sofV--O Commercial

Airplane 737 Group Service Bulletin

-- ALERT_ -- _-

Number 737-53A1166 Date: June 30, 1994 Summary ATA System: 5311

| SUBJECT: FUSELAGE - FRAMES -BODY STATION 727 OUTBOARD CHORD AT STRINGER 18A, INSPECTION AND PREVENTIVE MODIFICATION

BACKGROUND inspection again. Do the inspection at the times

Four operators sent given in the Compliance section until the preventive

outboard reports of cracks in the modification is installed. If the preventive

727 where 

chord 

Stringer 

of the frame at Body Station (BS) modification is installed, no more inspections per 18A is attached. The reports this bulletin are necessary. were of eight airplanes with 39,000 to 54,100 flight

cracks 

hours and 

were 

56,200 

caused 

to 73,200 flight cycles. The More work is necessary for operators that have

fretting of adjacent parts. 

by fatigue 

Operators 

that was started by replaced the outboard chord of the frame at BS 727

reports have also sent as shown in Service Bulletin (SB) 737-53-1088 of cracks in the outboard chord of Stringer (refer to Compliance). 1 8-A.

COMPLIANCE The changes shown in this service bulletin will decrease 

is a primary 

the probability 

structural 

of 

element. 

these cracks. This area This bulletin has a Flight Safety Inspection Program

cracks Operation with that is the minimum necessary to keep the structural in the frame will decrease the structural integrity of the outboard chord. integrity of this area.

As part of a service bulletin For airplanes with 27,000 flights to 50,000 flights, do

inspection, frame 

validation program, the the inspection initially within 4,500 flights after you

modification was 

chord replacement, and preventive get this bulletin. Do the inspection again at intervals

(Group 2) before completed on airplane PG576 of 15,000 flights until the airplane collects more than the initial release of this bulletin. 50,000 flights.

ACTION For airplanes with 50,000 flights to 60,000 flights, do

Make an inspection the inspection initially within 2,500 flights after you

frame at BS 727 where 

of the outboard chord of the get this bulletin. Do the inspection again at intervals

Look for cracks. Do Stringer 18A is attached. of 7,500 flights until the airplane collects more than the inspection at the times 60,000 flights. given in the Compliance section.

Also, make an inspection For airplanes with 60,000 flights to 70,000 flights, do

Stringer 18A at Station 

of the outboard chord of the inspection initially within 1,500 flights after you

the outboard 

727. If cracks are found in get this bulletin. Do the inspection again at intervals

instructions from 

chord 

Boeing. 

of Stringer 18A, get repair of 5,000 flights until the airplane collects more than 70,000 flights.

frame 

If cracks 

at BS 

are 

727, 

found in the outboard chord of the For airplanes with more than 70,000 flights, do the

replace the chord 

install the time limited repair or inspection initially within 500 flights after you get this

preventive modification. and, optionally, install the bulletin. Do the inspection again at intervals of If no cracks are found, 3,000 flights. install the preventive modification or do the

BOEING COMMERCIALAIPLANE GROUP P.O. BOX 3707 8EATTLE WASHINGTON YR24-2207 Summary Page 1 of 2
BOEING SERVICE BULLETiN 737-53A1166

For airplanes with the lower part of the chord EFFECTIVITY

replaced by SB 737-53-1088, do the inspection at

the intervals shown above. All 737-100 and 737 -200 airplanes. Line Numbers

1-999, in 4 groups. For airplanes with the upper part of the chord

replaced by SB 737-53-1088, do the inspection MANPOWER

initially within 30,000 flight cycles after the chord

was replaced. Do the inspection again at the Refer to Paragraph I.F. Manpower. intervals shown above for flight cycles after the

chord was replaced. MATERIAL INFORMATION

Boeing Supplied Kits

Refer to Paragraph k.G.. Material - Price and

Availability.

EXAMINE AREA AROUND

STRINGER 18-A TWO FASTENER HOLES

(ON SOME AIRPLANES STA

THE OUTER CHORD OF 727

STRINGER 18-A IS

A FLAT STRAP)

000

TYPICA 0 0

C RACK

00

EXAMINE FORWAR

EDGE OF FLANGE 0 0

EXAMINE SURFACE OF S-18A

AROUND TWO FASTENER HEADS

LEFT SIDE SHOWN

RIGHT SIDE OPPOSITE

(WIN6-TO-BODY FAIRING NOT SHOWN)

Jun 30/94

Summary Page 2 of 2
D -XfW- O Commercial Airplane 737 Group Service Bulletin

-ALERTNumber: 737-53A1166

Date: June 30. 1994

ATA System: 5311

SUBJECT: FUSELAGE - FRAMES - BODY STATION 727 OUTBOARD CHORD AT STRINGER 1 8A, INSPECTION AND PREVENTIVE MODIFICATION

THIS 

IN PARAGRAPH 

SERVICE BULLETIN IS SENT TO THE OPERATORS OF RECORD OF THE AIRPLANES SHOWN

SERVICE l.A., EFFECTIVITY. IF AN AIRPLANE HAS BEEN LEASED OR SOLD, SEND THIS

THIS SERVICE 

BULLETIN 

BULLETIN 

TO THE NEW OPERATOR, IF APPLICABLE SPARES HAVE BEEN SOLD, SEND TO THE NEW OWNER.

