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

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Unpublished Work - All Rights Reserved

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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

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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.

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The 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

Original Issue: April 16, 2010

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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.

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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.

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BLANK PAGE
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.

GROUP CONFIGURATION DESCRIPTION

1 - Airplanes Line Number 2508 to 2707

2 - Airplanes Line Number 2708 and on

3 - Airplanes Line Number 1 to 2507

Airplane Models:

737-600, 737-700, 737-700C, 737-800, 737-900, 737-900ER

Variable Number Group

YA001 - YA099 3

YA101 - YA199 3

YA201 - YA211 3

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Variable Number Group

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 3

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Variable Number Group

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 3

YB633 - YB635 2

YB651 3

YB656 3

YB671 - YB672 3

YB851 - YB863 3

YB871 - YB874 3

YB881 - YB893 3

YB901 - YB903 3

YB911 3

YB961 - YB973 3

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Variable Number Group

YB974 1

YB975 2

YB981 2

YB986 - YB987 1

YB988 - YB996 2

YC001 - YC030 3

YC051 - YC084 3

YC091 - YC094 3

YC095 2

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 3

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Variable Number Group

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 3

YD111 - YD113 2

YD121 - YD126 3

YD151 - YD159 3

YD171 - YD172 3

YD201 - YD203 3

YD206 - YD209 3

YD216 - YD219 3

YD251 - YD254 3

YD256 - YD257 3

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Variable Number Group

YD261 3

YD301 - YD334 3

YD391 3

YD401 - YD410 3

YD412 - YD414 3

YD415 1

YD416 - YD417 2

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 3

YF001 1

YF002 - YF011 2

YF021 - YF026 1

YF027 - YF049 2

YF051 - YF052 1

YF053 - YF065 2

YF086 1

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Variable Number Group

YF087 2

YF106 - YF107 3

YF111 3

YF112 - YF114 2

YF116 - YF119 2

YF121 - YF128 2

YF176 - YF178 1

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 2

YG001 - YG044 3

YG061 - YG064 3

YG066 - YG089 3

YG091 - YG099 3

YG101 - YG103 3

YG104 2

YG111 - YG114 3

YG116 - YG119 3

YG120 1

YG121 - YG128 2

YG201 - YG205 3

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Variable Number Group

YG211 - YG214 3

YG221 - YG224 2

YG251 - YG252 3

YG501 - YG509 3

YG510 - YG511 2

YG601 - YG602 3

YG701 3

YG711 1

YH001 - YH010 3

YH011 - YH012 1

YH031 - YH050 2

YH051 - YH052 3

YH053 - YH054 1

YH055 2

YH071 - YH078 2

YH101 - YH102 3

YH103 - YH115 1

YH116 - YH132 2

YH201 - YH202 1

YH206 - YH207 1

YH301 1

YH302 - YH306 2

YH321 - YH322 2

YJ001 - YJ008 3

YJ009 - YJ010 1

YJ011 - YJ013 3

YJ021 3

YJ471 - YJ480 3

YJ501 - YJ517 3

YJ531 - YJ559 3

YJ560 - YJ566 1

YJ567 - YJ579 2

YJ591 - YJ596 3

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Variable Number Group

YJ597 1

YJ598 - YJ599 2

YJ631 - YJ632 3

YJ671 - YJ694 3

YJ801 - YJ867 3

YJ871 - YJ873 3

YJ874 - YJ875 1

YJ876 - YJ880 2

YJ901 - YJ903 3

YJ904 1

YJ908 1

YJ909 - YJ910 2

