SUBJECT: FUSELAGE

- MAINWHEEL WELL PRESSURE FLOOR INSPECTION, MODIFICATION AND REPAIR
NOTE:This revision includesall pages ofthe service bulletin. SUMMARY This revision is sent to provide information about a new top kit and new supplemental kits. The inspection area is expanded to examine the beads at Body Station 950. Also an inspection threshold and a repeat inspection interval are added for all areas not repaired or preventively modified as described in Part III of the Accomplishment Instructions. The intent of 727-53-0149NSC1 and727-53-0149NSC2 are also added. Airplane Effectivityshows changes of airplaneoperators. No morework is necessaryon airplanes changed by Revision3 ofthis service bulletin. Morework is necessaryon airplanes changed bythe original issue, Revision 1or Revision2ofthis service bulletin. The work necessary is to add the additional doublers at right and left buttock line 50tothe side ofthe body, between bodystation 920 and950. Vertical lines on the left edge of each page showthe location of data changes. If no vertical lines are shownon a page, no importantchanges were made onthat page.
REVISION HISTORY Original Issue: May 4, 1979 Revision 1: September 19, 1980 Revision 2: March 20, 1981 Revision 3: November 2, 1989 Revision 4: June 27, 1991ATA System: Number: Date: Revision 4: 5314 

## Summary 727-53-0149 May 4, 1979 June 27,1991
SUBJECT: FUSELAGE

- MAINWHEEL WELL PRESSURE FLOOR INSPECTION, MODIFICATION AND REPAIR
BACKGROUND Based ona structural reviewofthe 727 airplane, incorporation ofthe modification per this service bulletin is recommendedon aging airplanes. Eight operators have reported 34 cracks on 20 airplanes, each along the ends of the pressure floor reinforcing beads at Stations 930 and 940. The cracks ranged from 0.38to 15.25 inches in length. Propagation of undetected cracks could result incabin pressurizationdifficulties. Since Revision 3 ofthis service bulletin, similar cracks have been reported at Body Station 950. The airplanes had accumulated between 24,000 and 42,200flight cycles and24,000 and 49,500 flight hours. Althoughthere have been no reportsof cracking at Stations 880 and 890, the possibility exists that cracks maydevelop atthese stations also. This service bulletin is the subject of FAA Airworthiness Directive 90-17-06 Amendment 39-6691 which supersedes existing Federal Aviation Administration (FAA) Airworthiness Directive88-26-02,Amendment 39-6089. ACTION (PRR 24311 ) As recommended by the 727 Aging Fleet Structures Working Group, accomplish modification per the Accomplishment Instructions at or before the accumulation of 60,000flight cycles. When the airplane has 20,000 flight cycles, or within the next 2500 cycles, whichever is later, inspect the ends of the pressure floor beads adjacent to Stations 880, 890, 930, 940 and 950. If the previous inspection is High Frequance Eddy Current, examine at 5000 flight cycle intervals. If the previous inspection is visual or dye penetrant, examine at 4000 flight cycle intervals. Repeat inspection until preventive modification or permanent repair is accomplished. Cracks in specified areas may be repaired with doublers. An interim repair may be accomplished providing a permanent repair is made within600flightsthereafter. Airplanes previously modified per the original release, or Revision 1 or 2 of this bulletin, or Group 2 airplanes require repeat inspection for cracks inthe pressurefloor web at BS 930, 940 and 950 between Buttock Lines 50 and 63 until additional doublers are installed per this Revision 4. Airplanes previously repaired using fasteners require replacing fasteners accumulating 10,000flight cycles. blind upon
EFFECTIVITY All 727 airplanes Group 1
- Line Position 1-1432 Group2
- Line Position 1433-1832 MANPOWER Total Manhours

- 274 per airplane ElapsedTime

- 42 Hours MATERIAL INFORMATION Kit 69-70864-3 69-70864-4 69-70864-5
* See Paragraph I. applicable to information Price* $3282.00 $5565.00 

# $

3624.00

F. for terms and conditions

price and delivery

BOEING COMMERCIAL AIRPLANE GROUP P.O.BOX 3707 SEATTLE, WASHINGTON 98124-2207 Summary Page 1of 2May4/79 Rev. 4: Jun 27/91 Summary Page 2of 2ATA System: Number: Date: Revision 4: 5314 727-53-0149 May 4, 1979 June27,1991 SUBJECT: FUSELAGE

- MAIN WHEELWELL PRESSURE FLOOR INSPECTION, MODIFICATION AND REPAIR

I. PLANNING INFORMATION A. Effectivity 1. Airplanes Referto Service Bulletin Index Document D6-9825, Part 3 for Airplane Variable Number, Line Number, and Serial Numberdata. An equivalent change was incorporated in production in accordance with PRR 24311 on applicable airplanesotherthanthose listedbelow.

LISTING BY CUSTOMER, CUSTOMER CODE, GROUP AND VARIABLE NUMBER CUSTOMER GROUPVARIABLE NUMBER A. L. I. (IBA)

1 E3026 ACES (ACE)

1 E0130 E3116
E3148 AERO CHASQUI (CHQ) 1 E3501 E3653 AERO PERU (PER) 1 E3503 E3621 E3651

E5278 AEROEJECUTIVO (AEJ)

1 E0101 E0404 AEROLINEAS ARGENTINAS (ARG)

1 QD601-QD602 2 QD450 QD603-QD607 AERONICA (ANC) 1 E0133 AIR ALGERIE (ALG) 1 QA574-QA576 QB451-QB453 2 QB454-QB458 AIR CANADA (ACN)

1 QD205 QD209-QD210 2 QD215-QD223 QD225 QD231-QD239

May 4/79 Rev. 4: Jun 27/91 727-53-0149 Page 1 of 53LISTING BY CUSTOMER, CUSTOMER CODE,GROUPAND VARIABLE NUMBER, (continued) CUSTOMER GROUP VARIABLE NUMBER AVIANCA (AVI) 1 E3036 E3064 E3402 E3406 QD553-QD554 2 QD581-QD583 QD991-QD992 AVIATION CONSULTANTS (ACT) 1 E3076 AVIATION SALES CO., INC. (ASC) 1 QA038 QA908 E3068-E3069 E5451 E3141-E3143 E5453 E3204 QA572 E3221-E3224 QB031-QB033

QA918 AVIOGENEX AIR TRANSPORT (AVG) 1 QD006 QD191-QD192 2 QD518 BAHRAIN, GOVT OF (BHR) 2 QD451 BELGIAN AIR FORCE (BLG) 1 E5351-E5352 BRADLEY AIR SERVICES (BRS) 1 E3065 E5112 BRANIFFAIRLINES (BNF) 1 QA002 QA359 BRITHEN LTD. (BTN) 1 E0211 BURLINGTON NORTHERN (BNR) 1 E3509 CARNIVALAIR (CVL) 1 E3030 QA636 CHINESE AIR FORCE (CAF) 1 E3506 E3512 E5141 E5481-E5483

QA641
E5409 E5435 CITICORP INDUSTRIAL CREDIT (CIC) 1 QD206 CLAY LACY AVIATION, INC. (CYA) 1 E3077 CONNIE KALITTA FLYING SERVICES (CKF)

1 E0304 E5050 CONTINENTAL AIRLINES, INC. (CAL)

1 E0038-E0042 E0202 E0205 E3247 E3253 E5201 QA301-QA304 QA306 QA308-QA314 QD501-QD509 2 QA345-QA349 QB901-QB904 QD510 E3001 E5455 QA325-QA344 E3241 E3245 QA019-QA021 QA059-QA072 QA870-QA893 QA896 QD512-QD517

