Commercial 

Airplanes 737

Service Bulletin

ALERT

Number: 737-27A1297

Original Issue: April 16, 2010

ATA System: 2731

SUBJECT: FLIGHT CONTROLS - Elevator Tab Control Mechanism Detailed Inspection

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ECCN: 9E991

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2.0
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BLANK PAGE
Table of Contents

Summary ...................................................... 5

1. PLANNING INFORMATION ........................................ 9

A. Effectivity ................................................ 9

1. Airplanes ............................................. 9

2. Spares Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

B. Concurrent Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

C. Reason . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

D. Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

E. Compliance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

H. Weight and Balance Changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

1. Existing Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

2. Data supplied with this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

3. Installation Drawings Used in the Preparation of this Service Bulletin . . . . . . . . . . . . 19

K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

2. MATERIAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

A. Material - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

C. Parts Necessary For Each Airplane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

1. Kits/Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

2. Parts and Materials Supplied by the Operator . . . . . . . . . . . . . . . . . . . . . . . . 21

3. Parts Modified and Reidentified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

4. Parts Removed and Not Replaced . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

D. Parts Necessary to Change Spares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

E. Special Tooling - Price and Availability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

F. Special Tooling Necessary to do this Service Bulletin . . . . . . . . . . . . . . . . . . . . . . . 22

3. ACCOMPLISHMENT INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

B. WORK INSTRUCTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

FIGURE 1: ACCESS PANEL REMOVAL & INSTALLATION - LEFT SIDE . . . . . . . . . . . . . . . . 32

FIGURE 2: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - LEFT SIDE . . . . . . . 34

FIGURE 3: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - LEFT SIDE . . . . . . 39

FIGURE 4: ACCESS PANEL REMOVAL & INSTALLATION - RIGHT SIDE . . . . . . . . . . . . . . . 44

FIGURE 5: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - RIGHT SIDE . . . . . . 46

FIGURE 6: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - RIGHT SIDE . . . . . 51

FIGURE 7: DETERMINING IF REPLACEMENT MECHANISM IS NOT BOEING BUILT . . . . . . . . 56

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BLANK PAGE
Commercial 

Airplanes 737

Service Bulletin

ALERT

Summary Number: 737-27A1297

Original Issue: April 16, 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 until

the elevator tab control mechanism is replaced. 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

(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.

ACTION

Remove the seal plate and lower hinge cover to gain access to the elevator tab control mechanism and do a

detailed inspection of the aft attach lugs (lugs). Look for any gaps and look for rotation of the spacer. Also, use

a feeler gage to look for any gaps at certain locations. If there is a gap or a loose spacer, then replace the

elevator control tab mechanism per the AMM and this SB. If there is no gap or a loose spacer, then return the

airplane to a serviceable condition. For Group 1 airplanes, do repeat inspections in accordance with this SB at

the times specified in paragraph 1.E., Compliance. Do the repeat inspections until the elevator tab control

mechanism (mechanism) is replaced in accordance with this SB within the compliance time specified in paragraph

1.E, Compliance. Group 2 airplanes do not have to do repeat inspections unless they have a discrepant

mechanism and they replace it with a non-Boeing built mechanism.

EFFECTIVITY

737-700, -700C, -800, and -900ER Airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected

airplanes.

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COMPLIANCE

Refer to Paragraph 1.E., Compliance.

The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service

bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin

mandatory.

INDUSTRY SUPPORT INFORMATION

At the time of release of this service bulletin, warranty remedies have not been determined. A subsequent

revision or Information Notice will address the warranty remedies available, if any.

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

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

GROUP CONFIGURATION DESCRIPTION

1 - Airplanes Line number 2508 to 2707

2 - Airplanes Line Number 2708 to 3250

1 That have ETOPS operational approval

2 That do not have ETOPS operational approval

Airplane Models:

