### Commercial **Airplanes** 

# 727 Service Bulletin **SPECIAL ATTENTION Number: 727-57-0187**  Original Issue: March 08, 2012 ATA System: 5714 **SUBJECT:** WINGS - Wing Center Box - Upper Skin and Rear Spar Upper Chord 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## BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2012 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter.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BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 1 of 49 3.0BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 2 of 49 **BOEING SERVICE BULLETIN 727-57-0187**

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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 I. Electrical Load Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 J. References. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 1. Existing Data. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 2. Data supplied with this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 3. Installation Drawings Used in the Preparation of this Service Bulletin. . . . . . . . . . . . 22 K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23 L. Interchangeability and Intermixability of Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . 23 2. MATERIAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 B. Industry Support Information. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 C. Parts Necessary For Each Airplane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 1. Kits/Parts. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 2. Parts and Materials Supplied by the Operator. . . . . . . . . . . . . . . . . . . . . . . . 25 3. Parts Modified and Reidentified. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 4. Parts Removed and Not Replaced. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 26 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 A. GENERAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 FIGURE 1: WINGS - WING CENTER BOX - INTERNAL FUEL TANK INSPECTION OF THE REAR SPAR UPPER CHORD HORIZONTAL FLANGE. . . . . . . . . . . . . . . . . . . . . . . . . . 32 FIGURE 2: WINGS - WING CENTER BOX - INTERNAL FUEL TANK INSPECTION OF THE REAR SPAR UPPER CHORD RADIUS [Group 1]. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 FIGURE 3: WINGS - WING CENTER BOX - INTERNAL FUEL TANK INSPECTION OF THE REAR SPAR UPPER CHORD RADIUS REQUIRING SEALANT REMOVAL [Group 2]. . . . . . . . . . 38 FIGURE 4: WINGS - WING CENTER BOX - INTERNAL FUEL TANK INSPECTION OF THE REAR SPAR UPPER CHORD RADIUS WITHOUT SEALANT REMOVAL. . . . . . . . . . . . . . . . 41 FIGURE 5: WINGS - WING CENTER BOX - EXTERNAL FUEL TANK INSPECTION OF THE UPPER SKIN AND PRESSURE SEAL AT STA 870. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 FIGURE 6: WINGS - WING CENTER SECTION - REAR SPAR UPPER CHORD - INTERNAL FUEL TANK SEALANT APPLICATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 3 of 49 **BOEING SERVICE BULLETIN 727-57-0187**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 4 of 49 **BOEING SERVICE BULLETIN 727-57-0187**

BLANK PAGE

### Commercial **Airplanes** 

# 727 Service Bulletin **SPECIAL ATTENTION Summary**  **Number: 727-57-0187** Original Issue: March 08, 2012 ATA System: 5714 **SUBJECT:** WINGS - Wing Center Box - Upper Skin and Rear Spar Upper Chord Inspection BOEING RECOMMENDS THAT EACH OPERATOR EXAMINE THIS SERVICE BULLETIN IMMEDIATELY. **CONCURRENT REQUIREMENTS** None. **BACKGROUND** This service bulletin gives instructions to inspect the upper skin and the rear spar upper chord of the wing center box, at Body Station (STA) 870 for cracking or corrosion. The upper skin and the rear spar upper chord of the wing center box are classified as principal structural elements. If the work in this service bulletin is not done, undetected cracking or corrosion in this area could severely limit the load carrying capabilities of the structure which could result in the inability of the remaining structure to carry limit load which would preclude the continued safe flight of the airplane. Several operators have reported spanwise cracks and corrosion in the upper skin and rear spar upper chord between Left Buttock Line (LBL) 70.50 and Right Buttock Line (RBL) 70.50, at STA 870. The crack sizes ranged from 0.125 inches to 12 inches. The airplanes had accumulated between 31, 679 and 61,359 total flight hours and between 17,754 and 58,796 total flight cycles. Analysis has shown that the cracks are a result of stress corrosion which is a common problem in the 7178-T651 and 7178-T6511 aluminum from which the wing center box upper skin and some rear spar upper chords are manufactured. All 727-100/-200 airplanes were delivered with 7178-T651 aluminum plate upper skin panels and therefore all these airplanes are affected. Corrosion occurrences in the wing center section are known issues. Boeing Service Bulletin 727-57-0170 was issued for inspections and application of a corrosion inhibitor for external portions of the wing center section. Additionally, multiple Structural Item Interim Advisories (SIIA) were issued for corrosion incidences to wing center section stiffeners, webs, upper skins and chords at the rear spar. However, none of these documents resolves the issue of cracking or corrosion at the wing center box upper skin and rear spar. Accomplishment of this service bulletin will make sure that cracking or corrosion at the upper skin and the rear spar upper chord at the wing center box, STA 870 are detected. Boeing Service Related Problem (SRP) 727-SRP-52-0228 is related to this service bulletin. Boeing Fleet Team Digest (FTD) 727 FTD 57-08003 is related to this service bulletin. This table is provided to operators for planning purposes only. Refer to the applicable sections for more information.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 5 of 49**Reference Affected**  **Planning Data** Paragraph 1.A.2., Spares Affected No Spares Affected Paragraph 1.E., Compliance No AD Related Paragraph 1.H., Weight and Balance Changes No Weight and Balance Change Paragraph 1.I., Electrical Load Data No Electrical Load Changed Paragraph 1.K., Publications Affected No Publications Affected Paragraph 1.K., Publications Affected No Airplane Flight Operations Affected (Flight Crew Operations Manual and/or FAA Approved Airplane Flight Manual) Paragraph 2.C.1., Kits/Parts No Kits/Parts Required Paragraph 2.C.2., Parts and Materials Supplied by the Operator Yes Operator Supplied Material Paragraph 2.F., Special Tooling Necessary to do this Service Bulletin No Special Tooling Required