May 4/79 Rev. 4: Jun 27/91 727-53-0149 2LISTING BY CUSTOMER, CUSTOMER CODE, GROUP AND VARIABLE NUMBER, (continued) CUSTOMER GROUPVARIABLE NUMBER AIR COLUMBUS (COB) 1 QL001-QL002 AIR FRANCE (AFA) 1 QA351-QA352 QA551 QA554 2 QD761-QD769 QD781-QD782 AIR JAMAICA (JAM) 1 QD281-QD284 AIR PANAMA INTERNATIONAL (PAN)

1 E3115 AIR TRANSAT (AIJ)

1 QD206-QD207 QD212 AIRCRAFT SUPPORT GROUP (ASG) 1 E3202 AIRLINE CREDITCONSULTANTS (ACJ) 1 E0340 E3070 E3076 QA561-QA562 QA565-QA570

ALASKAAIRLINES (ASA) 1 E3401 E3521 QD902 QD904-QD905 2 QB619 QB622 QD909 QD952-QD954 E5058 QD931-QD932 QB624-QB628 E5142 QD951 QD555 QA378
QD558 QA894-QA895
QD791
ALLRED INTERNATIONAL, INC. (RED) 1 E0206 AMERICANAIRLINES, INC. (AAL) 1 E0301-E0303 E0305-E0309 E0336-E0339 E0345 QA101-QA178 QA854 2 QA179-QA199 QB801-QB810 E0311-E0326 E0348-E0349 QA856-QA869 E0328-E0330 E3075 E0332 E0334 E3519-E3520 QA014

AMERICAN TRANS AIR (AAT)

1 E3029 E3032-E3033 E3286-E3289 AMERIJET INTERNATIONAL, INC. (AMJ)

1 E0104 E3028 E3073-E3074 E3145 E5403 AMWAY PRODUCTS (AMA) 1 E3681 ANSETTAIRLINESOF AUSTRALIA (ANS) 1 E0119 QD034 2 QD040 QD043-QD046 ARIANA AFGAN AIRLINES CO., LTD (AFG)

1 E5410 E5424

May 4/79 Rev. 4: Jun 27/91 E3341 E5161

727-53-0149 3LISTING BY CUSTOMER, CUSTOMER CODE, GROUP AND VARIABLE NUMBER, (continued) CUSTOMER GROUP VARIABLE NUMBER AUSTRALIAN AIRLINES LIMITED (AUS) 1 QD001-QD004 QD007-QD008 2 QD009-QD012 AVENSA (AVN) 1 E0034-E0036 E3072 E3244 QA036 QA039 QA041-Q AVIANCA (AVI)

1 E3036 E3064 E3069 E3204 E3221-E3224 E3402 QA572 QB031-QB033 QD553-Q 2 QD581-QD583 QD991-QD992 AVIATION SALES CO., INC. (ASC) 1 QA038 QA908 QA918 AVIOGENEX AIR TRANSPORT (AVG) 1 QD006 QD191-QD192 2 QD518 BAHRAIN, GOVT OF (BHR) 2 QD451 BELGIAN AIR FORCE (BLG) 1 E5351-E5352 BRADLEY AIR SERVICES (BRS) 1 E3065 E5112 E5141 BRANIFF AIRLINES (BNF) 1 QA002 QA359 BRITHEN LTD. (BTN) 1 E0211 BURLINGTON NORTHERN (BNR) 1 E3509 CARNIVAL AIR (CVL) 1 E3030 QA636 QA641 CHINESE AIR FORCE (CAF) 1 E3506 E3512 E5409 CITICORP INDUSTRIAL CREDIT (CIC) 1 QD211 CLAY LACY AVIATION, INC. (CYA) 1 E3077 CONNIE KALITTA FLYINGSERVICES (CKF) 1 E0304 E5050 E3246 A043 QA853

D554 

### E3141-E3143 E3406



### E5481-E5483

E5435

May 4/79 Rev. 4: Jun 27/91 727-53-0149 4 E3248 QD121
E3146 E5451 E3511

E3149 E5453LISTING BY CUSTOMER, CUSTOMER CODE,GROUPAND VARIABLE NUMBER, (continued) CUSTOMER GROUP VARIABLE NUMBER CONTINENTAL AIRLINES, INC. (CAL) 1 E0038-E0042 E0202 E0205 E3247 E3253 E5201 QA301-QA304 QA306 QA308-QA314 QD501-QD509 2 QA345-QA349 QB901-QB904 QD510 CORSAIR (CRA) 1 E3002 E3001 E5455 QA325-QA344 E3241 E3245 QA019-QA021 QA059-QA072 QA870-QA893 QA896 QD512-QD517
E3011-E3012 CRUZEIRO DO SUL (CRU) 1 E3071 E3345 DALLAH AVCO (AVO) 1 E3038 DAN AIR (DAN) 1 QB035 QB114 QL031-QL032 DAVIS OIL CO. (DOC) 1 E3206 E3781-E3783

QD033 QD123

DELTA AIR LINES, INC. (DAL) 1 QA073-QA079 QA081-QA092 QA096-QA099 QA907 QA929-QA933 QB501-QB552 2 QA939-QA946 QA949 QB553-QB558 QB560-QB575 DHL CORPORATION/WORLDWIDE COURIER EXP. (DHL) 1 E0030 E0124 E3622 E5046-E5047 E5382 E5402 QA552-QA553 QA555-QA556 DIRECTORATE OF POLICE AVIATION (OMAN) (OMA) 1 E0210 DOMINICANA AIRLINES (DOM)

1 E3755 E5404 QD903 QL004-QL005

QA909-QA917 QA919-QA926

E5273-E5274 E5281 QA563-QA564

QD351 DONREY, INC. (DON) 1 E3014 DONVAN ENTERPRISES, INC. (DNV) 1 E0351 E-SYSTEMS (ESM) 2 QD908 EASTERN AIR LINES, INC. (EAL) 1 QA601-QA605 QA607-QA620 QA622 QA642-QA653 2 QA659-QA671 QA673-QA684 QA686-QA688 ECHO BAY MINES (EKO) 1 E5418

May4/79 Rev. 4: Jun 27/91 QA624 QA628 QA630-QA634

727-53-0149 5LISTING BY CUSTOMER, CUSTOMER CODE, GROUP AND VARIABLE NUMBER, (continued) CUSTOMER GROUP VARIABLE NUMBER EMERY WORLDWIDE (EAF) 1 E5003 E5005 EMIRATES AIRLINES (EAD) 2 QB065 QD452 E5007-E5011 QD972 ETHIOPIAN AIRLINES, CORP. (ETH) 2 QD661-QD663 QD971 EUROPE AERO SERVICE (EUR)

1 QA573 QA855 EUROPEAN AIR TRANSPORT (EPT)

1 E3701-E3703 EVERGREEN INTERNATIONAL AIRLINES (EVR)

1 E3101 E3151-E3152 E3275-E3276 E5277 E3652 E5104-E5105 E5426 F.A.M.C.O. (AVIATION) (FAM) 1 E5353 FAHAD AL-TAMEEMI (TMI)

1 E3410 FAUCETT (COMPANIA DEAVIATION S.A. (FCT)

1 QA901 QA904 FEDERAL AVIATION ADMINISTRATION (FAA) I E0201 E5241 FEDERAL EXPRESS (FED) 1 E0023-E0028 E0310 E3254-E3274 E5056-E5057 E5226-E5240 QA897-QA899 2 QB610-QB617 E0120 E0331 E3277-E3283 E5059-E5063 E5242 QB601 -QB609 QD039 E0122-E0123 E0333 E3290 E5067 E5408 QD035-QD038 QD041-QD042 E0125-E0129 E0335 E3577 E5101-E5102 E5420 QD201-QD204 QD224 E0131-E0132 E0341-E0344 E5048-E5049 E5163-E5164 E5454 QD208 QD226-QD230 E0134-E0138 E0346-E0347 E5052-E5054 E5221-E5224 QA093-QA095 QD213-QD214 QL501-QL515 FORBES, INC. (FRB)

