeing.com 10. Send all removed elevator tab control mechanisms to:

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 42 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT**Spares Distribution Center Repair Overhaul and Exchange Services, SSA 111 Boeing Commercial Airplane Group 2201 South 142nd, Door W10 Seatac, Washington USA 98168

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1: August 02, 2010 43 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT FIGURE 1: ACCESS PANEL REMOVAL & INSTALLATION - LEFT SIDE**  **(SHEET 1 OF 2)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 44 of 68 **BOEING SERVICE BULLETIN 737-27A1297 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 one side of the airplane.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  1

- seal plate Remove / Keep 1 1

- elevator hinge lower cover Remove / Keep 2

1

- elevator hinge lower cover Install (Kept) 3

1

- seal plate Install (Kept) 4

**FIGURE 1: ACCESS PANEL REMOVAL & INSTALLATION - LEFT SIDE (SHEET 2 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 45 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT FIGURE 2: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - LEFT SIDE**  **(SHEET 1 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 46 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT FIGURE 2: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - LEFT SIDE**  **(SHEET 2 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 47 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT FIGURE 2: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - LEFT SIDE**  **(SHEET 3 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 48 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT FIGURE 2: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - LEFT SIDE**  **(SHEET 4 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 49 of 68 **BOEING SERVICE BULLETIN 737-27A1297 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**  **CAUTION:**DO NOT APPLY FORCE WITH ANYTHING OTHER THAN YOUR HAND. DO NOT APPLY EXCESSIVE FORCE OR YOU MAY DAMAGE THE ELEVATOR TAB CONTROL MECHANISM LUGS OR BEARINGS. A BENT LUG OR LOOSE BEARING COULD LEAD TO UNWANTED ELEVATOR TAB FREEPLAY AND THEN TAB VIBRATION WHICH COULD LEAD TO STRUCTURAL FAILURE OF THE ELEVATOR OR THE HORIZONTAL STABILIZER.Using hand pressure, apply force tothe mechanism alternating between theinboard and outboard direction whiledoing the inspections in the following steps. The force canbe applied at any location on the mechanism, but no morethan four inches forward of the elevator front spar. - - force Apply 1

(b) 1

- spacer Inspect 2 (a) If there is sealant in the interface, do not remove it. 1

- swage ring/lug interface Inspect 3

(c) If there is sealant in the interface, do not remove it. 1

- lug/lug interface Inspect 4

(c) If there is sealant in the interface, do not remove it. 1

- lug/spacer interface Inspect 5

(a) Using a feeler gage, make sure that there is no gap between the swage ring and the outer face of the lug such that a 0.005 inch feeler gage can be inserted more than 0.025 inch. Do the inspection at a single location between the allowable outer limits defined in Detail D. Apply force to the mechanism alternating between the inboard and outboard direction as you use the feeler gage. (b) As you apply force to the mechanism alternating between the inboard and outboard direction, use finger pressure and try to rotate the spacer. (c) Using a feeler gage, Make sure that there is no gap between the two nested lugs or between the inner face of the lug and the spacer such that a 0.005 inch feeler gage can be inserted more than 0.16 inch. Do the inspection at a single location between the allowable outer limits defined in Detail D. Apply force to the mechanism alternating between the inboard and outboard direction as you use the feeler gage.