**ACTION** Defuel all tanks. Get access to the lower surface of the wing center box upper skin near the aft rear spar through the center fuel tank. Between LBL 70.50 and RBL 70.50, at STA 870, do the following inspections: Do a High Frequency Eddy Current (HFEC) inspection or a detailed inspection for cracking around the forward fastener row in the rear spar upper chord horizontal flange. Do a Low Frequency Eddy Current (LFEC) inspection around the aft fastener row in the rear spar upper chord horizontal flange for cracking in the upper skin and the rear spar upper chord horizontal flange. Do a HFEC inspection or a detailed inspection for cracking in the rear spar upper chord radius. If any crack is found, contact Boeing for repair instructions and do the repair. If no cracking is found, do the repeat inspections at the intervals given in Paragraph 1.E., Compliance. Get access to the upper surface of the wing center box upper skin near the rear spar by removing floor panels at the wing center box. Between LBL 70.50 and RBL 70.50, at STA 870, do the following inspections: Do a detailed inspection or a HFEC inspection for cracking in the upper skin around the forward fastener row common to the rear spar upper chord horizontal flange. Do a detailed inspection for any damage, cracking or corrosion in the pressure seal. If any damage, cracking or corrosion is found, contact Boeing for repair instructions and do the repair. If no cracking is found, do the repeat inspections at the intervals given in Paragraph 1.E., Compliance. **EFFECTIVITY** All 727, 727-100, 727-100C, 727-200, 727-200F, 727C Airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes. **COMPLIANCE** Refer to Paragraph 1.E., Compliance. **INDUSTRY SUPPORT INFORMATION** Boeing warranty remedies are not available for the inspection procedures given in this service bulletin.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 6 of 49 **BOEING SERVICE BULLETIN 727-57-0187 MANPOWER**  Refer to Paragraph 1.G., Manpower. **MATERIAL INFORMATION** Operator Supplied Parts/Materials. Refer to Paragraph 2.A., Material - Price and Availability.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 7 of 49 **BOEING SERVICE BULLETIN 727-57-0187**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 8 of 49 **BOEING SERVICE BULLETIN 727-57-0187**

### Commercial **Airplanes** 

# 727 Service Bulletin **SPECIAL ATTENTION Number: 727-57-0187**  Original Issue: March 08, 2012 ATA System: 5714 **SUBJECT:** WINGS - Wing Center Box - Upper Skin and Rear Spar Upper Chord Inspection BOEING RECOMMENDS THAT EACH OPERATOR EXAMINE THIS SERVICE BULLETIN IMMEDIATELY. **1. PLANNING INFORMATION A. Effectivity**  1. Airplanes

**DESCRIPTION CONFIGURATION**  **GROUP** 727, 727C, 727-100, 727-100C, and 727-200 airplanes with bladder fuel cells at the wing center section. - 1
727, 727-100 and 727-200, 727-200F airplanes with an integral fuel tank at the wing center section. - 2

Airplane Models: 727, 727-100, 727-100C, 727-200, 727-200F, 727C **Group Variable Number**  1 E0001 - E0042 1 E0101 - E0140 1 E0201 - E0216 1 E0301 - E0351 1 E0401 - E0423 1 E3001 - E3006 1 E3011 - E3014 1 E3021 - E3040 1 E3059

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 9 of 49**Group Variable Number**  1 E3061 - E3077 1 E3101 - E3103 1 E3111 - E3118 1 E3141 - E3152 1 E3171 - E3177 1 E3201 - E3206 1 E3221 - E3224 1 E3241 - E3290 1 E3341 - E3350 1 E3401 - E3421 1 E3451 - E3452 1 E3471 - E3474 1 E3501 - E3513 1 E3516 - E3522 2 E3523 1 E3551 - E3553 1 E3571 - E3578 1 E3601 - E3604 1 E3621 - E3622 1 E3651 - E3655 1 E3677 1 E3681 - E3682 2 E3683 - E3684 1 E3701 - E3704 1 E3751 - E3755 1 E3781 - E3784 1 E5001 - E5011 1 E5031 - E5068 1 E5101 - E5116 1 E5141 - E5143 1 E5161 - E5164 1 E5201 - E5203 1 E5221 - E5245

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 10 of 49 **BOEING SERVICE BULLETIN 727-57-0187 Group**  **Variable Number** 1 E5251 - E5252 1 E5271 - E5281 1 E5301 - E5306 1 E5351 - E5353 1 E5381 - E5382 1 E5401 - E5424 1 E5426 - E5429 1 E5433 1 E5435 1 E5451 - E5455 1 E5481 - E5483 1 E5501 - E5502 1 QA001 - QA021 2 QA022 - QA023 1 QA024 - QA025 2 QA026 - QA046 1 QA051 - QA058 2 QA059 - QA099 1 QA101 - QA141 2 QA142 - QA199 1 QA201 - QA225 1 QA301 - QA316 2 QA317 - QA324 1 QA325 - QA329 2 QA330 - QA349 1 QA351 - QA368 2 QA369 - QA376 2 QA378 1 QA401 - QA428 2 QA429 - QA499 1 QA501 - QA532 2 QA533 - QA537 1 QA551 - QA567

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 11 of 49 **BOEING SERVICE BULLETIN 727-57-0187 Group**  **Variable Number** 2 QA568 - QA573 1 QA574 - QA575 2 QA576 1 QA577 - QA578 2 QA579 2 QA581 - QA585 1 QA601 - QA626 2 QA627 - QA688 1 QA701 - QA724 2 QA725 - QA753 1 QA801 - QA805 1 QA851 - QA853 2 QA854 - QA899 1 QA901 - QA906 2 QA907 - QA946 2 QA949 1 QB001 - QB002 1 QB031 - QB033 2 QB034 - QB049 2 QB051 - QB068 1 QB101 - QB102 2 QB103 - QB110 2 QB114 - QB119 2 QB121 - QB149 2 QB151 - QB158 2 QB201 - QB220 2 QB301 - QB316 2 QB351 - QB352 2 QB401 - QB407 2 QB451 - QB458 2 QB501 - QB575 2 QB601 - QB629 2 QB651

