### Commercial **Airplanes** 

# MD90 Service Bulletin **ALERT Number: MD90-57A030**  Original Issue: February 14, 2012 ATA System: 5710 **SUBJECT:** WINGS - Main Frame - Inspect/Repair Stringer 11 at the Outboard Flap, Inboard Drive Hinge at Station Xrs=164.000 Left and Right Wings 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## BOEING PROPRIETARY, CONFIDENTIAL, AND/OR TRADE SECRET Copyright © 2012 The Boeing Company Unpublished Work - All Rights Reserved Boeing claims copyright in each page of this document only to the extent that the page contains copyrightable subject matter.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BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 1 of 23 2.0BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 2 of 23 **BOEING SERVICE BULLETIN MD90-57A030 ALERT**  **ALERT**

BLANK PAGE**Table of Contents** Summary...................................................... 5 1. PLANNING INFORMATION ........................................ 7 A. Effectivity................................................ 7 1. Airplanes............................................. 7 2. Spares Affected ......................................... 9 B. Concurrent Requirements....................................... 9 C. Reason................................................. 9 D. Description............................................... 9 E. Compliance. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 F. Approval . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 G. Manpower . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 H. Weight and Balance Changes. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 I. Electrical Load Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 J. References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 1. Existing Data: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2. Data supplied with this Service Bulletin: . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 3. Installation Drawings Used in the Preparation of this Service Bulletin:. . . . . . . . . . . 13 K. Publications Affected . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 L. Interchangeability and Intermixability of Parts . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2. MATERIAL INFORMATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 A. Material - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 B. Industry Support Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 C. Parts Necessary For Each Airplane. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 1. Kits/Parts: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2. Parts and Materials Supplied by the Operator:. . . . . . . . . . . . . . . . . . . . . . . . 17 3. Parts Modified and Reidentified: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 4. Parts Removed and Not Replaced:. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 D. Parts Necessary to Change Spares. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 E. Special Tooling - Price and Availability. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 F. Special Tooling Necessary to do this Service Bulletin. . . . . . . . . . . . . . . . . . . . . . . 18 3. ACCOMPLISHMENT INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 A. GENERAL INFORMATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 B. WORK INSTRUCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 FIGURE 1: STRINGER 11 AT THE OUTBOARD FLAP, INBOARD DRIVE HINGE AT STATION XRS=164.000 - EDDY CURRENT, HIGH FREQUENCY INSPECTION. . . . . . . . . . . 22

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 3 of 23 **BOEING SERVICE BULLETIN MD90-57A030 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 4 of 23 **BOEING SERVICE BULLETIN MD90-57A030 ALERT**  **ALERT**

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### Commercial **Airplanes** 

# MD90 Service Bulletin **ALERT Summary**  **Number: MD90-57A030** Original Issue: February 14, 2012 ATA System: 5710 **SUBJECT:** WINGS - Main Frame - Inspect/Repair Stringer 11 at the Outboard Flap, Inboard Drive Hinge at Station Xrs=164.000 Left and Right Wings 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** Three MD-80 operators reported four instances of cracks found in Stringer 11 at the outboard flap, inboard drive hinge at Station Xrs=164.000. The cracking occurs at the end fastener of the wing bulkhead clip attachment to the stringer. The cracked stringers were found by chance, during maintenance, except in one case when the rear spar cap had been removed during a spar cap splice repair. No cracks have been reported by MD-90 operators. The MD-90 however shares the same structure design as that of the MD-80 and is thus susceptible to cracking. Boeing investigation and analysis have shown that the Stringer 11 cracking is due to fatigue. If undetected, a crack in the stringer may grow until the stringer severs, initiating a crack in the wing lower skin. Continuing damage into the wing skin may result in the wing structure not being capable of sustaining the required loads. Inspection of the affected areas will determine the condition of the stringer, prevent any crack migration, and ensure repairs are done before additional damage occurs. A splice repair for crack found on the affected stringer can be accomplished by installing a segment of stringer. If not corrected, fuel leaks and damage to the wing skin or other structure may occur, resulting in possible loss of the structural integrity of the wing. Boeing Fleet Team Digest (FTD) MD-90 FTD MD-90-FTD-57-11001 is related to this service bulletin. **ACTION** This service bulletin provides instructions to do an Eddy Current, High Frequency (ETHF) inspection for cracks in Stringer 11 at the outboard flap, inboard drive hinge at Station Xrs=164.000 left and right wings. Refer to Paragraph 1.D., Description, for the required corrective action based on the results of the inspection. **EFFECTIVITY** MD-90-30 Airplanes. Refer to Paragraph 1.A.1., Airplanes, for the list of affected airplanes.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 5 of 23**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** Boeing Supplied Kits/Parts. Refer to Paragraph 2.A., Material - Price and Availability.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 6 of 23 **BOEING SERVICE BULLETIN MD90-57A030 ALERT**  **ALERT**