**FIGURE 2: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - LEFT SIDE (SHEET 5 OF 5)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 50 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT FIGURE 3: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - LEFT SIDE**  **(SHEET 1 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 51 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT FIGURE 3: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - LEFT SIDE**  **(SHEET 2 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 52 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT FIGURE 3: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - LEFT SIDE**  **(SHEET 3 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 53 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT FIGURE 3: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - LEFT SIDE**  **(SHEET 4 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 54 of 68 **BOEING SERVICE BULLETIN 737-27A1297 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**  **CAUTION:**DO NOT APPLY FORCE WITH ANYTHING OTHER THAN YOUR HAND. DO NOT APPLY EXCESSIVE FORCE OR YOU MAY DAMAGE THE ELEVATOR TAB CONTROL MECHANISM LUGS OR BEARINGS. A BENT LUG OR LOOSE BEARING COULD LEAD TO UNWANTED ELEVATOR TAB FREEPLAY AND THEN TAB VIBRATION WHICH COULD LEAD TO STRUCTURAL FAILURE OF THE ELEVATOR OR THE HORIZONTAL STABILIZER.Using hand pressure, apply force tothe mechanism alternating between theinboard and outboard direction whiledoing the inspections in the following steps. The force canbe applied at any location on the mechanism, but no morethan four inches forward of the elevator front spar. - - force Apply 1

(b) 1

- spacer Inspect 2 (a) If there is sealant in the interface, do not remove it. 1

- swage ring/lug interface Inspect 3

(c) If there is sealant in the interface, do not remove it. 1

- lug/lug interface Inspect 4

(c) If there is sealant in the interface, do not remove it. 1

- lug/spacer interface Inspect 5

(a) Using a feeler gage, make sure that there is no gap between the swage ring and the outer face of the lug such that a 0.005 inch feeler gage can be inserted more than 0.025 inch. Do the inspection at a single location between the allowable outer limits defined in Detail D. Apply force to the mechanism alternating between the inboard and outboard direction as you use the feeler gage. (b) As you apply force to the mechanism alternating between the inboard and outboard direction, use finger pressure and try to rotate the spacer. (c) Using a feeler gage, Make sure that there is no gap between the two nested lugs or between the inner face of the lug and the spacer such that a 0.005 inch feeler gage can be inserted more than 0.16 inch. Do the inspection at a single location between the allowable outer limits defined in Detail D. Apply force to the mechanism alternating between the inboard and outboard direction as you use the feeler gage.

**FIGURE 3: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - LEFT SIDE (SHEET 5 OF 5)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 55 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT FIGURE 4: ACCESS PANEL REMOVAL & INSTALLATION - RIGHT SIDE**  **(SHEET 1 OF 2)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 56 of 68 **BOEING SERVICE BULLETIN 737-27A1297 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 one side of the airplane.
**MORE DATA QTY**  **IDENTIFICATION NAME**  **TASK STEP**  1

- seal plate Remove / Keep 1 1

- elevator hinge lower cover Remove / Keep 2

1

- elevator hinge lower cover Install (Kept) 3

1

- seal plate Install (Kept) 4

**FIGURE 4: ACCESS PANEL REMOVAL & INSTALLATION - RIGHT SIDE (SHEET 2 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 57 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT FIGURE 5: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - RIGHT SIDE**  **(SHEET 1 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 58 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT FIGURE 5: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - RIGHT SIDE**  **(SHEET 2 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 59 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT FIGURE 5: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - RIGHT SIDE**  **(SHEET 3 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 60 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT FIGURE 5: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - RIGHT SIDE**  **(SHEET 4 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 61 of 68 **BOEING SERVICE BULLETIN 737-27A1297 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**  **CAUTION:**DO NOT APPLY FORCE WITH ANYTHING OTHER THAN YOUR HAND. DO NOT APPLY EXCESSIVE FORCE OR YOU MAY DAMAGE THE ELEVATOR TAB CONTROL MECHANISM LUGS OR BEARINGS. A BENT LUG OR LOOSE BEARING COULD LEAD TO UNWANTED ELEVATOR TAB FREEPLAY AND THEN TAB VIBRATION WHICH COULD LEAD TO STRUCTURAL FAILURE OF THE ELEVATOR OR THE HORIZONTAL STABILIZER.Using hand pressure, apply force tothe mechanism alternating between theinboard and outboard direction whiledoing the inspections in the following steps. The force canbe applied at any location on the mechanism, but no morethan four inches forward of the elevator front spar. - - force Apply 1