YJ911 - YJ929 3

YJ931 - YJ937 3

YJ941 - YJ956 3

YJ961 2

YJ976 - YJ977 3

YK001 - YK007 3

YK101 - YK104 3

YK111 - YK112 3

YK121 - YK122 3

YK131 - YK132 3

YK133 1

YK136 - YK139 3

YK141 - YK142 3

YK146 - YK148 3

YK151 - YK154 3

YK161 - YK166 3

YK167 1

YK171 3

YK176 1

YK177 2

YK186 2

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Variable Number Group

YK191 2

YK196 2

YK201 - YK202 2

YK301 - YK308 3

YK309 1

YK310 - YK314 2

YK321 - YK336 3

YK337 - YK338 1

YK339 - YK340 2

YK361 - YK372 3

YK373 - YK375 1

YK376 - YK378 2

YK401 - YK406 3

YK426 - YK427 3

YK431 - YK450 3

YK456 - YK460 3

YK461 - YK467 2

YK471 - YK473 2

YK476 3

YK480 - YK485 3

YK486 - YK487 2

YK491 2

YK495 1

YK496 - YK498 2

YK511 - YK516 3

YK521 - YK523 1

YK524 - YK530 2

YK551 - YK565 3

YK566 - YK569 1

YK570 2

YK571 3

YK576 - YK577 3

YK580 - YK585 3

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Variable Number Group

YK601 - YK602 3

YK606 - YK607 3

YK611 - YK614 3

YK615 - YK616 1

YK621 - YK625 3

YK626 - YK627 1

YK628 - YK630 2

YK631 - YK634 3

YK641 - YK644 3

YK651 - YK660 3

YK661 1

YK662 - YK665 2

YK671 1

YK672 2

YK676 - YK677 2

YK681 - YK686 2

YK691 2

YK701 - YK709 3

YK710 - YK712 1

YK713 2

YK716 - YK719 3

YK721 - YK741 3

YK751 - YK756 3

YK757 - YK760 1

YK761 - YK770 2

YK776 - YK778 2

YK781 - YK785 2

YK791 - YK792 3

YK796 - YK797 3

YK801 - YK870 3

YK871 - YK887 1

YK888 - YK899 2

YK901 - YK910 3

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Variable Number Group

YK911 1

YK912 2

YK918 3

YK919 2

YK921 - YK923 3

YK924 - YK927 1

YK928 2

YK941 - YK950 3

YK951 - YK952 1

YK953 - YK959 2

YK961 - YK971 3

YK972 - YK980 2

YK981 - YK984 3

YK985 1

YK986 - YK996 2

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 3

YL110 - YL116 1

YL117 - YL136 2

YL201 - YL205 3

YL206 - YL209 1

YL210 - YL226 2

YL271 - YL272 3

YL281 - YL282 3

YL283 - YL284 2

YL301 - YL303 3

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Variable Number Group

YL311 - YL312 3

YL313 - YL314 2

YL316 - YL319 1

YL320 - YL321 2

YL351 - YL353 2

YL371 - YL373 1

YL374 2

YL401 2

YL421 - YL425 3

YL426 1

YL427 - YL429 2

YL431 - YL437 3

YL438 - YL444 2

YL461 - YL471 3

YL472 - YL473 1

YL474 - YL478 2

YL501 - YL503 3

YL504 - YL505 1

YL506 - YL509 2

YL531 3

YL532 - YL533 1

YL534 2

YL541 - YL544 2

YL561 3

YL562 - YL565 1

YL566 - YL569 2

YL591 - YL592 1

YL593 - YL598 2

YL601 - YL604 3

YL605 - YL606 1

YL611 1

YL612 2

YL616 1

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Variable Number Group

YL617 2

YL621 1

YL626 2

YL631 - YL634 2

YL636 - YL637 2

YL661 - YL664 1

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 2

YL901 - YL903 3

YL904 - YL907 1

YL908 - YL910 2

YL921 - YL930 2

YL931 - YL932 3

YL933 - YL940 2

YL951 - YL952 1

YL953 - YL968 2

YM101 - YM103 3

YM201 - YM231 3

YM232 - YM238 1

YM239 - YM242 2

YM251 - YM299 3

YM301 - YM353 3

YM354 - YM374 1

YM375 - YM398 2

YM471 3

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Variable Number Group

YM481 - YM484 3

YM501 - YM515 3

YM521 - YM522 3

YM541 3

YM551 - YM553 3

YM571 - YM572 3

YM581 - YM582 3

YM591 - YM593 3

YM594 - YM599 2

YM631 - YM634 3

YM641 - YM646 3

YM647 - YM651 1

YM652 2

YM671 - YM672 3

YM673 - YM674 2

YM691 - YM692 1

YM693 - YM698 2

YM701 - YM702 1

YM703 - YM710 2

YM761 - YM765 2

YN001 - YN014 3

YN015 - YN016 1

YN021 - YN023 3

YN024 1

YN061 3

YN071 - YN079 3

YN080 - YN082 2

YN091 - YN092 3

YN101 - YN112 3

YN121 3

YN201 3

YN202 2

YN211 - YN214 3

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Variable Number Group