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 12 of 49 **BOEING SERVICE BULLETIN 727-57-0187 Group**  **Variable Number** 2 QB701 - QB705 2 QB801 - QB810 2 QB901 - QB904 2 QD001 - QD012 2 QD031 - QD046 2 QD085 - QD088 2 QD101 - QD105 2 QD121 - QD127 2 QD141 - QD149 2 QD161 - QD164 2 QD191 - QD192 2 QD201 - QD239 2 QD281 - QD284 2 QD301 - QD305 2 QD321 - QD330 2 QD351 2 QD401 - QD403 2 QD407 2 QD410 2 QD421 - QD427 2 QD441 - QD453 2 QD471 - QD475 2 QD501 - QD518 2 QD551 - QD558 2 QD571 - QD572 2 QD581 - QD583 2 QD601 - QD607 2 QD621 - QD624 2 QD641 2 QD661 - QD663 2 QD681 - QD685 2 QD691 - QD692 2 QD701 - QD702

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 13 of 49 **BOEING SERVICE BULLETIN 727-57-0187 Group**  **Variable Number** 2 QD711 - QD717 2 QD741 2 QD761 - QD769 2 QD781 - QD782 2 QD791 2 QD801 - QD804 2 QD821 - QD828 2 QD901 - QD910 2 QD931 - QD932 2 QD951 - QD954 2 QD971 - QD973 2 QD991 - QD992 2 QE001 - QE002 2 QL001 - QL008 2 QL031 - QL032 2 QL081 2 QL501 - QL515 2. Spares Affected None. **B. Concurrent Requirements** None. **C. Reason** This service bulletin gives instructions to inspect the upper skin and the rear spar upper chord of the wing center box, at Body Station (STA) 870 for cracking or corrosion. The upper skin and the rear spar upper chord of the wing center box are classified as principal structural elements. If the work in this service bulletin is not done, undetected cracking or corrosion in this area could severely limit the load carrying capabilities of the structure which could result in the inability of the remaining structure to carry limit load which would preclude the continued safe flight of the airplane.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 14 of 49 **BOEING SERVICE BULLETIN 727-57-0187**Several operators have reported spanwise cracks and corrosion in the upper skin and rear spar upper chord between Left Buttock Line (LBL) 70.50 and Right Buttock Line (RBL) 70.50, at STA 870. The crack sizes ranged from 0.125 inches to 12 inches. The airplanes had accumulated between 31, 679 and 61,359 total flight hours and between 17,754 and 58,796 total flight cycles. Analysis has shown that the cracks are a result of stress corrosion which is a common problem in the 7178-T651 and 7178-T6511 aluminum from which the wing center box upper skin and some rear spar upper chords are manufactured. All 727-100/-200 airplanes were delivered with 7178-T651 aluminum plate upper skin panels and therefore all these airplanes are affected. Corrosion occurrences in the wing center section are known issues. Boeing Service Bulletin 727-57-0170 was issued for inspections and application of a corrosion inhibitor for external portions of the wing center section. Additionally, multiple Structural Item Interim Advisories (SIIA) were issued for corrosion incidences to wing center section stiffeners, webs, upper skins and chords at the rear spar. However, none of these documents resolves the issue of cracking or corrosion at the wing center box upper skin and rear spar. Accomplishment of this service bulletin will make sure that cracking or corrosion at the upper skin and the rear spar upper chord at the wing center box, STA 870 are detected. Boeing Service Related Problem (SRP) 727-SRP-52-0228 is related to this service bulletin. Boeing Fleet Team Digest (FTD) 727 FTD 57-08003 is related to this service bulletin. **D. Description** Defuel all tanks. Get access to the lower surface of the wing center box upper skin near the aft rear spar through the center fuel tank. Between LBL 70.50 and RBL 70.50, at STA 870, do the following inspections: Do a High Frequency Eddy Current (HFEC) inspection or a detailed inspection for cracking around the forward fastener row in the rear spar upper chord horizontal flange. Do a Low Frequency Eddy Current (LFEC) inspection around the aft fastener row in the rear spar upper chord horizontal flange for cracking in the upper skin and the rear spar upper chord horizontal flange. Do a HFEC inspection or a detailed inspection for cracking in the rear spar upper chord radius. If any crack is found, contact Boeing for repair instructions and do the repair. If no cracking is found, do the repeat inspections at the intervals given in Paragraph 1.E., Compliance. Get access to the upper surface of the wing center box upper skin near the rear spar by removing floor panels at the wing center box. Between LBL 70.50 and RBL 70.50, at STA 870, do the following inspections: Do a detailed inspection or a HFEC inspection for cracking in the upper skin around the forward fastener row common to the rear spar upper chord horizontal flange. Do a detailed inspection for any damage, cracking or corrosion in the pressure seal. If any damage, cracking or corrosion is found, contact Boeing for repair instructions and do the repair. If no cracking is found, do the repeat inspections at the intervals given in Paragraph 1.E., Compliance. The work in this service bulletin is done in the maintenance zone(s) given below. **Group 1:**
**Affected Maintenance Zones Zone**  **Model** 1-74 727, 727-100, 727-100C, 727- 200, 727C

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 15 of 49 **BOEING SERVICE BULLETIN 727-57-0187 Group 2:** 
**Affected Maintenance Zones Zone**  **Model** 1-74 727, 727-100, 727-200, 727- 200F **E. Compliance**
**Group 1: Table 1: Wing Center Box - Internal Fuel Tank Inspection of the Upper Skin and Rear Spar Upper**  **Chord Repeat Interval**  **(Not to Exceed) Compliance Time**  **Action Condition** 

- - Do an inspection for cracking around the forward fastener rowin the rear spar upper chord horizontal flange between Left Buttock Line (LBL) 70.50 and Right Buttock Line (RBL) 70.50, at Body Station (STA) 870, using one of the following options: All Airplanes.