1 E3655 FREEPORT-MCMORAN (FMR)

1 E3346 FUNAIR (FUN)

1 E3419 GEORGETOWNAIRCRAFT SERVICES (GEO) 1 E0216 GLENHOLME ENTERPRISES INC. (GLE)

1 E3144 GOVERNMENT OF MEXICO (MXG) 1 E3037

May4/79 Rev. 4: Jun 27/91 727-53-0149 6 E5413 E5415

E5108LISTING BY CUSTOMER, CUSTOMER CODE,GROUPAND VARIABLE NUMBER, (continued) CUSTOMER GROUP VARIABLE NUMBER GOVERNMENTOF SENEGAL (SEN) 1 QD402 GOVT. OF BURKINA FASO (HTV) 1 E3176 GUESS?, INC. (GES) 1 E3420 HAPAG LLOYD (HAP) 1 E3114 E3452 HCL AVIATION, INC. (HCL) 1 E3242 2 QA658 IBERIA (LINEAS AEREAS DE ESPANA S.A.) (IBE) 1 QB121-QB145 QB147-QB149 QB151-QB153 2 QB155-QB158 IMPERIAL PALACE AIR LTD. (IPA) 1 E0213 INTERNATIONAL AIR LEASES (IAL) 1 E3068 QA004 QA902 Q IRAN ISLAMIC REPUBLIC AIRLINE (IRN) 1 E0204 E3118 E3472-E3473 Q IRAQI AIRWAYS (IRQ) 1 QD421-QD423 2 QD424-QD426 ISTANBULAIRLINES (IST) 1 QA557-QA558 ITAPEMIRIM TRANSPORTES AEREOS S.A. (ITP) 1 E3344 JET AVIATION (JTA) 1 E3407 JET EAST, INC. (JTE) 1 E0418 E0420-E0422 E3117 E3 E3350 QD032 JUGOSLOVENSKIAEROTRANSPORT (JAT) 1 QD142-QD145 2 QD146-QD149 KABO AIR LIMITED (KAB) 1 E0103 E0107 KALAIR USA CORPORATION (KLA) 1 E3604 KELOWNA FLIGHTCRAFT AIR CHARTER LTD. (KEL) 1 E5001 E5428 A905-QA906 D101-QD105

3201 E3205

May4/79 Rev. 4: Jun 27/91 E3347-E3348

727-53-0149 7LISTING BY CUSTOMER, CUSTOMER CODE, GROUP AND VARIABLE NUMBER, (continued) CUSTOMER GROUPVARIABLE NUMBER KEY AIRLINES (KEY) 1 E0029 E0033 E3027 E3243 E3250-E3252 E3571 QA559-QA560 KOREAN AIR LINES, INC. (KAL) 1 QA015 QA022 QA024-QA025 QA033-QA035 QA037 QA040 QA044-QA046 KUWAITAIRWAYS CORPORATION (KUW) 2 QD801-QD804 LACSA (LAC) 1 E3654 QD031 2 QD701-QD702 QD907 LADECO (LDE) 1 E0032 E3103 E3517 E3573 LIBYAN ARAB (LAA) 1 QA316-QA324 QB651 LILTIJARA CO., LTD. (LIL) 2 QD973 LINA CONGO (LNA) 2 QD446 LLOYD AERO BOLIVIANO (LAB) 1 E3102 E3522 E5421 QD161-QD163 LUFTHANSA GERMANAIRLINES (DLH) 1 QB105-QB106 QB108-QB109 QB16 QB305 QB307-QB308 QB310-QB315 2 QB316 MCNALLAVIATION (MCN) 1 E3035 MEXICAN AIR FORCE (MXA) 1 E3171-E3172 E3175 MEXICANA (CMA) 1 QA654-QA656 QB034 QB036-QB045 QD085-QD088 QD444 2 QA657 QB046-QB049 QB051-QB058 QB060-QB064 QD556-QD557 QD571-QD572 MEZEL AIR LTD. (MEZ) 1 QD906 MGM GRAND AIR (MGM) 1 E3504-E3505 E3510 MIAMI AIR INTERNATIONAL INC. (MIB) 2 QA672 MME AVIATION (CAYMAN ISLANDS) LTD. (MME) 1 E0209 MRH AVIATION LTD. (BLA) 1 E3005

May 4/79 Rev. 4: Jun 27/91 727-53-0149 8LISTING BY CUSTOMER, CUSTOMER CODE, GROUP AND VARIABLE NUMBER, (continued) CUSTOMER GROUPVARIABLE NUMBER NIGERIA, GOV OF (NGA) 2 QL081 NOBLE AIR (NOB) 1 QB351-QB352 2 QB219 NOMADS, INC. (NOM) 1 E5279 NORTHWEST AIRLINES, INC. (NWA) 1 E3021-E3023 E3025 E3031 QA701-QA703 QA705-QA706 QA708-QA720 QD445 2 QA746-QA753 QD447-QD449 QD453 OCCIDENTAL PETROLEUM CORP (OCP) 1 E3004 OLYMPIC AIRWAYS (OLY)

1 QA001 QA801-QA805 QB117-QB118 PAN AMERICAN WORLD AIRWAYS, INC. (PAA) 1 QA003 QA057-QA058 QA201-QA207 QA369-QA371 QA627 QA629 QA707 QA721 QA851-QA852 QB110 QB115 QB301-QB304 2 QD691-QD692 QD821-QD828 PANAMANIAN AIR FORCE (PAF) 1 E3203 PINECROFT, LIMITED (PCT) 1 E3507 QD401 PRIVATE JET EXPEDITIONS, INC. (PJE) 1 E0413 QATAR (QAT)

1 QD403 R. B. HARIRI (RBH) 2 QE002 REEVE ALEUTIAN AIRWAYS, INC. (RVV) 1 E5035 E5040 RELIANCE GROUP, INC. (RGI) 1 E3285 REPUBLIC OF CAMEROON (CMR) 1 QD410 REPUBLIC OF ZAIRE (ZAR) 1 E0214 E3034 E3039-E3040 E3173 QA722-QA723 QA725-QA745 QD441-QD443 QD711-QD717

QB309 QA209-QA214 QA216-QA225 QA366 QA635 QA637-QA640 QA704 QB001-QB002 QB101-QB104 QB107

May 4/79 Rev. 4: Jun 27/91 727-53-0149 9LISTING BY CUSTOMER, CUSTOMER CODE, GROUP AND VARIABLE NUMBER, (continued) CUSTOMER GROUPVARIABLE NUMBER RESBERY CORPORATION (INI)

1 E3150 RICH INTERNATIONALAIRWAYS (RIH)

1 E3013 ROYAL AIR MAROC (RAM)

1 QA577-QA579 QA581-QA584 2 QA585 ROYAL BRUNEI (RBA) 1 E0212 2 QD407 ROYALJORDANIANAIRLINE (RJA) 2 QD124-QD126 ROYAL NEPALAIRLINES (RNA) 1 E3784 E5419 ROYAL NEW ZEALAND AIR FORCE (RNZ) 1 E5065 E5068 RYAN INTERNATIONAL AIRLINES (RYN) 1 E3003 E3409 E3411 E5006 E5031-E5032 E5037 E5381 E5411 E5433 SAETA OF ECUADOR (SAE) 1 E0414 E3576 SCIBE-AIRLIFT KINSHASA (SAK) 1 E0208 E3451 SERVICIOSAEREOS NACIONALES, S.A. (SAN) 1 E3684 SHERRARD AVIATION PTY LTD. (SHD) 1 E5501 SIGAIR (SIG) 1 E0207 SKYWAYS INTERNATIONAL, INC (SKL) 1 E3421 STERLING AIRWAYS (STR) 1 QL003 2 QD164 QD427 QD684-QD685 SUN COUNTRYAIRLINES (SCA) 1 QD005 2 QB629 SYRIAN ARAB AIRLINES (SYR) 1 QD471-QD473 