### Commercial **Airplanes** 

# MD90 Service Bulletin **ALERT Number: MD90-57A030**  Original Issue: February 14, 2012 ATA System: 5710 **SUBJECT:** WINGS - Main Frame - Inspect/Repair Stringer 11 at the Outboard Flap, Inboard Drive Hinge at Station Xrs=164.000 Left and Right Wings 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 This service bulletin is for the airplanes shown below.
**DESCRIPTION CONFIGURATION**  **GROUP** Inspect/Repair Stringer 11 at the Outboard Flap, Inboard Drive Hinge at Station Xrs=164.000 left and right wings. - 1

Airplane Models: MD-90-30 **Group Fuselage Num-**  **ber** 1 2094 - 2100 1 2115 1 2117 1 2120 1 2122 - 2123 1 2125 - 2126 1 2129

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 7 of 23**Group Fuselage Num-**  **ber** 1 2131 1 2133 1 2136 1 2138 1 2140 - 2144 1 2146 - 2147 1 2149 - 2150 1 2153 - 2154 1 2156 - 2159 1 2161 - 2166 1 2168 - 2173 1 2175 1 2177 1 2179 1 2181 - 2182 1 2184 1 2186 1 2190 - 2191 1 2193 - 2195 1 2197 - 2198 1 2200 1 2202 - 2203 1 2205 1 2207 1 2209 - 2213 1 2215 - 2217 1 2219 - 2233 1 2235 - 2238 1 2240 1 2242 - 2243 1 2245 - 2246 1 2248

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 8 of 23 **BOEING SERVICE BULLETIN MD90-57A030 ALERT**  **ALERT Group**  **Fuselage Num- ber**  1 2250 - 2251 1 2253 1 2255 - 2263 1 2288 - 2290 2. Spares Affected None. **B. Concurrent Requirements** None. **C. Reason** Three MD-80 operators reported four instances of cracks found in Stringer 11 at the outboard flap, inboard drive hinge at Station Xrs=164.000. The cracking occurs at the end fastener of the wing bulkhead clip attachment to the stringer. The cracked stringers were found by chance, during maintenance, except in one case when the rear spar cap had been removed during a spar cap splice repair. No cracks have been reported by MD-90 operators. The MD-90 however shares the same structure design as that of the MD-80 and is thus susceptible to cracking. Boeing investigation and analysis have shown that the Stringer 11 cracking is due to fatigue. If undetected, a crack in the stringer may grow until the stringer severs, initiating a crack in the wing lower skin. Continuing damage into the wing skin may result in the wing structure not being capable of sustaining the required loads. Inspection of the affected areas will determine the condition of the stringer, prevent any crack migration, and ensure repairs are done before additional damage occurs. A splice repair for crack found on the affected stringer can be accomplished by installing a segment of stringer. If not corrected, fuel leaks and damage to the wing skin or other structure may occur, resulting in possible loss of the structural integrity of the wing. Boeing Fleet Team Digest (FTD) MD-90 FTD MD-90-FTD-57-11001 is related to this service bulletin. **D. Description** This service bulletin provides instructions to do an Eddy Current, High Frequency (ETHF) inspection for cracks in Stringer 11 at the outboard flap, inboard drive hinge at Station Xrs=164.000 left and right wings, and based on inspection results does as follows: **Condition 1 (No Crack Found)** 1. Does repeat ETHF inspection for cracks in Stringer 11 at the outboard flap, inboard drive hinge at Station Xrs=164.000. **Condition 2 (Crack Found)** 1. Does splice repair. 2. Does ETHF inspection for cracks in Stringer 11 at the outboard flap, inboard drive hinge at Station Xrs=164.000.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 9 of 23 **BOEING SERVICE BULLETIN MD90-57A030 ALERT**  **ALERT**The work in this service bulletin is done in the maintenance zone(s) given below.
**Affected Maintenance Zones Zone**  **Model** 531, 631 MD-90-30 **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. Accomplish the required actions, based on the applicable conditions, in Table 1, in accordance with Paragraph 3. Accomplishment Instructions. **Table 1: Inspect Stringer 11 for Crack at the Outboard Flap, Inboard Drive Hinge at Station Xrs=164.000 left and right wings.**  **Repeat Interval**  **(Not to Exceed)**  **Compliance Time (Whichever Occurs Later)**  **Action Condition** 