6 years. Within 3 years af-ter the original issue date of this service bulletin. OPTION 1: Do a High Frequency Eddy Current (HFEC) inspectionin accordance with Accomplishment Instructions paragraph 3.B.2.a.(1)(a). OR 3 years. Within 3 years af-ter the original issue date of this service bulletin.OPTION 2: Do a detailed inspection in accordance with Accomplishment Instructions paragraph 3.B.2.a.(1)(b).

- Before further flight.Contact Boeing for repair instructions and do the repair instructed by Boeing. Any crack found.

6 years. Within 3 years af-ter the original issue date of this service bulletin.Do a Low Frequency Eddy Current (LFEC) inspection around the aft fastener row in the rear spar upper chord horizontal flange for cracking in the upper skin and the rear spar upper chord horizontal flange between LBL 70.50 andRBL 70.50, at STA 870, in accordance with Accomplishment Instructions paragraph 3.B.2.a.(2). All Airplanes.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 16 of 49 **BOEING SERVICE BULLETIN 727-57-0187 Group 1:**  **Table 1: Wing Center Box - Internal Fuel Tank Inspection of the Upper Skin and Rear Spar Upper Chord**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- Before further flight.Contact Boeing for repair instructions and do the repair instructed by Boeing. Any crack found.

- - Do an inspection for cracking in the rear spar upper chord radius between LBL 70.50 and RBL 70.50, at STA 870, using one of the following options: All Airplanes.

3 years. Within 3 years af-ter the original issue date of this service bulletin.OPTION 1: Do a detailed inspection in accordance with Accomplishment Instructions paragraph 3.B.2.a.(3)(a). OR 6 years. Within 3 years af-ter the original issue date of this service bulletin. OPTION 2: Do a HFEC inspectionin accordance with Accomplishment Instructions paragraph 3.B.2.a.(3)(b).

- Before further flight.Contact Boeing for repair instructions and do the repair instructed by Boeing. Any crack found.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 17 of 49 **BOEING SERVICE BULLETIN 727-57-0187 Group 2:**  **Table 2: Wing Center Box - Internal Fuel Tank Inspection of the Upper Skin and Rear Spar Upper Chord**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- - Do an inspection for cracking around the forward fastener rowin the rear spar upper chord horizontal flange between Left Buttock Line (LBL) 70.50 and Right Buttock Line (RBL) 70.50, at Body Station (STA) 870, using one of the following options: All Airplanes.

6 years. Within 3 years af-ter the original issue date of this service bulletin. OPTION 1: Do a High Frequency Eddy Current (HFEC) inspectionin accordance with Accomplishment Instructions paragraph 3.B.2.a.(1)(a). OR 3 years. Within 3 years af-ter the original issue date of this service bulletin.OPTION 2: Do a detailed inspection in accordance with Accomplishment Instructions paragraph 3.B.2.a.(1)(b).

- Before further flight.Contact Boeing for repair instructions and do the repair instructed by Boeing. Any crack found.

6 years. Within 3 years af-ter the original issue date of this service bulletin.Do a Low Frequency Eddy Current (LFEC) inspection around the aft fastener row in the rear spar upper chord horizontal flange for cracking in the upper skin and the rear spar upper chord horizontal flange between LBL 70.50 andRBL 70.50, at STA 870, in accordance with Accomplishment Instructions paragraph 3.B.2.a.(2). All Airplanes.

- Before further flight.Contact Boeing for repair instructions and do the repair instructed by Boeing. Any crack found.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 18 of 49 **BOEING SERVICE BULLETIN 727-57-0187 Group 2:**  **Table 2: Wing Center Box - Internal Fuel Tank Inspection of the Upper Skin and Rear Spar Upper Chord**  **Repeat Interval (Not to Exceed)**  **Compliance Time Action**  **Condition**

- - Do an inspection for cracking in the rear spar upper chord radius between LBL 70.50 and RBL 70.50, at STA 870, using one of the following options: All Airplanes.

3 years. Within 3 years af-ter the original issue date of this service bulletin.OPTION 1: Do a detailed inspection in accordance with Accomplishment Instructions paragraph 3.B.2.a.(4)(a). OR 6 years. Within 3 years af-ter the original issue date of this service bulletin. OPTION 2: Do a HFEC inspectionin accordance with Accomplishment Instructions paragraph 3.B.2.a.(4)(b). OR 6 years. Within 3 years af-ter the original issue date of this service bulletin. OPTION 3: Do a HFEC inspectionin accordance with Accomplishment Instructions paragraph 3.B.2.a.(4)(c). NOTE: Removal of sealant from the rear spar upper chord radiusis not required for Option 3 inspection.

- Before further flight.Contact Boeing for repair instructions and do the repair instructed by Boeing. Any crack found.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 19 of 49 **BOEING SERVICE BULLETIN 727-57-0187**All Groups: **Table 3: Wing Center Box - External Fuel Tank Inspection of the Upper Skin and Pressure Seal Repeat Interval**  **(Not to Exceed) Compliance Time**  **Action Condition** 

- - Do an inspection for cracking in the upper skin around the forward fastener row common to the rear spar upper chord horizontal flange between LBL 70.50 and RBL 70.50, at STA 870, using one of the following options: All Airplanes.