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

Variable Number Group

YB633 - YB635 2

YB974 1

YB986 - YB987 1

YB988 - YB995 2

YC095 2

YD415 1

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Variable Number Group

YD416 2

YF001 1

YF002 - YF006 2

YF021 - YF026 1

YF027 - YF039 2

YF046 2

YF051 - YF052 1

YF053 - YF060 2

YF086 1

YF112 - YF114 2

YF116 - YF117 2

YF121 - YF123 2

YF176 - YF178 1

YF191 - YF192 2

YF201 - YF244 2

YF401 - YF402 2

YF451 - YF455 2

YF501 - YF576 2

YF701 - YF705 2

YF801 - YF802 2

YF831 - YF832 2

YF901 - YF903 2

YF921 2

YG120 1

YG121 - YG125 2

YG221 - YG223 2

YG711 1

YH011 - YH012 1

YH031 - YH048 2

YH053 - YH054 1

YH055 2

YH103 - YH115 1

YH116 - YH130 2

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Variable Number Group

YH201 - YH202 1

YH206 - YH207 1

YH301 1

YH302 - YH305 2

YH321 - YH322 2

YJ009 - YJ010 1

YJ560 - YJ566 1

YJ567 - YJ576 2

YJ597 1

YJ598 - YJ599 2

YJ874 - YJ875 1

YJ876 - YJ880 2

YJ904 1

YJ908 1

YJ909 - YJ910 2

YK133 1

YK167 1

YK176 1

YK177 2

YK186 2

YK191 2

YK196 2

YK201 - YK202 2

YK309 1

YK310 - YK313 2

YK337 - YK338 1

YK339 - YK340 2

YK373 - YK375 1

YK376 - YK378 2

YK461 - YK465 2

YK471 2

YK486 - YK487 2

YK495 1

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Variable Number Group

YK496 - YK497 2

YK521 - YK523 1

YK524 - YK529 2

YK566 - YK569 1

YK570 2

YK615 - YK616 1

YK626 - YK627 1

YK628 - YK630 2

YK661 1

YK662 - YK665 2

YK671 1

YK672 2

YK676 - YK677 2

YK681 - YK686 2

YK691 2

YK710 - YK712 1

YK713 2

YK757 - YK760 1

YK761 - YK770 2

YK776 - YK778 2

YK871 - YK887 1

YK888 - YK899 2

YK911 1

YK912 2

YK919 2

YK924 - YK927 1

YK951 - YK952 1

YK953 - YK956 2

YK972 - YK980 2

YK985 1

YK986 - YK992 2

YL110 - YL116 1

YL117 - YL131 2

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ALERT ALERT
Variable Number Group

YL206 - YL209 1

YL210 - YL218 2

YL283 - YL284 2

YL316 - YL319 1

YL320 - YL321 2

YL351 - YL353 2

YL371 - YL373 1

YL374 2

YL401 2

YL426 1

YL427 - YL429 2

YL438 - YL444 2

YL472 - YL473 1

YL474 - YL478 2

YL504 - YL505 1

YL506 - YL509 2

YL532 - YL533 1

YL534 2

YL541 - YL544 2

YL562 - YL565 1

YL566 - YL568 2

YL591 - YL592 1

YL593 2

YL605 - YL606 1

YL611 1

YL612 2

YL616 1

YL617 2

YL621 1

YL626 2

YL631 - YL633 2

YL661 - YL664 1

YL676 - YL681 2

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ALERT ALERT
Variable Number Group

YL691 2

YL701 - YL703 2

YL731 2

YL751 - YL752 2

YL761 - YL771 2

YL801 - YL809 2

YL904 - YL907 1

YL908 - YL910 2

YL921 - YL930 2

YL933 - YL936 2

YL951 - YL952 1

YL953 - YL962 2

YM232 - YM238 1

YM239 - YM242 2

YM354 - YM374 1

YM375 - YM390 2

YM594 - YM599 2

YM647 - YM651 1

YM652 2

YM673 - YM674 2

YM691 - YM692 1

YM693 - YM696 2

YM701 - YM702 1

YM703 - YM710 2

YM761 - YM762 2

YN015 - YN016 1

YN024 1

YN080 - YN082 2

YN202 2

YN215 - YN216 1

YN217 - YN219 2

YN232 1

YN233 - YN235 2

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ALERT ALERT
Variable Number Group

YN261 2

YQ001 - YQ003 2

YQ011 2

2. Spares Affected

Examine your spares supply for the parts or components identified in Paragraph 2.C., Parts

Necessary for Each Airplane. If any parts or components are found, refer to Paragraph 2.C. for

the recommended use.