### E3415-E3418 E5002 E5039 E5041-E5042 E5502

85 QL006-QL008

May 4/79 Rev. 4: Jun 27/91 727-53-0149 10 E5004 E5280LISTING BY CUSTOMER, CUSTOMER CODE, GROUP AND VARIABLE NUMBER, (continued) CUSTOMER GROUP VARIABLE NUMBER T A PORTUGUESES (TAP)

1 QD302 2 QD303-QD305 TAESA (TES) 1 E3024 E3174 E3553 TAN SAHSA HONDURASAIRLINES (SAH) 1 E3113 THE K. B. A. FOUNDATION (KBA) 1 E3574 THE LIMITED, INC. (L11) 1 E3704 TNT-SAVA (TNN)

1 E3508 E5114 TOROSAIR (TOS) 1 QA903 TRACINDA CORPORATION (TRD) 1 E3284 TRANSWORLD AIRLINES, INC.(TWA) 1 E0401 E0405-E0408 E0412 QA501-QA527 QA529-QA537 QB201-QB203 2 QB204-QB218 QB220 E0416-E0417

TRANSPORTES AEREOS MILITAR EQUATORIANOS (TAM) 1 E3513 E3516 E3682 2 QD741 TRIANGLE AIRCRAFT SERVICES CORP. (TRI) 2 QD910 TRUMP SHUTTLE, INC. (TSI)

1 E0106 E0116 QA010-QA012 QA017-QA018 QA625-QA626 2 QD474-QD475 E0121 E0140 QA353-QA355 QA357 E3342-E3343 QA606

TUNIS AIR (TUN) 1 QA571 QB401-QB407 TUR EUROPEAN AIRWAYS (TOU) 1 QB119 QB306 TURKISH AIRLINES (THY)

1 QD321-QD322 QD324-QD325 2 QD327-QD330 QD511 UNITED AIR LINES, INC. (UAL) 1 E0003 E0005-E0022 2 QA469-QA499 QB701-QB705 QA401 -QA468

May 4/79 Rev. 4: Jun 27/91 727-53-0149 11 E0419 E0423

E3349 QA623LISTING BY CUSTOMER, CUSTOMER CODE, GROUP AND VARIABLE NUMBER, (continued) CUSTOMER GROUPVARIABLE NUMBER UNITED PARCEL SERVICE (UPS) 1 E5033-E5034 E5036 E5038 E5043-E5045 E5051 E5109-E5111 E5113 E5115-E5116 E5162 E5225 E5251-E5252 E5271 E5275-E5276 E5301-E5306 E5401 E5417 E5422-E5423 E5427 E5429 QA927 2 QA934-QA938 UNITED STATES MARSHAL'SSERVICE (USV) 1 E0215 E3059 USAF

- 727 C-22A PROGRAM (U05) 1 E0203 USAF

- 727 C-22B PROGRAM (U06) 1 E3061 E3063 E3066-E3067 USAIR, INC. (USA)

1 QA005-QA009 QA023 QA026-QA032 QA051-QA056 QA358 QA367-QA368 QA372-QA373 QA928 2 QA374-QA376 QB066-QB068 QB618 QB620-QB621 QB623 USAL, LTD. (ULL) 1 E3523 VALLEJO CORPORATION (VAC)

1 E3683 VARIG AIRLINES (VAR)

11 E3572 E3575 E3751-E3754 E5272 E5406- VIEW TOP CORPORATION (VTC)

11 E3006 WEDGE AVIATION, INC (WST) 2 QE001 WESTFIELD AVIATION LTD. (WEF)

1 E0350 WORLDWAYS CANADA LTD (WWC)

1 E3601-E3603 YEMEN AIRWAYS (YEM) 2 QD621-QD624 QD641

May 4/79 Rev. 4: Jun 27/91 E5106-E5107 E5243-E5245 E5405 QD551-QD552

QA360-QA365 QD681-QD683

E5407 E5412



### 727-53-0149 12LISTING BY VARIABLE NUMBER

GROUP 1 E0001-E0042 E3011-E3014 E3141-E3152 E3401-E3421 E3571-E3578 E3701-E3704 E5141-E5143 E5301-E5306 E5435 QA101-QA178 QA501-QA537 QA851-QA899 QB121-QB149 QB451-QB453 QD085-QD088 QD201-QD214 QD410 QD601 -QD602 GROUP 2 QA179-QA199 QA746-QA753 QB204-QB220 QB801-QB810 QD164 QD446-QD453 QD603-QD607 QD701-QD702 QD801-QD804 QE001-QE002 E0101-E0140 E3021-E3040 E3171-E3177 E3451-E3452 E3601-E3604 E3751-E3755 E5161-E5164 E5351-E5353 E5451-E5455 QA201-QA225 QA551-QA579 QA901-QA933 QB151-QB153 QB501-QB552 QD101-QD105 QD281-QD284 QD421-QD423 QD901-QD906

QA345-QA349 QA934-QA946 QB316 QB901-QB904 QD215-QD239 QD474-QD475 QD621-QD624 QD711-QD717 QD821-QD828 QL006-QL008 E0201-E0216 E3059 E3201-E3206 E3471-E3474 E3621-E3622 E3781-E3784 E5201-E5203 E5381-E5382 E5481-E5483 QA301-QA344 QA581-QA584 QB001-QB002 QB201-QB203 QB601-QB609 QD121-QD123 QD301-QD302 QD441-QD445 QD931-QD932

QA374-QA376 QA949 QB454-QB458 QD009-QD012 QD303-QD305 QD510-QD518 QD641 QD741 QD907-QD910 QL081 E0301-E0351 E3061-E3077 E3221-E3224 E3501-E3513 E3651-E3655 E5001-E5011 E5221-E5245 E5401-E5424 E5501-E5502 QA351-QA373 QA601-QA656 QB031-QB045 QB301-QB315 QB651 QD141-QD145 QD321-QD326 QD471-QD473 QD951

QA469-QA499 QB046-QB049 QB553-QB575 QD039-QD046 QD327-QD330 QD555-QD558 QD661-QD663 QD761-QD769 QD952-QD954 QL501-QL515 E0401-E0423 E3101-E3103 E3241-E3290 E3516-E3523 E3677 E5031-E5068 E5251-E5252 E5426-E5429 QA001-QA046 QA378 QA701-QA745 QB101-QB110 QB351-QB352 QD001-QD008 QD161-QD163 QD351 QD501-QD509 QL001-QL005

QA585 QB051-QB068 QB610-QB629 QD124-QD127 QD407 QD571-QD572 QD681-QD685 QD781-QD782 QD971-QD973 E3001-E3006 E3111-E3118 E3341-E3350 E3551-E3553 E3681-E3684 E5101-E5116 E5271-E5281 E5433 QA051-QA099 QA401-QA468 QA801-QA805 QB114-QB119 QB401-QB407 QD031-QD038 QD191-QD192 QD401-QD403 QD551-QD554 QL031-QL032