YN215 - YN216 1

YN217 - YN219 2

YN231 3

YN232 1

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

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

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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

Model Zone

737-700, 737-700C, 737-800, 333, 334, 343, 344

737-900ER

Group 3:

Affected Maintenance Zones

Model Zone

737-600, 737-700, 737-700C, 333, 334, 343, 344

737-800, 737-900, 737-900ER

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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)

Condition Action

Within 30 days - 300 flight hours

after the Revision 1 date of

this service bulletin or within

300 flight hours

from the previous repeat inspection performed in accordance with the

original issue of

the service bulletin, whichever

occurs later.

Do a detailed inspection

of the mechanism in accordance with Step 2 of

paragraph 3.B., Work Instructions. (a)

Group 1

Within 14 days 300 flight hours

after the Revision 1 date of

this 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 control

mechanism in accordance with Step 2 of

paragraph 3.B., Work Instructions

Group 2

Within 180 days - 1,800 flight hours.

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 control

mechanism in accordance with Step 2 of

paragraph 3.B., Work Instructions

Group 3

300 flight hours if

mechanism is replaced due to a

finding of a discrepant mechanism.

Replace the elevator tab Before further flight -

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.

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Table 2: ELEVATOR TAB CONTROL MECHANISM INSPECTION - RIGHT SIDE

Repeat Interval

(Not to Exceed)

Compliance Time (Whichever

Occurs Later)

Condition Action

Within 30 days - 300 flight hours

after the Revision 1 date of

this service bulletin or within

300 flight hours

from the previous repeat inspection performed in accordance with the

original issue of

the service bulletin, whichever

occurs later.

Do a detailed inspection

of the mechanism in accordance with Step 5 of

paragraph 3.B., Work Instructions. (a)

Group 1

Within 14 days 300 flight hours

after the Revision 1 date of

this 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 control

mechanism in accordance with Step 5 of

paragraph 3.B., Work Instructions

Group 2

Within 180 days - 1,800 flight hours.

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 control

mechanism in accordance with Step 5 of

paragraph 3.B., Work Instructions

Group 3

300 flight hours if

mechanism is replaced due to a

finding of a discrepant mechanism.

Replace the elevator tab Before further flight -

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.

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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

Task Number of Persons Task Hours Elapsed Hours

Open Access 1 0.50 0.50

Figure 1 1 1.00 1.00

Figure 2 1 0.75 0.75

Figure 3 1 0.75 0.75

Close Access 1 0.50 0.50

TOTAL FOR EACH AIR- 3.50 3.50

PLANE

INSPECT RIGHT SIDE

Task Number of Persons Task Hours Elapsed Hours

Open Access 1 0.50 0.50

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INSPECT RIGHT SIDE

Task Number of Persons Task Hours Elapsed Hours

Figure 4 1 1.00 1.00

Figure 5 1 0.75 0.75

Figure 6 1 0.75 0.75

Close Access 1 0.50 0.50

TOTAL FOR EACH AIR- 3.50 3.50

PLANE

REPLACE MECHANISM LEFT SIDE

Task Number of Persons Task Hours Elapsed Hours

Remove Mechanism 1 1.50 1.50

Figure 2 1 0.75 0.75

Figure 3 1 0.75 0.75

Install Mechanism 1 1.50 1.50

Inspect 1 1.50 1.50

Part Mark 1 0.25 0.25

Functional Test 2 2.00 1.00

Flight Test 2 (a) (a)