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

and continues with repeat inspections until the elevator tab control mechanism is replaced. 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 (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.

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 any gaps and look for

rotation of the spacer. Also, use a feeler gage to look for any gaps at certain locations. If there is a gap

or a loose spacer, then replace the elevator control tab mechanism per the AMM and this SB. If there

is no gap or a loose spacer, then return the airplane to a serviceable condition. For Group 1 airplanes,

do repeat inspections in accordance with this SB at the times specified in paragraph 1.E., Compliance.

Do the repeat inspections until the elevator tab control mechanism is replaced in accordance with this

SB within the compliance time specified in paragraph 1.E, Compliance. Group 2 airplanes do not have

to do repeat inspections unless they have a discrepant mechanism and they replace it with a non-Boeing

built mechanism.

The work in this service bulletin is done in the maintenance zone(s) given below.

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ALERT ALERT
Group 1:

Affected Maintenance Zones

Model Zone

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

737-900ER

Group 2:

Affected Maintenance Zones

Model Zone

737-700, 737-800, 737-900ER 333, 334, 343, 344

E. Compliance

The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to

this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this

service bulletin mandatory.

Table 1: ELEVATOR TAB CONTROL MECHANISM INSPECTION - LEFT SIDE

Repeat Interval

(Not to Exceed)

Condition Action Compliance Time

300 flight hours (a)

(b)

Within 12 days after the date of the

original issue of

this service bulletin

except beginning 7

days after the date

of the original issue

of the service bulletin, no airplane

may operate an

ETOPS flight unless it has been inspected

Do a detailed inspection

of the elevator tab control

mechanism (mechanism)

in accordance with Step

2 of paragraph 3.B., Work

Instructions.

Group 1 airplanes.

Within 30 days af- (c)

ter the date of the

original issue of

this service bulletin

Do a detailed inspection

of the elevator tab control

mechanism in accordance with Step 2 of

paragraph 3.B., Work Instructions

Group 2, Configuration 1

Group 2, Configuration 2 No action required - -

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ALERT ALERT
Table 1: ELEVATOR TAB CONTROL MECHANISM INSPECTION - LEFT SIDE

Repeat Interval

(Not to Exceed)

Condition Action Compliance Time

Before further flight -

(a) (b)

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 airplanes:

Elevator tab control mechanism is found to be discrepant

OR

Replacement elevator tab

control mechanism is found

to be discrepant.

300 flight hours (a)

(b)

Within 300 flight

hours after installation of the nonBoeing built replacement mechanism

Do a detailed inspection

of the elevator tab control

mechanism in accordance with Step 2 of

paragraph 3.B., Work Instructions.

Group 2, Configuration 1

airplanes that installed a

non-Boeing built replacement mechanism

(a) Installing a Boeing built replacement mechanism in accordance with Step 7 of paragraph

3.B., Work Instructions of this SB terminates the repeat detailed inspections of the elevator

tab control mechanism in accordance with this SB.

(b) Installing a non-Boeing built replacement mechanism in accordance with Step 7 of paragraph 3.B., Work Instructions of this SB does not terminate the repeat detailed inspection

of the elevator tab control mechanism in accordance with this SB.

(c) If the mechanism is found to be discrepant and is replaced with a Boeing built mechanism,

then no repeat inspections are required. If the mechanism is found to be discrepant and

is replaced with a non-Boeing built mechanism, then repeat inspections are required in

accordance with this SB.

Table 2: ELEVATOR TAB CONTROL MECHANISM INSPECTION - RIGHT SIDE

Repeat Interval

(Not to Exceed)

Condition Action Compliance Time

300 flight hours (a)

(b)

Within 12 days after the date of the

original issue of

this service bulletin

except beginning 7

days after the date

of the original issue

of the service bulletin, no airplane

may operate an

ETOPS flight unless it has been inspected

Do a detailed inspection

of the elevator tab control

mechanism (mechanism)

in accordance with Step

5 of paragraph 3.B., Work

Instructions.

Group 1 airplanes.