I. PLANNING INFORMATION

A. Effectivity

1. Airplanes

Refer 

Number, 

to Service Bulletin Index Document D6-19567, Part 3 for Airplane Variable Number, Line and Serial Number data.

This service bulletin is for the airplanes shown below.

IDENTIFICATION BY CUSTOMER, CUSTOMER CODE, GROUP AND VARIABLE NUMBER

AER LINGUS (ARL) 2 PG255 PG573 PY322 3 PK029 PK641-PK642 PY281

AERO CONTROLS, INC (AEO) 2 PG629

AERO COSTA RICA (AOR) 3 PK872-PK873

AEROLINEAS ARGENTINAS (ARG) 2 PH705-PH708 PH741-PH742 PY007 3 PH743 PK102-PK103

AERON AVIATION (AAV) 2 PJ072

AIR ALGERIE (ALG) 3 PK361 PK631 PK633-PK634 PL717-PL725 PY051-PY053

Jun 30/94 737-53A1 166

Page 1 of 44
BOEING SERVICE BULLETIN 737-53A1166

AIR ATLANTA ICELANDIC (AID) 2 PY002

AIR FRANCE (AFA)

3 PL502-PL503 PN101-PN112

AIR GABON S.A. (GBN)

3 PY191

AIR GUINEE (GNE)

3 PY651

AIR MADAGASCAR (MAD) 2 PG375

3 PL793

AIR MALTA (MLT)

3 PL621-PL623

AIR NAURU (NAU)

3 PK356 PK581 PY286

AIR NEW ZEALAND, LTD. (ANZ) 3 PJ009 PJ117-PJ119 PK214 PY741

AIR ONE AB SWEDEN (AOW) 3 PJ003

AIR SOUTH. INC. (SOT)

3 PK462 PK466

AIR TANZANIA (TNZ) 3 PY611-PY612

AIR TOULOUSE INTERNATIONAL (TOL) 2 PL716

AIR ZAIRE (ZAI)

3 PY1il PY113

ALASKA AIRLINES (ASA)

3 PY112 PY134-PY135 PY270 PY461-PY462

ALBATROS AIRLINES (ABS) 2 PG251 PG253

ALL NIPPON AIRWAYS CO. LTD. (ANA)

2 PG584-PG586

3 PK711-PK716

ALOHA (ALO)

2 PG046

3 PK286-PK287 PK691-PK695 PK697 PY231 PY242 PY451

AMC AVIATION (AMF)

3 PK264

Jun 30/94 737-53A1 166

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BOEING SERVICE BULLETIN 737-53A1 166

AMERICA WEST AIRLINES, INC. (AMW) 2 PC004 PG036 PL801

3 PK283 PK696 PLO81 PL172 PL551-PL562

AMIRI FLIGHT (ABD)

3 PK495

ANGOLA AIRLINES (ANG) 3 PK661 PK664 PY162

ANSETT WORLDWIDE AVIATION SERVICES (AWW) 1 PA001 PA003-PA004

2 PCO03

ARAMCO ASSOCIATED CO. (ARM) 3 PL151 PY241 PY243-PY244

ARKIA ISRAELI AIRLINES, LTD (ARK) 2 PG575

ASEAN AVIATION (L) INC. (ASJ) 2 PG578-PG583

ATASCO USA, INC. (ATJ) 3 PL762

AVENSA (AVN)

3 PK042-PK043

AVIATECA (AVT)

2 PL737 PL740-PL741

3 PY201

AVIOGENEX AIR TRANSPORT (AVG) 3 PL501 PL506

BEST LEISURE (BES) 3 PJ108 PJ113

BHOJA AIR (BHO)

3 PK614

BOURAQ INDONESIA AIRLINES (PTB) 2 PJQ01 PL742 PL803

3 PK501 PL743-PL744

BRAATHENS S.A.F.E. (BRT) 3 PK882

BRITISH AIRWAYS (BAB) 3 PK731-PK749 PK771-PK772 PK774-PKm PK779 PNO01

CALDWELL AIRCRAFT TRADING CO. (CAS) 2 PG402

CAMEROON AIRLINES (CAM) 2 PY046-PY047

Jun 30/94 737-53AI1 66

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BOEING SERVICE BULLETIN 737-53A1166

CANADIAN AIRLINES INTERNATIONAL LTD. (CDI) 2 PY303-PY304

3 PK358 PK671-PK675 PK677-PK680 PK822 PK881 PK884 PL401-PL417 PL764-PL770 PM141-PM142 PY151-PY154 PY421-PY422 PY441

CARNIVAL AIR (CVL)

2 PG305 PG312 PL712

3 PJ007-PJ008

CASINO EXPRESS (CIN)

2 PG279 PG436

3 PK461

CAYMAN AIRWAYS (CAY)

3 PK222 PK561

CHINA SOUTHERN AIRLINES (GUN) 3 PK636-PK637

CIS AIR HOLDINGS, LTD. (CIS)

2 PG302

COMAIR (CML)