3 years. Within 3 years af-ter the original issue date of this service bulletin.OPTION 1: Do a detailed inspection in accordance with Accomplishment Instructions paragraph 3.B.2.b.(1)(a). OR 6 years. Within 3 years af-ter the original issue date of this service bulletin. OPTION 2: Do a HFEC inspectionin accordance with Accomplishment Instructions paragraph 3.B.2.b.(1)(b).

- Before further flight.Contact Boeing for repair instructions and do the repair instructed by Boeing. Any crack found.

3 years. Within 3 years af-ter the original issue date of this service bulletin.Do a detailed inspection for damage, cracking or corrosion in the pressure seal between LBL 70.50 and RBL 70.50, at STA 870, in accordance with Accomplishment Instructions paragraph 3.B.2.b.(2). All Airplanes.

- Before further flight.Contact Boeing for repair instructions and do the repair instructed by Boeing. Any damage,cracking or corrosion found. **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.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 20 of 49 **BOEING SERVICE BULLETIN 727-57-0187 G. Manpower**  The table below shows an estimate of the task hours necessary to do this service bulletin for each airplane. This estimate is for direct labor only, done by an experienced crew. Adjust the estimate with operator task hour data if necessary. The estimate does not include lost time. These are some examples of lost time: • Time to adjust to the workplace • Time to schedule the work • Time to inspect the work • Time to cure the materials • Time to make the parts • Time to find the tools. **Group 1: Elapsed Hours**  **Task Hours Number of Persons**  **Task** 2.00 8.00 4 Preparation 2.33 9.30 4 Open Access 5.00 10.00 2 FIGURE 1, OPTION 1 4.00 8.00 2 FIGURE 1, OPTION 2 1.50 3.00 2 FIGURE 2, OPTION 1 2.50 5.00 2 FIGURE 2, OPTION 2 3.00 6.00 2 FIGURE 5, OPTION 1 4.00 8.00 2 FIGURE 5, OPTION 2 2.00 8.00 4 Restoration 8.65 17.30 2 Close Access (a) (a) TOTAL FOR EACH AIRPLANE (a) The total task hours and total elapsed hours for each airplane depend on which inspection options are accomplished. Operators should add the hours for each applicable task to calculate the total hours for each airplane. **Group 2: Elapsed Hours**  **Task Hours Number of Persons**  **Task** 2.00 8.00 4 Preparation 4.33 17.30 4 Open Access 5.00 10.00 2 FIGURE 1, OPTION 1 4.00 8.00 2 FIGURE 1, OPTION 2 7.10 14.20 2 FIGURE 3, OPTION 1 8.15 16.30 2 FIGURE 3, OPTION 2

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 21 of 49 **BOEING SERVICE BULLETIN 727-57-0187 Group 2:**  **Elapsed Hours Task Hours**  **Number of Persons Task**  2.50 5.00 2 FIGURE 4, OPTION 3 3.00 6.00 2 FIGURE 5, OPTION 1 4.00 8.00 2 FIGURE 5, OPTION 2 7.75 15.50 2 FIGURE 6 2.00 8.00 4 Restoration 4.33 17.30 4 Close Access (a) (a) TOTAL FOR EACH AIRPLANE (a) The total task hours and total elapsed hours for each airplane depend on which inspection options are accomplished. Operators should add the hours for each applicable task to calculate the total hours for each airplane. **H. Weight and Balance Changes** None. **I. Electrical Load Data** Not applicable. **J. References** 1. Existing Data a. Boeing Service Bulletin 727-57-0170. b. Boeing Service Related Problem (SRP) 727-SRP-52-0228. c. Standard Overhaul Practices Manual (SOPM) 20-30-93, 20-41-05, 20-50-19. d. 727 Aircraft Maintenance Manual (AMM) 12-30-03, 28-10-00, 28-11-21, 28-12-01, 28-12-11, 28-23-00, 51-31-00, 53-20-11. e. 727 Fleet Team Digest (FTD) 57-08003. f. 727 Non-Destructive Testing (NDT) Manual Part 6, 51-00-00, Part 6, 51-00-27, Part 6, 57-10-28. 2. Data supplied with this Service Bulletin None. 3. Installation Drawings Used in the Preparation of this Service Bulletin
**Title Drawing Number**  REAR SPAR INSTALLATION - WING CENTER SECTION 65-16202

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 22 of 49 **BOEING SERVICE BULLETIN 727-57-0187**The table above lists applicable drawings used to prepare this service bulletin. The drawings are not necessary to make the specified changes, and are not supplied with this service bulletin. The drawings may not be applicable to all airplane configurations or operators. **K. Publications Affected** 1. Publications: 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** Accomplishment of this service bulletin does not affect interchangeability or intermixability of parts.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 23 of 49 **BOEING SERVICE BULLETIN 727-57-0187**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 24 of 49 **BOEING SERVICE BULLETIN 727-57-0187**

BLANK PAGE**2. MATERIAL INFORMATION A. Material - Price and Availability**  None. **B. Industry Support Information** Boeing warranty remedies are not available for the inspection procedures given in this service bulletin. **C. Parts Necessary For Each Airplane** 1. Kits/Parts None. 2. Parts and Materials Supplied by the Operator **Group 1:**
**Notes Name**  **QTY Part Number / Speci-**  **fication** (a) Corrosion Inhibiting Compound 5 oz BMS 3-23, Type 2 (a) Refer to the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data. **Group 2:**
**Notes Name**  **QTY Part Number / Speci-**  **fication** (a) Corrosion Inhibiting Compound 5 oz BMS 3-23, Type 2 (a) Sealant, Integral Fuel Tank 5 oz BMS 5-45, Class B (a) Refer to the Qualified Products List at the end of the Boeing Material Specification (BMS) for supplier data.
3. Parts Modified and Reidentified None. 4. Parts Removed and Not Replaced None. **D. Parts Necessary to Change Spares** None.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 25 of 49 **BOEING SERVICE BULLETIN 727-57-0187 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: March 08, 2012 727-57-0187 26 of 49 **BOEING SERVICE BULLETIN 727-57-0187 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 4. Use the approved fastener and process material substitutions in accordance with SRM Chapter 51. 5. 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. 6. 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. 7. Boeing Service Letter 727-SL-51-041, 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. 8. If it is necessary to remove more parts for access, you can remove those parts. If you can get access without removing identified parts, it is not necessary to remove all of the identified parts. Jacking and shoring limitations must be observed. **B. WORK INSTRUCTIONS** 1. PREPARATION AND ACCESS a. Defuel all tanks. Refer to 727 AMM 28-23-00 as an accepted procedure.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 27 of 49 **BOEING SERVICE BULLETIN 727-57-0187**b. **Group 1:** (1) Open the wing center fuel cell access panel. Refer to 727 AMM 28-12-11 as an accepted procedure. (2) Remove the wing center section fuel tank bladder cells. Refer to 727 AMM 28-12-01 as an accepted procedure.

