### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Number: 737-27A1302**  Original Issue: April 24, 2012 ATA System: 2731 **SUBJECT:** FLIGHT CONTROLS - Elevator Tab Control Mechanism Detailed Inspection Export of this technology is controlled under the United States Export Administration Regulations (EAR) (15 CFR 730-774). An export license may be required before it is used for development, production or use by foreign persons from specific countries. The controller of this data has the individual responsibility to abide by all export laws. 9E991 ECCN: 

## BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2012 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter. Boeing also claims copyright in this document as a compilation and/or collective work. This document includes proprietary information owned by The Boeing Company and/or one or more third parties. Treatment of the document and the information it contains is governed by contract with Boeing. For more information, contact The Boeing Company, P.O. Box 3707, Seattle, Washington 98124. Boeing, the Boeing signature, the Boeing symbol, 707, 717, 727, 737, 747, 757, 767, 777, 787, Dreamliner, BBJ, DC-8, DC-9, DC-10, KC-10, KDC-10, MD-10, MD-11, MD-80, MD-88, MD-90, P-8A, Poseidon and the Boeing livery are all trademarks owned by The Boeing Company; and no trademark license is granted in connection with this document unless provided in writing by Boeing.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 1 of 44 3.0BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 2 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**

BLANK PAGE**Table of Contents** Summary...................................................... 5 1. PLANNING INFORMATION........................................ 9 A. Effectivity................................................ 9 1. Airplanes............................................. 9 2. Spares Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 B. Concurrent Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 C. Reason. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 D. Description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 F. Approval. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 I. Electrical Load Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 J. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 1. Existing Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 2. Data supplied with this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 3. Installation Drawings Used in the Preparation of this Service Bulletin. . . . . . . . . . . . 18 K. Publications Affected. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 21 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 A. GENERAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 FIGURE 1: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - LEFT SIDE. . . . . . . 29 FIGURE 2: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - LEFT SIDE. . . . . . 33 FIGURE 3: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - RIGHT SIDE. . . . . . 37 FIGURE 4: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - RIGHT SIDE. . . . . 41

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 3 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 4 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Summary**  **Number: 737-27A1302** Original Issue: April 24, 2012 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** Boeing previously received a report from an 737NG operator where the failure of the aft attach lugs on the left elevator tab control mechanism resulted in unwanted elevator freeplay vibration during flight. Investigation revealed that the fractured aft attach lugs on the elevator tab control mechanism allowed freeplay of the mechanism, which led to vibration of the elevator during flight. Further investigation revealed that the bearings installed in the elevator tab control mechanism aft attach lugs were likely insufficiently swaged and became loose. 737NG service bulletin 737-27A1297 was issued to do a detailed inspection for looseness of these bearings. This service bulletin does inspection of these bearings for looseness similar to the inspections in 737-27A1297. Although the previously mentioned incident occurred on a 737NG, the design of the bearing lug retention is essentially the same as newer 737-200's which all have the 65-45190-7 & -8 Tab Control Mechanism installation. A loose bearing in the aft lug of the elevator tab control mechanism could lead to unwanted elevator tab freeplay and then tab vibration which could lead to structural failure of the elevator or the horizontal stabilizer which can result in unsafe flight conditions. This bulletin will ensure the integrity of bearing swages, whether performed in production or during any subsequent maintenance work done by an airline. This inspection was determined to be needed for the 737-200 because the design of the 737-200 bearing retention is essentially the same as for the 737NG. The 737NG event showed that the design used on both the 737-200 and the 737NG using the specification for installing the swage (BAC5435) may not be adequate. The related Elevator Tab service bulletin is 737-27A1297. **ACTION Group 1:**  Contact Boeing to get instructions for inspection, change and/or repair for this service bulletin, and do the work instructed by Boeing.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 5 of 44**Group 2:** Remove access panels 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. **EFFECTIVITY** 737-200, 200C Airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes. **COMPLIANCE** The Federal Aviation Administration (FAA) will possibly release an Airworthiness Directive related to this service bulletin. The Airworthiness Directive will make the compliance tasks and times given in this service bulletin mandatory. Refer to Paragraph 1.E., Compliance. **INDUSTRY SUPPORT INFORMATION** Boeing warranty remedies are not available for the inspection, and/or repair procedures given in this service bulletin. **MANPOWER** Refer to Paragraph 1.G., Manpower. **MATERIAL INFORMATION** None.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 6 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 7 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 8 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# 737 Service Bulletin **ALERT Number: 737-27A1302**  Original Issue: April 24, 2012 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