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ALERT ALERT
Table 2: ELEVATOR TAB CONTROL MECHANISM INSPECTION - RIGHT SIDE

Repeat Interval

(Not to Exceed)

Condition Action Compliance Time

Within 30 days af- (c)

ter the date of the

original issue of

this service bulletin

Do a detailed inspection

of the elevator tab control

mechanism in accordance with Step 5 of

paragraph 3.B., Work Instructions

Group 2, Configuration 1

Group 2, Configuration 2 No action required - -

Before further flight -

(a) (b)

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 airplanes:

Elevator tab control mechanism is found to be discrepant

OR

Replacement elevator tab

control mechanism is found

to be discrepant.

300 flight hours (a)

(b)

Within 300 flight

hours after installation of the nonBoeing built replacement mechanism

Do a detailed inspection

of the elevator tab control

mechanism in accordance with Step 5 of

paragraph 3.B., Work Instructions.

Group 2, Configuration 1

airplanes that installed a

non-Boeing built replacement mechanism

(a) Installing a Boeing built replacement mechanism in accordance with Step 8 of paragraph

3.B., Work Instructions of this SB terminates the repeat detailed inspections of the elevator

tab control mechanism in accordance with this SB.

(b) Installing a non-Boeing built replacement mechanism in accordance with Step 8 of paragraph 3.B., Work Instructions of this SB does not terminate the repeat detailed inspection

of the elevator tab control mechanism in accordance with this SB.

(c) If the mechanism is found to be discrepant and is replaced with a Boeing built mechanism,

then no repeat inspections are required. If the mechanism is found to be discrepant and

is replaced with a non-Boeing built mechanism, then repeat inspections are required in

accordance with this SB.

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.

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ALERT ALERT
G. Manpower

At the time of release of this service bulletin, manpower estimates have not been determined. A

subsequent revision or Information Notice will add manpower estimates.

H. Weight and Balance Changes

None.

I. Electrical Load Data

Not changed.

J. References

1. Existing Data

737-600/700/800/900 Airplane Maintenance Manual (AMM) 27-31-00, 27-31-34.

Boeing Standard Overhaul Practices Manual (BSOPM) 20-50-10.

Boeing Service Bulletin (SB) 737-27A1296.

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

BLANK PAGE
2. MATERIAL INFORMATION

A. Material - Price and Availability

None.

B. Industry Support Information

At the time of release of this service bulletin, warranty remedies have not been determined. A subsequent

revision or Information Notice will address the warranty remedies available, if any.

C. Parts Necessary For Each Airplane

1. Kits/Parts

None.

2. Parts and Materials Supplied by the Operator

Part Number / QTY Name Existing Part Number Notes

Specification

Do the inspection for

replaced

parts in accordance with

the appropriate step in

paragraph

3.B., Work

Instructions

(a)

251A2430-15 or -17 not

built by Boeing

Elevator Tab Control Mechanism -

Left

251A2430-15 or - 1

17 built by Boeing

Do the inspection for

replaced

parts in accordance with

the appropriate step in

paragraph

3.B., Work

Instructions

(a)

251A2430-16 or -18 not

built by Boeing

Elevator Tab Control Mechanism -

Right

251A2430-16 or - 1

18 built by Boeing

(a) You cannot use the existing part to replace the new part. After you install the new part, mark the new

Boeing built mechanism with the SB number in a location that is visible when the lower hinge cover is

removed.

3. Parts Modified and Reidentified

None.

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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. Refer to the SWPM 20-10-11 and SWPM 20-10-12 for the wire installation procedures,

and SWPM 20-10-19 for the wire separation requirements, as accepted procedures.

6. 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.

7. 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.

8. 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.

9. 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.

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B. WORK INSTRUCTIONS

1. OPEN ACCESS - LEFT SIDE:

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), look for

gaps and 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, look for gaps and 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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(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 0.050 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

0.050 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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(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), look for

gaps and 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, look for gaps and 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 0.050 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

0.050 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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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 inspections:

(a) Do a general visual inspection of the replacement mechanism in accordance with

Figure 7 to determine if it is a Boeing built mechanism or a non-Boeing built

mechanism.

1) If part number 251A2430-15, 251A2430-16, 251A2430-17, or 251A2430 -18

appears in the area shown in Figure 7, and if there is a manufacturers number

(MFR number) of 468280 within 0.5 inches of the part number, then the

replacement mechanism is not Boeing built.