- Within 9,470 flight cy- cles after the original issue date on this service bulletin.Before the accumulation of 14,000 total flight cycles. Do Eddy Current, High Frequency (ETHF) inspection for cracks in Stringer 11 at the outboard flap, inboard drive hinge at Station Xrs=164.000. All airplanes

31,000 flight cycles. - - Do ETHF inspection for cracks in Stringer 11 at the outboard flap, inboard drive hinge at Station Xrs=164.000. (a) Condition 1: (No Crack Found)

- - Before further flight. Do splice repair. Condition 2: (Crack Found) AND 31,000 flight cycles. - 42,000 flight cycles after splice repair. Do ETHF inspection for cracks in Stringer 11 at the outboard flap, inboard drive hinge at Station Xrs=164.000. (b) (a) If any crack is found, do the actions specified by Condition 2. (b) If any crack is found, contact The Boeing Company for repair instructions and do the repair.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 10 of 23 **BOEING SERVICE BULLETIN MD90-57A030 ALERT**  **ALERT F. Approval**  This service bulletin was examined by the Federal Aviation Administration (FAA). The changes specified in this service bulletin comply with the applicable regulations and are FAA approved, as well as European Aviation Safety Agency (EASA)/Joint Aviation Authorities (JAA) approved for all EASA/JAA approved airplanes listed in the service bulletin effectivity. This service bulletin and its approval were based on the airplane in its original Boeing delivery configuration or as modified by other approved Boeing changes. If an airplane has a non-Boeing modification or repair that affects a component or system also affected by this service bulletin, the operator is responsible for obtaining appropriate regulatory agency approval before incorporating this service bulletin. **G. Manpower** The table below shows an estimate of the task hours necessary to do the inspection/repair for each wing. 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 examine the work — Time to cure the materials — Time to make the parts — Time to find the tools. — Time to make reference standards. **Condition 1 (No Crack Found) Elapsed Hours**  **Task Hours Number of Persons**  **Task** 4.0 4.0 1 Defuel Tank 8.0 8.0 1 Purge Tank 1.0 1.0 1 FIGURE 1 13.0 13.0 TOTAL FOR EACH WING **Condition 2 (Crack Found) Elapsed Hours**  **Task Hours Number of Persons**  **Task** 4.0 4.0 1 Defuel Tank 8.0 8.0 1 Purge Tank 1.0 1.0 1 FIGURE 1 40.0 80.0 2 Splice Repair 53.0 93.0 TOTAL FOR EACH WING

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 11 of 23 **BOEING SERVICE BULLETIN MD90-57A030 ALERT**  **ALERT H. Weight and Balance Changes**  Condition 1 (No Crack Found) None. Condition 2 (Crack Found)

**Moment Change (MEW) IN.-LBS**  **Mfr's Empty Weight (MEW)**  **LBS Approximate Sta**  **tion (Inches) Airplane**  + 7562.8 + 7.4 + 1022.0 MD-90-30 (Left Wing Only) + 7562.8 + 7.4 + 1022.0 MD-90-30 (Right Wing Only) + 15525.6 + 14.8 + 1022.0 MD-90-30 (Both Wings)