**DESCRIPTION CONFIGURATION**  **GROUP** 737-200, 200C Airplanes Line Number 288 to 291; Contact Boeing

- 1 737-200, 200C Airplanes Line Number 292 to 1585

- 2

Airplane Models: 737-200, 737-200C **Group Variable Number**  2 PG584 - PG586 2 PH001 2 PH011 - PH013 2 PH021 - PH024 1 PH742 2 PH743 2 PJ003 - PJ009 2 PJ105 - PJ119 2 PJ201 - PJ219

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 9 of 44**Group Variable Number**  2 PK026 - PK029 2 PK041 - PK053 2 PK061 - PK070 2 PK081 - PK082 2 PK091 - PK099 2 PK101 - PK103 2 PK111 - PK120 2 PK141 - PK146 2 PK201 - PK204 2 PK211 - PK223 2 PK231 - PK241 2 PK251 - PK258 2 PK271 - PK274 2 PK281 - PK289 2 PK291 2 PK301 - PK318 2 PK341 2 PK351 - PK361 2 PK391 2 PK431 - PK433 2 PK451 - PK452 2 PK461 - PK469 2 PK495 2 PK501 - PK504 2 PK511 - PK515 2 PK519 2 PK521 - PK528 2 PK541 - PK565 2 PK581 2 PK591 - PK599 2 PK601 - PK617 2 PK621 - PK637 2 PK641 - PK642

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 10 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT Group**  **Variable Number** 2 PK661 - PK666 2 PK671 - PK681 2 PK691 - PK697 2 PK711 - PK716 2 PK731 - PK765 2 PK771 - PK779 2 PK801 - PK804 2 PK819 - PK827 2 PK830 2 PK861 - PK863 2 PK871 - PK874 2 PK881 - PK884 2 PK901 - PK938 2 PK971 - PK974 2 PL001 - PL028 2 PL061 2 PL081 2 PL101 - PL113 2 PL151 2 PL171 - PL172 2 PL201 - PL203 2 PL221 2 PL401 - PL417 2 PL421 2 PL441 2 PL451 - PL456 2 PL471 2 PL491 2 PL501 - PL506 2 PL551 - PL562 2 PL581 2 PL601 - PL603 2 PL611

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 11 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT Group**  **Variable Number** 2 PL621 - PL626 2 PL631 - PL632 1 PL712 1 PL716 2 PL717 - PL747 2 PL756 2 PL758 2 PL761 - PL770 2 PL781 - PL788 2 PL793 2 PM001 - PM006 2 PM016 - PM017 2 PM021 - PM023 2 PM051 - PM066 2 PM101 - PM119 2 PM141 - PM142 2 PM171 2 PM181 2 PM251 - PM255 2 PM281 - PM283 2 PN001 - PN002 2 PN021 - PN043 2 PN081 - PN086 2 PN101 - PN117 2 PN131 - PN163 2 PN401 - PN420 2 PN431 - PN433 2 PN451 - PN456 2 PN471 - PN474 2 PN481 2 PN491 - PN493 2 PN501 - PN502 2 PN511 - PN512

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 12 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT Group**  **Variable Number** 2 PN521 2 PY022 1 PY031 2 PY036 - PY037 2 PY046 - PY048 2 PY051 - PY053 2 PY056 - PY057 2 PY101 - PY103 2 PY111 - PY113 2 PY131 - PY135 2 PY141 - PY143 2 PY151 - PY154 2 PY156 - PY157 2 PY161 - PY162 2 PY166 2 PY191 2 PY201 2 PY221 - PY222 2 PY231 2 PY241 - PY244 2 PY270 - PY275 2 PY281 2 PY286 2 PY401 2 PY409 - PY411 2 PY421 - PY422 2 PY441 2 PY451 2 PY461 - PY463 2 PY591 - PY595 2 PY611 - PY612 2 PY621 2 PY631