c. **Group 2:** (1) Open the wing center section fuel tank access panel. Refer to 727 AMM 28-11-21 as an accepted procedure. (2) Purge the wing center section fuel tank. Refer to 727 AMM 28-10-00 as an accepted procedure. d. Open floor panels 3355, 3356, 3455 and 3456 to get access to the upper surface of the wing center section upper skin. Refer to 727 AMM 12-30-03 and 727 AMM 53-20-11 as accepted procedures. 2. INSPECTION a. Internal Fuel Tank Inspection (1) Do an inspection for cracking around the forward fastener row in the rear spar upper chord horizontal flange between Left Buttock Line (LBL) 70.50 and Right Buttock Line (RBL) 70.50, at Body Station (STA) 870, using one of the following options: (a) OPTION 1: Do a High Frequency Eddy Current (HFEC) inspection in accordance with FIGURE 1. 1) If any crack is found, contact Boeing for repair instructions and do the repair instructed by Boeing. 2) If no cracking is found, do the repeat inspections at the interval given in Paragraph 1.E., Compliance. (b) OPTION 2: Do a detailed inspection in accordance with FIGURE 1. 1) If any crack is found, contact Boeing for repair instructions and do the repair instructed by Boeing. 2) If no cracking is found, do the repeat inspections at the interval given in Paragraph 1.E., Compliance. (2) Do a Low Frequency Eddy Current (LFEC) inspection around the aft fastener row in the rear spar upper chord horizontal flange for cracking in the upper skin and the rear spar upper chord horizontal flange between LBL 70.50 and RBL 70.50, at STA 870, in accordance with FIGURE 1. (a) If any crack is found, contact Boeing for repair instructions and do the repair instructed by Boeing.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 28 of 49 **BOEING SERVICE BULLETIN 727-57-0187**(b) If no cracking is found, do the repeat inspections at the interval given in Paragraph 1.E., Compliance. (3) **Group 1:** Do an inspection for cracking in the rear spar upper chord radius between LBL 70.50 and RBL 70.50, at STA 870, using one of the following options: (a) OPTION 1: Do a detailed inspection in accordance with FIGURE 2. 1) If any crack is found, contact Boeing for repair instructions and do the repair instructed by Boeing. 2) If no cracking is found, do the repeat inspections at the interval given in Paragraph 1.E., Compliance. (b) OPTION 2: Do a HFEC inspection in accordance with FIGURE 2. 1) If any crack is found, contact Boeing for repair instructions and do the repair instructed by Boeing. 2) If no cracking is found, do the repeat inspections at the interval given in Paragraph 1.E., Compliance. (4) **Group 2:** Do an inspection for cracking in the rear spar upper chord radius between LBL 70.50 and RBL 70.50, at STA 870, using one of the following options: (a) OPTION 1: Remove the sealant from the rear spar upper chord radius and do a detailed inspection in accordance with FIGURE 3. 1) If any crack is found, contact Boeing for repair instructions and do the repair instructed by Boeing. 2) If no cracking is found, apply sealant to the rear spar upper chord radius in accordance with FIGURE 6 and do the repeat inspections at the interval given in Paragraph 1.E., Compliance. (b) OPTION 2: Remove the sealant from the rear spar upper chord radius and do a HFEC inspection in accordance with FIGURE 3. 1) If any crack is found, contact Boeing for repair instructions and do the repair instructed by Boeing. 2) If no cracking is found, apply sealant to the rear spar upper chord radius in accordance with FIGURE 6 and do the repeat inspections at the interval given in Paragraph 1.E., Compliance. (c) OPTION 3: Do a HFEC inspection in accordance with FIGURE 4. **NOTE:** Removal of sealant from the rear spar upper chord radius is not required for Option 3 inspection.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 29 of 49 **BOEING SERVICE BULLETIN 727-57-0187**1) If any crack is found, contact Boeing for repair instructions and do the repair instructed by Boeing. 2) If no cracking is found, do the repeat inspections at the interval given in Paragraph 1.E., Compliance. b. External Fuel Tank Inspection (1) Do an inspection for cracking in the upper skin around the forward fastener row common to the rear spar upper chord horizontal flange between LBL 70.50 and RBL 70.50, at STA 870, using one of the following options: (a) OPTION 1: Do a detailed inspection in accordance with FIGURE 5. 1) If any crack is found, contact Boeing for repair instructions and do the repair instructed by Boeing. 2) If no cracking is found, do the repeat inspections at the interval given in Paragraph 1.E., Compliance. (b) OPTION 2: Do a HFEC inspection in accordance with FIGURE 5. 1) If any crack is found, contact Boeing for repair instructions and do the repair instructed by Boeing. 2) If no cracking is found, do the repeat inspections at the interval given in Paragraph 1.E., Compliance. (2) Do a detailed inspection for damage, cracking or corrosion in the pressure seal between LBL 70.50 and RBL 70.50, at STA 870, in accordance with FIGURE 5. (a) If any damage, cracking or corrosion is found, contact Boeing for repair instructions and do the repair instructed by Boeing. (b) If no damage, cracking or corrosion is found, do the repeat inspections at the interval given in Paragraph 1.E., Compliance. 3. RESTORATION AND CLOSE ACCESS a. Apply BMS 3-23, Type 2 Corrosion Inhibiting Compound to the upper surface of the wing center box upper skin near the rear spar. Refer to SOPM 20-41-05 as an accepted procedure. b. Close floor panels 3355, 3356, 3455 and 3456. Refer to 727 AMM 12-30-03 and 727 AMM 53-20-11 as accepted procedures.