QA657-QA688 QB154-QB158 QB701-QB705 QD146-QD149 QD424-QD427 QD581-QD583 QD691-QD692 QD791 QD991-QD992

2. Spares None

May4/79 Rev. 4: Jun 27/91 727-53-0149 13B. Reason As a result of the FAA-sponsored Aging Fleet Conference, a 727 Structures Working Group with Airline and Boeing members and FAA observers was formed to review structural service bulletin modifications and recommend selected bulletinsfor incorporation on aging airplanes. This service bulletin modificaton has been recommendedfor incorporationon aging 727airplanes. Incorporation ofthe modification described inthis bulletinwill reducethe possibility of cracks inthe mainwheel well pressurefloor adjacentto the floor beams at BodyStations 880, 890, 930, 940 and 950. Propagation of undetected cracks could result inpressurization difficulties. Eight operators have reported 34 cracks on 20 airplanes along the ends of the pressure floor reinforcing beads at Stations 930 and 940. The cracks rangedfrom 0.38to 15.25 inches in length. The airplanes had accumulated between 24,000 and 42,200 flight cycles and 24,000 and 49,500 flight hours. Since Revision 3ofthis service bulletin, similar cracks have been reported at Body Station 950. Although there have been no reports of cracking at Stations 880 and 890,the possibility existsthat cracks may develop at these stations also. A preventive modification and repair for cracking at wheel well pressure web Stations 900through 920 is described in Service Bulletin727-53-124. Revision 1 was issued to provide detailed instructions for cutting and splicing fiberglass air conditioning ductsto allow access to reworkarea without removing aft bodyfuel tanks. Some ofthe ducts are made of polycarbonate and may not be cut and spliced. The splicing procedure is required onlywhen aft bodytanks are installedand it is not feasibleto removethem. In all other instances,to minimize airplanedowntime, entireduct should be removed during rework. Subsequent tothe issue of Revision 1 ofthis service bulletin operators requested an interim crack repair similar to that contained in Service Bulletin 727-53-124. In addition, one operator reported cracks beyond repairable limits contained in repair drawings included with this bulletin. Therefore, Revision 2 was issued to allow an optional interim repair for cracks within limits and to transmit revised drawings providing for expanded repairs in certain areas. Several previous kits have been replacedto accountfor expanded repairs. Revision 3 of this bulletin is issued to provide the recommendations of the Aging Fleet 727 Structures Working Group. Also provided is an additional modification kit to install a 0.100 inch thick doubler between Body Station 920 and Body Station 950 and between Buttock Line 50 and side of body on both left and right sides of airplane. Revision 4 ofthis bulletin is issuedto provide information about a newtop kit and new supplemental kits. The new top kit provides two doublers to cover the same area as the doubler provided in Revision 3 ofthis bulletin. The doublers 65-89360-129 and -130, provided by Revision 3 require rework to maketwo doublers 65-89360-137 andtwo doublers 65-89360-138. The new revisionto the drawing added information for installation of the doubler if existing repairs are at the same location. The inspection area is expanded to examine the beads at Body Station 950. Also an inspection threshold and a repeat inspection interval are added for all areas not repaired or preventively modified as described in Part III of the Accomplishment Instructions. The intent of 727-53-0149NSC1 and 727-53-0149NSC2 are also added.

/79 727-53-0149 MaY 4/ 

### Rev.4: Jun27/91 14C. Description Based on a structural review of the 727 airplane, it is recommended that the modification per Accomplishment Instructionsofthis service bulletin be accomplished priorto, or upon accumulation of 60,000flight cycles. When the airplane has 20,000 flight cycles, or within the next 2500 cycles, whichever is later, inspectthe ends ofthe pressurefloor beads adjacentto Stations880, 890, 930, 940and 950. Ifthe previous inspection is High Frequance Eddy Current, examine at 5000 flight cycle intervals. Ifthe previous inspection is visual or dye penetrant, examine at 4000 flight cycle intervals. Repeat inspection until preventive modification or permanent repair is accomplished. Eddy-current or penetrant inspectionis the preferred method of crackdetection. Preventive modification consists of addition of reinforcing strips along each inspectedfloor beam and replacement of one stiffener between Stations 870 and 880. In addition,doublers are installed between Body Station 920 and 950 and between right Buttock Line (BL) 50 and side of body and left BL 50 and side of body. Cracks may be repaired in specified areas by adding doublers and reinforcing strips.An interim repair consisting of stopdrilling and sealingof crackswithin limits may be accomplished providing the permanent repair is made within 600 flights thereafter. The preventive modification should be accomplished in unrepairedareas. On airplanesthat have Permanent Repair (shown in Figure 2) or Preventive Modification (shown in Figure 3) installed inone or part ofthe specified areas, inspectall remaining specified areas. Ifthe previous inspection is High Frequance EddyCurrent, examine at 5000 flight cycle intervals. Ifthe previous inspection is visual or dye penetrant, examine at 4000 flight cycle intervals. Repeat inspectionuntil Permanent Repair or PreventiveModification is installed. Airplanes previously modified perthe original issue, or Revisions 1or 2 ofthis bulletin, or Group 2 airplanes require repeat inspection for cracks inthe pressure floor web at Body Stations 930, 940 and 950 between Buttock Lines (BL) 50 and side of airplane body until additional doublers are installed per Revision3 orthis revision. Airplanes previously repaired perthe original issue, or Revisions 1, 2or 3 ofthis bulletin usingblind fasteners requireadditional workto replacefasteners after 10,000flight cycles. This service bulletin isthe subject of Federal AviationAdministration (FAA)Airworthiness Directive 90-17-06 Amendment 39-6691 which supersedes existing FAA Airworthiness Directive 88-26-02, Amendment39-6089. NOTE: 1. If not already accomplished, concurrent incorporation of Service Bulletin 727-53-124, "Main Wheel Well Pressure Floor Inspection, Modification and Repair", is suggested on commonly affectedairplanes. 2.This service bulletin is listed in Boeing Document D6-54860. D. Approval This service bulletin has been reviewed by the Federal Aviation Administration (FAA) and the repairs and modifications herein comply with the applicable Federal Aviation Regulations (FAR's) and are FAA approved. The FAA has determined that repair and modification in accordance with Revision 4 to service bulletin 727-53-0149 "FUSELAGE

- MAIN WHEEL WELL PRESSURE FLOOR INSPECTION, MODIFICATION AND REPAIR" provides an acceptable alternate means of compliance for FAA Airworthiness Directive 90-17-06, Amendment 39-6691 which supersedes existing FAA Airworthiness Directive 88-26-02,Amendment 39-6089.

May 4/79 727-53-0149 Rev. 4: Jun 27/91 15E. MaNpower Approximately 274 man-hours are necessaryto dothis modificationfor eachairplane. The data below shows an estimate of the man-hours necessary to do this modification for each airplane. This estimate is for direct labor only, done only by an experienced crew. Adjust these estimates with operator man-hour data if necessary. Itdoes not include losttime such as: time to adjust to the work place; schedule the work; examine the work; cure materials; make parts; find tools or other losttime. Elapsed Numberof Time Task Persons Man-Hours (Hours)
Examine 2 2 1 OpenAccess for Change 8 40 5 Change 6 162 27 Close Access 8 72 9
NOTE: Additional time may be necessary to do repair during modification. Repairtime will vary depending onextent of repair.

May 4/79 Rev. 4: Jun 27/91 727-53-0149 16F. Material

- Priceand Availability 1. 1. The modification kit identified in Paragraph II.A. may be obtained from Boeing within the terms and conditions defined below. After expiration ofthe quotation, price and delivery data will be provided upon request. The delivery quotation below is computed from date of receipt of customer purchase order. Improvedflow times may be possible if necessaryto support customers' planned modification schedules. It is therefore requestedthat customer purchase orders requiring earlier kit delivery include planneddates of kit incorporation.