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 13 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT Group**  **Variable Number** 2 PY651 2 PY671 - PY672 2 PY721 2 PY741 2. Spares Affected None. **B. Concurrent Requirements** None. **C. Reason** Boeing previously received a report from an 737NG operator where the failure of the aft attach lugs on the left elevator tab control mechanism resulted in unwanted elevator freeplay vibration during flight. Investigation revealed that the fractured aft attach lugs on the elevator tab control mechanism allowed freeplay of the mechanism, which led to vibration of the elevator during flight. Further investigation revealed that the bearings installed in the elevator tab control mechanism aft attach lugs were likely insufficiently swaged and became loose. 737NG service bulletin 737-27A1297 was issued to do a detailed inspection for looseness of these bearings. This service bulletin does inspection of these bearings for looseness similar to the inspections in 737-27A1297. Although the previously mentioned incident occurred on a 737NG, the design of the bearing lug retention is essentially the same as newer 737-200's which all have the 65-45190-7 & -8 Tab Control Mechanism installation. A loose bearing in the aft lug of the elevator tab control mechanism could lead to unwanted elevator tab freeplay and then tab vibration which could lead to structural failure of the elevator or the horizontal stabilizer which can result in unsafe flight conditions. This bulletin will ensure the integrity of bearing swages, whether performed in production or during any subsequent maintenance work done by an airline. This inspection was determined to be needed for the 737-200 because the design of the 737-200 bearing retention is essentially the same as for the 737NG. The 737NG event showed that the design used on both the 737-200 and the 737NG using the specification for installing the swage (BAC5435) may not be adequate. The related Elevator Tab service bulletin is 737-27A1297. **D. Description Group 1:**  Contact Boeing to get instructions for inspection, change and/or repair for this service bulletin, and do the work instructed by Boeing. **Group 2:** Remove access panels 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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 14 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**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.
**Affected Maintenance Zones Zone**  **Model** 7-9, 7-10, 7-11, 7-12 737-200, 737-200C **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) Compliance Time**  **Action Condition** 

- Within 1,500 Flight Cycles or2,000 Flight Hours, whichever occurs first, after the original issue date of this service bulletin.Contact Boeing to get instructions for inspection, change and/or repair for this service bulletin, and do the work instructed by Boeing in accordance with Part 1, Step 1 ofparagraph 3.B., Work Instructions. Group 1

1,500 Flight Cycles or 2,000 Flight Hours, whichever occurs first. Within 1,500 Flight Cycles or2,000 Flight Hours, whichever occurs first, after the original issue date of this service bulletin. Do a detailed inspection of the elevator tab controlmechanism in accordance with Part 2, Step 2 of paragraph 3.B., Work Instructions. Group 2

- Before further flight Replace the elevator tab control mechanism and do detailed inspection before and after installing it, in accordance with Part 2, Step 7 of paragraph 3.B., Work Instructions. Group 2:Elevator tab control mechanism is found to be discrepant. OR Replacement elevator tab control mechanism is found to be discrepant.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 15 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT Table 2: ELEVATOR TAB CONTROL MECHANISM INSPECTION - RIGHT SIDE**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- Within 1,500 Flight Cycles or2,000 Flight Hours, whichever occurs first, after the original issue date of this service bulletin .Contact Boeing to get instructions for inspection, change and/or repair for this service bulletin, and do the work instructed by Boeing in accordance with Part 1, Step 1 ofparagraph 3.B., Work Instructions. Group 1

1,500 Flight Cycles or 2,000 Flight Hours whichever occurs first. Within 1,500 Flight Cycles or2,000 Flight Hours, whichever occurs first, after the original issue date of this service bulletin . Do a detailed inspection of the elevator tab controlmechanism in accordance with Part 2, Step 5 of paragraph 3.B., Work Instructions. Group 2

- Before further flight Replace the elevator tab control mechanism and do detailed inspection before and after installing it, in accordance with Part 2, Step 8 of paragraph 3.B., Work Instructions. Group 2:Elevator tab control mechanism is found to be discrepant OR Replacement elevator tab control mechanism is found to be discrepant. **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. **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