2 PG354 PG356

CONQUEST SUN AIRLINES, INC. (CQT) 2 PG438

CONTINENTAL AIRLINES, INC. (CAL) 1 PA006-PA009 PA01 1 PG199

2 PA01 2 PA01 4 PA01 6-PA020 PG056 PG064 PG225 P0433 PG501-PG505 PG621-PG625 PG627-PG628 PG630 PG704 3 PLO00l

COPA COMPANIA PANAMENA DE AVIATION S.A. (COP) 2 PY341

3 PJ107 PJ112 PK465 PK617 PL745

CROATIA AIRLINES (CRH) 3 PK904 PK906-PK907 PK928 PK932

DAMANIA AIRWAYS LTD. (DAI)

3 PL451-PL452 PNO81-PNO82

DELTA AIR LINES, INC. (DAL) 3 PK611 PK613 PK623-PK624 PK632 PL221 PL611 4 PN131-PN13S

E G AND G (EGN)

2 PG037 PG208 PG210 PG215 PG431

3 PL763

EAS EUROPE AIRLINES (EUR)

3 PK203 PK215 PK282 PK359 PK564 PK612

EAST WEST AIRLINES (INDIA) (BOM) 3 PK615-PK616 PK819 PK824 PL171

Jun 30/94 737-53A1 166

4
BOEING SERVICE BULLETIN 737-53A1166

EDRESS, SHIEKH M. (SME) 3 PL505

EGYPTAIR (EGP) 3 PK255 PK257-PK258

EL AL ISRAEL AIRLINES, LTD. (ELA) 3 PL631-PL632

EURALAIR (ERA) 2 PG026 PGO28-PG029 PY004 PY006

FAR EASTERN AIR TRANSPORT (FAT) I PA002 PA005

2 PG055 PG226 PG228 PG230 3 PK562

FAUCETT (COMPANIA DE AVIATION S.A. (FCT) 2 PC002 PG034 PG213 PL711 3 PK241 PL758

FLIGHTSTAR AVIATION CORPORATION (FST) 2 P0274

FORTUNE AVIATION (FOR) 3 PK432

FRENCH POSTAL OFFICE (FPO) 2 PY302 PY344

3 PY101-PYl03

FRONTIER AIRLINES (FRO) 2 PG306 PG308

GATARI AIR SERVICE (GRI) 3 PL441

GB AIRWAYS (GBA)

3 PJ11O-PJiii

GOVERNMENT OF BRAZIL (BRZ) 3 PK068-PK069

GOVERNMENT OF MEXICO (MXG) 2 PC005 PG223

GOVERNMENT OF SHARJAH (SHJ) 3 PL581

GPA GROUP LTD. (GUI) 3 PK252 PK354-PK355

GULF AIR (GUL) 3 PK464 PK467-PK468

HAPAG LLOYD (HAP) 3 PL504

Jun 30/94 

737-53A1 166

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BOEING SERVICE BULLETIN 737-53A1166

HEAVYLIFT AIRCRAFT ENGINEERING (HVL) 3 PJ109

INDIAN AIR FORCE (IDF)

2 PH712-PH713

4 PM016-PM017

INDIAN AIRLINES (IND)

2 PH70S PH711

3 PHO21 PH024 PK231-PK233 PK235-PK240 PM001-PM006 PY631

INDONESIAN AIR FORCE (IDO)

3 PL601-PL602

4 PL603

INTEGRATED RESOURCES (INH)

1 PG271

2 PG273 PG403

INTERAMERICA S.A. DE C.V. (INJ)

2 PL761

INTERNATIONAL AIR LEASES (IAL) 2 PG043 PGO47-PGO48

INTERNATIONAL AIRLINE SUPPORT GROUP (ASG) 2 PG021

INTERNATIONAL PACIFIC TRADING CO. (IPT) 2 PG224 PG572 PG574 PJ102

IRAN AIR (IRN)

2 PH731 PY021

3 PK391 PY022

IRAQI AIRWAYS (IRQ)

3 PY141-PY142

JAPAN TRANSOCEAN AIR CO., LTD. (SWL) 3 PK521 PK523-PK525

JETALL HOLDING CORPORATION (JEL) 2 PY005

KENYA AIRWAYS (KEN)

3 PK253 PK256

LACSA (LAC)

3 PK357 PK871

LADECO (LDE)

2 PL802

3 PJ004-PJ006 PK212 PK281 PK826 PK830

LAN-CHILE S.A. (LAN)

3 PK360 PK825 PL025 PL028

Jun 30/94 737-53A1 166

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BOEING SERVICE BULLETIN 737-53A1i66

LAPA (LAZ)

2 PG355

3 PK047 PK051 PK463

LINA CONGO (LNA) 3 PY411

LINHAS AEREAS DE MOCAMBIQUE (LAM) 2 PH703 PY031

LITHUANIAN AIRLINES (LIJ) 3 PK563

LUFTHANSA GERMAN AIRLINES (DLH) 2 PY345-PY346

3 PK901-PK903 PK905 PK911-PK927 PK929-PK931

MALEV HUNGARIAN AIRLINES (HGA) 3 PK284-PK285 PK827

MANDALA AIRLINES (MND) 3 PK874 PLO27 PLO61 PL421 PNO02

MARKAIR, INC. (ALK) 4 PY056-PY057

MIDAIR (MAI)