Kit Number Description Delivery Weeks Unit Price Modification Kit Modification Kit Modification Kit (Group 1) Inactivefor procurement Inactivefor procurement 25 $5565.00

65-89360-127 Doubler Kit
- Inactivefor procurement 69-70864-5

69-70864-3 Modification Kit (Group 2) Kit- Supplements 69-70864-2 21 $3624.00

20 $3282.00
Date: June27,1991

May4/79 Rev. 4: Jun 27/91 727-53-0149 17 69-70864-1

69-70864-2

69-70864-42. It is recommended that the repair kits identified in Paragraph II.A. be furnished or fabricated from operator's existing stock or purchased directly from industry sources. The following Boeingprice data is providedfor planningpurposes or inthe event operators desire to purchase kits from Boeing. Deliverydatawill be provided upon request.
Kit Number
65-89360-71 65-89360-72 65-89360-73 65-89360-74 65-89360-75 65-89360-76 65-89360-77 65-89360-78 65-89360-79
65-89360-81 65-89360-82 65-89360-85 

### 65-89360-86 65-89360-103 65-89360-104 65-89360-105 65-89360-106
Date: June 27. 1991 Description Repair Kit Repair Kit Repair Kit Repair Kit Repair Kit Repair Kit Repair Kit Repair Kit Repair Kit Repair Kit Repair Kit Repair Kit Repair Kit Repair Kit Repair Kit Repair Kit Repair Kit Unit Price
Inactivefor Procurement Inactivefor Procurement Inactivefor Procurement Inactivefor Procurement $304.00 $304.00 $179.00 $179.00 $196.00 $213.00 $180.00 $191.00 $188.00 $860.00 $860.00 $901.00 $901.00

The prices quoted are subject tothe terms and conditions of Boeing's standard purchase order acknowledgment. Quotations are subject to acceptance within 180 days from date hereon. Pricesquoted in United States Dollars.Terms: Net30 days. Address purchase orders and correspondence pertainingtothis quotation to Director of Spares, and refertothis service bulletin number.

May 4/79 Rev. 4: Jun 27/91 727-53-0149 18G. Tooling - Price and Availability None H. Weight and Balance (ModificationOnly) Applicability

69-70864-2 69-70864-3 69-70864-4 69-70864-5 65-89360-127 Change in BasicWeight Pounds +24.5 +3.3
+23.2 +11.3 +10.2 Changein Basic Moment Pound-Inches +22,662 +3069 +21460
+10509 +9,486

May 4/79 Rev. 4: Jun 27/91 727-53-0149 19I. References 1. Existing Data

a. Engineering Change Memo PRR 24311 b. Structural Repair ManualSubject 51-30-2 and51-30-5
c. 727 Overhaul Manual Subject 20-50-12 d. Boeing Service Bulletin 727-53-124, 'Main Wheel Well Pressure Floor Inspection, Modification and Repair"
e. FAAAirworthiness Directive90-17-06, Amendment39-6691 f. Boeing Document D6-54860 "Aging Airplane Service Bulletin Structural Modification Program
- Model 727" 2. Newor revised data supplied withthis service bulletin:
Drawina No. Sht. DCN ADCN Title 65-89360 PL D
- Doubler Installation
- Pressure Floor Main 5 A 8 Gear Wheelwell 6
- 2 7 8 A 9 A

3. Process Data: Boeing Process Specifications that are listed on drawings supplied in support ofthis bulletin are not detailed in this bulletin since they are common practices which can be accomplished in accordance with operator's normal procedures. J. Publications Changed
Publication Chapter-Section 727Structural Repair Manual 53-10-02

May 4/79 Rev. 4: Jun 27/91 727-53-0149 20II. MATERIAL INFORMATION A. Parts Required Per Airplane 1. The following modification kit may be obtained from Boeing as noted in Paragraph I.F.: NOTES: 1. Onlyonetop kit is requiredto modify eachairplane. 2. On Group 2 airplanes or group 1 airplanes previously modified per the original issue, Revision 1or2 ofthis bulletinonly requirethe Modification Kit69-70864-5. 3. For operators that have ordered 65-89360-127 kit per Revision 3 of this bulletin only requirethe supplemental Kit 69-70864-3. 4. Forcontents of kits referto drawings supplied withthis service bulletin.

69-70864

- REINFORCEMENT INSTALLATION, PRESSURE FLOOR, MAIN GEARWHEEL WELL
-5 -4 -3 -2 -1
Part Number 69-70864-1 (a)(b) 69-70864-2 (a)(c) 69-70864-3 (c)(d) 69-70864-4 (a)(b)(c) 69-70864-5 (b)(d) 1 1 65-89360-83

1

. 65-89360-127 (b) 65-89360-135 65-89360-136 1 1 65-89619-1 Nomenclature Top Kit (Inactive) Top Kit (Inactive) Supplemental Kit Top Kit (Group 1) Top Kit (Group 2) Reinforcement Installation Doubler Installation Doubler Installation Doubler Installation Support Bracket Installation (a) Top Kit69-70864-4 supersedes69-70864-2 and69-70864-1. (b) Kit 69-70864-1 plus Kit65-89360-127 plus Kit 69-70864-3 is equivalentto 69-70864-4; also Kit69-70864-1 plus kit 69-70864-5 isequivalentto 69-70864-4 (c) Kit69-70864-2 plus Kit69-70864-3 is equivalentto 69-70864-4 (d) Kit 65-89360-127 plus Kit 69-70864-3 is equivalentto 69-70864-5, after rework of doublers 65-89360-129 and 65-89360-130 to two 65-89360-137 doublers and two 65-89360-138

May4/79 727-53-0149 Rev. 4: Jun 27/91 21 Quantity

1

1 1
1 1-doublers. 2. Thefollowing repair kits may befurnished by the operator or obtainedfrom Boeing as noted in Paragraph I.F.: NOTE: Forcontents of kits referto drawings suppliedwith this service bulletin.

65-89360
- DOUBLER INSTALLATION, PRESSURE FLOOR MAZN GEARWHEELWELL
-73 -72 -71 Part Number 65-89360-71 (a) 65-89360-72(b) 65-89360-73(c) Nomenclature Repair Kit- Left, Sta920-930, BL32-58 Repair Kit- Right, Sta 920-930, BL32-58 Repair Kit- Left, Sta 930-940, BL32-55 (a) Superseded by65-89360-105 (b)Superseded by65-89360-106 (c) Superseded by65-89360-103

65-89360
- DOUBLER INSTALLATION, PRESSURE FLOUR MAINGEAR WHEEL WELL
-76 -75 -74 Quantity Part Number 65-89360-74(d)

65-89360-75

65-89360-76 Nomenclature Repair Kit- Right, Sta 930-940, BL32-55 Repair Kit- Left, Sta 930-940, BL20-32 Repair Kit-Right, Sta 930-940,BL20-32 (d) Superseded by65-89360-104

May4/79 Rev. 4: Jun 27/91 Quantity

727-53-0149 22

### BOEING SERVICE BULLETIN727-53-0149

65-89360

- DOUBLER INSTALLATION, PRESSURE FLOOR MAINGEAR WHEEL WELL
-79 -7 8 -7 7 Part Number 65-89360-77

65-89360-78

65-89360-79 Nomenclature Repair Kit-Left, Sta 930-940, BL2-12 Repair Kit-Right Sta 930-940, BL2-12 Repair Kit -Left, Sta 920-930, BL2-16

65-89360

- DOUBLER INSTALLATION, PRESSURE FLOOR MAIN GEAR WHEELWELL
-86 -85 -82 -81 Part Number
65-89360-81

65-89360-82

65-89360-85

65-89360-86 Nomenclature Repair Kit-Left, Sta 880-890, BL 0-22 Repair Kit-Right, Sta 880-890, BL 0-12 Repair Kit-Left, Sta 890-900, BL 0-22 Repair Kit-Right, Sta 890-900, BL 0-15