c. **Group 1:** (1) Apply BMS 3-23, Type 2 Corrosion Inhibiting Compound to the inside of the wing center section where inspection was done. Refer to SOPM 20-41-05 as an accepted procedure. (2) Install the wing center section fuel tank bladder cells. Refer 727 AMM 28-12-01 to as an accepted procedure.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 30 of 49 **BOEING SERVICE BULLETIN 727-57-0187**(3) Close the wing center fuel cell access panel. Refer to 727 AMM 28-12-11 as an accepted procedure. d. **Group 2:** (1) Close the wing center section fuel tank access panel. Refer to 727 AMM 28-11-21 as an accepted procedure. e. Put the airplane back to a serviceable condition.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 31 of 49 **BOEING SERVICE BULLETIN 727-57-0187 FIGURE 1: WINGS - WING CENTER BOX - INTERNAL FUEL TANK INSPECTION OF THE REAR SPAR**  **UPPER CHORD HORIZONTAL FLANGE (SHEET 1 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 32 of 49 **BOEING SERVICE BULLETIN 727-57-0187 FIGURE 1: WINGS - WING CENTER BOX - INTERNAL FUEL TANK INSPECTION OF THE REAR SPAR**  **UPPER CHORD HORIZONTAL FLANGE (SHEET 2 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 33 of 49 **BOEING SERVICE BULLETIN 727-57-0187**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 each airplane.
**More Data Qty**  **Identification Name**  **Task Step**  (a) 1
- Rear Spar Upper Chord Inspect 1 (b)

- - Upper Skin and Rear Spar Upper Chord Inspect 2 (a) OPTION 1: Do a High Frequency Eddy Current (HFEC) inspection for cracking around the forward fastener row in the rear spar upper chord horizonal flange between Left Buttock Line (LBL) 70.50 and Right Buttock Line (RBL) 70.50 in accordance with 727 NDT Part 6, 57-10-28. OPTION 2: Do a detailed inspection for cracking around the forward fastener row in the rear spar upper chord horizontal flange between LBL 70.50 and RBL 70.50. (b) Do a Low Frequency Eddy Current (LFEC) inspection around the aft fastener row in the rear spar upperchord horizontal flange for cracking in the upper skin and the rear spar upper chord horizontal flange between LBL 70.50 and RBL 70.50 in accordance with 727 NDT Part 6, 57-10-28.

**FIGURE 1: WINGS - WING CENTER BOX - INTERNAL FUEL TANK INSPECTION OF THE REAR SPAR UPPER CHORD HORIZONTAL FLANGE**  **(SHEET 3 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 34 of 49 **BOEING SERVICE BULLETIN 727-57-0187 This Figure applies only to: Group 1.** 

**FIGURE 2: WINGS - WING CENTER BOX - INTERNAL FUEL TANK INSPECTION OF THE REAR SPAR UPPER CHORD RADIUS**  **(SHEET 1 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 35 of 49 **BOEING SERVICE BULLETIN 727-57-0187 FIGURE 2: WINGS - WING CENTER BOX - INTERNAL FUEL TANK INSPECTION OF THE REAR SPAR**  **UPPER CHORD RADIUS (SHEET 2 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 36 of 49 **BOEING SERVICE BULLETIN 727-57-0187**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 each airplane.
**More Data Qty**  **Identification Name**  **Task Step**  (a)

- - Rear Spar Upper Chord Radius Inspect 1 (a) OPTION 1: Do a detailed inspection for cracking in the rear spar upper chord radius between LBL 70.50 and RBL 70.50. OPTION 2: Do a High Frequency Eddy Current (HFEC) inspection for cracking in the rear spar upper chord radius between LBL 70.50 and RBL 70.50 in accordance with 727 NDT Part 6, 51- 00-00 Figure 23. Scan the probe in a manner to detect span wise cracks.

**FIGURE 2: WINGS - WING CENTER BOX - INTERNAL FUEL TANK INSPECTION OF THE REAR SPAR UPPER CHORD RADIUS**  **(SHEET 3 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 37 of 49 **BOEING SERVICE BULLETIN 727-57-0187 This Figure applies only to: Group 2.** 

**FIGURE 3: WINGS - WING CENTER BOX - INTERNAL FUEL TANK INSPECTION OF THE REAR SPAR UPPER CHORD RADIUS REQUIRING SEALANT REMOVAL**  **(SHEET 1 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 38 of 49 **BOEING SERVICE BULLETIN 727-57-0187 FIGURE 3: WINGS - WING CENTER BOX - INTERNAL FUEL TANK INSPECTION OF THE REAR SPAR**  **UPPER CHORD RADIUS REQUIRING SEALANT REMOVAL (SHEET 2 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 39 of 49 **BOEING SERVICE BULLETIN 727-57-0187**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 each airplane.
**More Data Qty**  **Identification Name**  **Task Step**  (a)

- - Sealant Remove 1 (b)

- - Rear Spar Upper Chord Radius Inspect 2 (a) Remove all the sealant from the rear spar upper chord radius between Left Buttock Line (LBL) 70.50 and Right Buttock Line (RBL) 70.50. Refer to SOPM 20-50-19 as an accepted procedure. (b) OPTION 1: Do a detailed inspection for cracking in the rear spar upper chord radius between LBL 70.50 and RBL 70.50. OPTION 2: Do a High Frequency Eddy Current (HFEC) inspection for cracking in the rear spar upper chord radius between LBL 70.50 and RBL 70.50 in accordance with 727 NDT Part 6, 51- 00-00 Figure 23. Scan the probe in a manner to detect span wise cracks.

