# McDonnell Douglas Service Bulletin A53-231: Revision 2 - Rights: © The Boeing Company. Filed by the FAA in regulations.gov docket FAA-2014-0288; AD 2014-22-04 incorporates this document by reference. Not covered by OpenAirDocs’ CC0 dedication. - Document: [McDonnell Douglas Service Bulletin A53-231](https://openairdocs.org/service-documents/boeing/a53-231.md) - Title as filed: U.S. DOT/FAA - SB-DC9-A53-231-r2 - Pages: 71 - PDF: https://openairdocs.org/files/sha256/7f/23/7f23c04eeae525fcc201687951b9777f7773c49ce3004a73685abb7b99932027 - Page: https://openairdocs.org/service-documents/boeing/a53-231/file/7f23c04eeae5 ## Text This text is OCR from a scan. OCR can misread letters and numbers. Each page's text from the PDF; open the PDF at a page with #page=N. ### Page 1 (OCR) DOUGLAS AIRCRAFT COMPANY ALERT MCDONNELL DOUGLAS OC-S BULLETIN A53-231 ¡SERVICE BULLETIN; REVISION TRANSMITTAL SHEET FUSELAGE - Main Frame - Inspect/Repair Aft Fuselage Non-Ventral Pressure Bulkhead Tee. This page transmits Revision 2 for DC-9 Alert Service Bulletin A53-231 to incorporate the following changes: NOTE: This revision constitutes a complete reissue and reflects current operators of affected aircraft at time of issue. Reason for Revision: To incorporate engineering released subsequent to prior issue of this Alert Service Bulletin, which adds a different eddy current probe for aircraft which have accomplished Alert Service Bulletin A53-147. A different eddy current probe is required because an operator could not inspect aft pressure bulkhead tee using the standard probe provided by prior issue of this Service Bulletin. This condition is due to the length of Hi-Lok pins used to modify aircraft per DC-9 Service Bulletin A53-147. No additional work is required by this revision for aircraft previously inspected/repaired by prior issue of this Alert Service Bulletin. Page 1: Changed page number to I of 50, was I of 46. Pages 6 Added NOTE under paragraph 1.C., Option II, Condition 2. and 7: Revised Approval statement. Pages 10 Changed Service Sketch to 3683D, was 3683C. and 11: Added DC-9 Service Bulletin A53-147 to References as new paragraph 1.J. (2). Reidentified subsequent paragraphs accordingly. Added paragraphs I.L and 1.M. Pages 12 Added new GENERAL NOTE 1, reidentified subsequent notes accordingly. 14, and 15: Added new paragraph 2.C, reidentified subsequent paragraphs accordingly. Added NOTE under paragraphs 2.A. (4) and 2.K. (4). McDonnell Douglas Corporation (MDC) proprietary rights are included in the information disclosed herein, and recipient by accepting this document agrees that the information is proprietary to MDC. MDC authorizes recipient to reproduce such information in other documents created for internal use if these documents are protected similarly by a proprietary legend. Bulletin A53-231 February 24/89 Page 1 of 2 Revision 2 June 25/93 ### Page 2 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT* Pages 19 Revised Figure 3 as follows: thru 35: Added NOTE under paragraph 8.f.(1) on Sheet 2 of 17. Added Note under paragraph B. (1)(a) and revised paragraph (1)(c) under Sequence 1 on Sheet 4 of 17. Revised paragraph (1)(c) under Sequence 2 on Sheet 5 of 17. Added new sheet 7, and 15 through 17. Reidentified sheets accordingly. Revised callout for eddy current probe on Sheet 6 of 17. Revised callout for eddy current probe on Sheet 8 of 17. Pages 45 Revised paragraphs 3.A(1) and 3.A.(3). and 46: Pages 47 Revised paragraphs 3.C. (1) and 3.C.(4). and 50: Revision Sequence: Original Date February 24/89 Revision l April 2/90 Revision 2 June 25/93 CAS LL-2 Bulletin A53-231 February 24/89 Page 2 Revision 2 June 25/93 McDonnell Dougles Corporation Proprietary Inforation. Ues or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 3 (OCR) DOUGLAS AIRCRAFT COMPANY ALERT MCDONNELL DOUGLAS DC-S PO 80x 1771 Long Beach, CA BULLETIN A53-231 90801 SERVICE BULLETIN FUSELAGE - Main Frame - Inspect/Repair Aft Fuselage Non-Ventral Pressure Bulkhead Tee. NOTE This Alert Service Bulletin is affected by Federal Aviation Administration Airworthiness Directive No. 89-06-04: Amendment 39-6152, effective March 24, 1989. This Alert Service Bulletin is applicable only to aircraft equipped with the non-ventral aft pressure bulkhead which have accumulated 25,000 or more landings. Replacement of all six aft pressure bulkhead tee sections with new improved parts per this Alert Service Bulletin constitutes closing action for the repetitive inspection requirements of this Alert Service Bulletin. This Alert Service Bulletin supersedes but does not cancel the requirements of DC-9 Alert Service Bulletin A53-191. Only aircraft listed in this Alert Service Bulletin that are contained in the Effectivity of Alert Service Bulletin A53-191 are affected by this contingency. This Alert Service Bulletin is issued as a partial record-type change. A service rework drawing or aperture cards are furnished in lieu of illustrations. I. Planning Information: A. Effectivity: (1) Aircraft Affected: 2c-2. Series 10. 30. and c-9 McDonnell Douglas Corporation (MDC) proprietary rights are included in the information disclosed herein, and recipient by accepting this document agrees that the information is proprietary to MDC. MDC authorizes recipient to reproduce such information in other documents created for internal use if these documents are protected similarly by a proprietary legend. February 24/89 Bulletin A53-231 | Revision 2 June 25/93 Page 1 of 50 ### Page 4 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN (a) Operator and Aircraft Number: Operator Factory Serial No. Operator Factory Serial No. 45845 GB 45728 47019 45874 47021 and 47022 47040 47024 47074 47069 thru 47071 47147 and 47148 47195 47165 47198 and 47199 47269 47265 and 47266 47384 47289 and 47290 47403 47292 thru 47294 47413 47340 thru 47342 47348 thru 47350 TI 47408 47353 and 47354 47422 JP 47392 47485 47546 ML and 47554 45838 thru 47557 and 47560 47592 47598 47611 47166 and 47167 BD . 45712 and 45713 47186 and 47187 45719 47214 45738 and 45739 47048 NK 47268 47423 and 47424 NW nayz pur 45708 EA 45733 and 45734 45833 and 45834 FALSE 45837 OLLSE 45863 thru 45865 45825 47161 6289₺ thru 45832 47181 47049 47215 47097 47327 and 47328 47139 47402 47141 thru 47145 47158 EZ 47220 47355 47162 47182 and thru 47164 47183 47414 47185 47376 FP 45702 Bulletin A53-231 February 24/89 Page 2 Revision 2 June 25/93 McDonnell Dougles Corporation Proprietary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 5 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN Operator Factory Serial No. Operator Factory Serial No. RS 45721 and 45722 ZCP 47151 45776 45780 and 45781 ZDF 45871 thru 45873 45783 47270 and 47271 47125 47127 ZGM 45778 45782 TW 47082 45784 47095 and 47096 47134 thru 47137 ZG4 47329 47409 ZIL 45698 and 45699 US 45846 47060 45868 47020 ZJ6 45775 47023 47053 and 47054 ZK7 45740 47057 and 47058 47066 ZNV 47041 47068 47221 47188 and 47189 47639 47216 47351 and 47352 Z3Z 45701 45709 VC 45875 45723 47036 47272 Z4B 45695 47330 and 47331 47399 Z5F 47123 47401 47119 XYX 45696 45711 Z5Y 45715 and 45716 45718 45735 45725 45737 45727 45741 and 45742 45795 45842 45843 45779 and 45844 YUZ 45720 Z6H 47217 ZCA 45714 Z7B 45730 45736 45743 Z8H 45706 47043 47059 47085 47122 47126 Bulletin A53-231 February 24/89 Page 3 Revision 2 June 25/93 McDonnell Douglas Corporation Proprietary Information. Les or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE ### Page 6 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN (b) Manufacturer's Fuselage and Factory Serial Numbers: EUS (ESN) FUS (ESN) EUS (FSN) EUS (ES12 EUS (ESN EUS (ESN) 10 (45715) 12(45701) 21 (45703) 23 (45842) 13 (45716) 14 (45728) 24 (45704) 27 (45720) 15 (45702) 16(45729) 17 (45718) 18(45719) 19(45725) 25(45735) 26 (45742) 28 (45843) 35(47048) 38(45746) 29 (45743) 37 (45730) 31(45744) 32(45745) 33 (45844) 45 (45736) 103 (45837) 200 (47041) 303 (47189) 406 (47329) 43 (45727) 44 (45721) 40(45747) 42 (47049) 9(45713) 1(45695) 2(45696) 5(45698) 6(45712) 7 (45714) 8 (45699) 4(45711) 101 (45781) 49 (45737) 57 (45770) 50 (45749) 56(45739) 47(45748) 48 (45733) 53(45705) 54(45738) 55(45722) 62 (45740) 60 (45734) 61(45706) 63 (45723) 65 (45795) 66 (45741) 67 (45825) 70(45707) 72 (45776) 68 (45829) 71(45775) 73 (45833) 75(45830) 76(45831) 77 (45708) 78 (45709) 88 (47043) 92 (45779) 82 (45778) 91(45845) 93 (45780) 96(45836) 84(45832) 85 (45834) 95(45835) 109 (47060) 112(45846) 107 (47053) 110 (47054) 113(47019) 104 (45838) 122 (47057) 128 (45783) 126 (47020) 114(45782) 116(45839) 117(45840) 123(47058) 124 (45863) 125(47059) 130 (45864) 137 (45865) 133 (47021) 138 139 140 144 160 (47068) 150 158 159 181 (47082) 175 (47069) 188(47071) 191(47095) 192(47096) 193 (47097) 169 (47139) 172 (47040) 176 (47070) (47085) (47024) (47066) (47022) (45866) (45784) (47023) 215(47134) 208 212(47140) 246(47148) 239(47144) 224 (47122) 227 232 (47142) 233(47135) 238 (47143) 243 (47136) 247 (47145) 248(47158) 249(47161) 253 (47123) 255(47162) 256(47163) 259 258 260 265 266 267 271 272 275 276 278 282 283 285 291 (47188) 296 (47220) 302 (47198) 290 (47147) (47141) (47137) (47187) (47164) (47167) (47185) (47165) (47166) (47182) (47181) (47195) (47183) (47186) (47151) (45868) (45867) 305 (47221) 306(47214) 313(47215) 315 321 360 (47217) 345 (45872) 350 (45873) 351 (45874) 322 331 339 (47265) 344 (45871) 353 (47289) 365 366 367 370 376 (47074) 383 (47292) 352 371 374 375 378 (47119) 389 (47271) 390 (47272) 391 (47327) 403 (47340) 384 (47293) 388 392 402 (47294) 404 (47341) 405 (47126) (47216) (47157) (45869) (47266) (47199) (47036) (45875) (45876) (47290) (47268) (47269) (47270) (47125) (47328) 430 (47399) 408 (47331) 417 (47127) 407 (47330) 418 419 420 431 (47350) 442 447 (47392) 467(47408) 471 (47353) 517 (47376) 521 (47413) 452 (47355) 543 (47384) 576 (47422) 444 (47401) 453 482 (47402) 483 497 (47409) 507 (47403) 536 (47414) 581 (47423) 658 (47554) 582 (47424) 655 (47546) 666 (47485) 712 (47592) 719(47598) 726(47611) 661 (47557) 735 (47639) 664 (47560) . (47351) (47342) (47348) (47352) (47349) (47354) This modification is applicable only to listed aircraft. (2) Spares Affected: None. February 24/89 Bulletin A53-231 Revision 2 June 25/93 