2) If either of the two following conditions is true, then the replacement mechanism

is Boeing built:

a) part number 251A2430-15, 251A2430-16, 251A2430-17, or 251A2430 -18

does not appear in the area shown in Figure 7.

b) part number 251A2430-15, 251A2430-16, 251A2430-17, or 251A2430 -18

appears in the area shown in Figure 7, but there is not a manufacturers

number (MFR number) of 468280 within 0.5 inches of the part number.

3) You can install either a Boeing built mechanism or a non Boeing built mechanism.

Refer to paragraph 1.E., Compliance, for compliance information related to

installing a non Boeing built mechanism.

(b) For the inboard attach lug of the elevator tab control mechanism, look for gaps and

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, look for gaps and

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.

NOTE: The figures in this service bulletin 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:

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ALERT ALERT
– Do not apply force as shown in the figures,

– 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 0.050 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 0.050 inch. If there is such a gap, then the replacement

mechanism is discrepant.

(c) 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.

(4) If the replacement mechanism is a Boeing built mechanism, then mark it with the SB

number. Put the mark in a location that is visible with the lower hinge cover removed.

Refer to BSOPM 20-50-10 as an accepted procedure for marking the mechanism.

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 27-31-34

as an accepted procedure.

8. REPLACEMENT OF A MECHANISM - RIGHT SIDE

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:

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ALERT ALERT
(1) Before you install the replacement mechanism, do the following inspections:

(a) Do a general visual inspection of the replacement mechanism in accordance with

Figure 7 to determine if it is a Boeing built mechanism or a non-Boeing built

mechanism.

1) If part number 251A2430-15, 251A2430-16, 251A2430-17, or 251A2430 -18

appears in the area shown in Figure 7, and if there is a manufacturers number

(MFR number) of 468280 within 0.5 inches of the part number, then the

replacement mechanism is not Boeing built.

2) If either of the two following conditions is true, then the replacement mechanism

is Boeing built:

a) part number 251A2430-15, 251A2430-16, 251A2430-17, or 251A2430 -18

does not appear in the area shown in Figure 7.

b) part number 251A2430-15, 251A2430-16, 251A2430-17, or 251A2430 -18

appears in the area shown in Figure 7, but there is not a manufacturers

number (MFR number) of 468280 within 0.5 inches of the part number.

3) You can install either a Boeing built mechanism or a non Boeing built mechanism.

Refer to paragraph 1.E., Compliance, for compliance information related to

installing a non Boeing built mechanism.

(b) For the inboard attach lug of the elevator tab control mechanism, look for gaps and

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, look for gaps and

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.

NOTE: The figures in this service bulletin 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:

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ALERT ALERT
– Do not apply force as shown in the figures,

– 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 0.050 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 0.050 inch. If there is such a gap, then the replacement

mechanism is discrepant.

(c) 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.

(4) If the replacement mechanism is a Boeing built mechanism, then mark it with the SB

number. Put the mark in a location that is visible with the lower hinge cover removed.

Refer to BSOPM 20-50-10 as an accepted procedure for marking the mechanism.

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 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:

Spares Distribution Center

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Repair Overhaul and Exchange Services, SSA 111

Boeing Commercial Airplane Group

2201 South 142nd, Door W10

Seatac, Washington USA 98168

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FIGURE 1: ACCESS PANEL REMOVAL & INSTALLATION - LEFT SIDE

(SHEET 1 OF 2)

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

(SHEET 1 OF 5)

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

(SHEET 2 OF 5)

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

(SHEET 3 OF 5)

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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 - -

Detailed. Look for

gaps.

2 Inspect swage ring/lug interface - 1

Detailed. Look for

gaps.

Inspect lug/lug interface - 1

Detailed. Look for

gaps.

Inspect lug/spacer interface - 1

3 Inspect spacer - 1 (b)

(a) If there is sealant

in the interface, do

not remove it.

4 Inspect swage ring/lug interface - 1

(c) If there is sealant

in the interface, do

not remove it.

5 Inspect lug/lug interface - 1

(c) If there is sealant

in the interface, do

not remove it.

6 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 within the interface area shown in bold. 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 4 OF 5)

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STEP TASK NAME IDENTIFICATION QTY MORE DATA

(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 0.050 inch.