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 16 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**• Time to inspect the work • Time to cure the materials • Time to make the parts • Time to find the tools. **INSPECT LEFT SIDE Elapsed Hours**  **Task Hours Number of Persons**  **Task** 1.00 1.00 1 Open Access 0.75 0.75 1 Figure 1 0.75 .0.75 1 Figure 2 1.00 1.00 1 Close Access 3.50 3.50 TOTAL FOR EACH AIR- PLANE
**INSPECT RIGHT SIDE Elapsed Hours**  **Task Hours Number of Persons**  **Task** 1.00 1.00 1 Open Access 0.75 0.75 1 Figure 3 0.75 0.75 1 Figure 4 1.00 1.00 1 Close Access 3.50 3.50 TOTAL FOR EACH AIR- PLANE
**REPLACE MECHANISM LEFT SIDE** Elapsed Hours Task Hours Number of Persons Task 1.50 1.50 1 Remove Mechanism 0.75 0.75 1 Figure 1 0.75 0.75 1 Figure 2 1.50 1.50 1 Install Mechanism 1.50 1.50 1 Inspect, Figures 1 & 2 1.00 2.00 2 Functional Test (a) (a) 2 Flight Test 7.00 8.00 TOTAL FOR EACH AIR- PLANE (a) Flight test hours not included in estimate.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 17 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT REPLACE MECHANISM RIGHT SIDE**  Elapsed Hours Task Hours Number of Persons Task 1.50 1.50 1 Remove Mechanism 0.75 0.75 1 Figure 3 0.75 0.75 1 Figure 4 1.50 1.50 1 Install Mechanism 1.50 1.50 1 Inspect, Figures 3 & 4 1.00 2.00 2 Functional Test (a) (a) 2 Flight Test 7.00 8.00 TOTAL FOR EACH AIR- PLANE (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 737-27A1297 b. Standard Wiring Practices Manual (SWPM) SWPM 20-10-11, SWPM 20-10-12, SWPM 20-10-19 c. 737-200 Aircraft Maintenance Manual (AMM) 737-100/200 AMM 12-31-81, 737-100/200 AMM 27-31-00, 737-100/200 AMM 27-31-121 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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 18 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**2. Damage Tolerance Based Structural Inspections: Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the Maintenance Program. This service bulletin does not affect FCS, therefore DTIs are not necessary. **L. Interchangeability and Intermixability of Parts** Refer to Paragraph 2.C., Parts Necessary for Each Airplane, for interchangeability and intermixability information.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 19 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 20 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**

BLANK PAGE**2. MATERIAL INFORMATION A. Material - Price and Availability**  None. **B. Industry Support Information** Boeing warranty remedies are not available for the inspection, and/or repair procedures given in this service bulletin. **C. Parts Necessary For Each Airplane** 1. Kits/Parts None. 2. Parts and Materials Supplied by the Operator
**Notes Existing Part Number**  **Name QTY**  **Part Number / Specification**  This part isonly necessary if the Elevator Tab Control Mechanismis found discrepant. 65-45190-7, -8 Installation Elevator Tab Control Mechanism 1 65-79425-2 or -3 or-4 or -5 or -6 Assembly