Page 4 McDonnell Douglas Corporation Propriatary Information. Use or discioure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 7 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN B. Reason: One operator reported a cracked aft pressure bulkhead attach tee section on one afrcraft. The aircraft was a non-ventral bulkhead aircraft. The crack in the upstanding leg of the tee extended circumferentially approximately 24 inches from the production end of the tee, at splice between longerons 17 and 18 left side, upward to longeron 15. The affected aircraft had accumulated 36,079 landings when the crack was found. Analysis of the failed part revealed that the crack initiated at multiple sites on the forward surface of the upstanding leg of the tee as the result of fatigue due primarily to bending loads. Five other operators reported cracks in a total of 39,172 and 81,915 landings. The predominant areas of cracks were at eight other aircraft. These eight aircraft had accumulated between the upper splice between longeron 6 and 7 (4 cases left side); one crack occurred respectively at longeron 8, 11, 12, 13, and 15 (predominately on left side); and lower pylon attach angle at or between longeron 16 and 17(5 cases left side and one case right side). If cracks are not detected and repaired, they could progress to the point that rapid decompression could occur. Inspection of high cycle aircraft and accomplishment of repairs based on condition will allow continued flight operation. C. Description: This Service Bulletin accomplishes the following on the fuselage aft pressure bulkhead. Option I (Inspection from aft side of bulkhead) Performs visual and low frequency eddy current inspections for cracked aft pressure bulkhead web-to-fuselage tee sections around the entire periphery of the fuselage from the aft side of the bulkhead and accomplishes the following: Condition (No Crack) Repetitively visually and low frequency eddy current inspects for cracks from aft side of bulkhead at intervals specified in Compliance paragraph. Condition 2 (Crack) Replaces cracked tee section with new like or improved part and repetitively visually and low frequency eddy current inspects for cracks from aft side of bulkhead at intervals specified in Compliance paragraph. February 24/89 Bulletin A53-231 Revision 2 June 25/93 Page 5 McDonnell Douglas Corporation Proprietary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 8 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN Option Il (Inspection from forward side of oulkhead) Performs high and low frequency eddy current inspections for cracked aft pressure bulkhead web-to-fuselage tee sections around the entire periphery of the fuselage from the forward side of the bulkhead and accomplishes the following: Condition 1 (No crack) Repetitively high and low frequency eddy current inspects for cracks from forward side of bulkhead at intervals specified in Compliance paragraph. Condition 2 (Crack) Replaces cracked tee section with new like or improved part and repetitively high and low frequency eddy current inspects for cracks from forward side of bulkhead at intervals specified in Compliance paragraph. NOTE: Replacement of all six aft pressure bulkhead tee sections with new improved parts constitutes closing action for the repetitive inspection requirements of this Alert Service Bulletin. D. Comp lance: It is recommended that initial inspection/repair of aft pressure bulkhead tee per Option I or II be accomplished as follows on aircraft having logged over 25,000 landings. Accumulated Landings Initial Inspection 25,000 to 49,999 Within 1500 landings from issue date of Revision 1 of this Service Bulletin 50,000 to 59,999 Within 1000 landings from issue date of Revision l of this Service Bulletin 60,000 and over Within 300 landings from issue date of Revision l of this Service Bulletin When aft pressure bulkhead tee section is replaced with new like part, the repetitive inspection for that section of tee may be discontinued until the aircraft has accumulated an additional 25,000 landings at which time the repetitive inspection for that section of tee are reinstated along with the ongoing repetitive inspections of the remaining original sections of tee. Bulletin A53-231 February 24/89 Page 6 Revision 2 June 25/93 McDonnell Dougles Corporation Propristary Information. Lee or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 9 (OCR) • ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN When aft pressure bulkhead tee section is replaced with new improved part per this Alert Service Bulletin, the repetitive inspection for that section of tee may be discontinued as this constitutes closing action for that section of tee. Perform the recommended Option I or Option II repetitive inspections on the remaining original tee sections. Replacement of all six aft pressure bulkhead tee sections with new improved parts per this Alert Service Bulletin constitutes closing action for the inspection requirements of this Alert Service Bulletin. It is recommended that repetitive inspection/repair of aft pressure bulkhead tee be accomplished per Option I or II as follows: Option I (Inspection from aft side of bulkhead) It is recommended that repetitive low frequency eddy current inspection for cracks of side areas above floor between longerons L7 and L17 on fuselage left and right sides, be accomplished at intervals not to exceed 2000 landings. It is recommended that repetitive visual inspection for cracks of top and lower areas from longeron L7 left side to longeron L7 right side, and lower fuselage longeron L17 to longeron L20 on fuselage left and right sides, be accomplished at intervals not to exceed 1500 landings. It is recommended that repetitive visual inspection for cracks of bottom areas from longeron L20 left side to L20 right side, be accomplished at intervals not to exceed 3500 landings. It is recommended that cracked tee section be replaced prior to further pressurized flight. Option II (Inspection from forward side of bulkhead) It is recommended that repetitive high and low frequency eddy current inspection for cracks around entire periphery of fuselage from forward side of bulkhead be accomplished at intervals not to exceed 2500 landings. It is recommended that cracked tee section be replaced prior to further pressurized flight. E. Approval: The resultant modification described in paragraph 1.C has been shown to comply with the applicable Federal Aviation Regulations and Revision 2 1s approved by the Manager, Los Angeles Aircraft Certification Office, FAA Northwest Mountain Region on June 17, 1993, and is approved as an alternate means of compliance with paragraphs A, B, and C of Airworthiness Directive No. 89-06-04. February 24/89 Bulletin A53-231 Revision 2 June 25/93 Page 7 McDonnell Douglas Corporation Propristary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 10 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN F. Manpower: Man-hours are estimated based on work to be performed by skilled personnel on aircraft/unit which has been placed in a maintenance status. The man-hour/elapsed time estimates do not include: 1. Preparation for the modification: Examples; defueling, purging, placing work stands, opening standard access doors, obtaining tools, and jacking when not essential to the modification. 2. Nonproductive elapsed time: Examples; sealant or adhesive cure time, cleaning, paint drying time, lunch and/or rest periods, and quality assurance inspections. 3. Administrative functions: Examples; planning, engineering liaison, parts requisition, shift change coordination, and report writing. Operators should take the above into consideration when scheduling this modification. Option I (Inspection from aft side of bulkhead) Optically aided visual inspection from the aft side of the fuselage aft pressure bulkhead may be accomplished in approximately 22.0 man-hours or 11.0 elapsed hours per aircraft. Low frequency eddy current inspection from the aft side of the fuselage aft pressure bulkhead may be accomplished in approximately 11.5 man-hours or 5.8 elapsed hours per aircraft. Man-hours do not include time for fabrication of flexible borescope guide tube. Option II (Inspection from forward side of bulkhead) Removal and reinstallation of lavatories, equipment, and sealant for access to the forward side of the fuselage aft pressure bulkhead tee may be accomplished in approximately 140.1 man-hours or 52.9 elapsed hours per aircraft. High and low frequency eddy current inspection from the forward side of the fuselage aft pressure bulkhead may be accomplished in approximately 8.0 man-hours or 4.0 elapsed hours per aircraft. Man-hours do not include time for fabrication of eddy current reference standard. Maximum total man-hours and elapsed hours are given for inspection per aircraft. Actual man-hours and elapsed hours for repair are contingent upon inspection findings and are to be estimated by the operator. Bulletin A53-231 February 24/89 Revision 2 June 25/93 Page 8 McDonnell Dougles Corporation Propristary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 11 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN G. Material - Cost and Availability: (1) Aircrait: Parts and materials required to accomplish this modification are listed in paragraph 3.A and are to be procured as indicated. Parts bearing Douglas Aircraft Company part numbers are proprietary parts and must be procured under the spare parts article of the purchase agreement, unless methods of manufacture are shown. Cost and availability of parts are to be negotiated between the operator and Douglas Aircraft Company. Reference this Service Bulletin number and direct inquiries to: Douglas Aircraft Company P.O. Box 1771 Long Beach, California 90801 Attn: Parts Sales - Commercial 78-22 (DC-9 Alert Service Bulletin A53-231) (2) Spares: Not applicable. H. Iooling - Price and Availability: Option I (Inspection from aft side of bulkhead) Special test equipment is required to accomplish the low frequency eddy current inspection per Option I outlined in this Service Bulletin. Special test equipment is to be procured from operator's stock, or sources indicated in paragraph 3.C. Douglas special eddy current reference standard shown in Figure 2 and listed in paragraph 3.C is required to accomplish low frequency eddy current inspection per Option I and will be made available to the operator at no charge. Procurement and availability of SB08530231-9 special eddy current Douglas Aircraft Company. Specify this Service Bulletin number and reference standard should be negotiated between the operator and the ire inquiries company. Douglas Aircraft Company 910 East 236th Street Carson, California 92805 Group Leader - Recovery and Modification Services 78-22 (DC-9 Alert Service Bulletin A53-231) Bulletin A53-231 February 24/89 Page 9 Revision 2 June 25/93 McDonnell Dougles Corporation Proprietary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 12 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN Option II (Inspection from forward side of bulkhead) (3) Test equipment required to accomplish high and low frequency eddy current inspections per Option II is listed in service sketch 3683D. Choice of test equipment is at operator's option and is to be procured from operator's stock or sources indicated in service sketch 36830. (4) Reference standard required to accomplish high and low frequency eddy current inspections per Option II is shown in service sketch 3683D. Reference standard may be procured from operator's stock, fabricated by the operator, or purchased from source indicated in paragraph 3.D. I. Weight and Balance: Weight change at appropriate fuselage stations by incorporation of any part of this Alert Service Bulletin is contingent upon the modification of each particular aircraft. Weight data is to be computed by the operator by weighing parts installed and parts removed during modification. Necessary revisions should be made to the appropriate weight and balance document. J. References: Federal Aviation Administration Airworthiness Directive No. 89-06-04: Amendment 39-6152, effective March 24, 1989. (2) Alert Service Bulletin A53-147. (3) Data used in preparation of this Alert Service Bulletin: Data Identification Change Iype of Data J060157 DMS 2082 Douglas Material Specification Service Rework Shoring J060157 MM Chapters 6, 20. Advance E.O. Maintenance Manual 21, 25, 26, 36, SRM Chapters 51 and 53 NDT Chapter 1-3 SR09530001 SR09530001 SR09530048 SR09530056 49, 52, and 53 New C D Nondestructive Testing Manual Advance E.O. Structural Repair Manual Service Rework Drawing Service Rework Drawing Service Rework Drawing SR09530056 SR09530083 New D Advance E.O. Service Rework Drawing 5910163 5910163 DG, DH, DF Drawing Advance E.O. and DJ 36830 Service Sketch (attached) February 24/89 Bulletin A53-231 Revision 2 June 25/93 Page 10 McDonnell Douglas Corporation Proprietary Information. Uss or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 13 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN (4) Data supplied in support of this Alert Service Bulletin: Data Identification Change Iype of Data J060157 Service Rework Shoring J060157 B Advance E.O. SR09530001 C Service Rework Drawing SR09530001 D Advance E.O. SR09530048 New Service Rework Drawing SR09530056 C Service Rework Drawing SR09530056 D Advance E.O. SR09530083 New Service Rework Drawing NOTE: Listed data are being furnished to each affected operator. K. Publications Affected: The modification outlined in this Alert Service Bulletin affects the DC-9 Weight and Balance Documents. L. Electrical Loao Data: Not affected. M. Software Accomplishment Summary: Not affected. February 24/89 Bulletin A53-231 Revision 2 June 25/93 Page 11 McDonnell Dougles Corporation Propriatary Information. Use or disctosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 14 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN 2. Accomplishment Instructions: WARNING: TO AVOID INJURY TO MAINTENANCE PERSONNEL OR DAMAGE TO EQUIPMENT, MAKE CERTAIN ADEQUATE PRECAUTIONS ARE TAKEN WHILE PERFORMING ANY WORK IF ELECTRICAL POWER IS APPLIED TO THE AIRCRAFT. CAUTION: ELECTRICALLY GROUND THE AIRCRAFT. GENERAL NOTES: 1. Replacement of all six aft pressure bulkhead tee sections with new improved parts constitutes closing action for the repetitive inspection requirements of this Alert Service Bulletin. If replacing all six aft pressure bulkhead tee sections, replacement should be accomplished one tee section at a time. Refer to sections of the Maintenance Manual (MM), Structural Repair Manual (SRM), and Non-Destructive Testing Manual (NDT). Refer to the following manual chapters for applicable operations: Manual Chapter Operation MM 20-30-0 Sealant Application NDT 1-3 Eddy Current Inspection SRM 51-10-4 Drilling and Countersinking SRM 51-30-1 Installing Bolts, Screws, and Washers SRM 51-30-2 Removing and Installing Rivets SRM 51-30-3 Removing and Installing Lockbolts SRM 51-30-5 Removing and Installing Pins SRM 51-60-0 Substitution and Interchangeability Option I (Inspection from aft side of bulkhead) Operator's Option - Access doors may be installed in skin on bottom of fuselage forward of auxiliary power unit (APU) door per service rework drawing SRO9530048 to facilitate inspection. Operator's Option - Fabricate guide tube (to be used with flexiscope) from flexible or thin wall tubing to fit outside diameter of flexiscope as shown on Figure 1. C. Operator's option - Fabricate reference standard as shown on Figure 2. D. Gain access to inspection areas on aft side of bulkhead by opening or removing and retaining the following access doors/panels as applicable to accomplish visual and/or low frequency eddy current inspection: Access NO. Access Area MM Chapter 5806A Auxiliary Exit Door, 6-12-0 Non-Ventral Bulkhead 5901A Thrust Reverser Control 6-11-4 Valve (Left Side) February 24/89 Bulletin A53-231 Revision 2 June 25/93 Page 12 McDonnell Dougles Corporation Propriatary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 15 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN Access No. Access area MM Chapter 5902A Thrust Reverser Control 6-17-4 Valve (Right Side) 5903A APU Service (Left Side) 6-11-4 5904A APU Service (Right Side) 6-11-4 NOTE: The following paragraphs 2.D through 2.H may be accomplished at operator's option and are applicable to visual inspection requirements. E. Remove and retain APU and attaching parts. (See MM chapter 49-10-0, paragraph entitled Removal/Installation Power Plant. • Fo Remove and retain APU compartment enclosure and attaching parts. (See MM chapter 53-20-5, paragraph entitled "Removal/Installation APU Compartment Enclosure.i) • G. Remove and retain lower firex bottle and attaching parts. (See MM chapter 26-20-1, paragraph entitled, Removal/Installation Fire Extinguishing Containers.") H. Remove and retain right pneumatic crossfeed valve pushrod and attaching parts. (See MM chapter 36-10-3, paragraph entitled "Removal/Installation Pneumatic Crossfeed Valve.") Remove and retain two upper 5953635 conditioned air duct assemblies, check valves, and attaching parts aft of pressure bulkhead center ceiling. (See MM chapter 21-20-2, paragraph entitled "Removal/Installation Conditioned and Cold Air Check Valve.") J. Roll back or remove and retain insulation blankets from aft side of aft pressure bulkhead. (See MM chapter 25-22-0, paragraph entitled "Removal/Installation Insulation Blankets.") K. Perform optically aided visual and low frequency eddy current inspection/repair of the aft pressure bulkhead web to fuselage skin attach tee sections from the aft side of the bulkhead as follows: (1) Inspect the upstanding leg of 5910163 non-ventral bulkhead tee on Figure 3 sections from aft side of bulkhead around the periphery of the bulkhead as shown on Figure 3 and accomplish the following: Condition 1 (No Crack) (2) Perform repetitive visual and/or low frequency eddy current inspections from aft side of bulkhead at intervals specified in Compliance paragraph. Bulletin A53-231 February 24/89 Page 13 Revision 2 June 25/93 McDonnell Dougles Corporation Proprietary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 16 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN Condition 2 (Crack) Replace cracked tee section with new like or improved part per Figure 4 (See Table I for configuration) prior to further pressurized flight. Perform repetitive visual and/or low frequency eddy current inspections from aft side of bulkhead at intervals specified in Compliance paragraph. (4) If any tee section is to be replaced, remove and retain engines 1 and 2. (See MM chapter 71-00-0, paragraph entitled "Removal/Installation Power Plant.") NOTE: If replacing all six aft pressure bulkhead tee sections, replacement should be accomplished one tee section at a time. (5) Shore aircraft as shown on Figure 5. L. Record and report all results negative and positive of inspection to DAC. Include fuselage number, factory serial number, crack location, crack length, flight-hours, and accumulated landings of aircraft. Forward to: Douglas Aircraft Company P.O. Box 1771 Long Beach, California 90801 Attn: Manager, Customer Service 76-40 (DC-9 Alert Service Bulletin A53-231) • M. Apply PR-1422 B-2 sealant around entire periphery of the bulkhead tee sections, as applicable. • N. Reinstall retained insulation blankets on aft side of aft pressure bulkhead. (See MM chapter 25-22-0, paragrapn entitled, "Removal/Installation Insulation Blankets.") • O. Reinstall right pneumatic crossfeed valve pushrod and attaching parts as applicable. (See MM chapter 36-10-3, paragraph entitled "Removal/Installation Pneumatic Crossfeed Valve.") P. Reinstall two upper 5953635 conditioned air duct assemblies, check valves, and attaching parts as applicable, (See MM chapter 21-20-2, paragraph entitled 'Removal/Installation Conditioned and Cold Air Check Valve.") Q. Reinstall lower firex bottle and attaching parts as applicable. (See MM chapter 26-20-1, paragraph entitled, Removal/Installation Fire Extinguishing Containers.") R. Reinstall APU compartment enclosure, as applicable. (See MM chapter 53-20-5. paragraph entitled removal/Installation APU Compartment Enclosure.") February 24/89 Bulletin A53-231 Revision 2 June 25/93 Page 14 McDonnell Douples Corporation Proprietary Informadon. Lee or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 17 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN S. Reinstall APU and attaching parts as applicable. (See MM chapter 49-10-0, paragraph entitled "Removal/Installation Power Plant.") T. Reinstall engines 1 and 2 as applicable. (See MM chapter 71-00-0, paragraph entitled "Removal/Installation Power Plant.") U. Remove shoring as shown on Figure 5 as applicable. V. Close/reinstall access doors/panels as outlined under Option I paragraph 2.C. Option II (Inspection from forward side of bulkhead) A. Perform high and low frequency eddy current inspections of the aft pressure bulkhead web to fuselage skin attach tee sections from the forward side of the bulkhead as follows: (1) Operator's Option - Fabricate eddy current reference standard as shown on service sketch 3683D, Figure 5. (2) Remove and retain Items as outlined in service sketch 3683D, Table I, as applicable. Inspect the standing leg of 5910163 or SB09530056 non-ventral bulkhead tee sections from forward side of bulkhead around the entire periphery of the bulkhead as shown on service sketch 3683D, and accomplish the following: Condition 1 (No Crack) Perform repetitive high and low frequency eddy current inspections from forward side of bulkhead at intervals specified in Compliance paragraph. Condition 2 (Crack) Replace cracked tee section with new like or improved part per Figure 4 (See Table I for configuration) prior to further pressurized flight. Perform repetitive high and low frequency eddy current inspections from forward side of bulkhead at intervals specified in Compliance paragraph. (4) If any tee section is to be replaced, remove and retain engines 1 and 2. (See MM chapter 71-00-0, paragraph entitled "Removal/Installation Power Plant.") Shore aircraft as shown on Figure S. NOTE: If replacing all six aft pressure bulkhead tee sections, replacement should be accomplished one tee section at a time. Bulletin A53-231 February 24/89 Page 15 Revision 2 June 25/93 McDonnell Dougles Corporstion Proprietary Information. Usa or discto uns of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 18 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN B. Record and report all results negative and positive of inspection to DAC. Include fuselage number, factory serial number, crack location, crack length, flight-hours, and accumulated landings of aircraft. Forward to: Douglas Aircraft Company P.O. Box 1771 Long Beach, California 90801 Attn: Manager, Customer Service 76-40 (DC-9 Alert Service Bulletin A53-231) C. Apply PR-1422 B-2 sealant around entire periphery of the bulkhead tee sections, as applicable. D. Reinstall engines 1 and 2 as applicable. (See MM chapter 71-00-0, paragraph entitled "Removal/Installation Power Plant.") E. Remove shoring as shown on Figure 5 as applicable. F. Close/reinstall retained items as outlined in service sketch 3683D Table I, as applicable. February 24/89 Bulletin A53-231 Revision 2 June 25/93 Page 16 McDonnel Dougles Corporation Proprietary Information. Use or declosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 19 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN TUBE I.D. TO FIT O. D. OF FLEXISCOPE - STA X=-20.000 FLEXISCOPE GUIDE TUBE STA 7=-40.000 FLEXIBILE OR THIN WALL TUBING APPROX 3 FEET DETAIL FLEXISCOPE GUIDE TUBE MAKE FROM COMMERCIAL FLEXIBLE OR THIN WALL TUBING 3/8 OR 1/2-INCH DIAMETER STA X=-10.000 - INTERCOSTAL VIEW LOOKING FORWARD RIGHT SIDE AT FRAME INSTALLATION AFT OF PRESSURE BULKHEAD ILLUSTRATION OF GUIDE TUBE USE APPROX 2-3 INCHES FLEXIBLE BORESCOPE GUIDE TUBE - FABRICATION AND USE Bulletin A53-231 FIGURE 1 February 24/89 Revision 2 June 25/93 Page 17 McDonnell Douglas Corporation Propriatary Information. Usa or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 20 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN EDM NOTCH - EDM NOTCH EDM NOTCH NO. 3 NO. 2 NO. 1 FORWARD 1.906 IN. (34.92 MM) 1.375 IN. 1.906 IN. SURFACE (48.41 MM) (48.41 MM) 1.000 IN. (25.40 MM) 2.750 IN. (69.85 MM) 4.500 IN (114.30 MM 6.000 IN. (152.40 M1) LENGTH — DEPTH DETAIL SB09530231-9 EDDY CURRENT REFERENCE STANDARD MAKE FROM 1D0008S TEE-EXTRUDED SECTION (2024-0) HEAT TREAT TO 2024742. GENERAL NOTES: EDM NOTCH (TYP) 1. EDM NOTCH MAXIMUM WIDTH .010-INCH (.25 MM). 2. NOTCH TO BE ON AND PERPENDICULAR TO FORWARD SURFACE. EDM NOTCH 3. SCALE NONE. 1 2 3 4. THIS SB09530231-9 EDDY CURRENT REFERENCE LENGTH 1.000 1.000 1.000 STANDARD REQUIRED TO ACCOMPLISH OPTION I DEPTH 0.055 0.050 0.028 WILL BE MADE AVAILABLE BY DAC AT NO CHARGE, SEE PARAGRAPH 1.H. TOLERANCES IN. = INCHES MM = MILLIMETERS ANGLES + 0° 30' 3 PLACE DECIMAL ‡.015 IN. (0.38 MM) 2 PLACE DECIMAL ‡.03 IN. (0.8 MM) EDDY CURRENT REFERENCE STANDARD - FABRICATION February 24/89 FIGURE 2 Bulletin A53-231 Revision 2 June 25/93 Page 18 McDonnell Dougies Corporation Proprietary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE ### Page 21 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN GENERAL NOTES: 1. PERFORM INSPECTION PROCEDURE A, SEQUENCES 1 THROUGH 3 BEFORE CLEANING THE TEE AND AFTER CLEANING THE TEE AS NOTED. 2. PROCEDURE A - DESCRIBES AN OPTICALLY AIDED VISUAL INSPECTION OF DC-9 AFT PRESSURE BULKHEAD WEB TO FUSELAGE SKIN ATTACH TEE SECTIONS TO DETECT FATIGUE CRACKS IN THE UPSTANDING LEG OF TEE SECTIONS. 3. PROCEDURE B - DESCRIBES A LOW FREQUENCY EDDY CURRENT INSPECTION OF DC-9 AFT PRESSURE BULKHEAD WEB TO FUSELAGE SKIN ATTACH TEE SECTIONS TO DETECT FATIGUE CRACKS IN THE UPSTANDING LEG OF TEE SECTIONS. 4. INSPECTION OF THE BULKHEAD TEE FOR CRACKS BY PROCEDURE A OR B IS MADE FROM THE AFT SIDE OF THE AFT PRESSURE BULKHEAD. 5. INSPECTION BY PROCEDURE A IS DIVIDED INTO THREE SEQUENCES BASED ON ACCESS LOCATION. 6. INSPECTION BY PROCEDURE B IS DIVIDED INTO TWO SEQUENCES BASED ON INSPECTION PROBE DESIGN. a. INSPECTION PROCEDURE B, SEQUENCE 1, INSPECTS THE TEE ACUTE ANGLE TANGENT AREA OF THE UPSTANDING LEG OF TEE USING A MOLDED PROBE THAT CONFORMS TO THE RADIUS. INSPECTION PROCEDURE B, SEQUENCE 2, INSPECTS EXTENDED AREA OF UPSTANDING LEG OF TEE. AREA EXTENDS FROM THE VICINITY OF THE INBOARD ROW OF ATTACHMENTS INSTALLED THROUGH THE TEE UPSTANDING LEG AND THEN EXTENDS OUTBOARD TO AND OVERLAPS THE AREA INSPECTED IN SEQUENCE 1. INSPECTION IS MADE USING A 90 DEGREE PROBE. 7. SIGNS OF NICOTINE STAINS MAY INDICATE CRACKS. 8. THE FOLLOWING EQUIPMENT OR EQUIVALENT IS REQUIRED: SEE PARAGRAPH 3.C FOR TEST EQUIPMENT SUPPLIERS. VISUAL EQUIPMENT: a. FLASHLIGHT. b. INSPECTION MIRROR WITH ADJUSTABLE VIEWING ANGLE. ENDOSCOPE EQUIPMENI: ONE 70 OR 90 DEGREE ENDOSCOPE OF ANY DIAMETER WITH 18-INCH (457.2 MM) MINIMUM LENGTH AND LIGHT SOURCE SUCH AS: (1) ENDOSCOPE MODEL 10320D, 70 DEGREE (FOREOBLIQUE) ANGLE, 19-INCH (482.6 MM) LONG, 0.217-INCH (5.51 MM) DIAMETER. (2) FIBER OPTIC LIGHT BUNDLE MODEL 495NL. (3) ENDOSCOPE LIGHT SOURCE NUMBER 00482 (110 OR 220 VOLT) OR NUMBER E0590 (110 VOLT ONLY). (4) SYLVANIA PROJECTOR LAMP (150 WATT, 120 VOLT). AFT PRESSURE BULKHEAD TEE - INSPECTION •Bulletin A53-231 FIGURE 3 (SHEET 1 OF 17) February 24/89 Page 19 Revision 2 June 25/93 McDonnell Dougles Corporation Propriatary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 22 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN FLEXIBLE BORESCOPE: d. ONE FORWARD VIEWING ENDOSCOPE OF ANY DIAMETER WITH 30 INCH MINIMUM LENGTH SUCH AS: (1) OLYMPUS MODEL 1F8D3, 29.8 (757 MM)-INCH LONG, 0.315 (8 MM) -INCH DIAMETER. (2) COLD LIGHT SUPPLY NUMBER 1LK-4 (100 TO 230 VOLT). EDDY CURRENT EQUIPMENT: e. ONE EDDY CURRENT FLAW DETECTOR WITH FLYING DOT CRT SUCH AS: STAVELEY/NORTEC EDDY CURRENT INSTRUMENT, TYPE NDT-18 OR NDT-19 OR ZETEC EDDY CURRENT INSTRUMENT, MIZ-20A f. HIGH FREQUENCY EDDY CURRENT PROBES SUCH AS: (1) MOLDED PROBE OPERATING BETWEEN 5 AND 50 KHZ: CATALOG NUMBER 935-0120, PART NUMBER APB/MSP, ZETEC INCORPORATED; OR MODEL SPO-4080 STAVELEY INSTRUMENTS. (SEE SHEET 6.) NOTE: IF SERVICE BULLETIN 53-147 HAS BEEN ACCOMPLISHED, SUBSTITUTE STAVELEY INSTRUMENTS SPO-5222 IN PLACE OF PROBES LISTED IN PARAGRAPH F.(1). (SEE SHEET 7.) (2) PENCIL 90 DEGREE ANGLE PROBE OPERATING BETWEEN 5 AND 50 KHZ: CATALOG NUMBER 910-5830, PART NUMBER APB-5830, ZETEC INCORPORATED; OR MODEL SPO-4081 STAVELEY INSTRUMENTS. (SEE SHEET 8. g. SBO9530213-9 EDDY CURRENT REFERENCE STANDARD, SEE FIGURE 2. AFT PRESSURE BULKHEAD TEE - INSPECTION •February 24/89 FIGURE 3 (SHEET 2 OF 17) Bulletin A53-231 Revision 2 June 25/93 Page 20 McDonnell Dougles Corporation Propriatery Information. Use or diectoure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 23 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN INSPECTION PROCEDURE A. VISUAL INSPECTION PROCEDURE A: SEQUENCE 1: PERFORM MIRROR/FLASHLIGHT OR ENDOSCOPE INSPECTION OF UPPER FUSELAGE TEE SECTIONS FROM LONGERON L7 LEFT SIDE TO LONGERON L7 RIGHT SIDE, LOWER FUSELAGE LONGERON L17 LEFT SIDE TO LONGERON L20 LEFT SIDE, AND LONGERON L17 RIGHT TO LONGERON L19 RIGHT SIDE. (2) PERFORM ENDOSCOPE OR FLEXIBLE BORESCOPE INSPECTION OF LOWER FUSELAGE TEE SECTIONS FROM LONGERON L19 RIGHT SIDE TO LONGERON L20 RIGHT SIDE. SEQUENCE 2: (1) PERFORM MIRROR/FLASHLIGHT OR ENDOSCOPE INSPECTION OF LOWER FUSELAGE TEE SECTION THROUGH THRUST REVERSER LOCKOUT ACCESS OPENING 590TA FROM LONGERON L20 LEFT SIDE TO LONGERON L23 LEFT SIDE. (2) PERFORM MIRROR/FLASHLIGHT OR ENDOSCOPE INSPECTION OF LOWER FUSELAGE TEE SECTION THROUGH THRUST REVERSER LOCKOUT ACCESS OPENING 5902A FROM LONGERON L20 RIGHT SIDE TO LONGERON L24 RIGHT SIDE. NOTE: SEQUENCE 2 AND 3 MAY BE ACCOMPLISHED USING INSPECTION MIRROR AND FLASHLIGHT IF SUFFICIENT ACCESS IS AVAILABLE. SEQUENCE 3: PERFORM VISUAL INSPECTION OF LOWER FUSELAGE TEE SECTIONS WITH FLASHLIGHT FROM LONGERON L23 LEFT SIDE TO LONGERON L24 RIGHT SIDE. REMOVE SEALANT FROM INSPECTION AREA OF TEE SECTIONS THAT MAY HINDER INSPECTION. CLEAN DIRT, GREASE, AND ALL FOREIGN MATERIALS FROM INSPECTION AREA OF TEE SECTIONS USING LINT-FREE WIPER AND 1,1,1 TRICHLOROETHANE SOLVENT OR EQUIVALENT. PERFORM INSPECTION SEQUENCES 1 THROUGH 3 AFTER CLEANING THE TEE SECTIONS. B. LOW FREQUENCY EDDY CURRENT INSPECTION PROCEDURE B: NOTE: PROCEDURE B, LON FREQUENCY EDDY CURRENT INSPECTION PROCEDURE IS APPLICABLE TO AREA OF TEE SECTION BETWEEN LONGERONS L7 AND L17 ON LEFT AND RIGHT SIDES OF FUSELAGE THAT ARE NOT COVERED BY SPLICE PLATES OR SHOVEL CLIPS. AFT PRESSURE BULKHEAD TEE - INSPECTION #Bulletin A53-231 FIGURE 3 (SHEET 3 OF 17) February 24/89 Page 21 Revision 2 June 25/93 McDonnell Douglas Corporation Propriatary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 24 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN SEQUENCE 1: (1) CALIBRATE EDDY CURRENT EQUIPMENT AS FOLLOWS: (a) CONNECT MOLDED PROBE TO EDDY CURRENT INSTRUMENT AND SET OPERATING FREQUENCY AT 7 KHZ PER MANUFACTURER'S INSTRUCTIONS. NOTE: IF SERVICE BULLETIN 53-147 HAS BEEN ACCOMPLISHED, USE STAVELEY INSTRUMENT SPO-5222 PROBE. IF SERVICE BULLETIN 53-147 HAS NOT BEEN ACCOMPLISHED, USE MOLDED PROBE LISTED IN PARAGRAPH F.(1). (SEE SHEETS 6 AND 7.) (b) PLACE MOLDED PROBE ON REFERENCE STANDARD IN AN AREA FREE FROM NOTCH OR EDGE EFFECTS. NULL/BALANCE THE INSTRUMENT AND ADJUST LIFT OFF PER MANUFACTURER'S INSTRUCTIONS. SCAN ACROSS REFERENCE STANDARD EDM NOTCH 1 WITH MOLDED PROBE AND ADJUST SENSITIVITY AND PHASE CONTROLS TO OBTAIN A DISPLAY SIMILAR TO THAT SHOWN ON SHEET 15 FOR STANDARD PROBE, OR SHEET 16 FOR MODIFIED PROBE. (2) PERFORM EDDY CURRENT INSPECTION OF AFT PRESSURE BULKHEAD TEE AS FOLLOWS: (a) PLACE MOLDED PROBE IN THE RADIUS OF UPSTANDING LEG OF TEE AFT SIDE IN AREA FREE FROM EDGE OR FASTENER EFFECTS, SCAN THE TANGENT AREA OF TEE, AND RENULL/BALANCE INSTRUMENT. NOTE: THE MOLDED PROBE WILL NOT FIT INTO THE TEE RADIUS IN THE AREA OF LONGERON SHOVEL CLIPS. PORTIONS OF THESE AREAS WILL BE INSPECTED IN SEQUENCE 2 PROCEDURE. (b) PROGRESSIVELY SCAN ENTIRE LENGTH OF TEE TANGENT AREA BETWEEN LONGERONS L7 AND L17 ON FUSELAGE LEFT AND RIGHT SIDES. NOTE: ONE TECHNICIAN IS TO OPERATE THE PROBE WHILE ANOTHER TECHNICIAN EVALUATES THE EDDY CURRENT RESPONSE. THE TECHNICIAN WATCHING THE DISPLAY SHOULD PERIODICALLY ERASE LIFT-OFF TRACE TO AVOID MISSING A SMALL CRACK INDICATION. TECHNICIAN WATCHING DISPLAY MUST BE IN CONSTANT COMMUNICATION WITH TECHNICIAN OPERATING PROBE TO MAKE SURE PROBE IS MAKING GOOD CONTACT WITH TEE SECTION SURFACE. AFT PRESSURE BULKHEAD TEE - INSPECTION February 24/89 FIGURE 3 (SHEET 4 OF 17) Bulletin A53-231 Revision 2 June 25/93 Page 22 McDonnell Douglas Corporation Propriatary Information. Use or declosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 25 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN SEQUENCE 2: (1) CALIBRATE EDDY CURRENT EQUIPMENT AS FOLLOWS: (a) CONNECT 90 DEGREE PROBE TO EDDY CURRENT INSTRUMENT AND SET OPERATING FREQUENCY AT 10 kHz PER MANUFACTURER'S INSTRUCTIONS. PLACE 90 DEGREE PROBE ON REFERENCE-STANDARD IN AN AREA FREE FROM NOTCH OR EDGE EFFECTS. NULL/BALANCE THE INSTRUMENT AND ADJUST LIFT-OFF PER MANUFACTURER'S INSTRUCTIONS. (c) SCAN ACROSS REFERENCE STANDARD EDM NOTCH 2 WITH 90 DEGREE PROBE AND ADJUST SENSITIVITY AND PHASE CONTROLS TO OBTAIN A DISPLAY SIMILAR TO THAT SHOWN ON SHEET 17. (2) PERFORM EDDY CURRENT INSPECTION OF AFT PRESSURE BULKHEAD TEE AS FOLLOWS: PLACE 90 DEGREE PROBE ON AFT SIDE OF TEE UPSTANDING LEG IN AN AREA FREE OF FASTENER EFFECTS, SCAN AND RENULL/BALANCE INSTRUMENT. PROGRESSIVELY SCAN THE EXTENDED AREA OF THE UPSTANDING LEG OF TEE FROM THE VICINITY OF THE INBOARD ROW OF ATTACHMENTS THROUGH THE TEE UPSTANDING LEG THEN OUTBOARD TO AND OVERLAPING THE TANGENT AREA SCANNED IN SEQUENCE 1. HOLE: SCAN ONLY THOSE AREAS WHERE THE PROBE WILL FIT EASILY IN THE AREA OF LONGERON SHOVEL CLIPS. ONE TECHNICIAN IS TO OPERATE THE PROBE WHILE ANOTHER TECHNICIAN EVALUATES THE EDDY CURRENT RESPONSE. THE TECHNICIAN WATCHING THE DISPLAY SHOULD PERIODICALLY ERASE LIFT-OFF TRACE TO AVOID MISSING A SMALL CRACK INDICATION. TECHNICIAN WATCHING DISPLAY MUST BE IN CONSTANT COMMUNICATION WITH TECHNICIAN OPERATING PROBE TO MAKE SURE PROBE IS MAKING GOOD CONTACT WITH TEE SECTION SURFACE. RAPID SCANNING OF TEE SURFACE CAN GENERATE EXCESSIVE NOISE WHICH COULD MASK A SMALL CRACK INDICATION. (c) ANY INDICATION WHICH EXHIBITS SAME RELATIVE PHASE ANGLE AND AN AMPLITUDE EQUAL TO OR GREATER THAN 50 PERCENT OF THAT OBTAINED FROM REFERENCE STANDARD IS CONSIDERED A CRACK. (d) RECORD LENGTH AND LOCATION OF EACH CRACK AND DISTANCE BETWEEN MULTIPLE CRACKS. REPORT ALL CRACK INDICATIONS TO DAC AS NOTED IN PARAGRAPH 2.K. AFT PRESSURE BULKHEAD TEE - INSPECTION Bulletin A53-231 FIGURE 3 (SHEET 5 OF 17) February 24/89 Revision 2 June 25/93 Page 23 McDonnell Dougles Corporation Proprietary Information. Use or disctosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 26 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN TOLERANCES IN. = INCHES MM = MILLIMETERS ANGLES + 0° 30' 3 PLACE DECIMAL ‡.015 IN. (0.38 MM) 2 PLACE DECIMAL ‡ .03 IN. (0.8 MM) •625 IN. (15.88 MM) .312 IN. - .187 IN. SIDE VIEW (7.92 MM) (4.75 MM) •562 IN. (14.27 MM) •687 IN. (17.45 MM) .812 IN. (20.62 MM) .375 IN. (9.52 MM) ZETEC INCORPORATED C/N 935-0120 P/N APB/MSP LOW FREQUENCY EDDY CURRENT PROBE OR EQUIVALENT AFT PRESSURE BULKHEAD TEE - INSPECTION February 24/89 FIGURE 3 (SHEET 6 OF 17) Bulletin A53-231 Revision 2 June 25/93 Page 24 McDonnell Dougles Corporation Proprietary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 27 (OCR) ALERT DOUGLAS AIRCRAFT cOMPANY ALERT SERVICE BULLETIN .203 IN. .062 IN. (5.16 MM) .375 IN. (9.52 MM) RADIUS .187 IN. RADIUS .234 IN. - .687 IN.- (5.94 MM) (17.45 MM) .625 IN. .187 IN. (15.88 MM) (4.75 MM) • 043 IN. (21.41 MM) REFLECTANCE COIL PLACEMENT .281 IN. (7.14 MM) SPO-5222 OR EQUIVALENT AFT PRESSURE BULKHEAD TEE - INSPECTION •Bulletin A53-231 FIGURE 3 (SHEET 7 OF 17) February 24/89 Page 25 Revision 2 June 25/93 McDonnell Dougles Corporation Propriatary Information. Use or disctosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 28 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN •250 IN DIA COTI 1700214) 4.00 IN. (101.6 MM) ZETEC INCORPORATED C/N 910-5830 P/N APB/90DP LOW FREQUENCY EDDY CURRENT PROBE OR EQUIVALENT AFT PRESSURE BULKHEAD TEE - INSPECTION •February 24/89 FIGURE 3 (SHEET 8 OF 17) Bulletin A53-231 Revision 2 June 25/93 Page 26 McDonnell Douglee Corporation Proprietary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 29 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN FUSELAGE LONGERON NUMBERING VIEW LOOKING FORWARD AT AFT PRESSURE BULKHEAD TEE 9 8 / 8 _ 9 11.10 / 1011 1312 - 13 14 - 14 15 . 15 16 - 16 1718- ^1817 19 20 19 *ENDOSCOPE OR 20 FLEXISCOPE INSPECTION SEQUENCE 1 FUSELAGE CUSP LINE. 20- 2122, 23 24 23 INSPECTION SEQUENCE 2 FUSELAGE CUSP LINE- 23 22 26/26.30 26 26 25 27 29 29 INSPECTION SEQUENCE 3 VISUAL INSPECTION PROCEDURE A SEQUENCES FOR AFT PRESSURE BULKHEAD TEE AFT PRESSURE BULKHEAD TEE - INSPECTION •Bulletin A53-231 FIGURE 3 (SHEET 9 OF 17) February 24/89 Page 27 Revision 2 June 25/93 McDonnell Douglas Corporation Proprietary Information. Uss or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 30 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN FUSELAGE LONGERON NUMBERING VIEW LOOKING FORWARD AT AFT PRESSURE BULKHEAD TEE 9 → 9 10 • 10 • 11 -12 13 — 13 - 14 15 16- — 15 16 17 -17 LOW FREQUENCY EDDY CURRENT INSPECTION AREAS OF AFT PRESSURE BULKHEAD FOR PROCEDURE B AFT PRESSURE BULKHEAD TEE - INSPECTION •February 24/89 FIGURE 3 (SHEET 10 OF 17) Bulletin A53-231 Revision 2 June 25/93 Page 28 McDonnell Dougles Corporation Propriatary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 31 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN 5910163-89 OR 5910163-257 OR SR09530056-3 OR SR09530056-17 TEE 5910163-91 OR 5910163-259 OR R2 • L8 SR09530056-5 OR R2 R4 / 19 5910163-92 OR SR09530056-15 L10 —L10 5910163-260 TEE L11 R6 R6 —L11 SR09530056-6 OR R9 OR L12. R9 - L12 SR09530056-16 TEE L13- R12 - L13 R12 L14- R14 • L14 •LL UPPER -LL UPPER- L15- PYLON R14 PYLON - L15 L16- PYLO LL LOWER: •PYLON •LL LOWER. - L16 R16 R16 L17- - L17 R18 R18 -S — FRP L18— R20 R20 ~L18 L19- → 119 R22 5910163-93 5910163-261 OR L20 L21 R24 RZZ \ 221 L20 5910163-94 5910163-262 OR SR09530056-7 OR L22 SR09530056-8 OR SR09530056-13 OR L23 L24 126127128129130129128 127 126 25124 L23 SR09530056-14 OR TEE L25 TEE 5910163-95 OR 5910163-263 OR FRP = FUSELAGE REFERENCE PLANE LL = LOFT LINE SR09530056-9 L = LONGERONS OR R = RADIALS SR09530056-11 S * PRODUCTION SPLICE TEE VIEW LOOKING FORWARD DC-9 NON-VENTRAL AFT PRESSURE BULKHEAD SCHEMATIC DIAGRAM SHOWING TEE LOCATIONS AFT PRESSURE BULKHEAD TEE - INSPECTION •Bulletin A53-231 FIGURE 3 (SHEET 11 OF 17) February 24/89 Revision 2 June 25/93 Page 29 McDonnell Dougles Corporation Propriatary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 32 (OCR) ALERT DoUGLAS AIRCRAFT cOMPANY ALERT SERVICE BULLETIN ANGLE 5910163 OR 5910130 - BULKHEAD TEE FWD VISUAL INBD INSPECTION AREA CRACK - WEB • 70° OR 90° ENDOSCOPE DETAIL A - ENDOSCOPE VISUAL INSPECTION - ANGLE 5910163 OR • CRACK VISUAL 5910130 INSPECTION BULKHEAD AREA TEE — • WEB INSPECTION MIRROR FLASHLIGHT DETAIL B - MIRROR FLASHLIGHT VISUAL INSPECTION SEQUENCE 1 VISUAL AND ENDSCOPE INSPECTION OF BULKHEAD TEE AFT PRESSURE BULKHEAD TEE - INSPECTION February 24/89 FIGURE 3 (SHEET 12 OF 17) Bulletin A53-231 Revision 2 June 25/93 Page 30 McDonnail Douglas Corporation Propriatary Information. Use or disciosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 33 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN - RADIAL 14 RADIAL 14 - - FRP FRP RADIAL 18 RADIAL 18 LOOKING FORWARD TEE TEE SPLICE PLATE- CRACK• CRACK WEB OUTBD WEB FWD ANGLE SECTION A-A SECTION B-B DC-9 NON-VENTRAL AFT PRESSURE BULKHEAD. TEE CAP CRACKS. AFT PRESSURE BULKHEAD TEE - INSPECTION #Bulletin A53-231 FIGURE 3 (SHEET 13 OF 17) February 24/89 Page 31 Revision 2 June 25/93 McDonnell Douglas Corporation Propriatary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 34 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN LFEC INSPECT THIS SURFACE USING MOLDED • WEB PROBE -LFEC INSPECT THIS SURFACE AS SHOWN BELOW USING 90 DEGREE PROBE START OF RADIUS SCANNING PATTERN FOR LFEC INSPECTION OF SUBJECT SURFACE USING 90 DEGREE PROBE INSPECTION AREA ON TEE AFT PRESSURE BULKHEAD TEE - INSPECTION February 24/89 FIGURE 3 (SHEET 14 OF 17) Bulletin A53-231 Revision 2 June 25/93 Page 32 McDonnell Dougles Corporation Propriatary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 35 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN EDM NOTCH NO. 3 EDM NOTCH EDM NOTCH (NOT USED) NO. 2 NO. 1 SB09530231-9 REFERENCE STANDARD STANDARD MOLDED PROBE CALIBRATION PROCEDURE FOR SEQUENCE 1 - CRACK INSTRUMENT - NDT-18 PROBE - ZETEC C/N 935-0120 P/N APB/MSP FREQUENCY - 7 KHz GAIN - 32 dB VERTICAL - 0.2 HORIZONTAL - 2.0 ROTATION - 9:00 FILTER - OFF NOTE: SETTINGS LISTED WERE USED TO DEVELOP PROCEDURE. VALUES MAY VARY FROM SCOPE PRESENTATION INSTRUMENT TO INSTRUMENT LIFT-OFF NO CRACK AFT PRESSURE BULKHEAD TEE - INSPECTION • Bulletin A53-231 FIGURE 3 (SHEET 15 OF 17) February 24/89 Revision 2 June 25/93 Page 33 McDonnali Dougies Corporation Prope any Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 36 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN EDM NOTCH NO. 3 - EDM NOTCH - EDM NOTCH (NOT USED NO. 2 NO. 1 SB09530231-9 REFERENCE STANDARD MODIFIED MOLDED PROBE CALIBRATION PROCEDURE FOR SEQUENCE 1 SPO-5222 OR EQUIVALENT WITH MODIFIED PROBE AFTER SB 53-147 HAS BEEN ACCOMPLISHED NO CRACK CRACK INSTRUMENT - NDT-18 PROBE - SPO-5222 FREQUENCY - 7 KHz GAIN - 35dB VERTICAL - 0.2 HORIZONTAL - 2.0 ROTATION - 8:00 FILTER - OFF NOTE: SETTINGS LISTED WERE USED TO DEVELOP PROCEDURE. VALUES MAY VARY FROM INSTRUMENT TO INSTRUMENT - LIFT-OFF AFT PRESSURE BULKHEAD TEE - INSPECTION February 24/89 FIGURE 3 (SHEET 16 OF 17) Bulletin A53-231 Revision 2 June 25/93 Page 34 McDonnell Douglas Corporation Proprietary Information. Use or diaclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 37 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN EDM NOTCH - EDM NOTCH - EDM NOTCH (NOT USED) NO. 3 NO. 2 NO. 1 - SB09530231-9 REFERENCE STANDARD 90° PROBE - CALIBRATION PROCEDURE FOR SEQUENCE 2 CRACK INSTRUMENT - NDT-18 PROBE - ZETEC C/N 910-583 P/N APB/ 90DP FREQUENCY - 10 KHZ NO CRACK GAIN - 35 dB VERTICAL - 0.2 HORIZONTAL - 2.0 ROTATION - 7:30 FILTER - OFF NOTE: SETTINGS LISTED WERE USED TO DEVELOP PROCEDURE. VALUES MAY VARY FROM INSTRUMENT TO INSTRUMENT LIFT-OFF SCOPE PRESENTATION AFT PRESSURE BULKHEAD TEE - INSPECTION • Bulletin A53-231 FIGURE 3 (SHEET 17 OF 17) February 24/89 Page 35 Revision 2 June 25/93 McDonnell Douglas Corporation Propriatary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 38 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN GENERAL NOTES: 1. FINAL SHAPE AND SIZE OF MODIFICATION TO BE DETERMINED BY THE OPERATOR AND TRIMMED ON ASSEMBLY. 2. SMOOTH AND BLEND OUT ALL EVIDENCE OF CORROSION, 63-MICROINCH FINISH. 3. 125-MICROINCH SURFACE FINISH TYPICAL.- 4. BREAK ALL SHARP EDGES .020/.030-INCH RADIUS. 5. SHIM AS REQUIRED TO RELIEVE PRELOAD. 6. PROTECT MODIFICATION AREA AGAINST CORROSION AND DISSIMILAR METALS PER SRM CHAPTER 51-10-3. 7. APPLY A FAYING SURFACE SEAL OF PR-1422 B-2 SEALANT BETWEEN ALL DOUBLERS, FILLERS, SPLICES, SHIMS, ANGLES, STIFFENERS, TEES, AND FITTINGS. INSTALL BOLTS, HI-LOKS, AND RIVETS WET WITH SEALANT UNDER HEADS, BETWEEN WASHERS AND MATING SURFACES PER SRM CHAPTER 51-20-0. 8. LOCATE ATTACHMENTS FROM PART EDGES AS FOLLOWS: 2D + .06 (1.524 MM) INCH FOR DETAIL PARTS. 2D MINIMUM ACCEPTABLE ON ASSEMBLY. 9. ADDED ATTACHMENTS TO BE LOCATED 2D FROM JOGGLES. 10. "EQUAL SPACED" ATTACHMENT TOLERANCE TO BE WITHIN .06 (1.524 MM) INCH. 11. OVERSIZE ATTACHMENT MUST BE USED WHEN THE EXISTING HOLE DIAMETER EXCEEDS THE MAXIMUM DIAMETER SPECIFIED FOR THE ATTACHMENT. 12. SEE TABLE III FOR REPLACEMENT FASTENERS. SEE SERVICE REWORK DRAWING SR09530083 FOR REPLACEMENT FASTENERS IF DC-9 SERVICE BULLETIN 53-147 HAS BEEN ACCOMPLISHED. 13. IT IS PERMISSIBLE TO USE SELF-ALIGNING NUTS IN PLACE OF NAS679A3 OR MS21042L3 NUTS. 14. SPLICING OF TEE IS ACCEPTABLE TO FACILITATE INSTALLATION AND ASSEMBLY, SPLICE PER SERVICE REWORK DRAWING SR09530001 AND/OR STRUCTURAL REPAIR MANUAL CHAPTERS 51-10 AND 53-03. 15. AT OPERATORS OPTION IT IS PERMISSIBLE TO CUT 5910163-73 ANGLE AND USE SRM CHAPTER 53-03 FIGURE 14 TO FABRICATE A MODIFICATION SPLICE IN ANGLE TO GAIN ACCESS IN RESTRICTED AREA ON FORWARD SIDE OF TEE SECTION. A MAXIMUM OF ONE SPLICE PER SIDE IS PERMITTED. AFT PRESSURE BULKHEAD TEE - INSPECTION February 24/89 FIGURE 4 (SHEET 1 OF 6) Bulletin A53-231 Revision 2 June 25/93 Page 36 McDonnel Dougles Corporation Proprietary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FRST PAGE. ### Page 39 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN TABLE I QUANTITY PER VENTRAL BULKHEAD CONDITION DOUBLER CONFIGURATION WITH 9918572. DOUBLER WITHOUT 9918572 DOUBLER PART NO. KEY WORD QTY QTY HL325-5-4 PIN 4 HL325-5-5 PIN 131 HL325-5-6 PIN 13 HLT335-6-6 PIN HLT335-6-7 PIN HLT41-5-4 PIN HLT41-5-5 PIN 234 HLT41-5-6 PIN HLT425-6-3 PIN 1LT434-6-6 PIN PIN HLT435- PIN HLT436-6-5 PIN HLT436-6-6 PIN HLT436-6-7 PIN HLT634-6-6 PIN HLT634-6-7 PIN HLT635-6-5 PIN HLT635-6-6 PIN HLT635-6-7 PIN MS20470AD5-6 RIVET MS20470AD5-7 RIVET MS20470AD6-6 RIVET MS20470AD6-7 RIVET MS21042L3 NUT NAS1097AD5-9 RIVET NAS1097AD6-10 RIVET NAS1097AD6-9 RIVET NAS1252-10L WASHER S2931983-30A06 WASHER S4931919-6-3 PIN S4931919-6-4 PIN S4931919-6-5 PIN S4931919-6-6 PIN S4931919-6-7 PIN S4931920-6-5 PIN 54931920-6-6 PIN S4931920-6-7 PIN SR09530056-3 TEE OR 5910163-389 SR09530056-5 TEE OR 5910163-391 SR09530056-6 TEE OR 5910163-392 SR09530056-7 TEE 1 OR 5910163-393 SR09530056-8 TEE 1 OR 5910163-394 SR09530056-9 TEE 1 OR 5910163-387 300006-08 NUT ASSY 8 472 3D0006-3 NUT ASSY 1370 730 AFT PRESSURE BULKHEAD TEE - INSPECTION Bulletin A53-231 FIGURE 4 (SHEET 2 OF 6) February 24/89 Page 37 Revision 2 June 25/93 McDonnell Douglas Corporation Proprietary Information. Lee or dieclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 40 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN STA Y=817.000 (SERIES 10) Y=996.000 (SERIES 30) TABLE II NON-VENTRAL AFT PRESSURE BULKHEAD MAY BE REPLACED WITH NEW IMPROVED GLASS OLD PART NO. SHOT PEENED PART NO. 5910163-89 SRO9530056-3 TEE OR OR 5910163-257 5910163-389 OR SR09530056-17 5910163-91 SRO9530056-5 TEE OR OR 5910163-259 5910163-391 OR SR09530056-15 5910163-92 SR09530056-6 TEE OR OR 5910163-260 5910163-392 OR SR09530056-16 5910163-93 SR09530056-7 TEE OR OR 5910163-261 5910163-393 _ OR SR09530056-13 5910163-94 SR09530056-8 TEE OR OR 5910163-262 5910163-394 OR SR09530056-14 5910163-95 SRO9530056-9 TEE OR OR 5910163-263 5910163-387 OR SR09530056-11 AFT PRESSURE BULKHEAD TEE - INSPECTION February 24/89 FIGURE 4 (SHEET 3 OF 6) Bulletin A53-231 Revision 2 June 25/93 Page 38 McDonnell Dougles Corporation Proprietary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 41 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN FLUSH HEAD HI-LOK FASTENERS (TYP) REPLACE ALL FASTENERS WITH HI-LOK OR RIVET FASTENERS (TYP) VIEW B-B REPLACE ALL FASTENERS WITH FLUSH HEAD FASTENERS (TYP) - SR09530056-3 OR 5910163-389 SR09530065-5 OR TEE - SR09530056-6 5910163-391 TEE - 5910163-392 OR TEE - PRODUCTION SPLICE (TYP) SR09530056-7 OR 5910163-393 FUSELAGE TEE REFERENCE PLANE SRO9530056-9 SR09530056-8 OR OR 5910163-387 5910163-394 TEE B TEE VIEW A-A VIEW LOOKING FORWARD AT NON-VENTRAL AFT PRESSURE BULKHEAD AFT PRESSURE BULKHEAD TEE - INSPECTION Bulletin A53-231 FIGURE 4 (SHEET 4 OF 6) February 24/89 Revision 2 June 25/93 Page 39 McDonnell Dougles Corporation Propriatary Information. Use or disctosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 42 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN TABLE III REFERENCE CODE USED ON DRAWINGS 5910130 OR FASTENER TO REPLACE WITH 5910163 BE REMOVED - FASTENER HL326-5-X PIN, S4931920-6-X PIN, S4933653-3 NUT ASSY 300006-3 NUT ASSY HL329-5-X PIN, S4931919-6-X PIN, S4933653-08 NUT ASS1 3D0006-08 NUT ASSY B|5 HL328-5-X PIN, 50006-3 NUT ASSY S4933653-08 NUT ASSY BF 4 MS20427M4 RIVET HLT41-5-X PIN, 3D0006-08 NUT ASSY BF 5 MS20427M5 RIVET S4931919-6-X PIN, 3D0006-3 NUT ASSY BJ|5 MS20470AD5-X RIVET SAME, OR 54931920-6-X PIN, NAS1252-10L WASHER, MS21042L3 NUT BJ 6 MS20470AD6-X RIVET SAME, OR HLT634-6-X PIN, S293198-30A06 WASHER, MS21042L3 NUT Cx 5 MS20470DD5-X RIVET 3D0006-3 NUT ASSY S4931919-6-X PIN, NAS1252-8L WASHER, HL328-5-X PIN, NAS1252-1OL WASHER, S4931920-6-X PIN, MS21042L08 NUT MS21042L3 NUT S4931920-6-X PIN, HLT334-6-X PIN, S4933653-3 NUT ASSY 3D0006-3 NUT ASSY LN A MS20615M4 RIVET 3D0006-08 NUT ASSY HL325-5-X PIN, AFT PRESSURE BULKHEAD TEE - INSPECTION February 24/89 FIGURE 4 (SHEET 5 OF 6) Bulletin A53-231 Revision 2 June 25/93 Page 40 McDonnell Douglas Corporation Propn ery Information. Les or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 43 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN TABLE III (CONT) REFERENCE CODE USED ON DRAWINGS 5910130 OR FASTENER TO REPLACE WITH 5910163 BE REMOVED FASTENER LN 5 MS20615-5M RIVET S4931919-6-X PIN, 3D0006-3 NUT ASSY LZ 5. NAS1097AD5-X RIVET SAME, OR NAS1097AD6-X RIVET LZ 6 NAS1097AD6-X RIVET SAME, OR HLT635-6-X PIN, 3D0006-3 NUT ASSY MC 5 NAS1097DD5-X RIVET HLT335-6-X PIN, 3D0006-3 NUT ASSY XFM 5_ S4579428-5-X RIVET S4931919-6-X PIN, 3D0006-3 NUT ASSY XFM 6_ S4579428-6-X RIVET HLT635-6-X PIN, 3D0006-3 NUT ASSY XFV 6 S4931920-6-X PIN, 12731953-30206 MASHER, S4932389-3 NUT MS21042L3 NUT 4931919-6-X PIN, HLT435-6-X PIN, S4932389-3 NUT S2931983-30A06 WASHER, MS21042L3 NUT ( GB 6 S4579428DD6 RIVET HLT635-6-X PIN, 3D0006-3 NUT ASSY XKF| 6 S4931920-6-X PIN, HLT436-6-X PIN, S4933653-3 NUT ASSY 300006-3 NUT ASSY AFT PRESSURE BULKHEAD TEE - INSPECTION Bulletin A53-231 FIGURE 4 (SHEET 6 OF 6) February 24/89 Page 41 Revision 2 June 25/93 McDonnell Douglas Corporation Proprietary Information. Uss or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 44 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN GENERAL NOTES: 1. THE PURPOSE OF THIS FIGURE IS TO PROVIDE SPECIFIC MINIMUM RECOMMENDED SHORING PROVISIONS FOR THE SPLICING IN OR REPLACEMENT OF A CRACKED 5910163 TEE, NON-VENTRAL AFT PRESSURE BULKHEAD, PER DAC SERVICE REWORK DRAWING SR09530001 OR SRO9530056. 2. RAISE AND LEVEL AIRCRAFT AND SHORE AS SHOWN. REFER TO THE DC-9 MAINTENANCE MANUAL AND APPLICABLE LIFTING, LEVELING AND SHORING INSTRUCTIONS, CAUTIONS AND LIMITATIONS: (A) 7-11-0 WING AND FUSELAGE LIFTING" (B) 7-20-0 "SHORING" (C) 8-10-0 "LEVELING" AIRCRAFT TO BE LEVEL WITHIN 2 DEGREES. 3. INSTALL AFT FUSELAGE JACK FOR AIRCRAFT WITH NON-VENTRAL AFT PRESSURE BULKHEAD. 4. USE -1 SHORING CONFIGURATION ONLY FOR SIDE TEE REPLACEMENT BETWEEN LONGERON 6.5 TO LONGERON 22.5 (LEFT AND RIGHT SIDES), PART NUMBERS 5910163-91, -92, -93 OR -94. DO NOT REPLACE LEFT AND RIGHT SIDES TEES AT SAME TIME. 5. ADD -501 SHORING CONFIGURATION FOR UPPER TEE REPLACEMENT BETWEEN LONGERON 6.5 (LEFT SIDE) AND LONGERON 6.5 (RIGHT SIDE), PART NUMBER 5910163-89. FOR LOWER TEE REPLACEMENT BETWEEN LONGERON 22.5 (LEFT SIDE) AND LONGERON 22.5 (RIGHT SIDE), PART NUMBER 5910163-95. 6. REMOVE TAILCONE PER MAINTENANCE MANUAL 53-50-3. 7. INSTALL DAC SERVICE REWORK DRAWING J060157 SHORING PROVISIONS ON AFT CANTED FRAME. 8. AFTER INSTALLING SUPPORT AT AFT CANTED FRAME, ACCOMPLISH THE FOLLOWING: a. APPLY 50 ‡ 25 POUND FORCE PRELOAD TO PROVIDE POSITIVE UP LOAD ON JACK. D. MEASURE GAP BETWEEN SKINS PRIOR TO REMOVAL OF ANY ATTACHMENTS (TYPICALLY •010 TO 120). C. AFTER START OF ATTACHMENT REMOVAL, CHECK GAP AND POSSIBLE HOLE MISALIGNMENT. APPLY LOAD TO JACK AS REQUIRED TO MAINTAIN GAP BETWEEN SKINS NOTED PREVIOUSLY. SHORING INSTRUCTIONS - NON-VENTRAL AFT PRESSURE BULKHEAD TEE REPLACEMENT February 24/89 FIGURE 5 (SHEET 1 OF 3) Bulletin A53-231 Revision 2 June 25/93 Page 42 McDonnell Douglas Corporation Propriatary Information. Use or diactosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 45 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN CAUTION: INSTALL CRADLES ONLY AFTER AIRCRAFT IS LEVEL AND ON WING AND AFT FUSELAGE JACKS. REMOVE CRADLES BEFORE RELEASING WING AND AFT FUSELAGE JACKS. SEVERE STRUCTURAL DAMAGE WILL OCCUR IF WING JACKS ARE RELEASED WHEN CRADLE AND JACK AT AFT FUSELAGE JACK POINTS ARE INSTALLED. - WING JACK AT STA Xrs=111.875 (LS AND RS) INSTALL CRADLE AT STA Y=110.000 (SEE CAUTION) -501 (SEE SHEET 3) REMOVE BOTH ENGINES (REF: MAINTENANCE CRADLE AT MANUAL CHAPTER 71-00-0) STA Y=718.000 (SERIES 10 AND 20) AFT FUS JACK POINT STA Y=897.000 (NON-VENTRAL A/C (SERIES 30) AFT PRESSURE BULKHEAD ONLY STAY Y=916.000 (SEE CAUTION) STA Y=817.000 (SERIES 10) (SERIES 10 AND 20) STA Y=996.000 (SERIES 30) SEE GENERAL NOTE 3) STA Y 1095.000 (SERIES 30) -1 SHORING CONFIGURATION SHORING INSTRUCTIONS - NON-VENTRAL AFT PRESSURE BULKHEAD TEE REPLACEMENT Bulletin A53-231 FIGURE 5 (SHEET 2 OF 3) February 24/89 Revision 2 June 25/93 Page 43 McDonnell Douglas Corporation Propriatary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 46 (OCR) ALERT DOuGLAS AIRCRAFT cOMPANY ALERT SERVICE BULLETIN 5910163 NON-VENTRAL AFT PRESSURE BULKHEAD TEE CENTERLINE DOOR SHORING - FRP PROVISIONS P/N J060157-1 STA Y=989.407 (SERIES 10 AND 20) STA Y=1168.407 - P/N 2958 Y=916.000 (SERIES 30) JACK (REF) STA (SERIES 10 AND 20) Y=817.000 Y=1095.000 (SERIES 10 AND 20) (SERIES 30) Y=996.000 (SERIES 30) -501 SHORING CONFIGURATION SHORING INSTRUCTIONS - NON-VENTRAL AFT PRESSURE BULKHEAD TEE REPLACEMENT February 24/89 FIGURE 5 (SHEET 3 OF 3) Bulletin A53-231 Revision 2 June 25/93 Page 44 McDonnell Dougles Corporation Proprietary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 47 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN 3. Material Information: A. Ihe basis for the following material data is per aircraft. (1) Parts to be purchased as end item spares. NOTE: Parts requirements are contingent upon inspection findings indicating the existence of crack(s) in a tee section. Maximum quantities required per Figure 4, TABLE I are listed. Actual parts requirements are to be determined by the operator. Quantities listed are for record purposes only. Parts within parentheses are production equivalent part numbers. Part No. Qty Key Hore SR09530056-3 1 Tee (5910163-389) SR09530056-5 Tee (5910163-391) SR09530056-6 Tee (5910163-392) SR09530056-7 Tee (5910163-393) SR09530056-8 Tee (5910163-394) SR09530056-9 Tee (5910163-387) S2931983-30A06 297 washer S4931919-6-3 12 Pin S4931919-6-4 4 Pin S4931919-6-5 315 Pin S4931919-6-6 300 Pin S4931919-6-7 30 Pin S4931920-6-5 55 Pin S4931920-6-6 73 Pin S4931920-6-7 18 Pin 3D0006-08 472 Nut Assy 3D0006-3 1370 Nut Assy (2) Fastener kit consists of the following parts and may be purchased from DAC or may be procured from operator's stock or source indicated. Maximum quantities are listed, actual fasteners required are contingent upon inspection findings and are to be determined by the operator. February 24/89 Bulletin A53-231 Revision 2 June 25/93 Page 45 McDonnel Douglas Corporation Proprietary Information. Use or disclosure o THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 48 (OCR) ALERT DOUGLAS AIRCRAFT cOMPANY ALERT SERVICE BULLETIN Qty Kit Part/Material SB09530231-3 CAGE Supplier HLT335-6-6 Pin 20 73197 Hi-Shear Corporation HLT335-6-7 Pin 10 2600 Skypark Drive HLT41-5-4 Pin 4 Torrance, California HLT41-5-5 Pin 234 90506 HLT41-5-6 Pin 234 HLT425-6-3 Pin HLT434-6-6 Pin 20 HLT435-6-4 Pin HLT435-6-6 Pin 18 HLT436-6-5 Pin 15 HLT436-6-6 Pin 72 HLT436-6-7 Pin 72 HLT634-6-6 Pin 120 HLT634-6-7 Pin 120 HLT635-6-5 Pin 237 HLT635-6-6 Pin 275 HLT635-6-7 Pin 72 HL325-5-4 Pin 4 HL325-5-5 Pin 132 HL325-5-6 Pin 132 MS20470AD5-6 Rivet 214 MS20470AD5-7 Rivet 267 MS20470AD6-6 Rivet 123 MS20470AD6-7 Rivet 114 MS21042L3 Nut 551 NAS1097AD5-9 Rivet 50 NAS1097AD6-10 Rivet 10 NAS1097AD6-9 Rivet 375 NAS1252-10L Washer 275 (3) Material to be procured from operator's stock or source indicated. Part/Material Oty CAGE Supplier PR-1422 B-2 Sealant 1 Qt 83574 Courtaulds Aerospace (DMS 2082) 5430 San Fernando Road or Glendale, California 91209 Equivalent Bulletin A53-231 February 24/89 Revision 2 June 25/93 Page 46 McDonnell Dougles Corporation Proprietary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 49 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN B. Ihe basis for the following material data is per spares. None. C. Ihe basis for the following tooling data is per operator. (1) Option I - Test equipment to be procured from operator's stock or sources indicated. NOTE: One 70 or 90 degree endoscope of any diameter with 18 inch minimum length and matching light source may be used. Test Equipment IypE Qty CAGE Supplier Endoscope 70 Degree Model 1 54341 Expanded Optics, (Foreoblique) Angle 10320D Incorporated 19 (304.8 MM)-Inch Long 301-C West Dyer Road 0.217 (5.51 MM)-Inch Santa Ana, California Diameter 92702-3427 or Equivalent Fiber Optic Model Light Bundle 1F8D3 and Endoscope Light Source No. 00482 110 or 220 Volt or No. E0590 and Sylvania Projector Lamp 150 Watt, 120 Volt NOTE: Similar or equivalent endoscopes and 1lluminators may be obtained from the following sources. Bulletin A53-231 February 24/89 Revision 2 June 25/93 Page 47 McDonnell Dougles Corporation Proprietary Information. Use or declosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 50 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN Iest Equipment IyRe QtY CAGE Supplier Alva Ingenieros Velazquez 121 Madrid 6, Spain or Automation Instruments Service 47 Birch Street Bankston 2200, Australia Or 3 G Electronics Sede Commercial 20135 Milano Via Perugino 9, Italy or 50958 Richard Holt Medical Instrument Corporation 7046 Lyndon Avenue Rosemont, Illinois 60018-3470 or Inspection Instruments NDT Limited 32 Duncan Terrace London N188R, England or Karl Storz KG D 7200 Tuttlingen West Germany Flexible Borescope Model 32212 Olympus Corporation 29.8 (757 MM)-Inch Long 1F8D3 Scientific Products Group 0.315 (8 MM)-Inch 4 Nevada Drive Diameter Lake Success, New York 11040-1114 Cold Light Supply No. ILK-4 1 100 to 230 Volt or Equivalent Eddy Current Flaw Detector with NDT-18 or 29192 Staveley Instruments Incorporated Impedance Plane NDT-19 421 North Quay Street Display or Kennewick, Washington 99336-7735 Zetec Eddy Current Instrument MIZ-20A 51327 Zetec Incorporated 1320 North West Mall P.O. Box 140 Equivalent or Issaquah, Washington 98027-8921 Bulletin A53-231 February 24/89 Page 48 Revision 2 June 25/93 McDonnelt Dougtes Corporation Proprietary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 51 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN Test Equipment IyRE Qtx CAGE Supplier Eddy Current Low Model (Zetec Incorporated) Frequency Molded Probe 5-50 kHz C/N 935-0120 P/N APB/MSP Operating Frequency Eddy Current Low Frequency Molded or Model SPO-4080 (Staveley Instruments Incorporated) Probe 5-50 kHz Operating Frequency Eddy Current Low Model (Zetec Incorporated) Frequency 90 Degree C/N 910-5830 Probe 5-50 kHz P/N APB/ 90DP Operating Frequency Eddy Current Low Frequency 90 Degree or Model SPO-4081 (Staveley Instruments Incorporated) Probe 5-50 kHz Operating Frequency or Eddy Current Low Model Frequency 90 Degree SPO-5222 Probe 5-50 KHz Operating Frequency NOTE: When ordering Eddy Current probes specify type of Eddy Current instrument the probe will be used with so that proper mating connectors or adapter will be provided. (2) Option I - One SB09530231-9 Eddy Current Reference Standard required to accomplish Option I low frequency eddy current inspection will be made available at no charge. (See paragraph l.H.) (3) Option II - Test equipment required to accomplish Option II high and low frequency eddy current inspections including procurement sources, is listed in service sketch 3683D. Choice of equipment is at operator's option and is to be procured from operator's stock or sources indicated in service sketch 3683D. February 24/89 Bulletin A53-231 Revision 2 June 25/93 Page 49 McDonnell Douglas Corporation Propriatary Information. Use or disclosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 52 (OCR) ALERT DOUGLAS AIRCRAFT COMPANY ALERT SERVICE BULLETIN (4) Option II - The following reference standard required to accomplish the Option II high and low frequency eddy current inspections is to be procured from operator's stock or as indicated. Instructions- Part No. Oty Key Horo Disposition MS20470AD5-6 Rivet MS20470AD5-7 Rivet SB09530231-11 Plate SB09530231-13 Web SB09530231-15 1 Tee SB09530231-17 1 Reference Standard Assy 1/ May be purchased from: VM Products Incorporated CAGE 11298 62nd Avenue 60761 Puyallup, Washington 98373 J May be fabricated by the operator. (See service sketch 3683D.) 2/ May be procured from operator's stock. Detail of SB09530231-17 reference standard assembly. May be fabricated by the operator from 7075-T6 clad aluminum sheet Material Specification QQ-A-250/13 Temper T6 or 7075-T6 bare aluminum plate Material Specification QQ-A-250/12 Temper T6, .047/.053 × 2-1/4 x 3 inches. (See service sketch 3683D.) May be fabricated by the operator from 7075-16 clad aluminum sheet Material Specification QQ-A-250/13 Temper T6 or 7075-T6 bare aluminum plate Material Specification QQ-A-250/12 Temper T6, .039/.045 × 2-1/4 x 4-1/2 inches. (See service sketch 3683D.) May be fabricated by the operator from 2024-T3 clad aluminum sheet Material Specification Q0-A-250/5 Temper T3 or 2024-74 bare aluminum plate Material Specification QQ-A-250/4 Temper T4. .075/.085 x 3 x 4-1/2 inches. (See service sketch 3683D.) Any inquiries regarding accuracy, timeliness, completeness, and legibility of this Alert Service Bulletin should be directed to the local DAC Field Representative, or: Douglas Aircraft Company P.O. Box 1771 Long Beach, California 90801 Attn: Business Unit Manager Service Bulletins Service Changes and Modification Kits Product Support 76-40 (DC-9 Alert Service Bulletin A53-231) ENW/CAS GJH/LL Bulletin A53-231 February 24/89 Page 50 Revision 2 June 25/93 McDonnell Douglae Corporation Proprietary Information. Use or diactosure of THESE DATA SUBJECT TO RESTRICTIVE LEGEND ON TITLE PAGE OR FIRST PAGE. ### Page 53 (OCR) INSPECTION PROCEDURE 1. GENERAL NOTES: This procedure describes high and low frequency Eddy Current inspection of DC-9 aft pressure bulkhead tee sections to detect fatigue cracks in standing leg of tee sections. Inspection of either ventral or nonventral bulkhead tee sections for cracks is made from the forward side of the aft pressure bulkhead. (See Figures 1 and 2.) 2. JEST EQUIPMENT: A. Eddy Current Equipment: (1) Eddy Current CRT Instruments: Nortec NDT-15, NTD-18, or NDT-19 or Staveley/Instruments 421 North Quay Kennewick, Washington 99336-7735 CAGE: 29192 Zetec EM3300, or EM4300 Zetec Incorporated 1320 N.W. Ma11 P. O. Box 140 Issaquah, Washington 98027-8921 CAGE: 51327 or Hocking Aeromaster G. Hocking NDT Limited AV10B or AV100 Charles Professional Center Route 301, Suite 507 waldorf, Maryland 20601 CAGE: 61031 C ADDED A53-231RI DATA E. Whitman D. Hagemaier DLC 89-07-19 FAA/DER APPROVED ON 89-07-27 AS AN ALTERNATE MEANS OF COMPLIANCE TO AD 89-06-04, AMEND 39-6152. (NEVER RELEASED) REF: DC-9 S/B A53-191, A53-231, AND A53-232 REV DESCRIPTION PREP BY APPR DATE DOUGL co vY TITLE HIGH AND LOW FREQUENCY EDDY CURRENT INSPECTION - AFT PRESSURE BULKHEAD TEE SECTIONS SCALE SERVICE SKETCH MCDO "NONE APPR. HAGEMMER MODEL APPR. WHITMAN 3683D SHEET 1 LONG BEACH, CALIF. 90801 DC-9 OFTSMN. ¡POSTON 7-10-81 OF 19 DAC 68-729A (12-68) ### Page 54 (OCR) Hocking Electronics Limited St. Albans, Hertfordshire or England Equivalent NOTE: Eddy current instruments with meters are not acceptable for this inspection. (2) High Frequency Eddy Current Probes. (See Figure 4.) Shielded pencil/surface (90 angle) operating at about 200 kHz, 0.125-inch maximum diameter. Model MP901-60B 90° Angle NDT Products Engineering Model MP901-60FX 90° Angle Kent, Washington 98032 7056 South 220 Street CAGE: 61100 or Model 1R90F-6-1/16 J GK Engineering Corporation 21610 Lassen Street Suite 1 Chatsworth, California 91311-4121 or CAGE: 58136 Equivalent. NOTE: When ordering Eddy Current probes specify type of Eddy Current instrument the probe will be used with so that proper mating connectors or adapter will be provided. (3) Low Frequency Eddy Current Probe. (See Figure 4.) Right angle, 1/2-inch drop, surface probe operating at 1-40 kHz. Model SPO 1071 Staveley Instruments Incorporated 421 North Quay Street Kennewick, Washington 99336-7735 or CAGE: 29192 Equivalent (4) Eddy Current Reference Standard - Local Manufacture. (See Figure 5.) NOTE: May be purchased from: VM Products Incorporated 11298 62nd Avenue Puyallup, Washington 98373 CAGE: 60761 DC-9 S/B A53-191, A53-231, REF: AND A53-232 SERVICE SKETCH SHEET NO. - 3683D OF - 19 ### Page 55 (OCR) 3. ACCESS PREPARATION FOR INSPECTION: a. Gain access to work area by removing and retaining items outlined in Table I, as applicable. Access below the FRP is through cargo compartment access panels. (See Figure 3.) b. Remove and retain, or loosen wire bundles, ducting, hydraulic lines, and attaching parts, as required. c. Remove sealant from inspection area and clean with lint-free wiper and 1,1,1 trichloroethane solvent or equivalent. TABLE I MM CHAPTER REMOVE AND RETAIN REFERENCE PARAGRAPH TITLE AFT LAVATORY EQUIPMENT, TOILET 25-30-0 WASTE TANKS, WASTE PLUMBING THRU AND LAVATORY(IES), PARTITIONS 25-41-0 AND/OR AFT GALLEY(IES), AND ATTACHING PARTS AS APPLICABLE 38-30-1 IMMEDIATELY FORWARD OF AFT AND/OR PRESSURE BULKHEAD. 53-20-3 CARPETING AND FLOOR PANELS, 25-20-0 LAVATORY FLOOR PANS AND/OR AND/OR GALLEY FLOOR PANELS, AND 53-20-7 ATTACHING PARTS AS APPLICABLE, IMMEDIATELY FORWARD OF AFT PRESSURE BULKHEAD. INSULATION BLANKETS AND 25-22-0 ATTACHING PARTS ON FORWARD AND SIDE OF AFT PRESSURE BULKHEAD 25-52-1 AS NECESSARY TO GAIN ACCESS TO INSPECTION AREA. REMOVALS/INSTALLATION (AS APPLICABLE.) GENERAL, AND REMOVAL/INSTALLATION GALLEY FLOOR COVERING. REMOVAL/INSTALLATION INSULATION BLANKETS AND REMOVAL/INSTALLATION SIDEWALL, CEILING, AND FLOOR PANELS. THRUST REVERSER CONTROL VALVE SECTOR AND BRACKET. APPLICABLE TO DC-9 SERIES MD-80 AIRCRAFT ONLY - CABIN AIR RECIRCULATION FAN. 78-31-2 REMOVAL/INSTALLATION THRUST REVERSER CONTROL VALVE SECTOR. 21-20-13 REMOVAL/INSTALLATION CABIN AIR RECIRCULATION FAN. DC-9 S/B A53-191, A53-231, REF: AND A53-232 SERVICE SKETCH SHEET _ NO. 3683D OF _ 19 ### Page 56 (OCR) 4. HIGH FREQUENCY PROCEDURE: NOTE: High frequency procedure is applicable to Eddy Current inspection in area of tee sections not covered by the bulkhead web. A. Connect high frequency Eddy Current probe and set frequency at approximately 200 kilohertz. Place probe on reference standard and balance instrument per manufacturer's instructions. (See Figure 6.) B. Set sensitivity and phase controls to obtain CRT response from notch 5. without changing sensitivity, scan notches 5 and 6 and observe CRT resentation of crack. See Figures 6 and 7. C. Place probe on tee and slowly scan surface toward and away from the vertex of tee angle. Do not adjust balance, phase, or sensitivity controls. With the exception of tee splice plate areas, progressively scan entire 360 degrees of tee sections forward perimeter. (See Figure 8.) NOTE: One technician is to operate the probe while another technician evaluates the Eddy Current response on the CRT. Technician watching CRT should periodically erase the lift-off traces from the scope to avoid missing a small crack indication as shown in Figure 9 views (a) and (b). Technician watching scope must continually talk to technician operating probe to indicate if probe is making good contact with metal surface as illustrated in View (c). D. Any indication which exhibits same relative phase angle and an amplitude equal to or greater than 50 percent of CRT presentation obtained from calibration notch 6 in the reference standard is considered a crack. E. Measure length of each crack and distance between multiple cracks. Report all crack indications to DAC as noted. 5. LOW FREQUENCY PROCEDURE: NOTE: Low frequency procedure is applicable to Eddy Current inspection of tee sections covered by the bulkhead web. Fo Connect low frequency Eddy Current probe and set frequency at approximately five kilohertz. Place probe on reference standard at probe position A and scan notches 2 and 4 and observe CRT presentation of crack. (See Figure 10.) DC-9 S/B A53-191, A53-231, REF: AND A53-232 SERVICE SKETCH SHEET NO. 3683D OF - 19 ### Page 57 (OCR) G. Set sensitivity and phase controls to obtain CRT response from notches 2 and 4 as shown on Figure 11 (a). H. Without changing sensitivity place probe on web and scan around each fastener in the splice plate area paying particular attention to area near edge of web. Progressively scan entire 360 degrees of tee sections splice plate areas forward perimeter. (See Figure 12.) NOTE: One technician is to operate the probe while another technician evaluates the Eddy Current response on the CRT. Technician watching CRT should periodically erase the lift-off traces from the scope to avoid missing a small crack indication as shown in Figure 9, Views (a) and (b). Technician watching scope must continually talk to technician operating probe to indicate if probe is making good contact with metal surface as illustrated in View (c). I. Recalibrate instrument at two kilohertz with probe at position B on reference standard. Scan across notches 1 and 3. Set sensitivity and phase controls to obtain CRT response from notches 1 and 3 as shown on Figure 11 (b). Without changing sensitivity, place probe on tee splice plate area and scan around fasteners paying particular attention to area near edge of splice plate. (See Figure 12.) J. Any indication which exhibits the same relative phase angle and an amplitude equal to or greater than 50 percent of CRT presentation obtained from the half thickness notches 3 and 4 in reference standard is considered a crack. Cracks may be confirmed by checking the aft side of the tee using the high frequency procedure in paragraphs A through E. Cracks which do not break through to the aft surface of the tee may be checked using this low frequency procedure of paragraphs F through K. K. Measure length of each crack and distance between multiple cracks. Report all crack indications to DAC as noted. DC-9 S/B A53-191, A53-231, REF: AND A53-232 SERVICE SKETCH SHEET - NO.. 36830 OF 19 ### Page 58 (OCR) TAINEA NON FRP FIGURE 1. DC-9 AFT PRESSURE BULKHEAD VIEW LOOKING AFT VENTRAL DC-9 S/B A53-191, A53-231, REF: AND A53-232 SERVICE SKETCH SHEET NO. 3683D OF - 19 ### Page 59 (OCR) RADIAL 14° - RADIAL 14 A FRP FRP RADIAL 18 RADIAL 18 LOOKING FORWARD TEE TEE SPLICE PLATE CRACKS CRACKS (TYP) WEB OUTBD WEB FWD VIEW A-A VIEW B-B FIGURE 2. DC-9 NON-VENTRAL AFT PRESSURE BULKHEAD. TYPICAL FOR VENTRAL AFT PRESSURE BULKHEAD. DC-9 S/B A53-191, A53-231, REF: AND A53-232 SERVICE SKETCH SHEET . NO. 36830 OF - 19 ### Page 60 (OCR) - FLOOR ACCESS PANELS ACCESS PANEL LOCATION AFT END OF CARGO COMPARTMENT (LOOKING AFT) FIGURE 3. DC-9 S/B A53-191, A53-231, REF: AND A53-232 SERVICE SKETCH SHEET — NO. 36830 OF - 19 The text continues at https://openairdocs.org/service-documents/boeing/a53-231/file/7f23c04eeae5.md?from=61 --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. 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