May 4/79 Rev. 4: Jun 27/91 Quantity

Quantity

727-53-0149 2365-89360
- DOUBLER INSTALLATION, PRESSURE FLOOR MAINGEAR WHEELWELL
-106 -105 -104 -103 Part Number

- 65-89360 -103(e)

65-89360 -104(f)

65-89360 -105(g)

65-89360 -106(h) Nomenclature Repair Kit- Left Sta 930
- 940, BL 32-61 Repair Kit- Right Sta 930
- 940, BL 32-61 Repair Kit- Left Sta 920
- 930, BL 32-61 Repair Kit- Right Sta 920
- 930, BL 32-61 (e) Supersedes 65-89360-73 (f) Supersedes 65-89360-74 (g) Supersedes 65-89360-71 (h) Supersedes 65-89360-72

May4/79 Rev. 4: Jun 27/91 727-53-0149 24 Quantity3. The following materialsareto be supplied bythe operator forairplanes with aft bodyfuel tanks installed (See Figure5for requirements):

Quantity As Required As Required As Required

As Required
As Required
As Required As Required As Required
As Required As Required As Required Part Number R110 (a) R110 (a) BMS 9-3 (b) (c) (c) BMS 8-39, Type I (d) Composition A BMS 8-39, Type IV (d) Composition A Type 12 (e) Type 48 (e) Schnee Moorhead No. 5144 (f) Foster 9B2 (g) BMS 8-201, Type I (h) BMS 8-201,Type II (h)(i) Nomenclature Resin Mix Resin Mix 181 Fabric Polyvinylchloride (PVC) Polyvinylalcohol(PVA) Insulation
Insulation
Adhesive Adhesive Sealing Compound Sealing Compound Resin Resin (a) See Bac 5419for sourcesof components of resin mix R110 or R111. (b) BFG Industries, Inc. P.O. Box 21207 3330 West FriendlyAve. Greensboro, NC27420 Clark-Schwebel FiberGlass Corp. P.O. Box 2627 2200 South MurrayAvenue Anderson, SC29622 6M825 Clark-Schwebel International S.A. Battice, Belgium V B1353 Hexcel Corporation 11711 Dublin Blvd. Dublin, CA 94566 04621 (c) Reynolds MetalsCompany 2819 FirstAvenue Seattle, WA 98121

May 4/79 Rev. 4: Jun 27/91 727-53-0149 25(d) General Plastics Manufacturing Company P.O. Box 9097 Tacoma,WA 98409 28014 Scotfoam Corporation 1500 East2nd. Street Chester, PA 19013 (e) See 727Overhaul ManualSubject 20-50-12. (f) Schnee Moorehead Chemicals, Inc. Irving,TX 75060-3153 53309 (g) Atacs Products Inc. 1120 SW 16th Renton, WA98055 61426 (h) Furane Products Company 5121 San Fernando RoadWest Los Angles, CA 90039 (i) Ren Plastics A Ciba-Geigy Company 4917 DawnAvenue East Lansing, MI48823-2821 02684

B. ParTsRequired to Modify Spares None C. Special Tools and Equipment Required None

May4/79 Rev. 4: Jun 27/91 727-53-0149 26D. Existing PartsAccountability The parts shown below are changed bythis service bulletin. changed onthe airplane. Quantity (Qty) is the number of parts

Existing PartNumber 69-14165-1 69-14165-2 69-14165-3 69-14172-1 65-26122-1 65-26122-2 65-28410-1 65-28410-2 65-28410-7 65-28410-8 Part Name BracketAssembly BracketAssembly BracketAssembly BracketAssembly BracketQuadrant BracketQuadrant BracketAssembly BracketAssembly BracketAssembly BracketAssembly Quantity 1 1 1 1 1 1 1 1 1 1 RUC DIS DIS DIS DIS RWK RWK RWK RWK RWK RWK New Part Number 69-66838-1 69-66838-2 69-66838-3 69-66838-4 65-89360-149 65-89360-150 65-89360-151 65-89360-152 65-89360-151 65-89360-152

RUC Recommend Use Code DIS

- Discard the part. RWK

- Makethe changeasspecified inthis service bulletin. PNC Part Number Code N

- There isno equivalent Boeingpart numberforthe changed part. Show onthe part thatthis service bulletin has been done. S

- Newequivalentor replacementpart number. RC ReplacementCode A

- Not Interchangeable: Do not replaceone partwiththe other.

May4/79 Rev. 4: Jun 27/91 727-53-0149 27 PNC



### S S S S N N N N N N RC A A A A A A A A A ABLANK PAGE

May 4/79 Rev. 4: Jun 27/91 727-53-0149 28 (Blank)III. ACCOMPLISHMENT INSTRUCTIONS NOTES: 1. The paragraphs identifiedwith lettersgivethe generalwork instructions andthe necessary tests. The instructions identified with numbers on the figures give the recommended sequence of operations. 2. As stated in Paragraph I.D. interim crack repairs specified in Part II below are FAA approved contingent upon accomplishment of permanent repair per Part III or inspection as noted. 3. As recommended by the 727 Aging Fleet Structures Working Group, accomplish the modification perthis service bulletin, Part IV ofthe Accomplishment instructions prior to or uponthe accumulationof 60,000flights. Part I
- Inspection A. Inspect lower surface of pressure floor adjacent to Body Stations 880, 890, 930,940 and 950 for cracks inthe left and right mainwheel wells per Figure 1. B. If no cracks are found, accomplish preventive modification per Part IV or repeat inspection per Paragraph A above at maintenance intervals as shown in Paragraph I.C. Description, until Accomplishment Instructions Part IV Preventive Modification or Part III Permanent Repair is accomplished. C. On airplanes previously modified per the original issue, or Revisions 1or 2 of this bulletin or all Group 2airplanes, inspectforcracks in mainwheel well pressurefloor at BodyStations 930,940 and 950 between left and right Buttock Line (BL) 50 and side of body per Figure 1. D. If no cracks are found per Paragraph C above, accomplish doubler installation per Figure 3 Circle Note 5 and Drawing 65-89360 Sheet 8 and 9, or repeat inspection per Paragraph C above at maintenance intervals as shown in Paragraph I.C. Description, until Accomplishment Instructions Part IV Preventive Modification or Part III Permanent Repair is accomplished. E. If cracks arefound per ParagraphsA. orC. above, do Interim Repairper Part IIor Permanent Repair per Part III. F. On airplanesthat have Permanent Repair (shown in Figure 2) or Preventive Modification (shown in Figure 3) installed in one or part of the specified areas, inspect all remaining specified areas at maintenance intervals as shown in Paragraph I.C. Description, until Permanent Repair or Preventive Modification is installed in allareas.

May 4/79 727-53-0149 Rev. 4: Jun 27/91 29Part II
- Interim Repair (optional): If cracks are found which do not exceed limits specified in Table I, stop drill cracks with 0.190 inch diameter drill, apply pressure and environmental sealant per operator's standard procedures and accomplishpermanent repair per Part IIIwithin600flights.