2 PY342

MODILUFT (MOU) 3 PK908-PK910

MONTELY II (MOY)

2 PJ031

NASA (NAS)

1 PA099

NATIONAL AIRLINES (NAW) 2 PJ104

3 PJ105-PJ106

NICA (NICARAGUENCE DE AVIACION) (NIC) 3 PK823

NIGERIA AIRWAYS, LTD. (NIA) 3 PL781-PL782 PL784-PL788

NORDAM (NOP)

3 PK221

NORDIC EAST (NOE) 2 PJ002

NWT AIR (NTA)

2 PX701

3 PY132-PY133

Jun 30/94 

737-53A1 166

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BOEING SERVICE BULLETIN 737-53A1166

OLYMPIC AIRWAYS (OLY) 3 PK301-PK304 PK307-PK310 PM021-PM023

P. T. AIRFAST (PTF)

2 PG204 PG278 PY343

PETROLAIR SYSTEMS S. A. (PTS) 3 PL471

PLUNA (PLU)

3 PL201-PL203

POLARIS AIRCRAFT LEASING CORP. (PLS) 1 PG272

2 PG202 PG205 PG207 PG218-PG219 PG276 PG651-PG652 3 PK026-PK028

PRESIDENTIAL AIR (PRB) 2 PG432

REPUBLIC OF NIGER (NIR) 3 PY166

ROYAL AIR MAROC (RAM)

3 PK271-PK274 PY671

4 PY672

RYANAIR (RYR)

3 PJ114-PJ115 PK801-PK804

SABENA S.A. (SAB)

3 PK041 PK044-PK046 PK048-PK050 PK052-PK053 PK431 PK433 PY272-PY275

SAETA S.A. (SAE) 3 PK211 PK213

SAHARA INDIAN AIRLINES (SAQ) 3 PK820

SAHSA (SERVICIO AEREO DE HONDURASS.A.) (SAH) 2 PJ032 PJ071 PL736

SAUDI ARABIAN AIRLINES CORP. (SVA) 2 PL728-PL728 PY036-PY037

3 PK311-PK317 PL729-PL735

SAUDI ROYAL FLIGHT (SRF) 3 PK318

SERVICIOS AEREOS RUTAS ORIENTE, (SARO) (SEV) 2 PA015 PA021-PA022

3 PK351 PK353

SHAHEEN AIR INTERNATIONAL (SHK) 3 PK514

Jun 30/94 737-53A1 166

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BOEING SERVICE BULLETIN 737-53A1166

SHANNONAIR LEASING LTD. (SLE) 3 PK352

SIERRA PACIFIC AIRLINES (SRP) 3 PK627

SOUTH AFRICAN AIRWAYS (SAA) 2 PG353

3 PL101-PL113

SOUTHWEST AIRLINES CO. (SWA) 3 PK082 PK091-PK099 PK541-PK560 PK621 PK628-PK630 PM051-PM062

SUDAN (SUD)

3 PY156-PY157

T A PORTUGUESES (TAP) 3 PK971 PK973-PK974 PNO83

4 PN084-PNO86

TACA INTERNATIONAL AIRLINES, INC. (TAC) 2 PG059 PG352

3 PK223 PY131

TAESA (TES)

3 PK622 PK625-PK626

TAT EUROPEAN AIRLINES (TTR) 2 PY003 PY301 PY321 PY361 -PY362

THAI AIR FORCE (TAF) 4 PK519

THAI AIRWAYS INTERNATIONAL, INC. (TII) 3 PK511

TRANSAERO (TRX)

3 PK451-PK452 PK773

TRANSAVIA AIRLINES (TAV) 2 PG074

3 PK502-PK504 PK821

TRANSMILE AIR SERVICES (TML) 2 PY323 PY381

TUNIS AIR (TUN) 3 PK861-PK863 PY621

UNITED AIR LINES, INC. (UAL) 1 PGO01-PGO04 PGO06-PGO08

2 PGO09-PGO13 PGO15-PGO19 PG022-PG025 PG027 PGO30 PG032-PG033 PGO38-PGo4o PG045 PGO51-PGo54 PG057 PGO60-PGO63 PGO65-PG072 PG075

3 PK201-PK202 PLC02-PL023

UNITED STATES AIR FORCE (USF) 3 PJ201-PJ219

Jun 30/94 737-53A1 166

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BOEING SERVICE BULLETIN 737-53A1166

USAIR, INC. (USA) 2 PGO41-PG042 PG073 PG206 PG301 PG303-PG304 PG307 PG309-PG311 PG313-PG314 PG474 PG576

3 PK288-PK289 PK591-PK599 PK601-PK610 PK883 PM101-PM117 PNO21-PN028 4 PM1 18-PM119 PN029-PN038

USL CAPITAL (USL)

2 PY001

VARIG AIRLINES (VAR)

3 PK111-PK116 PK118-PK120 PK141-PK146 PL453-PL454

VARSA (VAB)

2 PC-351

VASP (VSP)