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

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 21 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 22 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT 3. ACCOMPLISHMENT INSTRUCTIONS**  **A. GENERAL INFORMATION CAUTION:**  KEEP THE WORK AREA, WIRES AND ELECTRICAL BUNDLES CLEAN OF METAL PARTICLES OR CONTAMINATION WHEN YOU USE TOOLS. UNWANTED MATERIAL, METAL PARTICLES OR CONTAMINATION CAUGHT IN WIRE BUNDLES CAN CAUSE DAMAGE TO THE BUNDLES. DAMAGED WIRE BUNDLES CAN CAUSE SPARKS OR OTHER ELECTRICAL DAMAGE. **NOTE:** 1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References, for definition of the acronyms. 2. Obey all of the warnings and cautions given in the specified manual sections. 3. Unless shown differently, these dimensions and tolerances are used: – Linear dimensions are in inches – Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus or minus 0.03 inch – Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch – Angular tolerance is plus or minus 2 degrees – Hole dimensions for standard solid rivets and fasteners are in Structural Repair Manual (SRM) Chapter 51 – Torque limits to tighten nuts and bolts are in SRM Chapter 51 4. Use the approved fastener and process material substitutions in accordance with SRM Chapter 51. 5. 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. The necessary conditions for selection of clamp type and size are included in SWPM 20-10-12. If any wire bundle support clamp specified in this service bulletin does not make a correct fit on the wire bundle, refer to SWPM 20-10-12 as an accepted procedure to select a clamp that fits correctly. 7. If the length of any fastener specified in this service bulletin does not meet installation standards given in SRM Chapter 51, then a fastener of the same specification, or an approved substitute, with a length which meets the installation standards given in SRM Chapter 51 may be used. In addition, washers may be installed for fastener grip length in accordance with SRM Chapter 51. 8. A Detailed Inspection is defined as: An intensive examination of a specific item, installation, or assembly to detect damage, failure, or irregularity. Available lighting is normally supplemented with a direct source of good lighting at an intensity deemed appropriate. Inspection aids such as mirrors, magnifying lenses, etc. may be necessary. Surface cleaning and elaborate procedures may be required.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 23 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**9. 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. 10. 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. 11. Boeing Service Letter , 737-SL-51-042, Damage Reporting and Repair Plan/Design Guidelines, is an acceptable procedure to request information from Boeing for additional structural repair instructions. The Service Letter describes what information must be provided to Boeing before a structural repair can be provided. 12. The instructions in Paragraph 3.B., Work Instructions and the figures can include operation of tools or test equipment. Boeing Engineering Tool Drawings, the Illustrated Tool and Equipment Manual, and the Special Tool and Ground Handling Drawing Index contain data on versions of the tools or test equipment that you can use. It is permitted to use replaced tools. It is not permitted to use superseded tools. 13. If it is necessary to remove more parts for access, you can remove those parts. If you can get access without removing identified parts, it is not necessary to remove all of the identified parts. Jacking and shoring limitations must be observed. 14. Where the work instructions include installation of a kept part, a new or serviceable part with the same part number can be installed as an alternative to the kept part. 15. This service bulletin includes functional test procedures for the systems changed by this service bulletin. More functional tests can possibly be necessary in accordance with standard maintenance practices because of interruption to other airplane systems. 16. Some Boeing parts are supplied in a temporary configuration. Those parts are identified with a 'U', 'W', or 'Y' in place of the '-' (dash) in the part number. It is permitted to install parts identified with a 'U', 'W', or 'Y' as an alternative to the '-' (dash) part number. Boeing Drawing 005W0900 contains more data. 17. Shaded areas in Figures are reference only. Shaded areas in Figures may look different than your airplane. **B. WORK INSTRUCTIONS Part 1 Group 1 airplanes**  1. Contact Boeing to get instructions for inspection, change and/or repair for this service bulletin, and do the work instructed by Boeing.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 24 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT Part 2 Group 2 airplanes**  1. OPEN ACCESS - LEFT SIDE: a. Gain access as required. Refer to 737-100/200 AMM 12-31-81 and 737-100/200 AMM 27-31-121 as an accepted procedure. 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 1 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 1. 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 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. (1) Spacer: If the spacer moves or rotates, then the mechanism is discrepant (2) 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 0.010 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. Close access as required. Refer to 737-100/200 AMM 12-31-81 and 737-100/200 AMM 27-31-121 as an accepted procedure. 4. OPEN ACCESS - RIGHT SIDE a. Gain access as required. Refer to 737-100/200 AMM 12-31-81 and 737-100/200 AMM 27-31-121 as an accepted procedure. 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 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. 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 4 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 4. (1) Spacer: If the spacer moves or rotates, then the mechanism is discrepant