(b) 1

- spacer Inspect 2 (a) If there is sealant in the interface, do not remove it. 1

- swage ring/lug interface Inspect 3

(c) If there is sealant in the interface, do not remove it. 1

- lug/lug interface Inspect 4

(c) If there is sealant in the interface, do not remove it. 1

- lug/spacer interface Inspect 5

(a) Using a feeler gage, make sure that there is no gap between the swage ring and the outer face of the lug such that a 0.005 inch feeler gage can be inserted more than 0.025 inch. Do the inspection at a single location between the allowable outer limits defined in Detail D. Apply force to the mechanism alternating between the inboard and outboard direction as you use the feeler gage. (b) As you apply force to the mechanism alternating between the inboard and outboard direction, use finger pressure and try to rotate the spacer. (c) Using a feeler gage, Make sure that there is no gap between the two nested lugs or between the inner face of the lug and the spacer such that a 0.005 inch feeler gage can be inserted more than 0.16 inch. Do the inspection at a single location between the allowable outer limits defined in Detail D. Apply force to the mechanism alternating between the inboard and outboard direction as you use the feeler gage.

**FIGURE 5: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - RIGHT SIDE (SHEET 5 OF 5)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 62 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT FIGURE 6: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - RIGHT SIDE**  **(SHEET 1 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 63 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT FIGURE 6: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - RIGHT SIDE**  **(SHEET 2 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 64 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT FIGURE 6: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - RIGHT SIDE**  **(SHEET 3 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 65 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT FIGURE 6: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - RIGHT SIDE**  **(SHEET 4 OF 5)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 66 of 68 **BOEING SERVICE BULLETIN 737-27A1297 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**  **CAUTION:**DO NOT APPLY FORCE WITH ANYTHING OTHER THAN YOUR HAND. DO NOT APPLY EXCESSIVE FORCE OR YOU MAY DAMAGE THE ELEVATOR TAB CONTROL MECHANISM LUGS OR BEARINGS. A BENT LUG OR LOOSE BEARING COULD LEAD TO UNWANTED ELEVATOR TAB FREEPLAY AND THEN TAB VIBRATION WHICH COULD LEAD TO STRUCTURAL FAILURE OF THE ELEVATOR OR THE HORIZONTAL STABILIZER.Using hand pressure, apply force tothe mechanism alternating between theinboard and outboard direction whiledoing the inspections in the following steps. The force canbe applied at any location on the mechanism, but no morethan four inches forward of the elevator front spar. - - force Apply 1

(b) 1

- spacer Inspect 2 (a) If there is sealant in the interface, do not remove it. 1

- swage ring/lug interface Inspect 3

(c) If there is sealant in the interface, do not remove it. 1

- lug/lug interface Inspect 4

(c) If there is sealant in the interface, do not remove it. 1

- lug/spacer interface Inspect 5

(a) Using a feeler gage, make sure that there is no gap between the swage ring and the outer face of the lug such that a 0.005 inch feeler gage can be inserted more than 0.025 inch. Do the inspection at a single location between the allowable outer limits defined in Detail D. Apply force to the mechanism alternating between the inboard and outboard direction as you use the feeler gage. (b) As you apply force to the mechanism alternating between the inboard and outboard direction, use finger pressure and try to rotate the spacer. (c) Using a feeler gage, Make sure that there is no gap between the two nested lugs or between the inner face of the lug and the spacer such that a 0.005 inch feeler gage can be inserted more than 0.16 inch. Do the inspection at a single location between the allowable outer limits defined in Detail D. Apply force to the mechanism alternating between the inboard and outboard direction as you use the feeler gage.

**FIGURE 6: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - RIGHT SIDE (SHEET 5 OF 5)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 67 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT FIGURE 7: DETERMINING IF REPLACEMENT MECHANISM IS NOT BOEING BUILT**  **(SHEET 1 OF 1)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 16, 2010 737-27A1297 Revision 1 August 02, 2010 68 of 68 **BOEING SERVICE BULLETIN 737-27A1297 ALERT**  **ALERT**