TOTAL FOR EACH AIR- 8.25 7.25

PLANE

(a) Flight test hours not included in estimate.

REPLACE MECHANISM RIGHT SIDE

Task Number of Persons Task Hours Elapsed Hours

Remove Mechanism 1 1.50 1.50

Figure 5 1 0.75 0.75

Figure 6 1 0.75 0.75

Install Mechanism 1 1.50 1.50

Inspect 1 1.50 1.50

Part Mark 1 0.25 0.25

Functional Test 2 2.00 1.00

Flight Test 2 (a) (a)

TOTAL FOR EACH AIR- 8.25 7.25

PLANE

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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.

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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

Kit Number Name

002A0001-100 Kit - Elevator Tab Mechanism $7,285.00

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

2 002A0001-101 KIT - ELEVATOR TAB MECHANISM - HANGAR JOINT

2 002A0001-102 KIT - ELEVATOR TAB MECHANISM - LUG ATTACH JOINT

KIT - ELEVATOR TAB MECHANISM - FWD TAB ROD ATTACH

JOINT

2 002A0001-103

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ALERT ALERT
KIT - ELEVATOR TAB MECHANISM - AFT TAB ROD ATTACH

JOINT

2 002A0001-104

2. Parts and Materials Supplied by the Operator

Part Number / QTY Name Existing Part Number Notes

Specification

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

Left

251A2430-15 or - 1

17

Elevator Tab Control Mechanism - 251A2430-16 or -18 -

Right

251A2430-16 or - 1

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.

.

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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:

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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

Row Col Number Name

B 10 C00207 FLIGHT CONTROL STAB TRIM CONT

D 10 C00840 FLIGHT CONTROL STAB TRIM ACTUATOR

(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.

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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

Row Col Number Name

B 10 C00207 FLIGHT CONTROL STAB TRIM CONT

D 10 C00840 FLIGHT CONTROL STAB TRIM ACTUATOR

(3) Make sure that the main cutout switch, S272 is in the NORMAL position.

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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

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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.

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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

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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.

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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:

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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

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
FIGURE 1: ACCESS PANEL REMOVAL & INSTALLATION - LEFT SIDE

(SHEET 1 OF 2)

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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.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Remove / Keep seal plate - 1

elevator hinge lower - 1

cover

2 Remove / Keep

elevator hinge lower - 1

cover

3 Install (Kept)

4 Install (Kept) seal plate - 1

FIGURE 1: ACCESS PANEL REMOVAL & INSTALLATION - LEFT SIDE

(SHEET 2 OF 2)

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ALERT ALERT
FIGURE 2: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - LEFT SIDE

(SHEET 1 OF 5)

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
FIGURE 2: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - LEFT SIDE

(SHEET 2 OF 5)

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
FIGURE 2: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - LEFT SIDE

(SHEET 3 OF 5)

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
FIGURE 2: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - LEFT SIDE

(SHEET 4 OF 5)

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

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 to

the mechanism alternating between the

inboard and outboard direction while

doing the inspections in the following

steps. The force can

be applied at any location on the mechanism, but no more

than four inches forward of the elevator

front spar.

1 Apply force - -

2 Inspect spacer - 1 (b)

(a) If there is sealant

in the interface, do

not remove it.

3 Inspect swage ring/lug interface - 1

(c) If there is sealant

in the interface, do

not remove it.