**I. Electrical Load Data** Not changed. **J. References** 1. Existing Data: a. Non-Destructive Test Standard Practices Manual (NDTSPM) 06-10-01.001. b. MD-90 Aircraft Maintenance Manual (AMM) 06-35-00, 06-36-00, 12-11-01, 28-00-00, 28-10-01. c. MD-90 Fleet Team Digest (FTD) MD-90-FTD-57-11001. d. MD-90 Structural Repair Manual (SRM) 51, 51-10-09 Volume II 2. Data supplied with this Service Bulletin: No data is supplied with this service bulletin. To obtain the data necessary to support this service bulletin submit a data request to: Data and Services Management MS D800-0019 3855 Lakewood Boulevard Long Beach, California 90846 Phone: (562) 593-6996 Fax: (562) 593-2001 E-mail: dse.boecom@boeing.com a. Drawings:
**ADCN DCN/REV**  **Sheet Title**  **Drawing No**

- - DWG STRG 11 REPAIR, LWR WING, XRS 164.000 SR90570009

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 12 of 23 **BOEING SERVICE BULLETIN MD90-57A030 ALERT**  **ALERT**3. Installation Drawings Used in the Preparation of this Service Bulletin: None. **K. Publications Affected** 1. Publications: None. 2. Damage Tolerance Based Structural Inspections: Boeing has evaluated the repairs and/or changes in this service bulletin for effects on Fatigue Critical Structure (FCS) and for changes to Damage Tolerance Inspections (DTI) required in the Maintenance Program. This service bulletin affects FCS. DTI requirements for the structure affected are contained in Paragraph 1.E., Compliance of this service bulletin. **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: February 14, 2012 MD90-57A030 13 of 23 **BOEING SERVICE BULLETIN MD90-57A030 ALERT**  **ALERT**BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 14 of 23 **BOEING SERVICE BULLETIN MD90-57A030 ALERT**  **ALERT**

BLANK PAGE**2. MATERIAL INFORMATION A. Material - Price and Availability**  Boeing can supply the kit shown in Paragraph 2.C., Parts Necessary for Each Airplane . Operators are encouraged to share schedule requirements with Boeing for incorporation of the service bulletin. The kit is subject to the terms and conditions of the Boeing standard purchase order acknowledgment. Prices are in United States Dollars. Terms: Net 30 days. Reference this service bulletin and submit your purchase order by one of these methods: 1. Order on-line via ATA Spec 2000 or The Boeing PART Page 2. Fax to (206) 662-7145 **REFER TO THE BOEING PART PAGE ON MYBOEINGFLEET.COM OR CONTACT FIRST RESPONDER AT FR@BOEING.COM FOR THE LATEST REORDER LEAD TIME (ROLT) AND PRICE INFORMATION** 
**Unit Price as of the original issue** **date of this Ser vice Bulletin (US**  **Dollars) ROLT as of the**  **original issue date of this Ser** **vice Bulletin (Cal endar Days)**  **Name Kit Number** 

$28,126.00 119 Service Kit SB90570030-3 **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: To get the kits/parts shown below, refer to Paragraph 2.A., Material - Price and Availability. **Condition 1 (No Crack Found)** a. None. **Condition 2 (Crack Found)** a. One top kit per wing and the items shown in Paragraph 2.C.2., Parts and Materials Supplied by the Operator, are necessary for each airplane.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 15 of 23 **BOEING SERVICE BULLETIN MD90-57A030 ALERT**  **ALERT ALL** 
**Kit SB90570030 Notes**  **Existing Part Number**  **Name QTY**  **New Part Number -3** 

- SB90570030-3 (a) NUT ASSY 40 3D0006-3 (a) NUT ASSY 64 3D0006-4 PIN 1 HLT435-8-13 PIN 2 HLT435-8-15 PIN 3 HLT436-10-12 PIN 1 HLT436-10-21 PIN 2 HLT436-6-14 PIN 2 HLT436-8-5 PIN 4 HLT436-8-7 PIN 12 HLT439-6-10 PIN 4 HLT439-6-11 PIN 4 HLT439-6-12 PIN 1 HLT439-6-14 PIN 2 HLT439-6-15 PIN 4 HLT439-8-8 PIN 10 HLT639-8-11 PIN 13 HLT639-8-12 PIN 18 HLT639-8-13 PIN 8 HLT639-8-14 PIN, OVERSIZE 2 HST112-8-14 NUT 13 MS21042L3 NUT 2 MS21042L4 NUT 4 MS21042L5 WASHER 2 NAS1252-416L WASHER 4 NAS1252-516L WASHER 17 NAS1401-3D3 WASHER 52 NAS1401-4D3 (a) PIN 8 S4931920-6-6 (a) PIN 7 S4931920-6-7