2 PG435 PG437 PG439-PG440 PG471-PG473 PL756 PX071 3 PHC11-PHO13 PK061-PK062 PK065-PK067

VENEZUELA - GOVERNMENT OF (VNZ) 3 PK070

VISCOUNT AIR SERVICE INC. (VAS) 2 PG201 PG203 PG209 PG212 PG216-PG217 PG220-PG222 PJ1O1 PJ103

3 PK305-PK306

WHIRLPOOL FINANCIAL CORP (ZZW) 2 PG214

XIAMEN AIRLINES CO. LTD. (XIA) 3 PK635

YEMEN AIRWAYS (YEM)

3 PK341

ZAMBIA AIRWAYS (ZAM) 3 PK291 PL026

IDENTIFICATION BY VARIABLE NUMBER

GROUP 1

PA001 -PA01 1 PA099 PGOO1-PG008 PG199 PG271 -PG272

GROUP 2

PA012-PA022 PA231-PA232 PCO01-PCO05 PG009-PGO75 PG201-PG230 PG251-PG255 PG273-PG279 PG301-PG314 PG331-PG332 PG351-PG356 PG375 PG401-PG403 PG431-PG442 PG471 -PG475 PG501-PG505 PG571-PG586 PG621-PG630 PG651 -PG652 PG701-PG705 PH701-PH715 PH731-PH732 PH741-PH742 PJ001-PJ002 PJ031-PJ032 PJ071-PJ072 PJ101-PJ104 PL711-PL712 PL716 PL726-PL728 PL736-PL742 PL756 PL761 PL801-PL803 PX071 PX701 PY001-PY008 PY021 PY031 PY036-PY037 PY046-PY047 PY301-PY304 PY321-PY323 PY341-PY346 PY361-PY362 PY381

Jun 30/94 737-43A1 168

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BOEING SERVICE BULLETIN 737-53A1166

GROUP 3

PJ201-PJ219 

PH001 PHO11-PHo13 PHO21-PH024 PH743 PJ003-PJ009 PJ105-PJ119

PK101-PK103 

PK026-PK029 PK041-PK053 PK061 -PK070 PK081-PK082 PK091 -PK099

PK231-PK241 

PK1 1 1-PK120 PK141-PK146 PK201-PK204 PK21 1-PK215 PK221-PK223 PK251-PK258 PK271-PK274 PK281-PK289 PK291 PK301-PK318 PK341 PK351-PK361 PK391 PK431 -PK433 PK451 -PK452 PK461-PK469 PK495 PK501-PK504 PKS11-PK514 PK521-PK525 PK541-PK564 PK5S81 PK591-PK599 PK601-PK617 PK621-PK637 PK641-PK642 PK661-PK664 PK671-PK680 PK691-PK697 PK711-PK716 PK731-PK749 PK771-PK779 PK801-PK804 PK819-PK827 PK830 PK861 -PK863 PK871-PK874 PK881-PK884 PK901-PK932 PK971-PK974 PLO01-PL028 PLO61 PLO81 PL101-PL113 PL151 PL171-PL172 PL201-PL203 PL221 PL401-PL417 PL421 PL441 PL451-PL454 PL471 PL491 PL501-PL506 PL551-PL562 PL581 PL601-PL602 PL611 PL621-PL623 PL631-PL632 PL717-PL725 PL729-PL735 PL743-PL74S PL758 PL762-PL770 PL781-PL788 PL793 PM001-PM006 PM021-PM023 PM051-PM062 PM101-PM117 PM141-PM142 PNO01-PNO02 PNO21-PN028 PNO81-PN083 PN101-PN112 PY022 PY048 PY051-PY053 PY101-PY103 PY111-PY113 PY131-PY135 

PY191 

PY141-PY143 PY151-PY154 PY156-PY157 PY161-PY162 PY166 PY201 PY221-PY222 PY231 PY241-PY244 PY270-PY275 PY281 PY286 PY401 PY411 PY421-PY422 PY441 PY451 

PY671 

PY461-PY462 PY611-PY612 PY621 PY631 PY651 PY741

GROUP 4

PK519 PL603 PM016-PM017 PM118-PM119 PN029-PNo38 PN084-PNO86 PN131-PN135 PY056-PY057 PY672

2. Spares

None

0

Jun 30/94 737-53A1 166

11
BOEING SERVICE BULLETIN 737-53A1 166

B. Reason

Boeing Supplemental Structural Inspection Document D6-37089, Section 8.2. SSI Number F.29, is related to this service bulletin.

Boeing Structural Item Interim Advisory (SIIA) 737-131 is related to this service bulletin.

The changes shown in this service bulletin will decrease the probability of cracks in the frame at Body Station (BS) 727 where Stringer 18A is attached. This area is a primary structural element. Operation with cracks in the frame will decrease the structural integrity of this area Unscheduled downtime can be necessary to replace a frame that has a crack.

Four operators sent reports of cracks in the outboard chord of the frame at BS 727. The reports were of eight airplanes with 39,000 to 54,100 flight hours and 56,200 to 73,200 flight cycles. The cracks

were found in the chord at the lower row of fasteners where Stringer 18A is attached. The cracks

were in a forward and aft direction and measured approximately 1.4 to 3.0 inches in length. The cracks were caused by fatigue that was started by fretting of adjacent pans. Operators have also sent reports of cracks in the outboard chord of Stringer 1 8-A.