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 25 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**(2) 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 0.010 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. Close access as required. Refer to 737-100/200 AMM 12-31-81 and 737-100/200 AMM 27-31-121 as an accepted procedure. 7. REPLACEMENT OF A MECHANISM- LEFT 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 737-100/200 AMM 12-31-81 and 737-100/200 AMM 27-31-121 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 1, 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 2, except as noted below, and determine if the replacement mechanism is discrepant. **NOTE:** Figures 1 and 2 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) 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 0.010 inch feeler gage can be inserted more than 0.16 inch. If there is such a gap, then the replacement mechanism is discrepant.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 26 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**(b) If the replacement mechanism is discrepant, then it cannot be installed. (2) Install the replacement mechanism. Refer to 737-100/200 AMM 27-31-121 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 737-100/200 AMM 12-31-81 and 737-100/200 AMM 27-31-121 as an accepted procedure. d. Functional tests and (Manual mode and Power Mode) flight test of the airplane are required when an elevator tab control mechanism is replaced. Refer to 737-100/200 AMM 27-31-00 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 737-100/200 AMM 12-31-81 and 737-100/200 AMM 27-31-121 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 3, 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 4, except as noted below, and determine if the replacement mechanism is discrepant. **NOTE:** Figures 3 and 4 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

BOEING PROPRIETARY -

Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 27 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**2) 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 0.010 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 737-100/200 AMM 27-31-121 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 737-100/200 AMM 12-31-81 and 737-100/200 AMM 27-31-121 as an accepted procedure. d. Functional tests (Manual mode and Power Mode) flight test of the airplane are required when an elevator tab control mechanism is replaced. Refer to 737-100/200 AMM 27-31-00 as an accepted procedure. 9. Return the airplane to a serviceable condition.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 28 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT FIGURE 1: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - LEFT SIDE**  **(SHEET 1 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 29 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT FIGURE 1: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - LEFT SIDE**  **(SHEET 2 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 30 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT FIGURE 1: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - LEFT SIDE**  **(SHEET 3 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 31 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
**More Data Qty**  **Identification Name**  **Task Step**  **CAUTION:** DO NOT APPLY FORCE WITH ANYTHING OTHER THAN YOUR HAND. DO NOT APPLY EXCESSIVE FORCE OR YOU MAY DAMAGE THE ELEVATOR TAB CONTROL MECHANISM LUGS OR BEARINGS. A BENT LUG OR LOOSE BEARING COULD LEAD TO UNWANTED ELEVATOR TAB FREEPLAY AND THEN TAB VIBRATION WHICH COULD LEAD TO STRUCTURAL FAILURE OF THE ELEVATOR OR THE HORIZONTAL STABILIZER.Using hand pressure, apply force tothe mechanism alternating between theinboard and outboard direction whiledoing the inspections in the following steps. The force canbe applied at any location on the mechanism, but no morethan four inches forward of the elevator front spar. - - force Apply 1

(a) 1

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

- lug/spacer interface Inspect 3

(a) As you apply force to the mechanism alternating between the inboard and outboard direction, use finger pressure and try to rotate the spacer. (b) Using a feeler gage, Make sure that there is no gap between the inner face of the lug and the spacersuch that a 0.010 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 C. Apply force to the mechanism alternating between the inboard and outboard direction as you use the feeler gage.

**FIGURE 1: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - LEFT SIDE (SHEET 4 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 32 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT FIGURE 2: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - LEFT SIDE**  **(SHEET 1 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 33 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT FIGURE 2: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - LEFT SIDE**  **(SHEET 2 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 34 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT FIGURE 2: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - LEFT SIDE**  **(SHEET 3 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 35 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure
**More Data Qty**  **Identification Name**  **Task Step**  **CAUTION:** DO NOT APPLY FORCE WITH ANYTHING OTHER THAN YOUR HAND. DO NOT APPLY EXCESSIVE FORCE OR YOU MAY DAMAGE THE ELEVATOR TAB CONTROL MECHANISM LUGS OR BEARINGS. A BENT LUG OR LOOSE BEARING COULD LEAD TO UNWANTED ELEVATOR TAB FREEPLAY AND THEN TAB VIBRATION WHICH COULD LEAD TO STRUCTURAL FAILURE OF THE ELEVATOR OR THE HORIZONTAL STABILIZER.Using hand pressure, apply force tothe mechanism alternating between theinboard and outboard direction whiledoing the inspections in the following steps. The force canbe applied at any location on the mechanism, but no morethan four inches forward of the elevator front spar. - - force Apply 1