Do the inspection within the interface area shown in bold. 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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FIGURE 3: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - LEFT SIDE

(SHEET 1 OF 5)

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BOEING SERVICE BULLETIN 737-27A1297

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

(SHEET 2 OF 5)

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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
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 - -

Detailed. Look for

gaps.

2 Inspect swage ring/lug interface - 1

Detailed. Look for

gaps.

Inspect lug/lug interface - 1

Detailed. Look for

gaps.

Inspect lug/spacer interface - 1

3 Inspect spacer - 1 (b)

(a) If there is sealant

in the interface, do

not remove it.

4 Inspect swage ring/lug interface - 1

(c) If there is sealant

in the interface, do

not remove it.

5 Inspect lug/lug interface - 1

(c) If there is sealant

in the interface, do

not remove it.

6 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 within the interface area shown in bold. 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 4 OF 5)

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
STEP TASK NAME IDENTIFICATION QTY MORE DATA

(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 0.050 inch.

Do the inspection within the interface area shown in bold. 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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Original Issue: April 16, 2010

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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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Copyright © Unpublished Work - See page 1 for details.

Original Issue: April 16, 2010

737-27A1297

46 of 57

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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Copyright © Unpublished Work - See page 1 for details.

Original Issue: April 16, 2010

737-27A1297

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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)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

Original Issue: April 16, 2010

737-27A1297

48 of 57

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 - -

Detailed. Look for

gaps.

2 Inspect swage ring/lug interface - 1

Detailed. Look for

gaps.

Inspect lug/lug interface - 1

Detailed. Look for

gaps.

Inspect lug/spacer interface - 1

3 Inspect spacer - 1 (b)

(a) If there is sealant

in the interface, do

not remove it.

4 Inspect swage ring/lug interface - 1

(c) If there is sealant

in the interface, do

not remove it.

5 Inspect lug/lug interface - 1

(c) If there is sealant

in the interface, do

not remove it.

6 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 within the interface area shown in bold. 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 4 OF 5)

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Copyright © Unpublished Work - See page 1 for details.

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
STEP TASK NAME IDENTIFICATION QTY MORE DATA

(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 0.050 inch.

Do the inspection within the interface area shown in bold. 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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Copyright © Unpublished Work - See page 1 for details.

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737-27A1297

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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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Copyright © Unpublished Work - See page 1 for details.

Original Issue: April 16, 2010

737-27A1297

51 of 57

BOEING SERVICE BULLETIN 737-27A1297

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

(SHEET 2 OF 5)

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Copyright © Unpublished Work - See page 1 for details.

Original Issue: April 16, 2010

737-27A1297

52 of 57

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

53 of 57

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 - -

Detailed. Look for

gaps.

2 Inspect swage ring/lug interface - 1

Detailed. Look for

gaps.

Inspect lug/lug interface - 1

Detailed. Look for

gaps.

Inspect lug/spacer interface - 1

3 Inspect spacer - 1 (b)

(a) If there is sealant

in the interface, do

not remove it.

4 Inspect swage ring/lug interface - 1

(c) If there is sealant

in the interface, do

not remove it.

5 Inspect lug/lug interface - 1

(c) If there is sealant

in the interface, do

not remove it.

6 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 within the interface area shown in bold. 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 4 OF 5)

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details.

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
STEP TASK NAME IDENTIFICATION QTY MORE DATA

(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 0.050 inch.

Do the inspection within the interface area shown in bold. 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)

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Copyright © Unpublished Work - See page 1 for details.

Original Issue: April 16, 2010

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT
FIGURE 7: DETERMINING IF REPLACEMENT MECHANISM IS NOT BOEING BUILT

(SHEET 1 OF 2)

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Copyright © Unpublished Work - See page 1 for details.

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56 of 57

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

Look in both areas

shown. Look for Part

number 251A2430-

15, 251A2430-16,

251A2430-17 , or

251A2430 -18

1 Inspect Part Number - 1

Within 0.5 inch of

the part number,

look for MFR (manufacturer) number of

468280.

2 Inspect MFR number - 1

FIGURE 7: DETERMINING IF REPLACEMENT MECHANISM IS NOT BOEING BUILT

(SHEET 2 OF 2)

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BOEING SERVICE BULLETIN 737-27A1297

ALERT ALERT