As part of a service bulletin validation program, the inspection, frame chord replacement, and preventive modification was completed on airplane PG576 before the initial release of this bulletin. Airplane PG576 had the configuration of a Group 2 airplane.

C. Description

The airplane effectivity is divided in 4 groups because of differences in airplane configuration. There is a preventive modification kit for each of the airplane configurations.

Do the inspections that follow at the times given in the Compliance section.

Make a visual inspection of the edge of the forward flange of the outboard chord of the frame at BS 727. Look for cracks.

Make an inspection of the outboard chord under Stringer 18-A. Use the Pulse Echo Shear Wave (PESW) Inspection procedure. Look for cracks in the area of the two forward lower fastener holes in the chord where Stringer 18A is attached.

NOTES:

1. Airplanes with 60,000 to 70.000 cycles can omit the next step only at the initial inspection at 1500 flights after you get this bulletin.

2. Airplanes with more than 70.000 cycles can omit the next step only at the initial inspection at 500 flights after you get this bulletin.

Remove the two forward lower fasteners. Make an inspection of the fastener holes in the outboard chord of BS 727. Use a high frequency eddy current (HFEC) inspection procedure. Look for cracks.

Also, make an inspection of the outboard surface of the outboard chord of Stringer 18A at Station 727. Examine the surface around the heads of two fasteners. Use a high frequency eddy current (HFEC) inspection procedure. Look for cracks. If cracks are found in the outboard chord of Stringer 1 8A, get repair instructions from Boeing.

If cracks are found in the outboard chord of the frame at BS 727, install the time limited repair or replace the chord. Refer to Boeing Service Bulletin 737-53-1088 for instructions to replace the chord. When you replace the chord, Boeing recommends that you also install the preventive modification. At the operators option, the preventive modification can be installed later.

Jun 30/94 737-53A1 166

12
BOEING SERVICE BULLETIN 737-53A1166

installed, 

The repair 

replace 

is time limited. 

the 

Within 4500 flight cycles, but not more than 18 months, after the repair was

takes the place 

chord as specified in Boeing Service Bulletin 737-53-1088. The repair chord

737-53-1088. When 

of the forward splice angle of the chord replacement kit per Service Bulletin you replace the chord, Boeing recommends modification. At the operators that you also install the preventive option, the preventive modification can be installed later.

If no cracks are found, install the preventive modification or do the inspection again.

Do 

installed.

the inspection at the times given in the Compliance section until the preventive modification is

If the preventive modification 

necessary.

is installed, no more inspections, per this service bulletin, are

More 

737-53-1088 

work is 

(refer 

necessary for operators that have replaced the chord as shown in Service Bulletin (SB) to Compliance section).

An 

of the 

evaluation 

quality of 

form 

this 

is 

service 

attached to this service bulletin. Please use this form to tell us what you think bulletin.

NOTES:

1. The 

Inspection changes 

and 

given 

Repair", 

in Boeing Service Bulletin 737-53A1039, "Fuselage - Skin Lap Joint

given in 

can be made on applicable airplanes before or during the changes this service bulletin.

2. The 

Beam changes given in Boeing Service Bulletin 737-53-1066, "Fuselage - Stringer 18A Shear

during 

Inspection, Repair and Modification", can be made on applicable airplanes before or the changes given in this service bulletin.

3. The 

Splices 

changes 

and Bonded 

given in 

Doublers 

Boeing Service Bulletin 737-53-1076, "Fuselage - Circumferential Butt

airplanes before Inspection, Repair and Modification", can be made on applicable or during the changes given in this service bulletin.

4. The 

Repair, changes 

and Modification 

given in Boeing Service Bulletin 737-53-1077, "Fuselage - Skin Inspection,

made on applicable 

Aft of Body Station 727 Between Stringer S-18 and S-21", can be airplanes before or during the changes given in this service bulletin.

5. The 

17 Inspection 

changes given 

and 

in 

Preventive Boeing Service 

Modification", 

Bulletin 737-53-1089, "Fuselage -Skin Cracks at Stringer

during the changes can be made on applicable airplanes before or given in this service bulletin.

6. The 

(Tear 

changes 

Straps) given in Boeing Service Bulletin 737-53-1124, "Fuselage - Bonded Doublers

259 andl 016", - Inspection and Repair - For Delamination above Stringer 26 Between Stations

service bulletin.

can be made on applicable airplanes before or during the changes given in this

PLEASE 

RESULTS 

SEND 

WHEN 

A 

EACH 

REPORT OF YOUR INSPECTION PROGRAM. ALSO, SEND THE INSPECTION INSPECTION IN THE ADDENDUM, IS COMPLETE. REFER TO THE FLIGHT SAFETY SECTION

Jun 30/94 

737-53A1 166

13
BOEING SERVICE BULLETIN 737-53A1166

D. Compliance

This bulletin has a Flight Safety Inspection Program that is the minimum necessary to keep the structural integrity of the outboard chord.

For airplanes with 27,000 flights to 50,000 flights, do the inspection initially within 4,500 flights after

you get this bulletin. Do the inspection again at intervals of 15,000 flights until the airplane collects

more than 50,000 flights.

For airplanes with 50,000 flights to 60,000 flights, do the inspection initially within 2,500 flights after

you get this bulletin. Do the inspection again at intervals of 7,500 flights until the airplane collects

more than 60,000 flights.