4 Inspect lug/lug interface - 1

(c) If there is sealant

in the interface, do

not remove it.

5 Inspect lug/spacer interface - 1

(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)

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
FIGURE 3: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - LEFT SIDE

(SHEET 1 OF 5)

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
FIGURE 3: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - LEFT SIDE

(SHEET 2 OF 5)

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
FIGURE 3: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - LEFT SIDE

(SHEET 3 OF 5)

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
FIGURE 3: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - LEFT SIDE

(SHEET 4 OF 5)

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
The step numbers shown below agree with the numbers shown in the circle symbols in the figure

STEP TASK NAME IDENTIFICATION QTY MORE DATA

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 to

the mechanism alternating between the

inboard and outboard direction while

doing the inspections in the following

steps. The force can

be applied at any location on the mechanism, but no more

than four inches forward of the elevator

front spar.

1 Apply force - -

2 Inspect spacer - 1 (b)

(a) If there is sealant

in the interface, do

not remove it.

3 Inspect swage ring/lug interface - 1

(c) If there is sealant

in the interface, do

not remove it.

4 Inspect lug/lug interface - 1

(c) If there is sealant

in the interface, do

not remove it.

5 Inspect lug/spacer interface - 1

(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)

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
FIGURE 4: ACCESS PANEL REMOVAL & INSTALLATION - RIGHT SIDE

(SHEET 1 OF 2)

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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.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

1 Remove / Keep seal plate - 1

elevator hinge lower - 1

cover

2 Remove / Keep

elevator hinge lower - 1

cover

3 Install (Kept)

4 Install (Kept) seal plate - 1

FIGURE 4: ACCESS PANEL REMOVAL & INSTALLATION - RIGHT SIDE

(SHEET 2 OF 2)

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
FIGURE 5: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - RIGHT SIDE

(SHEET 1 OF 5)

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
FIGURE 5: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - RIGHT SIDE

(SHEET 2 OF 5)

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
FIGURE 5: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - RIGHT SIDE

(SHEET 3 OF 5)

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
FIGURE 5: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - RIGHT SIDE

(SHEET 4 OF 5)

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

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 to

the mechanism alternating between the

inboard and outboard direction while

doing the inspections in the following

steps. The force can

be applied at any location on the mechanism, but no more

than four inches forward of the elevator

front spar.

1 Apply force - -

2 Inspect spacer - 1 (b)

(a) If there is sealant

in the interface, do

not remove it.

3 Inspect swage ring/lug interface - 1

(c) If there is sealant

in the interface, do

not remove it.

4 Inspect lug/lug interface - 1

(c) If there is sealant

in the interface, do

not remove it.

5 Inspect lug/spacer interface - 1

(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)

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
FIGURE 6: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - RIGHT SIDE

(SHEET 1 OF 5)

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ALERT ALERT
FIGURE 6: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - RIGHT SIDE

(SHEET 2 OF 5)

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ALERT ALERT
FIGURE 6: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - RIGHT SIDE

(SHEET 3 OF 5)

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ALERT ALERT
FIGURE 6: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - RIGHT SIDE

(SHEET 4 OF 5)

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

STEP TASK NAME IDENTIFICATION QTY MORE DATA

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 to

the mechanism alternating between the

inboard and outboard direction while

doing the inspections in the following

steps. The force can

be applied at any location on the mechanism, but no more

than four inches forward of the elevator

front spar.

1 Apply force - -

2 Inspect spacer - 1 (b)

(a) If there is sealant

in the interface, do

not remove it.

3 Inspect swage ring/lug interface - 1

(c) If there is sealant

in the interface, do

not remove it.

4 Inspect lug/lug interface - 1

(c) If there is sealant

in the interface, do

not remove it.

5 Inspect lug/spacer interface - 1

(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

Revision 1 August 02, 2010 737-27A1297

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

Revision 1 August 02, 2010 737-27A1297

68 of 68

BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT