# ALERT

BULLETINA53-232

FUSELAGE
- Main Frame - Inspect/RepairAft FuselageVentral PressureBulkhead Tee.
This page transmits Revision 2 for DC-9Alert Service BulletinA53-232 to incorporatethe following changes:
NOTE: This revision constitutes a complete reissue and reflects current operators of affected aircraft at time of issue.

Reason for Revision: To add two aircraft to thisAlert Service Bulletin Effectivity which are affected by thismodification.

No additional work is required by this revisionfor aircraft previously inspected/repaired byprior issue of this Alert Service Bulletin. Pages 2

and 8: Added two aircraft to Service Bulletin effectivity as follows:
OPR FUS (FSN)



### AM 718 (47602) OPR FUS (FSN)

ZXE 173 (47016) Page 15: RevisedApproval.
Page 55: Revised supplier address inparagraph 3.C.(1).

Revision Sequence: Original Revision Revision Date 1 2 March 28/90 June 25/93 April 28/95

ENW AMM-3

DOUGLASAIRCRAFT COMPANY MCDONNELL DOUGLAS CORPORATION PRODUCT SUPPORT

BulletinA53-232 March 28/90

Revision 2 April 28/95 Page 1 of 1

# ALERT

BULLETINA53-232

FUSELAGE
- Main Frame - Inspect/RepairAft FuselageVentral Pressure Bulkhead Tee.

NOTE
This Alert Service Bulletin is affected by Federal Aviation AdministrationAirworthiness Directive No. 89-16-12:Amendment 39-6287, effective September 7, 1989.
This Alert Service Bulletin is applicable only to aircraft equippedwithventral aft pressure bulkhead whichhave accumulated 35,000 or more landings. Replacement of all six aft pressurebulkhead tee sections with new improvedparts per thisAlert Service Bulletinconstitutes closing action for the repetitive inspection requirements of this Alert Service Bulletin.
This Alert Service Bulletin supersedesbut does not cancel the requirementsof DC-9 Alert Service Bulletin A53-191. Only aircraft listed in this Alert Service Bulletin that are contained in the Effectivity ofAlert Service BulletinA53-191 are affected by this contingency.
ThisAlert Service Bulletin is issued as apartial record-type change. A service rework drawingor aperture cards are furnished in lieu of illustrations.

March 28/90 Revision 2 April 28/95 BulletinA53-232
Page 1 of 58

# ALERT

1. Planning Information:

A. Effectivity:
(1) Aircraft Affected:
DC-9, Series 10,20, 30, 40, 50, and C-9, DC-9-81. -82. and -83 (MD-81.-82. and -83) (a) Operator andAircraft Number:
Operator FactorySerial No. 

# ALERT

ODerator Factory Serial No.
AA 49145 49155 49158 49161 49167 49171 49251 49253 49269 49286 49331
AM 47006 

### 47106 

### 47394 47501 47549 

### 47594 47602 47607 47609 

### 47650 48067 48083 48125 

### 48150 49149 49188

AO 47076 

### 47080 47090 47452 47455 47461 

### 47504 47542 47556 47637 and thru and thru

thru thru thru and 49159 49163 49168 49181
49259 49273 49329 49332

thru 48069
thru 48130 and 48151
thru 49190

thru 47092 AO 47640 

### (cont) 47642 

### 47675 47678 47704 47707 48104
AS 48079 

### 49103 49111 

### 49126 49231 

### 49363 49386

AU 47262 

### 47365 47446 47454 48024
AY 47604 

### 47613 47694 47736 47771 

### 48134 49150 49252 49284
AZ 47038 

### 47046 47101 

### 47128 47222 

### 47228 47283 

## thru 47644

thru 48106 and 48080 and 49104


## thru thru and

and and 

## thru and 

## thru thru thru thru thru

and and and 

## thru thru 

### 49236 49365 49387



### 47447 

### 48025

47606 

### 47614 47696 47738 

### 47773 48136 49152

47039 47047 

### 47129 47226 47238



## Bulletin A53-232 March28/90 

## Revision 2 April 28/95 Page 2

# ALERT ALERT

Operator Factory Serial No. 

## Operator Factory Serial No.

AZ 47311 (cont) 47339 47432 47502 47518 47533 47544 47553 47575 47591 47641 47653 49192 thru 47438
and 47519

thru 49218

BD 47484 47523 47555 47559 47648 47666

BVZ 47430 47468 47516

BW 49390

CBF 49415 49425 49428 49502

CEA 49140 49355 49501 and 49141 CO 47539 (cont) 47638 47765 47788 47797 48022 48027 48044 48056 48062 48066 48073 48111 49102 49112 49116 49120 49125 49127 49222 49229 49246 49249 49260 49370 49391 49478 thru 47799

and 48045
and 48063
and 48074 thru 48113
thru thru thru

and thru and thru thru 49114 49118 49122

49250 49265 49371 49394 49482

EA 47120

EZ 47044 47061 47191 47194 47279
CO 45789 45791 45847 47094 47110 47218 47281 47487 47490 47520 47524 47531 47535 thru 45793

thru 47112 and 47219

and 

### 47521 FP 45731

GA 47385 47481 47569 47601 47635 47701 47722 47730 47740 47744 47789 and 47386

thru 47795

March 28/90 BulletinA53-232 Revision 2 April 28/95 Page 3

# ALERT

Operator Factory Serial No.
GB 45717 47003 47008 47065 47072 47084 47176 47201 47203 47257 47273 47291 47314 47317 47325 47363 47380 47419 47426 47462 47464 47492 47497 47509 47522 47528 47543 47550 47608 47612 47615 47619 47759

GEC and 47004 and 47009

and 47258

and and
and
and thru thru thru 47364 47381
47427
47465 47494 47499 47512



### thru 47552

and and 47616 

### 47620

47783
GH 47755

HA 47204 47654 47658 47661 47689 47726 47735 47742 47763 47784 47796 48122 and 47662 

# ALERT

Operator Factory Serial No.

IB 47037 47079 47088 47093 47312 47368 47453 47456 47702 47706 48103

IG 47655 47713 49247

JD 47760 47767 47780 48029 48070 49280 and 47089
and 47313

thru thru and
thru and and thru thru thru 47657 47715 49248
47762 47768 47781 48033 48072 49283

JP 47239 47530 47570 48046 48048 48087 49379 49440

JU 47460 47470 47532 47562 47567 47571 47582 and 47563 and 47568

KE 49373 and 49374 49416 and 49417

LM 49123 and 49124

and 47764 LV 47000 47703 47705 47712 47719 

### thru 47721
Bulletin A53-232 March 28/90 Page 4 Revision 2 April 28/95

# ALERT 

# ALERT

Operator Factory Serial No. Operator Factory Serial No.

LV 47727 (cont) 47752 47770 47782 49395


### NK 45788 47113 

### 47131 47478 47526 

### 47547

NW 45787 45790 45827 47031 47042 47063 47073 47078 47083 47103 47114 47138 47149 47160 47171 47175 47178 47205 47244 47246 

### 47252 47263 

### 47280 47282 47286 47315 47337 47346 47362 47369 47382 47389 47395 47404 and 47064



## thru 47117

and 47150

thru 47180 and 47206
and thru and

thru and and and
and and thru and thru 

### 47247 47256 47264

47288 47316 47338 47347
47370 

### 47383 47391 47396 

### 47406 NW 47415 (cont) 47425 

### 47439 47450 47458 47469 47472 47479 47517 47566 47572 47647 47651 

### 47659 47664 47682 47708 47716 47724 47729 47739 47756 47769 47774 47785 48054 

### 48057 48086 48088 48100 48107 

### 48121 

### 48148 49110
OS 48015 

### 48059 49115 49164 49278 49372 thru 47417 and

and 

### 47440
47459 

### and 47473 and 47480

and
and and 

### 47573
47652 

### 47660


## thru 47710 thru 47718

thru 47758
thru thru and

thru thru thru 

### 47776 47787 48055



### 48091 48102 48110


### and 48149

thru 48021



### and 49279

QA 47018 

### QD 47278 

### 47319

March28/90 BulletinA53-232 Revision 2 April 28/95 Page 5

# ALERT ALERT

Operator Factory Serial No. Operator Factory SerialNo.
SK 47301 47305 47360 47513 47596 

### 47599 47610 47623 47626 47646 47725 

### 47747 47750 47766 

### 47777 49381 49420 49422 49436

SR 48002 49100 49356

TK 47397 47442


### TW 45772 

### 45798 47001 

### 47027 47033 47035 47107 47172 47248 47324 47343 47357 47411 47491 

### 47589 47603 47617 47669 47676 47686 

### 47688 47693 thru thru and 47303 47308 47361
and 47597

and 47624 thru 47634

and 47748

thru 47779 thru 49385



### and 49423


## thru 48014 thru 49358

and 45773 and 45799
thru 47030

thru thru thru 

### 47109 47174 

### 47251 

## thru 47345

and

and 

### 47412

47618 TW 47711 (cont) 47728 47731 47746 47749 47751 47753 48123 49153 49156 49160 49165 49169 49182 49230 49245 49266 49366

US 47026 47050 47099 47130 47146 47207 47212 47310 47332 47334 47371 47420 47429 47505 47507 47564 47574 47576 47583 47588 47590 47593 48026 48028 48034 48049 48052 48092 48114 48131 thru 47734

and and and
and and thru 

### 48124 49154 49157 49166 49170 49187

and 49267 thru 49369



### thru 47052

thru 47210

thru thru and

and 

### 47336 47375 

### 47421

47508

thru 48043
and 48053 thru 48099 thru 48120

BulletinA53-232 March 28/90
Revision 2 April 28/95 Page 6

# ALERT ALERT

ODerator Factory Serial No. Operator Factory SerialNo.
US 48138 (cont) 48154 49119 49138 49142 49237 49429 49443 thru 48147 thru 48159 ZAF

and 49139 and 49143

VC 47098 47679 47743 47745 47241 47295 47297 47366 47448 47467 47471 47475 47495 47536 47540 47668 47670 

### and 47242
thru and and 47300 47367 47449

thru 47538 and 47541

and 47671
VE 45710 47104 47121 47665 47683 47685 47692 XLL
XQQ

XYX

XZD

X5A

YBB 

### and 47105 ZBM
ZB2 

### 47087 47276

ZCA 45785 and 45786
ZCH 

### 49402 ZEZ
49380 49421 49424

45841 47102 47132 47190 47672 47680 48132 ZE9 47169
47525
47527 47548

ZIG 47595 47600
and 47133
and 47673
and 48133 ZKG

ZNA

ZNV
45826 47011 47152
45828 47014 47055 47086 47153 47240

49101 49277 47690 and 47691
47418
47410 47428 47431 47474 47476 47496 47545 47565 47577 47580 47584 47681 47684 47687 47698 48137 48165 and

and and thru 47477

47578 47581 47587

thru 47700
and 48166
March 28/90 

## Bulletin A53-232 Revision 2 April 28/95 Page 7Operator Factory SerialNo.
ZOQ

Z09

ZQO 

### 47274 47284 Operator Factory Serial No. ZVQ 47486 (cont) 47488 47534 47674 47723 47663 47677 48051 48058
47193 ZQ9 47005 47156 47168 47170 47202 47326 47514

ZRS 

### 45797

ZUS
ZVQ 45732
45774 47177 47261 47275 47277 47285 47318 47320 47359 47377 47443 47451 Z5B

Z6K
Z6R

thru 47323
thru 47379 thru 47445 Z8F 47007 47358
49396
47697 47754 

### 47010 47015
1K 47012 47062 and 

### 47013

(b) Other Aircraft:
Factory Serial No. 

### 47260 48000

NOTE: Aircraft listed under OtherAircraft are affectedby this Service Bulletin but were not assigned to any specific operator at time of Service Bulletin issue.

Bulletin A53-232 March 28/90 Revision 2 April 28/95 

# ALERT ALERT

and 

### 47489

ZVX

ZW7 

### 49144 47466

ZXE 

### 47016 47045 47154 

### and
and 

### 47017 47155

ZXH

ZXU 47067
47259
47529 Z4U

Page 8

# ALERT

(c) Manufacturer's Fuselageand Factory Serial Numbers:
FUS (FSN) FUS (FSN) FUS (FSN) FUS (FSN) FUS (FSN) FUS (FSN)

20 (45717) 30 (45772) 34 (45731) 39 (45773) 41 (45732) 46 (45841) 51 (45797) 59 (45798) 64 (45785) 69 (45799) 79 (45826) 81 (47004) 83 (47000) 86 (47003) 87 (47007) 90 (45786) 94 (47001) 97 (47010) 98 (47008) 99 (47006) 100 (45710) 102 (47011) 108 (47098) 111 (47063) 115 (47012) 118 (47050) 119 (47026) 120 (47064) 121 (47037) 127 (45787) 129 (47013) 131 (47051) 132 (47027) 134 (47076) 135 (45827) 136 (47038) 141 (47014) 142 (47052) 143 (47067) 145 (47028) 146 (47078) 147 (47033) 149 (47094) 151 (47005) 152 (47009) 154 (47039) 156 (47015) 157 (47029) 161 (47073) 163 (47079) 164 (47080) 165 (47044) 167 (47110) 168 (47046) 170 (47152) 171 (45788) 173 (47016) 174 (47030) 177 (47083) 178 (47035) 179 (47084) 180 (47088) 182 (47111) 183 (47047) 184 (47045) 185 (47153) 186 (47017) 187 (47031) 189 (47089) 190 (47090) 194 (47055) 195 (47101) 197 (47099) 198 (47102) 199 (47112) 201 (47154) 202 (47149) 203 (47018) 205 (47103) 206 (47091) 207 (47061) 209 (47120) 210 (47128) 211 (47130) 213 (47113) 214 (47131) 216 (47155) 217 (45789) 218 (47114) 219 (47086) 220 (47104) 221 (47105) 222 (47092) 223 (47062) 225 (47129) 226 (47146) 228 (47156) 229 (47132) 230 (47133) 234 (47087) 235 (47106) 236 (47107) 237 (47093) 240 (47190) 241 (47160) 242 (45828) 244 (47251) 245 (47204) 250 (47205) 251 (47108) 252 (47109) 257 (47248) 261 (47115) 262 (47312) 263 (47172) 264 (45790) 268 (47313) 269 (47065) 270 (47072) 273 (47173) 277 (47121) 279 (47314) 280 (47191) 281 (47241) 284 (47150) 286 (47174) 292 (47246) 293 (47207) 294 (47252) 295 (47253) 297 (47249) 298 (47175) 299 (47222) 300 (47223) 301 (47254) 304 (47242) 307 (47208) 308 (47116) 309 (47250) 310 (47255) 311 (47193) 312 (47218) 314 (47176) 316 (47224) 317 (47225) 318 (47138) 319 (47117) 320 (47263) 323 (47178) 324 (47194) 325 (47219) 326 (47256) 327 (47209) 328 (47206) 329 (47264) 330 (47177) 333 (47226) 335 (47179) 336 (45774) 337 (47279) 340 (47295) 341 (47210) 342 (47247) 343 (47291) 346 (47240) 347 (47273) 348 (47274) 349 (45791) 354 (47180) 355 (47228) 356 (47229) 359 (47286) 363 (47275) 364 (47287) 368 (47212) 369 (47288) 372 (45792) 373 (47276) 377 (47297) 379 (47277) 380 (47278) 381 (45793) 382 (47301) 385 (47317) 386 (47257) 387 (47258) 394 (45847) 395 (47230) 396 (47231) 397 (47283) 398 (47311) 399 (47298) 400 (47202) 401 (47203) 409 (47259) 410 (47260) 411 (47261) 412 (47262) 413 (47284) 414 (47285) 415 (47337) 416 (47338) 421 (47299) 4£2 (47302) 423 (47168) 424 (47169) 425 (47170) 426 (47318) 427 (47281) 428 (47232) 429 (47233) 432 (47303) 433 (47315) 434 (47319) 435 (47234) 436 (47235) 437 (47339) 438 (47300) 439 (47316) 441 (47305) 445 (47363) 446 (47282) 449 (47310) 450 (47236) 451 (47237) 454 (47320) 455 (47321) 456 (47322) 458 (47394) 459 (47201) 460 (47343) 461 (47332) 462 (47306) 463 (47307) 464 (47346) 465 (47238) 466 (47239) 468 (47323) 469 (47324) 472 (47344) 473 (47171) 474 (47308) 475 (47360) 476 (47357) 477 (47358) 478 (47347) 479 (47382) 480 (47410) 484 (47364) 485 (47345) 486 (47042) 487 (47405) 488 (47361) 489 (47389) 490 (47390) 491 (47391) 492 (47362) 493 (47334) 494 (47335) 495 (47359) 496 (47377) 498 (47244) 499 (47406) 500 (47336) 501 (47439) 502 (47440) 504 (47365) 505 (47368) 506 (47371) 508 (47378) 509 (47379) 511 (47415) 512 (47416) 513 (47372) 514 (47380) 515 (47325) 516 (47326) 518 (47417) 519 (47381) 520 (47431) 522 (47373) 523 (47374)



### March28/90 

### Bulletin A53-232 Revision 2 April 28/95 

# ALERT

Page 9

# ALERT ALERT

FUS (FSN) FUS (FSN) FUS (FSN) FUS (FSN) FUS (FSN) 

### 524 (47442) 525 (47432) 526 (47433) 527 (47488) 528 (47489) 

### 529 (47369) 530 (47366) 531 (47375) 

### 532 (47429) 533 (47411) 534 (47412) 535 (47450) 537 (47434) 538 (47383) 

### 539 (47367) 540 (47435) 541 (47436) 

### 542 (47385) 544 (47437) 545 (47438) 547 (47451) 548 (47448) 

### 549 (47459) 550 (47386) 551 (47370) 

### 552 (47449) 553 (47487) 554 (47404) 555 (47395) 

### 556 (47420) 557 (47396) 558 (47421) 

### 559 (47492) 560 (47490) 561 (47446) 562 (47493) 

### 563 (47447) 564 (47462) 565 (47453) 

### 566 (47498) 567 (47454) 568 (47499) 569 (47476) 

### 570 (47418) 571 (47501) 

### 572 (47426) 573 (47427) 574 (47502) 575 (47464) 577 (47443) 578 (47444) 579 (47455) 580 (47456) 583 (47517) 584 (47465) 585 (47445) 586 (47505) 589 (47425) 590 (47469) 591 (47470) 

### 593 (47523) 594 (47507) 595 (47508) 596 (47472) 597 (47280) 

### 598 (47473) 599 (47491) 600 (47474) 601 (47494) 

### 602 (47419) 603 (47526) 

### 604 (47497) 605 (47479) 606 (47522) 607 (47480) 609 (47430) 

### 610 (47535) 611 (47468) 612 (47478) 

### 613 (47477) 614 (47518) 615 (47519) 616 (47481) 617 (47528) 618 (47527) 619 (47514) 621 (47466) 622 (47547) 

### 623 (47550) 624 (47530) 625 (47529) 626 (47532) 627 (47460) 

### 628 (47486) 629 (47521) 630 (47516) 631 (47525) 632 (47524) 

### 633 (47548) 634 (47551) 635 (47520) 636 (47397) 637 (47539) 638 (47531) 

### 639 (47549) 640 (47552) 641 (47533) 

### 642 (47553) 643 (47509) 644 (47534) 645 (47510) 646 (47458) 647 (47467) 

### 648 (47484) 650 (47471) 651 (47504) 652 (47542) 653 (47475) 

### 654 (47543) 656 (47495) 657 (47556) 659 (47536) 

### 660 (47452) 662 (47537) 663 (47461) 

### 665(47538) 667 (47555) 668 (47540) 669 (47428) 670 (47541) 671 (47545) 672 (47559) 673 (47496) 675 (47565) 676 (47544) 677 (47511) 678 (47512) 

### 679 (47513) 680 (47575) 681 (47564) 682 (47576) 683 (47569) 684 (47570) 685 (47562) 686 (47577) 687 (47563) 688 (47567) 689 (47568) 

### 690 (47574) 691 (47566) 

### 692 (47581) 694 (47573) 695 (47571) 696 (47584) 697 (47583) 698 (47585) 699 (47588) 700 (47587) 701 (47582) 

### 702 (47578) 703 (47590) 704 (47580) 705 (47593) 

### 706 (47591) 707 (47586) 708 (47572) 709 (47595) 710 (47600) 711 (47589) 

### 713 (47597) 714 (47596) 715 (47601) 716 (47599) 717 (47594) 718 (47602) 720 (47603) 721 (47607) 

### 722 (47604) 723 (47609) 724 (47605) 725 (47610) 727 (47606) 728 (47623) 730 (47638) 731 (47637) 

### 732 (47608) 733 (47624) 734 (47640) 736 (47612) 738 (47626) 739 (47627) 740 (47628) 742 (47613) 743 (47631) 744 (47629) 745 (47630) 746 (47641) 747 (47614) 748 (47632) 749 (47642) 750 (47643) 751 (47615) 752 (47633) 

### 754 (47635) 755 (47646) 756 (47634) 

### 757 (47654) 759 (47616) 760 (47653) 761 (47648) 762 (47617) 

### 763 (47655) 764 (47618) 765 (47668) 767 (47644) 

### 768 (47619) 769 (47670) 771 (47650) 772 (47666) 

### 773 (47647) 774 (47671) 775 (47664) 776 (47669) 

### 777 (47620) 778 (47672) 779 (47673) 

### 780 (47651) 781 (47680) 

### 782 (47675) 783 (47656) 

### 784 (47681) 785 (47676) 786 (47684) 787 (47657) 

### 788 (47682) 789 (47678) 790 (47658) 791 (47677) 792 (47683) 

### 793 (47674) 794 (47685) 795 (47687) 796 (47665) 797 (47679) 

### 798 (47652) 799 (47688) 800 (47686) 801 (47699) 802 (47689) 803 (47692) 

### 804 (47693) 805 (47694) 806 (47695) 

### 807 (47659) 808 (47696) 

### 809 (47698) 810 (47660) 811 (47700) 812 (47661) 

### 813 (47708). 814 (47709) 815 (47712) 816 (47697) 817 (47702) 818 (47710) 819 (47704) 820 (47713) 821 (47706) 822 (47701) 

### 823 (47707) 824 (47714) 825 (47715) 826 (47722) 827 (47736) 828 (47730) 829 (47737) 830 (47738) 831 (47725) 832 (47716) 

### 833 (47717) 834 (47718) 835 (47740) 837 (47744) 838 (47723) 839 (47747) 840 (47691) 841 (47703) 842 (47705) 843 (47690) 

### 844 (47711) 845 (47719) 846 (47720) 847 (47721) 848 (47727) 

### 849 (47726) 850 (47662) 851 (47663) 852 (47739) 

### 853 (47724) 854 (47729)
Bulletin A53-232 March28/90 Page 10 

### Revision 2 April 28/95

# ALERT ALERT

FUS (FSN) FUS (FSN) FUS (FSN) FUS (FSN) FUS (FSN) FUS (FSN) 855 (47748) 856 (47754) 857 (47742) 858 (47728) 859 (47743) 860 (47731) 861 (47732) 862 (47733) 863 (47745) 864 (47746) 865 (47749) 866 (47751) 867 (47753) 868 (47734) 869 (47735) 870 (47750) 871 (47759) 872 (47752) 873 (47756) 874 (47760) 875 (47761) 876 (47762) 877 (47757) 878 (47755) 879 (47763) 880 (47758) 881 (47769) 882 (47764) 883 (47771) 884 (47774) 885 (47767) 886 (47766) 887 (47768) 888 (47775) 889 (47776) 890 (47772) 891 (47773) 892 (47770) 893 (47782) 894 (47780) 895 (47781) 896 (47777) 897 (47778) 898 (47779) 899 (47783) 900 (47765) 901 (47788) 902 (47784) 903 (47796) 904 (47785) 905 90 

### 90 90 90 91 911 91 91 91 915 916 91 91 92 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 5 (47786) (47789) 7 (47790) 8 (47791) 9 (48000) (47792) 1 (47793) 2 (47787) 3 (47797) (47798) 5 (47794) 6 (47795) (47799) (48114) (48115) (48116) (48117) (48111) (48015) (48103) (48112) (48100) (48104) (48105) (48113) (48101) (48102) (48106) (48123) (48121) (48107) (48108) (48002) (48109) (48131) (48016) (48118) (48119) (48003) (48110) (48034) (48125) (48024) (48120) (48004) 1 (48126) 1 (48025) 1 (48029) 1 (48124) 1 (48035) 1 95 95 95 95 96 96 96 96 96 96 96 96 96 96 97C 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 

### 990 991 992 993 994 995 996 997 

### 999 1000 1001 1002 1003 1004 1005 1006 1007 6 (48132 7 (48005 (48017 (48133: (48026: 1 (48127 (48030 3 (48036 4 (48128 5 (48037 6 (48006 (48044 (48129) (48031) (48045) (48007) (48122) (48027) (48052) (48051) (48130) (48046) (48032) (48028) (48134) (48008) (48137) (48049) (48148) (48009) (48053) (48135) (48033) (48149) (48058) (48010) (48136) (48011) (48018) (48054) (48012) (48070) (48013) (48019) (48038) (48039) (48071) (48048) (48040) (48055) ) 1008 (48041 ) 1009 (48042 ) 1010 (48043 1011 (48072: ) 1012 (48056 ) 1013 (48014:

1014 (48150 1015 (48062: 1016 (48079 1017 (48151) 1018 (48073) 1019 (48066 1020 (48063) 1021 (48138) 1022 (48080) 1023 (48057) 1024 (48139) 1025 (49100) 1026 (48074) 1027 (48140) 1028 (48067) 1029 (48086) 1030 (48141) 1031 (48068) 1032 (48069) 1033 (48142) 1034 (48092) 1035 (48087) 1036 (48143) 1037 (48088) 1038 (48089) 1039 (48144) 1040 (48090) 1041 (48091) 1042 (48145) 1043 (48083) 1044 (48146) 1045 (48020) 1046 (48154) 1047 (48059) 1048 (48147) 1049 (48093) 1050 (48155) 1051 (49101) 1052 (48156) 1053 (48094) 1054 (48157) 1055 (48095) 1056 (48158) 1057 (48096) ) 1058 (48159) ) 1059 (48097) ) 1060 (48098) ) 1061 (49116)

1062 (49110) 1063 (49117) 1064 (49111) 1065 (49118) 1066 (49114) 1067 (48099) 1068 (49112) 1069 (49113) 1070 (49119) 1071 (49120) 1072 (49121) 1073 (49122) 1074 (49125) 1075 (49123) 1076 (49102) 1077 (49124) 1078 (48021) 1079 (48022) 1080 (49126) 1081 (48165) 1082 (49127) 1083 (49103) 1084 (48166) 1085 (49104) 1086 (49149) 1087 (49150) 1088 (49151) 1089 (49152) 1090 (49138) 1091 (49139) 1092 (49140) 1093 (49141) 1094 (49142) 1095 (49143) 1096 (49144) 1097 (49145) 1098 (49166) 1099 (49167) 1100 (49168) 1101 (49153) 1102 (49154) 1103 (49155) 1104 (49156) 1105 (49157) 1106 (49158) 1 1107 (49159) 1

### 110 110 111 111 

### 1112 111

1114 1115 1116 

### 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157


### March28/90 

### Bulletin A53-232 Revision 2 April 28/95 (49160) 9 (49161) (49162) (49163) (49171) (49172) 49173) (49174) (49175) (49165) (49169) (49170) (49176) (49177) (49178) (49179) (49180) (49181) (49192) (49193) (49182) (49183) (49194) (49184) (49185) (49186) (49187) (49115) (49195) (49196) (49197) (49222) (49229) (49230) (49198) (49199) (49237) (49245) (49246) (49200) (49201) (49249) (49260) (49247) (49248) (49261) (49251) (49253) (49254) (49255)

Page 11

# ALERT ALERT

FUS (FSN)

1184 1185 1186 1187 1188 1189 

### 1190 1191 1192 1193 1194 

### 1195 1196 1197 1198 

### 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 (49205) (49265) (49250) (49288) (49206) (49207) (49208) (49209) (49210) (49289) (49280) (49290) (49366) (49367) (49368) (49369) (49281) (49373) (49211) (49233) (49234) (49379) (49370) (49371) (49374) (49284) FUS (FSN)

1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 (49291) (49292) (49293) (49294) (49295) (49296) (49297) (49298) (49299) (49300) (49301) (49302) (49303) (49304) (49355) (49380) (49305) (49306) (49307) (49308) (49279) (49381) (49382) (49212) (49235) FUS (FSN)

1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 (49236) (49383) (49384) (49266) (49267) (49425) (49428) (49429) (49213) (49385) (49214) (49309) (49310) (49311) (49312) (49356) (49357) (49372) (49215) (49420) (49313) (49314) (49315) (49316) (49317) FUS (FSN)

1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 (49415) (49402) (49216) (49421) (49422) (49318) (49319) (49320) (49217) (49390) (49391) (49416) (49392) (49321) (49218) (49363) (49364) (49365) (49417) (49393) (49322) (49323) (49282) (49423) (49424)

This modificationwill be incorporatedprior to delivery on all applicable DC-9, Series MD-80; MD-88 aircraft,manufacturer's fuselage number 1310 and subsequent. (2) SparesAffected: None.

B. Reason: Eight operators have reported cracks in theventral aftpressure bulkhead attach tee sections on eight aircraft. The affected aircraft had accumulatedbetween 45,492 and 60,969 landingswhen the cracks were found. The predominate areas of cracks are at the upper pylon attach angle between longerons 13 and 14 (6 cases) and lowerpylon attach angle between longerons 16 and 17 (2 cases). Longerons 2, 7, 11, and 18 eachhad one crack. The cracks exhibited similarbehavior, cracking circumferentially approximately 1.9 inches outboard of the inboard edge of the upstanding leg of the bulkhead attach tee sections. Cracks were found up to 8.8 inches in length. Analysis of failedparts revealed that the cracks 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. 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 repairsbased on condition will allow continued flight operation.
Bulletin A53-232 March 28/90 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 (49256) (49262) (49257) (49258) (49259) (49263) (49269) (49270) (49271) (49272) (49273) (49252) (49202) (49264) (49188) (49189) (49203) (49286) (49287) (49231) (49232) (49204) (49190) (49277) (49164) (49278) 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 (49394) (49395) (49386) (49387) (49324) (49325) (49443) (49501) (49478) (49358) (49326) (49327) (49479) (49480) (49283) (49502) (49328) (49329) (49436) (49440) (49396) (49331) (49332) (49481) (49482) FUS (FSN)

Page 12 

### Revision 2 April 28/95

# ALERT ALERT

C. Description:
This Service Bulletin accomplishesthe following on the fuselage aft pressure bulkhead. Option I (Inspectionfrom aft side of bulkhead) Performs visual and low frequencyeddy current inspectionsfor cracked aft pressure bulkhead web-to-fuselage tee sections around entire periphery of the fuselage from aft side of bulkhead and accomplishes the following:
Condition 1 (NoCrack) Repetitivelyvisually and low frequencyeddy current inspectsfor cracks from aft side of bulkhead at intervalsspecified in Complianceparagraph. Condition 2 (Crack) Replaces cracked tee sectionwith new like or improvedpart and repetitively visually and low frequency eddy current inspects for cracks from aft side of bulkhead at intervals specified in Complianceparagraph. ODtion II (Inspection from forward side of bulkhead) Performshigh and low frequency eddy current inspectionsfor cracked aft pressure bulkhead web-to-fuselage tee sections around the entire periphery of the fuselage from the forward side of thebulkheadand accomplishes the following:
Condition 1 (No crack) Repetitivelyhigh and low frequency eddy current inspects for cracks from forward side of bulkhead at intervals specified inCompliance paragraph.
Condition 2 (Crack) Replaces cracked tee sectionwith new like or improvedpart and repetitivelyhigh and low frequency eddy current inspectsfor cracks from forward side of bulkhead at intervals specified in Compliance paragraph.

NOTE: Replacement of all six aft pressure bulkhead tee sectionswith new improved parts constitutes closing action for the repetitive inspectionrequirements of this Alert Service Bulletin.

March 28/90 BulletinA53-232 Revision 2 April 28/95 Page 13

# ALERT ALERT

D. Compliance:

It is recommended that initial inspection/repairof aftpressure bulkhead tee per Option I or IIbe accomplished as follows on aircraft having loggedover 35,000 landings.
Accumulated Landings
35,000 to 49,999

50,000 to 59,999

60,000 and over Initial Inspection
Within 1500 landings from issuedate of this Service Bulletin.
Within 1000 landings from issue date of this Service Bulletin.
Within 300 landingsfrom issue date of this Service Bulletin.
When aft pressure bulkhead tee section is replacedwith new likepart, the repetitive inspection for that section of teemay be discontinued until the aircrafthas accumulated an additional35,000 landings at which time the repetitive inspection for that sectionof tee are reinstated along with the ongoing repetitive inspectionsof the remaining original sectionsof tee.
When aft pressurebulkhead tee section is replacedwith new improved part per this Service Bulletin, the repetitive inspection for that section of teemay be discontinuedas this constitutesclosing action for that section of tee. Perform the recommendedOption I or Option II repetitive inspectionson the remaining original tee sections. Replacement of improvedparts action for the all six aftpressure bulkhead tee sectionswith new per thisAlert Service Bulletin constitutes closing inspection requirementsof thisAlert Service Bulletin.
It is recommended that repetitive inspection/repairof aft pressure bulkhead tee be accomplishedper Option I or IIas follows: Option I (Inspection from aft sideof bulkhead)
It is recommended that repetitive low frequency eddy current inspection for cracks of side areas above floor between longerons7 and 17 on fuselage left and right sides,be accomplished at intervals not to exceed 1500 landings.

It is recommended that repetitivevisual inspection for cracks of top and lower areas from longeron7 left side to longeron7 right side, and lower fuselage longeron 17 to longeron 20 on fuselage left and right sides, be accomplishedat intervals not to exceed 1500 landings.



### Bulletin A53-232 March28/90 Page 14 

### Revision 2 April 28/95

# ALERT ALERT

It is recommended that repetitivevisual inspectionfor cracks of bottom areas from longeron20 left side to longeron20 right side, be accomplished at intervals not to exceed 3500 landings. 

### Itisrecommended that crackedtee section bereplaced prior to 

## further pressurized flight.
Option II (Inspectionfrom forward side of bulkhead)
It is recommended that repetitivehigh and low frequency eddy current inspection for cracksaround entire peripheryof fuselage from forward side of bulkheadbe accomplished at intervalsnot to exceed 2500 landings.

It is recommended thatcracked tee sectionbe replacedprior to further pressurized flight.

E. Approval:
The resultant modificationdescribed inparagraph 1.C has been shown to complywith the applicableFederalAviation Regulations and Revision 2 is approved by theManager, LosAngeles Aircraft Certification Office, FAA Northwest Mountain Region, on April 28, 1995, and is approved as an alternate means of compliancewith paragraphsA and B of Airworthiness Directive 89-16-12.

F. Manpower:
NOTE: Man-hours are estimatedbased on work to beperformed by skilledpersonnel on aircraft/unitwhich has been placed in amaintenance status. Only actual work performed on aircraft/unit is accounted for in man-hour estimates. Noman-hours have been estimated toperform the followingor other incidentalwork required to accomplish this Service Bulletin:
1. Preparationfor the modification: Examples; defueling, purging,placingwork stands,opening standard access doors, obtaining tools, and jackingwhen not essential to the modification.
2. Nonproductiveelapsed time: Examples; sealant or adhesive cure time, cleaning,paint drying time, lunch and/or restperiods, and quality assurance inspections.
3. Administrativefunctions: Examples;planning, engineeringliaison,parts requisition, shift change coordination,and report writing. Operators should take the above into considerationwhen scheduling thismodification.

March 28/90 Bulletin A53-232 

### Revision 2 April 28/95 Page 15

# ALERT ALERT

Option I (Inspection from aft side of bulkhead) Optically aidedvisual inspection from the aft sideof the fuselage aft pressure bulkheadmay be accomplished in approximately 22.0 man-hours or 11.0 elapsedhours per aircraft.
Low frequency eddy current inspection from the aft side of the fuselage aft pressurebulkheadmay be accomplished in approximately 11.5man-hours or 5.8 elapsedhours per aircraft.
Man-hours do not include time for fabrication of flexibleborescope guide tube. Option II (Inspection from forward side of bulkhead)
Removal and reinstallationof lavatories, equipment, and sealant for access to the forward side of the fuselage aft pressurebulkhead 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 fuselageaft pressure bulkhead may be accomplished in approximately 8.0man-hours or 4.0 elapsed hoursper aircraft. Man-hours do not include time for fabrication of eddy current reference standard.
Maximum totalman-hours and elapsed hours are given for inspection per aircraft. Actualman-hours and elapsed hours for repair are contingent upon inspection findings and are to be estimated by the operator.
G. Material

- Cost andAvailability:

(1) Aircraft:

Parts andmaterials required to accomplish thismodification are listed inparagraph 3.A and are to be procured as indicated. Parts bearing DouglasAircraft Company part numbers are proprietary parts and must beprocured under the spare parts article of the purchase agreement, unlessmethods of manufacture are shown.
Cost and availabilityof parts are tobe negotiated between the operator and DouglasAircraft Company. Reference this Service Bulletin numberand direct inquiries to: DouglasAircraft Company P.O. Box 1771 Long Beach, California 90801 Attn: Parts Sales

- Commercial 35-12 (DC-9 Alert Service BulletinA53-232) (2) Spares:

Not applicable.
BulletinA53-232 March 28/90 

## Revision 2 April 28/95 Page 16

# ALERT ALERT

H. Tooling

- Price andAvailability: Option I (Inspection from aft side of bulkhead) (1) 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 tobe procured from operator's stock,or sources indicated inparagraph 3.C. (2) Douglas 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 bemade available to the operator at no charge.

Procurement and availability of SB09530231-9 eddy current reference standard shouldbe negotiated between the operator and the Douglas Aircraft Company. Specify this Service Bulletin number and direct inquiries to: Douglas Aircraft Company 910 East 236th Street Carson, California 92805 Attn: Group Leader

- Recovery and Modification Services 35-35 (DC-9Alert Service BulletinA53-232) 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 3683D. (4) Reference standard required to accomplishhigh and low frequency eddy current inspections per Option II is shown in service sketch 3683D. Reference standard may be procured from operator's stock, fabricatedby the operator, or purchased from source indicatedin paragraph 3.D.

I. Weight and Balance: Weight change at appropriate fuselage stations by incorporation of any part of this Service Bulletin is contingent upon themodification of eachparticular aircraft. Weight data is to be computed by the operator byweighing parts installed and parts removed during modification. Necessary revisions shouldbemade to the appropriate

- weight and balance document.



### March28/90 Bulletin A53-232 

## Revision 2 April 28/95 Page 17

# ALERT ALERT

J. References: (1) Federal AviationAdministration AirworthinessDirective No. 89-16-12:Amendment 39-6287, effectiveSeptember 7, 1989. (2) Alert Service BulletinsA53-147 andA53-191. (3) Data used inpreparation of thisAlert Service Bulletin:

Data Identification DMS 2082 J060157 J060157 MM Chapters 6, 20,

21, 25, 26, 36, 49, 52, and 53 NDT Chapter 1-3 SRM Chapters 51 and 53 SR09530001 

### SR09530001 SR09530048 SR09530056 SR09530056 SR09530083 3683D 5910130 5930760 Change Typeof Data



### A B

C D New



### C D New

DY AM Douglas Material Specification Service Rework Shoring Advance E.O. MaintenanceManual

Nondestructive Testing Manual Structural Repair Manual Service Rework Drawing Advance E.O. Service Rework Drawing Service Rework Drawing Advance E.O. Service Rework Drawing Service Sketch (attached) Drawing Drawing (4) Data supplied in support of this Alert Service Bulletin: Data Identification
J060157 J060157 SR09530001 SR09530001 SR09530048 SR09530056 SR09530056 SR09530083 Change Type of Data
A B C D New

C D New Service Advance Service Advance Service Service Advance Service Rework Shoring E.O. Rework Drawing E.O. Rework Drawing Rework Drawing E.O. Rework Drawing
NOTE: Listed data are being furnished to each affected operator. K. Publications Affected:
The modification outlined in this Service Bulletinaffects the DC-9 Weight and Balance Documents.
L. Electrical Load Data:

Not affected. M. Software Accomplishment Summary:

Not affected. BulletinA53-232 Page 18 March 28/90 Revision 2 April 28/95

# ALERT ALERT

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 TOTHE AIRCRAFT.
CAUTION: ELECTRICALLY GROUNDTHE AIRCRAFT. GENERAL NOTES: 

### 1. Replacementof all sixaft pressure bulkheadtee sections with 

## newimprovedparts constitutes closing action for therepetitive 

## inspectionrequirements ofthisAlert ServiceBulletin. Ifreplacing allsix aft pressure bulkheadtee sections, replacement should beaccomplishedonetee section at a time. 2. Refer to sections of the MaintenanceManual(MM), Structural Repair Manual (SRM), and Non-Destructive Testing Manual (NDT). 

### 3. Refer to the following manualchapters for applicable operations: Manual Chapter Operation


### MM 20-30-0 Sealant Application NDT 1-3 EddyCurrent Inspection 

### SRM 51-10-4 Drilling AndCountersinking SRM 51-30-1 Installing Bolts, Screws, and Washers 

### SRM 51-30-2 RemovingAndInstalling Rivets SRM 51-30-3 RemovingAndInstalling Lockbolts SRM 51-30-5 RemovingAnd Installing Pins 4. For approved fastener and process material substitutions, see 

### DC-9SRMchapter 51-60-0, paragraphentitled "Interchangeability 

## of Fasteners"and"Interchangeability of Materials." 5. If the lengthof the fastenersspecified inthis ServiceBulletin donot meetacceptable installation standards, fasteners of the sametype, or approvedsubstitutions, oneincrement longer or shorter in length maybe used. 

### 6. Acombinedtotal of two (maximum)1/16-inch thick washersor four (maximum)1/32-inch thick washersor anycombination thereof not exceeding 1/8-inch total stackupthickness of the washertypes called for inthis Service Bulletin maybeusedunderfastener 

## heador nuttocounteractaccumulation of tolerances. 7. If substitutions are usedother thanthose in Douglasapproved publications, operator must obtain FAA approval from local authorized agency.


### March28/90 Bulletin A53-232 Revision 2 April 28/95 Page 19

# ALERT ALERT

Option I(Inspection fromaft side of bulkhead) A. Operator's Option

- Accessdoors maybe installed inskin on bottom of fuselage forward of auxiliary powerunit (APU)door per service 

## reworkdrawingSR09530048 to facilitate inspection. B. Operator's Option

- Fabricate guide tube (to be usedwith flexiscope) 

## fromflexible or thin wall tubing tofit outside diameterof flexiscope as shown on Figure 1. 

### C. Operator's option

- Fabricate reference standard as shownon Figure 2.
D. Gainaccessto inspection areasonaft side of bulkhead byopeningor removingandretaining the following accessdoors/panels asapplicable to accomplishvisual and/or lowfrequency eddycurrent inspection: Access No. Access Area MM Chapter 

## 5806A Auxiliary Exit Door, 6-12-0 Non-Ventral Bulkhead 

### 5901A Thrust ReverserControl 6-11-4 Valve (Left Side) 

### 5902A Thrust ReverserControl 6-11-4 Valve (Right Side) 5903A APUService (Left Side) 6-11-4 5904A APUService (Right Side) 6-11-4 

## 5910A Ventral Stair Ceilling 6-12-0 5911A Ventral Stair (Right Side) 6-12-0 

## 5912A Ventral Stair (Left Side) 6-12-0 NOTE: Thefollowing paragraphs 2.D through 2.H 

### maybeaccomplishedat operator's option 

## andareapplicableto visual inspection requirements.
E. Removeand retain APUand attaching parts. (See MM chapter 49-10-0, 

## paragraphentitled "Removal/Installation PowerPlant.")
F. Removeand retain APUcompartment enclosure and attaching parts. 

### (SeeMMchapter 53-20-5, paragraphentitled "Removal/Installation APUCompartment Enclosure.")



### Bulletin A53-232 March 28/90
Revision 2 April 28/95 Page 20

# ALERT ALERT

G. Remove and retain lower firexbottleand attaching parts. (See MM chapter 26-20-1, paragraph entitled "Removal/InstallationFire Extinguishing Containers.")

H. Remove and retain right pneumaticcrossfeedvalve pushrod and attaching parts. (See MM chapter36-10-3,paragraph entitled "Removal/Installation PneumaticCrossfeedValve.")
I. Remove and retain two upper conditionedair duct assemblies, check valves, and attaching parts aftofpressure bulkhead center ceiling. (SeeMM chapter 21-20-2, paragraphentitled "Removal/Installation Conditioned and Cold Air CheckValve.")
J. Rollback or remove and retain insulationblankets from aft sideof aft pressure bulkhead. (SeeMM chapter 25-22-0, paragraph entitled "Removal/Installation InsulationBlankets.")
K. Perform optically aided visual and low frequency eddy current inspection/repairof the aft pressurebulkheadweb to fuselage skin attach tee sections from the aft side of the bulkhead as follows: (1) Inspect the upstanding legof 5910130 ventralbulkhead tee sections from aft side ofbulkheadaround theperiphery 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 sideof bulkhead at intervals specified in Compliance paragraph.
Condition2 (Crack) (3) Replace cracked tee sectionwith new like or improvedpart per Figure 4 (See Table I for configuration) prior to further pressurized flight. Performrepetitivevisual and/or low frequency eddy current inspectionsfrom aft side of bulkhead at intervals specified inComplianceparagraph. (4) If any tee section is tobe replaced,remove and retain engines 1 and 2. (See MM chapter71-00-0, paragraph entitled "Removal/InstallationPower Plant.")
NOTE: If replacing all sixaft pressure bulkhead tee sections,replacement shouldbe accomplishedone tee section at a time.
(5) Shore aircraft as shown on Figure 5.



### March28/90 Bulletin A53-232 Revision 2 April 28/95 Page21

# ALERT ALERT

L. Record and report all results, both 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: DouglasAircraft Company P.O. Box 1771 Long Beach, California 90801 Attn: BusinessUnit Manager Customer Services

- Airframe Product Support 35-35 (DC-9Alert Service Bulletin A53-232)
M. Apply PR-1422 B-2 sealant around entireperiphery of the bulkhead tee sections,as applicable.

N. Reinstall retained insulationblankets on aft side of aft pressure bulkhead. (See MM chapter 25-22-0,paragraph entitled "Removal/InstallationInsulation Blankets.")
O. Reinstall rightpneumatic crossfeedvalvepushrod and attaching parts as applicable. (See MM chapter 36-10-3,paragraph entitled "Removal/InstallationPneumatic Crossfeed Valve.")
P. Reinstall two upper conditioned air duct assemblies, check valves, and attachingparts as applicable. (SeeMM chapter 21-20-2, paragraph entitled "Removal/InstallationConditioned and Cold Air Check Valve.") Q. Reinstall lowerfirex bottle and attachingparts as applicable. (See MM chapter 26-20-1,paragraph entitled "Removal/Installation Fire ExtinguishingContainers.")

R. ReinstallAPU compartment enclosure, as applicable. (See MM chapter 53-20-5, paragraph entitled "Removal/InstallationAPU Compartment Enclosure.")

S. ReinstallAPU and attachingparts 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/InstallationPower 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.

Bulletin A53-232 March 28/90 

### Revision 2 April 28/95 Page 22

# ALERT ALERT

ODtion II(Inspection fromforward side of bulkhead)

A. Performhigh and low frequency eddy current inspections of the aft pressure bulkheadweb 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. (3) Inspect the standing leg of ventral bulkhead tee sections from forward side of bulkhead around the entireperiphery of the bulkhead as shownon service sketch 3683D, and accomplish the following:

Condition 1 (No Crack) Perform repetitivehigh and low frequency eddy current inspections from forward side of bulkhead at intervals specified inCompliance 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/InstallationPower Plant.") Shore aircraft as shown on Figure 5.

NOTE: If replacing all six aft pressure bulkhead tee sections, replacement shouldbe accomplished one tee section at a time.
B. Record and report all results, both 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: DouglasAircraft Company P.O. Box 1771 Long Beach, California 90801 Attn: Business Unit Manager Customer Services

- Airframe Product Support 35-35 (DC-9Alert Service BulletinA53-232) March 28/90 BulletinA53-232 Revision 2 April 28/95 Page23

# ALERT ALERT

C. Apply PR-1422 B-2 sealant around entire periphery of thebulkhead 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 sketch3683D Table I, as applicable.



## Bulletin A53-232
Page 24 March 28/90 Revision 2 April 28/95

# ALERT

FLEXIBLE BORESCOPEGUIDE TUBE

- FABRICATIONAND USE March 28/90 1
Revision 2 April 28/95 

## Bulletin A53-232 Page 25 

# ALERT

# ALERT ALERT

DETAIL SB09530231-9 EDDY CURRENT REFERENCE STANDARDMAKEFROM 1D0008S TEE-EXTRUDED SECTION (2024-0) HEAT TREAT TO 2024T42. GENERALNOTES:

1. EDM NOTCH MAXIMUM WIDTH .010-INCH (.25 MM).

2. NOTCH TO BE ON AND PERPENDICULAR TO FORWARD SURFACE.

3. SCALE NONE.
4. THIS SB09530231-9 EDDY CURRENT REFERENCE STANDARD REQUIRED TO ACCOMPLISH OPTION I 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)

OPTION IEDDY CURRENT REFERENCE STANDARD

- FABRICATION Bulletin A53-232 Page 26 Revisio 

### March 28/90

n 2 April 28/95

# ALERT ALERT

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. b. 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 EQUIPMENT:

c. 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 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 BULKHEADTEE - INSPECTION
March 28/90 FIGURE 3 (SHEET 1OF 17) BulletinA53-232
Revision 2 April 28/95 Page 27

# ALERT ALERT

FLEXIBLE BORESCOPE:
d. ONE FORWARD VIEWING ENDOSCOPE OF ANY DIAMETER WITH 30 INCH MINIMUM LENGTH SUCH AS:
(1) OLYMPUS MODEL 1F8D3, 29.8-INCH (757 MM) LONG, 0.315-INCH DIAMETER.
(2) COLD LIGHT SUPPLY NUMBER 1LK-4 (100 TO 230 VOLT).

EDDY CURRENT EOUIPMENT:

e. ONE EDDY CURRENT FLAW DETECTOR WITH IMPEDANCE PLANE DISPLAY SUCH AS:

STAVELEY INSTRUMENTS EDDY CURRENT INSTRUMENT, TYPE NDT-18 OR NDT-19
OR

ZETEC EDDY CURRENT INSTRUMENT, MIZ-20A
f. LOW FREQUENCY EDDY CURRENT PROBES SUCH AS: (1) MOLDED PROBE OPERATING BETWEEN 5 AND 50 kHz: CATALOG NUMBER 935-0120, PARTNUMBERAPB/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 PROBESLISTED IN PARAGRAPHF.(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. SB09530231-9 EDDY CURRENT REFERENCE STANDARD.

AFT PRESSURE BULKHEAD TEE

- INSPECTION

BulletinA53-232 FIGURE 3 (SHEET2 OF 17) March 28/90

Page 28 Revision 2 April 28/95

# ALERT ALERT

INSPECTION PROCEDURE

A. VISUAL INSPECTION PROCEDURE A:

SEQUENCE 1:
(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 TEE SECTION THROUGH THRUST REVERSER LOCKOUT ACCESS OPENING LONGERON L20 LEFT SIDE TO LONGERON L23 LEFT SIDE.
(2) PERFORM MIRROR/FLASHLIGHT OR ENDOSCOPE INSPECTION OF LOWER TEE SECTION THROUGH THRUST REVERSER LOCKOUT ACCESS OPENING LONGERON L20 RIGHT SIDE TO LONGERON L24 RIGHT SIDE. FUSELAGE 5901A FROM

FUSELAGE 5902A FROM

NOTE: SEQUENCE 2 AND 3 MAY BE ACCOMPLISHED USING INSPECTION MIRROR AND FLASHLIGHT IF SUFFICIENT ACCESS IS AVAILABLE.

SEQUENCE 3:
(1) 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 FREOUENCY EDDY CURRENT INSPECTION PROCEDURE B:

NOTE: PROCEDURE B, LOW 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 BULKHEADTEE - INSPECTION
March 28/90 FIGURE 3 (SHEET3 OF 17) BulletinA53-232
Revision 2 April 28/95 Page 29

# ALERT ALERT

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. NQTE: IF SERVICE BULLETIN 53-147 HAS BEEN ACCOMPLISHED,USE STAVELEYINSTRUMENT 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. (c) SCAN ACROSS REFERENCE STANDARD EDM NOTCH 1 WITH MOLDED PROBE AND ADJUSTSENSITIVITYAND PHASE CONTROLSTOOBTAINA DISPLAYSIMILAR 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 WATCHINGTHEDISPLAY SHOULDPERIODICALLY ERASELIFT-OFFTRACE TOAVOID MISSINGA SMALLCRACK 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 Bulletin A53-232 FIGURE 3 (SHEET 4 OF 17) March 28/90 Page 30 Revision 2 April 28/95

# ALERT

March 

# ALERT

SEOUENCE 2: (1) CALIBRATE EDDY CURRENT EQUIPMENT AS FOLLOWS: (a) CONNECT 90 DEGREE PROBE TO EDDY CURRENT INSTRUMENT AND SET OPERATING FREQUENCY AT 10 kHz PERMANUFACTURER'SINSTRUCTIONS.
(b) 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'SINSTRUCTIONS. (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 SHOWNON SHEET 17. (2) PERFORM EDDY CURRENT INSPECTION OF AFT PRESSURE BULKHEAD TEE AS FOLLOWS: (a) PLACE 90 DEGREE PROBE ON AFT SIDE OF TEE UPSTANDING LEG IN AN AREA FREE OF FASTENER EFFECTS, SCAN AND RENULL/BALANCE INSTRUMENT. (b) PROGRESSIVELY SCAN THE EXTENDED AREA OF THE UPSTANDING LEG OF TEE FROM THE VICINITY OF THE INBOARD ROWOF ATTACHMENTS THROUGH THE TEE UPSTANDING LEG THEN OUTBOARD TO AND OVERLAPPING THE TANGENT AREA SCANNED IN SEQUENCE 1.
MQTE: SCAN ONLY THOSE AREAS WHERE THE PROBE WILL FIT EASILY IN THEAREAOF 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 WATCHINGDISPLAY MUSTBE IN CONSTANT COMMUNICATION WITH TECHNICIAN OPERATING PROBE TO MAKE SURE PROBE IS MAKING GOODCONTACTWITH TEESECTION SURFACE.
RAPID SCANNING OF TEE SURFACECAN 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 BULKHEADTEE

- INSPECTION
28/90 FIGURE 3 (SHEET 5 OF 17) Bulletin A53 

## Revision 2 April 28/95 -232 Page 31

# ALERT

Bulletin A53-232
Page 32 

# ALERT

ZETEC INCORPORATED C/N 935-0120 P/N APB/MSP LOW FREQUENCY EDDY CURRENT PROBE OR EQUIVALENT

AFT PRESSUREBULKHEAD TEE

- INSPECTION
FIGURE3 (SHEET 6 OF 17) March 28/90
Revision 2 April 28/95

# ALERT

AFT PRESSUREBULKHEAD TEE

- INSPECTION March 28/90 FIGURE3 (SHEET 7 OF 17) 

## Revision 2 April 28/95 Bulletin A53-232 Page 33 

# ALERT

# ALERT

BulletinA53-232
Page 34 

# ALERT

ZETEC INCORPORATED C/N 910-5830 P/N APB/90DP LOW FREQUENCY EDDY CURRENT PROBE OR EQUIVALENT
AFT PRESSURE BULKHEAD TEE

- INSPECTION
FIGURE 3 (SHEET 8 OF 17) March 28/90
Revision 2 April 28/95

# ALERT

VISUAL INSPECTION PROCEDURE A SEQUENCES FOR AFT PRESSURE BULKHEAD TEE

AFT PRESSURE BULKHEAD TEE - INSPECTION
March 28/90 FIGURE 3 (SHEET 9 OF 17)

Revision 2 April 28/95 BulletinA53-232
Page 35 

# ALERT

# ALERT

Bulletin A53-232
Page 36 

# ALERT

AFT PRESSURE BULKHEAD TEE

- INSPECTION

FIGURE3 (SHEET 10 OF 17) March 28/90
Revision 2 April 28/95

# ALERT ALERT

DC-9 VENTRAL AFT PRESSURE BULKHEAD SCHEMATIC DIAGRAM SHOWING TEE LOCATIONS

March 28/90 AFT PRESSURE BULKHEAD TEE

- INSPECTION

FIGURE 3 (SHEET 11 OF 17) Revision 2 April 28/95 

### Bulletin A53-232
Page 37

# ALERT

SEQUENCE 1 VISUAL AND ENDSCOPE INSPECTION OF BULKHEAD TEE



### BulletinA53-232

'age 38 AFT PRESSURE BULKHEAD TEE

- INSPECTION

FIGURE 3 (SHEET 12 OF 17) March 28/90
Revision2 April 28/95 

# ALERT

# ALERT

AFT PRESSURE BULKHEAD TEE - INSPECTION March 28/90 FIGURE 3 (SHEET 13 OF 17) Revision 2 April 28/95 BulletinA53-232
Page 39 

# ALERT

# ALERT

BulletinA53-232
Page 40 

# ALERT

AFT PRESSURE BULKHEAD TEE - INSPECTION

FIGURE 3 (SHEET 14 OF 17) March 28/90
Revision 2 April 28/95

# ALERT ALERT

March 28/90 AFT PRESSUREBULKHEAD TEE

- INSPECTION

FIGURE 3 (SHEET 15 OF 17) BulletinA53-232
Revision 2 April 28/95 Page 41

# ALERT

BulletinA53-232
Page 42 

# ALERT

AFT PRESSURE BULKHEAD TEE

- INSPECTION
FIGURE 3 (SHEET 16 OF 17) March 28/90 Revision2 April 28/95

# ALERT ALERT

March 28/90 AFT PRESSURE BULKHEADTEE

- INSPECTION
FIGURE 3 (SHEET 17 OF 17) 

## Bulletin A53-232 Revision 2 April 28/95 Page 43

# ALERT ALERT

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-INCH (1.5 MM) 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-INCH (1.5 MM). 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 - MODIFICATION BulletinA53-232 FIGURE 4 (SHEET 1 OF 6) March 28/90 

### Page44 Revision 2 April 28/95

# ALERT ALERT

TABLEI QUANTITYPER VENTRALBULKHEAD CONDITION DOUBLERCONFIGURATION WITH9918572 DOUBLER WITHOUT9918572 DOUBLER
PARTNO. KEYWORD QTY QTY

HL325-5-4 PIN 4 4 HL325-5-5 PIN 57 131 HL325-5-6 PIN 57 132 HLT335-6-6 PIN 20 10 HLT335-6-7 PIN 10 HLT41-5-5 PIN 234 HLT41-5-6 PIN 234 HLT434-6-6 PIN 20 20 HLT435-6-4 PIN 5 5 HLT435-6-6 PIN 18 18 HLT436-6-5 PIN 15 HLT436-6-6 PIN 72 15 HLT436-6-7 PIN 72 HLT634-6-6 PIN 120 120 HLT634-6-7 PIN 120 120 HLT635-6-5 PIN 198 237 HLT635-6-6 PIN 260 275 HLT635-6-7 PIN 72 40 MS20470AD5-6 RIVET 214 186 MS20470AD5-7 RIVET 267 239 MS20470AD6-6 RIVET 123 115 MS20470AD6-7 RIVET 114 97 MS21042L3 NUT 87 551 NAS1097AD5-9 RIVET 50 50 NAS1097AD6-10 RIVET 10 NAS1097AD6-9 RIVET 280 375 NAS1252-10L WASHER 275 S2931983-30A06 WASHER 297 297 S4931919-6-3 PIN 12 12 S4931919-6-4 PIN 4 4 S4931919-6-5 PIN 315 71 S4931919-6-6 PIN 300 56 S4931919-6-7 PIN 30 S4931920-6-5 PIN 55 33 S4931920-6-6 PIN 73 33 S4931920-6-7 PIN 18 SR09530056-3 TEE 1 1 OR 5910163-389 SR09530056-5 TEE 1 1 OR 5910163-391 SR09530056-6 TEE 1 1 OR 5910163-392 SR09530056-7 TEE 1 1 OR 5910163-393 SR09530056-8 TEE 1 1 OR 5910163-394 SR09530056-9 TEE 1 1 OR 5910163-387 3D0006-08 NUTASSY 8 472 3D0006-3 NUT ASSY 1368 728

AFT PRESSURE BULKHEADTEE
- MODIFICATION
March 28/90 FIGURE 4 (SHEET 2 OF 6) BulletinA53-232 

### Revision 2 April 28/95 Page 45

# ALERT ALERT

TABLEII VENTRAL AFT PRESSURE BULKHEAD

OLD PART NO.
5910130-51 OR 5919130-389 5910130-53 OR 5910130-391 5910130-54 OR 5910130-392 5910130-55 OR 5910130-393 5910130-56 OR 5910130-394 5910130-47 OR 

### 5910130-387

AFT PRESSURE BULKHEAD TEE MAY BE REPLACED WITH NEW IMPROVED GLASS SHOT PEENED PART NO.

SR09530056-3 TEE OR 5910163-389 SR09530056-5 TEE OR 5910163-391 SR09530056-6 TEE OR 5910163-392 SR09530056-7 TEE OR 

### 5910163-393 SR09530056-8 TEE OR 5910163-394 SR09530056-9 TEE OR 

### 5910163-387

- MODIFICATION Bulletin A53-232 FIGURE4 (SHEET3 OF 6) Page 46 

### Revision 2 March 28/90 

### April 28/95

# ALERT ALERT

AFT PRESSURE BULKHEAD TEE

- MODIFICATION March 28/90 FIGURE 4 (SHEET4 OF 6) Revision 2 April 28/95 

### Bulletin A53-232 Page 47

# ALERT ALERT

TABLE III

FASTENER TO BE REMOVED
HL326-5-X PIN, S4933653-3 NUT ASSY
HL329-5-X PIN, S4933653-08 NUTASSY
HL328-5-X PIN, S4933653-08 NUT ASSY
MS20427M4 RIVET

MS20427M5 RIVET

MS20470AD5-X RIVET

MS20470AD6-X RIVET

MS20470DD5-X RIVET

HL328-5-X PIN, NAS1252-8L WASHER, MS21042L08 NUT
S4931920-6-X PIN, S4933653-3 NUT ASSY
MS20615M4 RIVET REPLACEWITH FASTENER
S4931920-6-X PIN, 3D0006-3 NUTASSY
S4931919-6-X PIN, 3D0006-08NUT ASSY
S4931920-6-X PIN, 3D0006-3 NUT ASSY
HLT41-5-X PIN, 3D0006-08NUT ASSY
S4931919-6-X PIN, 3D0006-3NUT ASSY

SAME, OR S4931920-6-X PIN, NAS1252-10L WASHER, MS21042L3NUT
SAME, OR HLT634-6-X PIN, S2931983-30A06WASHER, MS21042L3 NUT
S4931919-6-X PIN, 3D0006-3 NUT ASSY
S4931920-6-X PIN, NAS1252-10L WASHER, MS21042L3 NUT
HLT334-6-XPIN, 3D0006-3NUT ASSY HL325-5-X PIN, 3D0006-08 NUT ASSY

Bulletin A53-232
Page 48 AFT PRESSUREBULKHEAD TEE - MODIFICATION

FIGURE 4 (SHEET 5OF 6) 

### March 28/90 

### Revision 2 April 28/95 REFERENCE CODE USED ON DRAWING

5910130

# ALERT ALERT

TABLE III (CONT)
REFERENCE CODE USED ON DRAWING 5910130 FASTENER TO BE REMOVED
MS20615-5MRIVET

NAS1097AD5-XRIVET

NAS1097AD6-XRIVET

NAS1097DD5-X RIVET

S4579428-5-X RIVET

S4579428-6-XRIVET

S4931920-6-X PIN, S4932389-3 NUT

4931919-6-X PIN, S4932389-3NUT

S4579428DD6 RIVET

S4931920-6-X PIN, S4933653-3 NUT ASSY REPLACEWITH FASTENER
S4931919-6-X PIN, 3D0006-3 NUTASSY
SAME, OR NAS1097AD6-XRIVET
SAME, OR HLT635-6-XPIN, 3D0006-3NUT ASSY
HLT335-6-XPIN, 3D0006-3 NUTASSY

S4931919-6-X PIN, 3D0006-3NUT ASSY
HLT635-6-XPIN, 3D0006-3NUT ASSY
HLT436-6-X PIN, S2931983-30A06WASHER MS21042L3NUT
HLT635-6-XPIN, S2931983-30A06WASHER MS21042L3 NUT
HLT635-6-X PIN, 3D0006-3NUT ASSY
HLT436-6-X PIN, 3D0006-3 NUT ASSY

AFT PRESSURE BULKHEAD TEE

- MODIFICATION
March 28/90 FIGURE 4 (SHEET 6 OF 6)
Revision2 April 28/95 BulletinA53-232
Page 49

# ALERT ALERT

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 5910130/5930760 (FUSELAGE NUMBER 1071 AND SUBSEQUENT) TEE, VENTRAL AFT PRESSURE BULKHEAD, PER DAC SERVICE REWORK DRAWING SR09530001 OR SR09530056. 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" BB) 7-20-0 "SHORING" (C) 8-10-0 "LEVELING"
AIRCRAFT TO BE LEVEL WITHIN 2 DEGREES. 3. INSTALL CRADLE FORAIRCRAFT WITH VENTRALPRESSUREBULKHEAD. CAUTION: THEAFT FUSELAGECRADLERESTS AGAINST SLOPINGFUSELAGESKIN SURFACE. RESTRAIN AIRCRAFT AND CRADLE FROM SLIPPAGE IFREQUIRED. 4. JACK AT AFT FUS JACK POINT SHALL BE REMOVEDDURINGMODIFICATION ORREPAIR OF AFT PRESSURE BULKHEAD.
5. USE -1 SHORING CONFIGURATION ONLY FOR SIDE TEE REPLACEMENT BETWEEN LONGERON 6.5 TO LONGERON 22.5 (LEFTAND RIGHT SIDES), PART NUMBERS 5910130-53, -54, -55 OR -56. DO NOT REPLACE LEFT AND RIGHT SIDES TEES AT SAME TIME. 6. ADD -501 SHORINGCONFIGURATIONFORUPPERTEE REPLACEMENT BETWEEN LONGERON 6.5 (LEFT SIDE) AND LONGERON 6.5 (RIGHT SIDE), PART NUMBER 5910130-51. ALSO FOR LOWER TEE REPLACEMENT BETWEEN LONGERON 22.5 (LEFT SIDE) AND LONGERON 22.5 (RIGHT SIDE), PARTNUMBER591013047.
7. REMOVETAILCONE PERMAINTENANCEMANUAL53-50-3. 8. INSTALL DAC SERVICE REWORK DRAWINGJ060157 SHORINGPROVISIONS ONAFT CANTEDFRAME.
9. AFTER INSTALLING SUPPORT AT AFT CANTED FRAME, ACCOMPLISH THEFOLLOWING:

a. APPLY 50 + 25 POUND FORCE PRELOAD TO PROVIDE POSITIVE UP LOAD ON JACK. b. MEASUREGAPBETWEENSKINS PRIORTO REMOVALOFANYATTACHMENTS (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

- VENTRALAFT PRESSURE BULKHEADTEE REPLACEMENT Bulletin A53-232 FIGURE5 (SHEET 1 OF 3) March 28/90 Page 50 Revision 2 April 28/95

# ALERT ALERT

CAUTION:
INSTALLCRADLESONLYAFTERAIRCRAFTIS LEVELANDONWINGAND AFT FUSELAGEJACKS.
REMOVE CRADLESBEFORERELEASINGWING AND AFT FUSELAGEJACKS. SEVERESTRUCTURAL DAMAGE WILL OCCURIF WINGJACKSARERELEASED WHEN CRADLEANDJACKATAFTFUSELAGEJACKPOINTSAREINSTALLED.



### -1 SHORINGCONFIGURATION

SHORING INSTRUCTIONS

- VENTRALAFT PRESSUREBULKHEADTEE REPLACEMENT
March 28/90 FIGURE 5 (SHEET 2 OF 3) Bulletin A53-232
Revision 2 April 28/95 Page 51

# ALERT ALERT

-501 SHORING CONFIGURATION

SHORING INSTRUCTIONS

- VENTRAL AFT PRESSURE BULKHEAD TEE REPLACEMENT BulletinA53-232 FIGURE 5 (SHEET 3 OF 3) March 28/90 Page 52 Revision 2 April 28/95

# ALERT ALERT

3. Material Information:

A. The basis for the following material data is per aircraft.
(1) Parts to be purchased as end item spares.
NOTE: Parts requirementsare contingent upon inspectionfindingsindicating the existence of crack(s) in a tee section. Maximum quantitiesrequiredper Figure4, Table I, are listed. Actual parts requirements are tobe determinedby the operator. Quantities listedare for recordpurposesonly.

Partswithin parenthesesare equivalentpart numbers.

Part No. 

### SR09530056-3 

### (5910163-389) SR09530056-5 (5910163-391) SR09530056-6 

### (5910163-392) SR09530056-7 (5910163-393) SR09530056-8 

### (5910163-394) SR09530056-9 (5910163-387) S2931983-30A06 

### S4931919-6-3 S4931919-6-4 

### S4931919-6-5 S4931919-6-6 S4931919-6-7 S4931920-6-5 

### S4931920-6-6 S4931920-6-7 3D0006-08 3D0006-3 production

Otv KeyWord

1 Tee

1 Tee

1 Tee

1 Tee

1 Tee

1 Tee 

### 297

12



### 4 315 300



### 30 55 73 18 

### 472 1368 Washer Pin Pin Pin Pin Pin Pin Pin Pin NutAssembly NutAssembly (2) Fastener kit consists of the followingparts andmay be purchased from DAC ormay beprocured from operator's stock or source indicated. Maximum quantities are listed, actual fasteners required are contingentupon inspection findings and are to be determinedby theoperator.



### March28/90 

### Bulletin A53-232 Revision 2 April 28/95 Page 53Part/Material
HLT335-6-6 Pin 

### HLT335-6-7Pin HLT41-5-5Pin HLT41-5-6Pin HLT434-6-6Pin HLT435-6-4Pin HLT435-6-6Pin HLT436-6-5Pin HLT436-6-6Pin HLT436-6-7Pin HLT634-6-6Pin HLT634-6-7 Pin HLT635-6-5 Pin 

### HLT635-6-6Pin HLT635-6-7Pin HL325-5-4Pin HL325-5-5Pin HL325-5-6Pin 

# ALERT

QtyKit SB09530232-3
20 10 

### 234 234

20

5 

### 18 15 72 72 120 120 237 

### 275

72



### 4 131 

### 132 Suppl 

### ier

73197 Hi-Shear Corporation 2600 Skypark Drive Torrance, California 90506



### MS20470AD5-6 Rivet MS20470AD5-7 Rivet 

### MS20470AD6-6 Rivet MS20470AD6-7Rivet MS21042L3Nut 

### NAS1097AD5-9 Rivet NAS1097AD6-10 Rivet NAS1097AD6-9Rivet NAS1252-1OLWasher
(3) Material to be procured from operator's stock or source indicated.
Part/Material 

### PR-1422 B-2Sealant

(DMS2082)



## or Equivalent 1 Qt 83574 Courtaulds Aerospace 5430 San Fernando Road 

## Glendale, California 91209

B. The basis for the followingmaterial data is per spares.

None.



## Bulletin A53-232 March 28/90

Revision 2 April 28/95 

# ALERT

214 267 123 114 551



### 50 10 375 

### 275


## Qty CAGE SuDD1 er

Page 54

# ALERT ALERT

C. The basis for the following tooling data is per ooerator. (1) Option I

- Test equipment to beprocured from operator's stockor sources indicated.
NQIE: One 70 or 90 degree endoscopeof any diameter with 18-inch (457.2MM) minimum length and matching light sourcemay be used. 

### Test Equipment Tyee 

## Supplier Endoscope70 Degree

(Foreoblique)Angle 19-Inch (482.6MM) Long 0.217-Inch Diameter or Equivalent
FiberOptic

LightBundle

and EndoscopeLight Source

110or 220 Volt

and Sylvania Projector Lamp

150Watt, 120Volt Model 10320D

Model

1F8D3 1 54341 Expanded Optics, Incorporated 7382 BolsaAvenue Westminster, California 92683

1

No. 00482 or No. E0590

1

NOTQIE: Similar or equivalent endoscopes and illuminatorsmay be obtained from the following sources.


### AlvaIngenieros Velazquez 121 Madrid 6, Spain or Automation Instruments

Service 

## 47Birch Street Bankston 2200, Australia 

## or

March28/90 BulletinA53-232 

### Revision 2 April 28/95 Page 55

# ALERT ALERT

Test Equipment

Flexible Borescope

29.8-Inch (757 MM) Long 0.315-Inch Diameter

Cold Light Supply

100 to 230 Volt or Equivalent Eddy Current Flaw

Detector with Impedance Plane Display or

Zetec Eddy Current

Instrument or Equivalent CAGE Suppl er
3 G Electronics Sede Commercial20135 MilanoVia Perugino 9,



## Italy
or 50958 RichardWolf Medical Instrument

Corporation 7046 LyndonAvenue Rosemont, Illinois 60018-3410 or Inspection Instruments

NDT Limited 10-12 EmeraldStreet LondonWC1, England or Karl Storz KG D 7200 Tuttlingen West Germany
Model

1F8D3

No. 1LK-4

NDT-18 or NDT-19

MIZ-20A 1 32212 Olympus Corporation ScientificProducts Group 2 Nevada Drive New Hyde Park,New York 

### 11040

1



### 1 29192 Staveley Instruments Incorporated 421 NorthQuay Street Kennewick,Washington 99336-7735
51327 Zetec Incorporated 1320NorthWest Mall P.O. Box 140 Issaquah,Washington 98027-8921
Eddy Current Low

Frequency Molded Probe 5-50 kHz Operating Frequency or Model C/N 935-0120 P/NAPB/MSP 1 (Zetec Incorporated)



## Bulletin A53-232 March28/90 Revision 2 April 28/95 Page 56

# ALERT

Test Equipment
Eddy Current Low

Frequency Molded Probe 5-50 kHz Operating Frequency

or Eddy Current Low

Frequency Molded Probe 5-50 kHz Operating Frequency (To be used after Service Bulletin 53-147 has been accomplished.) 

# ALERT
Suppli er

Model SPO-4080

Model SPO-5222 (StaveleyInstruments Incorporated)

(StaveleyInstruments Incorporated)

Eddy Current Low

Frequency 90 Degree Probe 5-50 kHz Operating Frequency Model C/N 910-5830 P/NAPB/90DP 1 (Zetec Incorporated)

or Eddy Current Low

Frequency 90 Degree Probe 5-50 kHz Operating Frequency Model SPO-4081 (StaveleyInstruments Incorporated)

NOTE: When ordering eddy currentprobes specify type of eddy current instrumentthe probe will be used with so thatpropermating connectors or adapterwill beprovided. (2) Option I

- One SB09530231-9eddy current reference standard required to accomplishOption I low frequency eddy current inspection will bemade available at no charge. (Seeparagraph 1.H.) (3) Option II

- Test equipment required to accomplishOption II high and low frequency eddy current inspections includingprocurement sources, is listed in servicesketch3683D. Choice of equipment is at operator's option and isto beprocured from operator's stock or sources indicated in service sketch 3683D.



### March28/90 

## Bulletin A53-232
Revision 2 April 28/95 Page 57

# ALERT ALERT

(4) Option II- The following reference standard required to accomplish theOption II high and low frequency eddy current inspections is to be_procuredfrom operator's stock or as indicated.InstructionsPartNo. Otv KeyWord Disposition
MS20470AD5-6 2 Rivet MS20470AD5-7 4 Rivet SB09530231-11 1 Plate SB09530231-13 1 Web SB09530231-15 1 Tee SB09530231-17 1 Reference StandardAssy
Maybe purchased from: VM Products Incorporated CA 11298 62nd Avenue 60761 Puyallup,Washington 98373 or Maybe fabricatedby the operator. (See service sketch 3683C.)
May be procured from operator's stock.
Detailof SB09530231-17 reference standard assembly.
May be fabricatedby the operator from 7075-T6 clad aluminum sheetMaterial SpecificationQQ-A-250/13 Temper T6 or 7075-T6 bare aluminumplate Material Specification QQ-A-250/12 Temper T6, .047/.053x 2-1/4 x 3 inches. (See service sketch 3683D.)
May be fabricated by the operator from 7075-T6 clad aluminum sheetMaterial SpecificationQQ-A-250/13 Temper T6 or 7075-T6 bare aluminum plate Material Specification QQ-A-250/12 Temper T6, .039/.045x 2-1/4 x4-1/2 inches. (See service sketch 3683D.) May be fabricated by the operator from 2024-T3 clad aluminum sheetMaterial SpecificationQQ-A-250/5 Temper T3 or 2024-T4 bare aluminum plate Material Specification QQ-A-250/4 Temper T4, .075/.085x 3 x 4-1/2 inches. (See service sketch 3683C.)
Any inquiries regarding accuracy, timeliness,completeness, and legibility of this Service Bulletin shouldbe directed to the local DAC Field Representative,or: DouglasAircraft Company P.O. Box 1771 Long Beach, California 90801 Attn: BusinessUnit Manager Service Bulletins Maintenance and Modification Engineering Product Support 35-35 (DC-9Alert ServiceBulletin A53-232) ENW/CAS/ENW LL/AMM


### Bulletin A53-232 March28/90 Revision 2 April 28/95 

### Page 58