(a) 1

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

- lug/spacer interface Inspect 3

(a) As you apply force to the mechanism alternating between the inboard and outboard direction, use finger pressure and try to rotate the spacer. (b) Using a feeler gage, Make sure that there is no gap between the inner face of the lug and the spacersuch that a 0.010 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 C. 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 - OUTBOARD LUG - LEFT SIDE (SHEET 4 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 36 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT FIGURE 3: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - RIGHT SIDE**  **(SHEET 1 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 37 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT FIGURE 3: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - RIGHT SIDE**  **(SHEET 2 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 38 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT FIGURE 3: AFT ATTACH LUG DETAILED INSPECTION - INBOARD LUG - RIGHT SIDE**  **(SHEET 3 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 39 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
**More Data Qty**  **Identification Name**  **Task Step**  **CAUTION:** DO NOT APPLY FORCE WITH ANYTHING OTHER THAN YOUR HAND. DO NOT APPLY EXCESSIVE FORCE OR YOU MAY DAMAGE THE ELEVATOR TAB CONTROL MECHANISM LUGS OR BEARINGS. A BENT LUG OR LOOSE BEARING COULD LEAD TO UNWANTED ELEVATOR TAB FREEPLAY AND THEN TAB VIBRATION WHICH COULD LEAD TO STRUCTURAL FAILURE OF THE ELEVATOR OR THE HORIZONTAL STABILIZER.Using hand pressure, apply force tothe mechanism alternating between theinboard and outboard direction whiledoing the inspections in the following steps. The force canbe applied at any location on the mechanism, but no morethan four inches forward of the elevator front spar. - - force Apply 1

(a) 1

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

- lug/spacer interface Inspect 3

(a) As you apply force to the mechanism alternating between the inboard and outboard direction, use finger pressure and try to rotate the spacer. (b) Using a feeler gage, Make sure that there is no gap between the inner face of the lug and the spacersuch that a 0.010 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 C. 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 - INBOARD LUG - RIGHT SIDE (SHEET 4 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 40 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT FIGURE 4: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - RIGHT SIDE**  **(SHEET 1 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 41 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT FIGURE 4: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - RIGHT SIDE**  **(SHEET 2 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 42 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT FIGURE 4: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - RIGHT SIDE**  **(SHEET 3 OF 4)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 43 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure.
**More Data Qty**  **Identification Name**  **Task Step**  **CAUTION:** DO NOT APPLY FORCE WITH ANYTHING OTHER THAN YOUR HAND. DO NOT APPLY EXCESSIVE FORCE OR YOU MAY DAMAGE THE ELEVATOR TAB CONTROL MECHANISM LUGS OR BEARINGS. A BENT LUG OR LOOSE BEARING COULD LEAD TO UNWANTED ELEVATOR TAB FREEPLAY AND THEN TAB VIBRATION WHICH COULD LEAD TO STRUCTURAL FAILURE OF THE ELEVATOR OR THE HORIZONTAL STABILIZER.Using hand pressure, apply force tothe mechanism alternating between theinboard and outboard direction whiledoing the inspections in the following steps. The force canbe applied at any location on the mechanism, but no morethan four inches forward of the elevator front spar. - - force Apply 1

(a) 1

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

- lug/spacer interface Inspect 3

(a) As you apply force to the mechanism alternating between the inboard and outboard direction, use finger pressure and try to rotate the spacer. (b) Using a feeler gage, Make sure that there is no gap between the inner face of the lug and the spacersuch that a 0.010 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 C. Apply force to the mechanism alternating between the inboard and outboard direction as you use the feeler gage.

**FIGURE 4: AFT ATTACH LUG DETAILED INSPECTION - OUTBOARD LUG - RIGHT SIDE (SHEET 4 OF 4)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: April 24, 2012 737-27A1302 44 of 44 **BOEING SERVICE BULLETIN 737-27A1302 ALERT**  **ALERT**