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 16 of 23 **BOEING SERVICE BULLETIN MD90-57A030 ALERT**  **ALERT ALL** 
**Kit SB90570030 Notes**  **Existing Part Number**  **Name QTY**  **New Part Number -3**  (a) PIN 13 S4931920-6-8 (a) PIN 2 S4931920-8-4 STRINGER 1 SR09570100-3 ANGLE 2 SR09570100-7 CHANNEL 2 SR09570100-9 ANGLE 1 SR09570100-11 ANGLE 1 SR09570100-12 (a) Or approved equivalent. Refer to the AEPL, Drawing 7595071. 2. Parts and Materials Supplied by the Operator: **Condition 1 (No Crack Found)** a. None. **Condition 2 (Crack Found)** a. Materials necessary to complete the action in this service bulletin.
**Notes Name**  **QTY Part Number / Specifica-**  **tion** (a) Sealant 1 Quart PR-1422 B-2 (DMS 2082) or Equivalent (b) MC Coating, Chemical Film 1 Quart Alodine 1200S (DPM 1453-5) or Equivalent (b) Coating, Fuel Tank, Inte- gral 1 Pint #833K086 Base; #930K088 Curing Solution (DMS 1850 Type 4 Composition C) or Equivalent (a) Can be purchased from: PRC - DeSoto International, Incorporated (CAGE: 85570), 11601 United Street, Mojave, California 93501.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 17 of 23 **BOEING SERVICE BULLETIN MD90-57A030 ALERT**  **ALERT Notes**  **Name QTY**  **Part Number / Specifica- tion**  (b) Can be purchased from: Henkel Corporation (CAGE 1N6B3), 32100 Stephenson Highway, Madison Heights, Michigan 48071.
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 Condition 1 (No Crack Found)**  1. None. **Condition 2 (Crack Found)** 1. The MD-90 SRM 51-10-09 Volume II gives data about cold working tools and sleeves necessary to do the work given in this service bulletin. These tools are available from industry sources. **F. Special Tooling Necessary to do this Service Bulletin Condition 1 (No Crack Found)**  1. 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. **Condition 2 (Crack Found)** 1. Cold working tools are necessary to do the change given in this service bulletin. Refer to Service Rework Drawing SR90570009. To get the cold working tools, refer to Paragraph 2.E., Special Tooling - Price and Availability.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 18 of 23 **BOEING SERVICE BULLETIN MD90-57A030 ALERT**  **ALERT 3. ACCOMPLISHMENT INSTRUCTIONS**  **A. GENERAL INFORMATION WARNING:**  IF ELECTRICAL POWER IS APPLIED TO THE AIRPLANE, MAKE SURE YOU OBEY ALL PRECAUTIONS WHILE YOU DO WORK. IF YOU DO NOT OBEY THE PRECAUTIONS, DEATH OR INJURY TO PERSONS, AND DAMAGE TO THE AIRPLANE CAN OCCUR. **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. **CAUTION:** ELECTRICALLY GROUND THE AIRPLANE. THIS WILL HELP TO PREVENT DAMAGE TO THE AIRPLANE OR EQUIPMENT. **NOTE:** 1. Manual titles are referred to by acronyms. Refer to Paragraph 1.J., References for definition of the acronyms. 2. Equivalent parts are listed in the AEPL, Drawing 7595071. 3. Use the approved fastener and process material substitutions, in accordance with MD-90 SRM 51. 4. If the length of any fastener specified in this service bulletin does not meet installation standards given in Structural Repair Manual (SRM) Chapter 51, then a fastener of the same specification, or an approved substitute, with a length which meets the installation standards given in MD-90 SRM 51 may be used. In addition, washers may be installed for fastener grip length in accordance with MD-90 SRM 51. 5. A 1/8-inch thick stack of the same type washers called for in this service bulletin is the maximum thickness which may be used under fastener head or nut to counteract accumulation of tolerances. EXCEPTION: When the available fastener length increments are greater than 1/16-inch, a 3/16-inch thick stack of the same type washers may be used. 6. 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 are in MD-90 SRM 51. – Torque limits to tighten nuts and bolts are in MD-90 SRM 51. 7. Obey all of the warnings and cautions given in the specified manual sections.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 19 of 23 **BOEING SERVICE BULLETIN MD90-57A030 ALERT**  **ALERT**8. These work instructions refer to procedures included in other Boeing documents. When the words "refer to" are used and the operator has an accepted alternative procedure, the accepted alternative procedure can be used. When the words "in accordance with" are included in the instruction, the procedure in the Boeing document must be used. 9. Some Boeing parts are supplied in a temporary configuration. Those parts are identified with a 'U' or 'Y' in place of the '-' (dash) in the part number. It is permitted to install parts identified with a 'U' or 'Y' as an alternative to the '-' (dash) number part. Boeing Drawing SE10000000, Sheets 5.0 and 6.0 contain more data. 10. 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. 11. 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. 12. 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. **B. WORK INSTRUCTIONS WARNING:**  BEFORE MOVING FLAP/SLAT HANDLE, MAKE CERTAIN THAT AREAS AROUND FLAPS AND SLATS ARE CLEAR OF PERSONNEL AND EQUIPMENT. 1. Defuel and purge left and right fuel tanks. Refer to MD-90 AMM 12-11-01, MD-90 AMM 28-00-00 and MD-90 AMM 28-10-01 as accepted procedures. 2. Remove/keep door numbers 520DT and 520CB on the left wing main tank and door numbers 620DT and 620CB on the right wing main tank and attaching parts. Refer to MD-90 AMM 06-35-00 and MD-90 AMM 06-36-00. 3. Prepare fuel tank for entry and gain access to the area of inspection of Stringer 11 at the outboard flap, inboard drive hinge at Station Xrs=164.000. 4. Do an in-tank Eddy Current, High Frequency (ETHF) inspection for cracks in Stringer 11 at the outboard flap, inboard drive hinge at Station Xrs=164.000 left and right wings in accordance with FIGURE 1, and based on inspection results do as follows:
**Condition 1 (No Crack Found)** a. Do repeat ETHF inspection for cracks in Stringer 11 at the outboard flap, inboard drive hinge at Station Xrs=164.000 in accordance with FIGURE 1, at intervals specified in Paragraph 1.E., Compliance. **Condition 2 (Crack Found)** a. Do splice repair in accordance with Service Rework SR90570009.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 20 of 23 **BOEING SERVICE BULLETIN MD90-57A030 ALERT**  **ALERT**b. Do ETHF inspection for cracks in Stringer 11 at the outboard flap, inboard drive hinge at Station Xrs=164.000 in accordance with Service Rework Drawing SR90570009, Zone 15, at intervals specified in Paragraph 1.E., Compliance. 5. Put the airplane back to a serviceable condition.

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 21 of 23 **BOEING SERVICE BULLETIN MD90-57A030 ALERT**  **ALERT FIGURE 1: STRINGER 11 AT THE OUTBOARD FLAP, INBOARD DRIVE HINGE AT STATION XRS=164.000**  **- EDDY CURRENT, HIGH FREQUENCY INSPECTION (SHEET 1 OF 2)** 

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 22 of 23 **BOEING SERVICE BULLETIN MD90-57A030 ALERT**  **ALERT**The step numbers shown below agree with the numbers shown in the circle symbols in the figure. The QTY numbers shown below are the number of parts necessary for each airplane.
**More Data QTY**  **Identification Name**  **Task Step**  (a) 1 5919236-507 Stringer Inspect 1 and 5919236-508 (a) Perform an Eddy Current, High Frequency (ETHF) surface inspection of Stringer 11 in the area of the bulkhead at Station Xrs = 164.000. Scan the forward face of the vertical flange of the stringer, around the four fasteners common with the angles shown. Scan looking for cracks originating at the fastener holes and propagating in the vertical direction. Scan around fasteners in accordance with NDTSPM 06-10-01.001, Procedure 1. Use calibration scan method "K" and Scan Method 44.

**FIGURE 1: STRINGER 11 AT THE OUTBOARD FLAP, INBOARD DRIVE HINGE AT STATION XRS=164.000 - EDDY CURRENT, HIGH FREQUENCY INSPECTION**  **(SHEET 2 OF 2)**

BOEING PROPRIETARY - Copyright © Unpublished Work - See page 1 for details. Original Issue: February 14, 2012 MD90-57A030 23 of 23 **BOEING SERVICE BULLETIN MD90-57A030 ALERT**  **ALERT**