TABLE I Crack Limits

May4/79 Rev. 4: Jun 27/91 727-53-0149 30Part III
- Permanent Repair: If cracksarefound, accomplishthe following: A. Gain access to upper surface of pressure floor by removing equipment and floor panels per operator's standard procedure. B. On affected airplanes prior to Line Position 1358, gain access to lower surface (if required along inboard edge) by removing wheel well ducts per operator's standard procedure (Ref. 727 Maintenance Manual Subject 21-20-4). Affected airplanes Line Position 1358 and on do not have ducts inthis area. NOTE: If airplane is equipped with aft body fuel tanks, the tanks must be removed per operator's standard procedure (Ref. 727 Maintenance Manual Subject 53-20-31) to allow duct removal. The inner ducts are made from either a polycarbonate or a fiberglass material. Instead oftank removal,the fiberglass ducts may be cut (to provide access) and spliced (after rework) per Figure 5. Polycarbonate ducts may not be cut and spliced. Inner duct material may be checked from above by removing floor panel over duct at Station 960. Identifytype of duct installedasfollows: 1. Polycarbonatematerial has the look of extruded plastic. It is usually black orgray with a smoothfinish. PVC Pipeis atypical exampleof extrudedsmooth plastic. 2. Fiberglass is generally light green with a roughertexture dueto a cloth lay-upwith resin. The ram air inlet ductsare atypical exampleoffiberglassducts. C. Stop drill each end of cracks with No. 11 (0.191 inch diameter) hole. Eddy current inspect to confirm crackcontainment. Ifso, increase hole sizewith 1/4-inchdrillto 0.250 inch diameter.

May 4/79 727-53-0149 Rev. 4: Jun 27/91 31D. Remove requiredfasteners, clips and bracketsand install repair parts per Figure2. NOTES: 1.Shorter or longer doublers than those included in the kits and shown on Drawing 65-89360 may be installed as a repair. 2. If existing repair doubler interferes with new repair, it will be necessary to remove the existing repairdoubler and installa new repairthat covers both areas. 3. If expedited repair is required,the repair parts may be installed,without gaining access to the upper surface ofthe pressure floor, with blind bolts, BACB30LB( )-( ), or Visu-Lok PLT210blind bolts, at all fastener locations. If blind fasteners are installed, however,they must be inspected when the airplane has 3000 cycles after installation and at intervals of approximately 2,500 flight cycles until replaced with fasteners specified on Drawing 65-89360, at or prior to 10,000 flight cycles since installation of the blind bolts. Install blind bolts per 727 Structural Repair Manual Subject 51-30-2 and51-30-5-Hole sizes for installation of blind boltsare specified inTable II. 4. Airplanes previously repaired using blind fasteners that have accumulated 10,000flight cycles, should replace the blind fasteners with solid fasteners per drawing 65-89360, within3,000 flights after receiptofthis Revision3.

TABLE II Hole Size (in inches) for Installationof Blind Bolts HoleSize Nominal Standard Fastener PLT210 Size BACB30LB()-() 3/16 0.199to 0.202

1/4 0.260to 0.263
E. Installlpreventive modification straps and doublers per Figure 3 in all remaining specified areas not repaired, or inspect all remaining specified areas not repaired at maintenance intervals as shown in Paragraph I.C. Description, until Permanent Repair or Preventive Modification is installed in all specilied areas. F. Replacetubing brackets specified in Figure4 and reinstall remaining clips and brackets. G. Finish reworkedareas to matchsurrounding areas per operator's standardprocedure. H. Return airplaneto operating configuration

May 4/79 Rev. 4: Jun 27/91 727-53-0149 32Part IV

- Preventive Modification Accomplish preventivemodification asfollows: A. Gain access to upper surface of pressure floor by removing equipment and floor panels per operator's standardprocedure. B. On affected airplanes prior to Line Position 1358, gain access to lower surface by removing wheel well ducts per operator's standard procedure (Ref. 727 Maintenance Manual Subject 21-20-4). Affected airplanes Line Position 1358 andon do nothaveducts inthis area. NOTE: If airplane is equipped with aft body fuel tanks, the tanks must be removed per operator's standard procedure (Ref. 727 Maintenance Manual Subject 53-20-31) to allow duct removal. The inner ducts are made from either a polycarbonate or a fiberglass material. Instead of tank removal,the fiberglass ducts may be cut (to provide access) and spliced (after rework) per Figure 5. Polycarbonate ducts may not be cut and spliced. Innerduct material may be checked from above by removing floor panel over duct at Station 960. Identifytype of duct installedasfollows: 1. Polycarbonate material hasthe look of extruded plastic. It is usually black or graywith a smoothfinish. PVC pipe is atypical exampleof extrudedsmooth plastic. 2. Fiberglass is generally light greenwith a roughertexture dueto a cloth lay-up with resin. The ram airinlet ducts are atypical example offiberglassducts. C. Remove requiredfasteners, clips and bracketsand modify per Figure3. NOTE: On airplanes previously modifiedby instructions inthe original issue or Revisions 1or2 and group 2 airplanes not modified by instructions in Revision 3 require installationof doublers 65-89360-137 and 65-89360-138per Figure3 circle note 5or 6. D. Replacetubing bracketsspecified in Figure4 and reinstall remainingclips and brackets. E. Finish reworked areato match surroundingarea per operator's standardprocedure. F. Returnairplaneto operatingconfiguration.

May 4/79 727-53-0149 Rev. 4: Jun 27/91 33Illustration Tableof Contents
Title Page Figure 1. Inspection 33 Figure 2

. Crack Repair 35 Figure 3. Preventive Modification 37 Figure 4. Tubing Bracket Replacement 47 Figure 5. Air Conditioning DuctCutting and Splicing 49

May 4/79 Rev. 4: Jun 27/91 727-53-0149 34FIGURE 1. INSPECTION May 4/79 Rev. 4: Jun 27/91 727-53-0149 35FIGURE 1. INSPECTION May 4/79 Rev. 4: Jun 27/91 727-53-0149 36FIGURE 2. CRACK REPAIR May4/79 Rev. 4: Jun 27/91 727-53-0149 37FIGURE 2. CRACK REPAIR
May 4/79 Rev. 4: Jun 27/91 727-53-0149 38FIGURE 3. PREVENTIVE MODIFICATION May4/79 Rev. 4: Jun 27/91 727-53-0149 39FIGURE 3. PREVENTIVE MODIFICATION May 4/79 Rev. 4: Jun 27/91 727-53-0149 40FIGURE 3. PREVENTIVE MODIFICATION May 4/79 Rev. 4: Jun 27/91 727-53-0149 41FIGURE 3. PREVENTIVE MODIFICATION May 4/79 Rev. 4: Jun 27/91 727-53-0149 42FIGURE 3. PREVENTIVE MODIFICATION May4/79 Rev. 4: Jun 27/91 727-53-0149 43FIGURE 3. PREVENTIVE MODIFICATION May4/79 Rev. 4: Jun 27/91 727-53-0149 44FIGURE 3. PREVENTIVE MODIFICATION May4/79 Rev. 4: Jun 27/91 727-53-0149 45FIGURE 3. PREVENTIVE MODIFICATION May 4/79 Rev. 4: Jun 27/91 727-53-0149 46FIGURE 3. PREVENTIVE MODIFICATION May 4/79 Rev. 4: Jun 27/91 727-53-0149 47FIGURE 3. PREVENTIVE MODIFICATION
May 4/79 Rev. 4: Jun 27/91 727-53-0149 48FIGURE 4. TUBING BRACKET REPLACEMENT May4/79 Rev. 4: Jun 27/91 727-53-0149 49FIGURE 4. TUBING BRACKET REPLACEMENT May 4/79 Rev. 4: Jun 27/91 727-53-0149 50FIGURE 5. AIR CONDITIONING DUCT CUTTING AND SPLICING May4/79 Rev. 4: Jun 27/91 727-53-0149 51FIGURE5. AIR CONDITIONING DUCTCUTTINGAND SPLICING
May 4/79 Rev. 4: Jun 27/91 727-53-0149 52FIGURE 5. AIR CONDITIONING DUCT CUTTING AND SPLICING May4/79 Rev. 4: Jun 27/91 727-53-0149 53SUBJECT: FUSELAGE

- MAIN WHEEL WELL PRESSURE FLOOR INSPECTION, MODIFICATION AND REPAIR
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