**FIGURE 3: WINGS - WING CENTER BOX - INTERNAL FUEL TANK INSPECTION OF THE REAR SPAR UPPER CHORD RADIUS REQUIRING SEALANT REMOVAL**  **(SHEET 3 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 40 of 49 **BOEING SERVICE BULLETIN 727-57-0187 FIGURE 4: WINGS - WING CENTER BOX - INTERNAL FUEL TANK INSPECTION OF THE REAR SPAR**  **UPPER CHORD RADIUS WITHOUT SEALANT REMOVAL (SHEET 1 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 41 of 49 **BOEING SERVICE BULLETIN 727-57-0187 FIGURE 4: WINGS - WING CENTER BOX - INTERNAL FUEL TANK INSPECTION OF THE REAR SPAR**  **UPPER CHORD RADIUS WITHOUT SEALANT REMOVAL (SHEET 2 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 42 of 49 **BOEING SERVICE BULLETIN 727-57-0187**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 each airplane.
**More Data Qty**  **Identification Name**  **Task Step**  (a)

- - Rear Spar Upper Chord Radius Inspect 1 (a) Do a High Frequency Eddy Current (HFEC) inspection for cracking in the rear spar upper chord radius between Left Buttock Line (LBL) 70.50 and Right Buttock Line (RBL) 70.50 in accordance with 727 NDTPart 6, 51-00-27. Scan the probe in a manner to detect spanwise cracks. Make sure to calibrate the instrument for the sealant thickness that is in the radius. The maximum thickness of the sealant allowed for this procedure is defined in 727 NDT Part 6, 51-00-27.

**FIGURE 4: WINGS - WING CENTER BOX - INTERNAL FUEL TANK INSPECTION OF THE REAR SPAR UPPER CHORD RADIUS WITHOUT SEALANT REMOVAL**  **(SHEET 3 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 43 of 49 **BOEING SERVICE BULLETIN 727-57-0187 FIGURE 5: WINGS - WING CENTER BOX - EXTERNAL FUEL TANK INSPECTION OF THE UPPER SKIN**  **AND PRESSURE SEAL AT STA 870 (SHEET 1 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 44 of 49 **BOEING SERVICE BULLETIN 727-57-0187 FIGURE 5: WINGS - WING CENTER BOX - EXTERNAL FUEL TANK INSPECTION OF THE UPPER SKIN**  **AND PRESSURE SEAL AT STA 870 (SHEET 2 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 45 of 49 **BOEING SERVICE BULLETIN 727-57-0187**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 each airplane.
**More Data Qty**  **Identification Name**  **Task Step**  (a)

- - Upper Skin Inspect 1 (b)

- - Pressure Seal Inspect 2 (a) OPTION 1: Do a detailed inspection for cracking in the upper skin around the forward fastener row common to the rear spar upper chord horizontal flange between Left Buttock Line (LBL) 70.50 and Right Buttock Line (RBL) 70.50. OPTION 2: Do a High Frequency Eddy Current (HFEC) inspection for cracking in the upper skin around the forward fastener row common to the rear spar upper chord horizontal flange between LBL 70.50 and RBL 70.50 in accordance with 727 NDT Part 6, 57-10-28. (b) Do a detailed inspection of the pressure seal between LBL 70.50 and RBL 70.50 for damage, cracking or corrosion. Examples of damage are missing, flaking, or blistering in the paint, primer, sealant, or corrosion inhibiting compound.

**FIGURE 5: WINGS - WING CENTER BOX - EXTERNAL FUEL TANK INSPECTION OF THE UPPER SKIN AND PRESSURE SEAL AT STA 870**  **(SHEET 3 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 46 of 49 **BOEING SERVICE BULLETIN 727-57-0187 FIGURE 6: WINGS - WING CENTER SECTION - REAR SPAR UPPER CHORD - INTERNAL FUEL TANK**  **SEALANT APPLICATION (SHEET 1 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 47 of 49 **BOEING SERVICE BULLETIN 727-57-0187 FIGURE 6: WINGS - WING CENTER SECTION - REAR SPAR UPPER CHORD - INTERNAL FUEL TANK**  **SEALANT APPLICATION (SHEET 2 OF 3)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 48 of 49 **BOEING SERVICE BULLETIN 727-57-0187**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 each airplane.
**More Data Qty**  **Identification Name**  **Task Step**  (a)

- - Rear Spar Upper Chord Radius and Web Clean 1 (b)

- BMS 5-45, CLASS B Sealant, Integral Fuel Tank Apply 2 (a) Clean the rear spar upper chord radius and the upper edge of the rear spar web between Left Buttock Line (LBL) 70.50 and Right Buttock Line (RBL) 70.50. Refer to SOPM 20-30-93 as an accepted procedure. (b) Apply a fillet seal common to the upper edge of the rear spar web and radius of the rear spar upper chord LBL 70.50 to RBL 70.50. Refer to 727 AMM 51-31-00 or SOPM 20-50-19 as an accepted procedure.

**FIGURE 6: WINGS - WING CENTER SECTION - REAR SPAR UPPER CHORD - INTERNAL FUEL TANK SEALANT APPLICATION**  **(SHEET 3 OF 3)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: March 08, 2012 727-57-0187 49 of 49 **BOEING SERVICE BULLETIN 727-57-0187**