For airplanes with 60,000 flights to 70,000 flights, do the inspection initially within 1,500 flights after

you get this bulletin. Do the inspection again at intervals of 5,000 flights until the airplane collects

more than 70,000 flights.

For airplanes with more than 70,000 flights, do the inspection initially within 500 flights after you get this bulletin. Do the inspection again at intervals of 3,000 flights.

For airplanes with the lower part of the chord replaced by SB 737-53-1088, do the inspection at the intervals shown above.

For airplanes with the upper part of the chord replaced by SB 737-53-1088, do the inspection initially within 30,000 flight cycles after the chord was replaced. Do the inspection again at the intervals shown above for flight cycles after the chord was replaced.

E. Approval

This service bulletin was examined by the Federal Aviation Administration (FAA). The changes specified in this service bulletin comply with the applicable Federal Aviation Regulations (FAR) and

are FAA approved. The service bulletin and the FAA approval were based on the airplane in its original Boeing delivery configuration or as modified by other FM approved Boeing changes and do not apply to airplanes on which other configuration changes have been made.

Jun 30/94 737-63A1 166

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BOEING SERVICE BULLETIN 737-53A1166

F. Manpower

The data below shows an estimate of the man-hours necessary to do the inspection, repair, and preventive modification for each airplane. This estimate is for direct labor only, done by an experienced crew. Adjust the estimate with operator man-hour data if necessary. The estimate does not include lost time. These are some examples of lost time:

- Time to adjust to the workplace - Time to schedule the work - Time to examine the work - Time to cure the materials - Time to make the parts - Time to find the tools.

Inspection only.

Task Number of Persons Man-Hours Elapsed Time (Hours)

Open Access

Inspection 1 1.5 1.5

Close Access 1 1 1

TOTAL FOR iNSuEClTiON 3.5

Time Limited Repair for the Outer Chord of BS 727 Frame.

Task Number of Persons Man-Hours Elapsed Time (Hours)

Open Access 2 6 3

Install Repair 2 30 15

Close Access 2 6 3

TOTAL FOR REPAIR 42 21

Preventive Modification.

Task Number of Persons Man-Hours Elapsed Time (Hours)

Open Access 2 32 16

Preventive 2 40 20 Modification

Close Access 2 27 13.5

TOTAL FOR MODIFICATION 99 49.5

Jun 30/94 737-53Al 166

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BOEING SERVICE BULLETIN 737-53A1166

G. Material - Price and Availability

Boeing can supply the kits shown in Paragraphs 1I.A., Parts Necessary For Each Airplane as shown below. Kit availability is shown in the Reorder Lead Time (ROLT). ROLT is calculated from the date

Boeing gets the purchase order.

ROLT Unit Price thru

Kit Number Name (weeks Sep 16/94

65C37277-1 Top Kit, Left Side 32 $1759

65C37277-2 Top Kit, Right Side 32 $1759

65G37277-3 Top Kit, Left Side 32 $1825

65C37277-4 Top Kit, Right Side 32 $1825

65C37277-5 Top Kit, Left Side 32 $1840

65C37277-6 Top Kit, Right Side 32 $1840

65C37277-7 Top Kit, Left Side 32 $1805

65C37277-8 Top Kit, Right Side 32 $1805

The kits are subject to the terms and conditions of the Boeing standard purchase order acknowledgment. After the Unit Price date, new price (and ROLT ) data is applicable. Prices are in

United States Dollars. Terms: Net 30 days.

Send purchase orders and letters about the supply data to the Director of Spares and refer to this service bulletin number.

H. Special Tools - Price and Availability

None

1. Welghtand Balance

Change in Weight Change in Moment

Task (Pounds) (Pound-Inches)

+() ()

Preventive Modification +3.7 +2690

Repair +6.5 +4755

Jun 30194 737-53A1 116

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BOEING SERVICE BULLETIN 737-53A1166

J. References

* 1. Existing Data:

a. 737 Maintenance Manual Subjects 26-21-11, 27-51-261, 53-23-1

b. 737 Structural Repair Manual Subjects 51-10-1, 51-10-2, 51-20-1, 51-20-4

c. 737 Nondestructive Test Manual D6-37239, Part 4, Subject 53-10-01

d. 737 Nondestructive Test Manual D6-37239, Part 6, Subject 51-00-00, Figure 1

e. 737 Maintenance Planning Data Manual D6-17594-2, Section 6-02

f. Boeing Service Bulletin 737-53-1088, "Fuselage - Body Station 727 Bulkhead, Outboard Chord Inspection and Replacement"

2. Data supplied with this service bulletin:

a. Drawings:

Drawing Number Sheet DCN ADCN Title

65C37277 PL - 1 Strap Installation - Station 727 Bulkhead,

1 - S-18 to S-20, Preventive Modification (Top Kit)

3. Installation Drawings:

Drawing Number Title

65-48654 Frame Installation - Aft Wing/Body Faking, Station 729.38

65-46877 Strap and Beam Installation - Stringer 1 8A, Station 639 to Station 747

These 

make the 

drawings specified 

were used to prepare this service bulletin. These drawings are not necessary to

not changes, and are not supplied with this service bulletin. These drawings may be applicable to all airplane configurations or operators.

4. Process Data

Boeing Process Specifications referred to on the drawings are not given in this service bulletin since these procedures are frequently used as standard shop practices.

K. Publications Changed

Publication Chanter-Section

737 Structural Repair Manual 53-10-2

737 Non-Destructive Test Manual Part 4

L. Electrical Load Data

Not changed

Jun 30/94 737-53A1 166

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BOEING SERVICE BULLETIN 737-53A1166

II. MATERIAL INFORMATION

A. Parts Necessary For Each Airplane

1. To get the kits shown below, refer to Paragraph I.G., Material - Price and Availability.

NOTE: One top kit and operator supplied materials specified in Paragraph II.A.2., Parts and

Materials Supplied by the Operator, are necessary for each side of the airplane.

65C37277- STRAP INSTALLATION - STATION 727 BULKHEAD, S-18 TO S-20, PREVENTIVE MODIFICATION (TOP KIT)

-4 -3 -2 -1

Quantity Part Number Name

- 65C37277-1 (a) (e) Top Kit (Left Side)

- . 65C37277-2 (a) (e) Top Kit (Right Side)

- . . 65C37277-3 (b) (e) Top Kit (Left Side)

65C37277-4 (b) (e) Top Kit (Right Side)

65C37277 - STRAP INSTALLATION - STATION 727 BULKHEAD, S-18 TO S-20, PREVENTIVE MODIFICATION (TOP KIT)

-8 -7 -6 -5

Quantitl Part Number Name

- 65C37277-5 (c) (e) Top Kit (Left Side)

- . 65C37277-6 (c) (e) Top Kit (Right Side)

65C37277-7 (d) (e) Top Ki (Left Side)

65C37277-8 (d) (e) Top Ki (Right Side)

a For Group 1 airplanes.

b. For Group 2 airplanes.

c. For Group 3 airplanes.

d. For Group 4 airplanes.

e. Refer to Drawing 65C37277, sent with this bulletin, for the list of parts.

Jun 30/94 737-53A1 168

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BOEING SERVICE BULLETIN 737-53A1 166

2. Parts and Materials Supplied by the Operator for the Preventive Modification:

Quantity Part Number (Specification) Name

As necessary BMS 5-92, or equivalent Adhesive

As necessary BMS 5-95, or equivalent Sealant

As necessary 8MS 10-11, Type 1, or equivalent Primer

As necessary BMS 10-11, Type 2, or equivalent, Gloss Enamel Color BAC702 White

3. Parts and Materials Supplied by the Operator if the Preventive Modification is not installed:

NOTE: Refer to 737 Structural Repair Manual Chapter 51 for alternative fasteners.

Quantity Part Number (Specification) Name

2 BACB30MB8A() (a) (b) (e) Hi-Lok

2 BACB30MC8A() (a) (c) (e) Hi-Lok

2 BACC3OX8 (a) (b) (c) Collar

2 BACB30MD8A() (a) (d) (e) Hi-Lok

2 BACC30AC8 (a) (d) Collar

(a) Use if the chord is not replaced and the preventive modification is not installed. Use oversize fasteners if necessary (refer to Ill. Accomplishment Instructions). Only two fasteners are necessary at each installation. Choose the appropriate size.

(b) Standard size.

(c) For 1/64 oversize.

(d) For 1/32 oversize.

(e) Choose the grip length the same as the fastener that is removed (refer to Figure 1).

Jun 30/94 737-53A1 166

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BOEING SERVICE BULLETIN 737-53A1166

4. Parts and Materials Supplied by the Operator for the Time Limited Repair:

The table that follows shows the repair parts necessary at each installation.

NOTE: Refer to 737 Structural Repair Manual Chapter 51 for alternative fasteners.

Quantity Part Number (Specification) Name

1 4 x 8 x 0.15 inch thick 7075-TO Aluminum Alloy Sheet

1 AND101 34-2008 x 20.8, 7075-T6 Extruded Angle or equivalent

1 1.25 x 4.25 x 0.032 inch thick 7075-T6 Aluminum Alloy Sheet

1 1.25 x 6 x 0.18 inch thick 7075-T6 Aluminum Alloy Sheet

1 1.4 x 8.2 x 0.18 inch thick 7075-T6 Aluminum Alloy Sheet

1 2.1 x 11.4 x 0.1 8 inch thick 7075-T6 Aluminum Alloy Sheet

1 1.2 x 8.7 x 0.18 inch thick 7075-T6 Aluminum Alloy Sheet

1 1.2 x 1.4 x 0.82 inch thick 7075-T6 Aluminum Alloy Sheet

As necessary BMS 5-95, or equivalent Sealant

As necessary BMS 10-11, Type 1, or equivalent Primer

As necessary BACB30MB8A() Hi-Lok

As necessary BACC30X8 Collar

B. Parts Necessary to Change Spares

None

C. Special Tools and Equipment

No special tools or equipment are necessary to do the change in this service bulletin. Also, maintenance and overhaul tools in manuals shown in Paragraph i.J., References, can be necessary. Examine operator tool supply to make sure all necessary tools are available.

D. Existing Parts Accountability

None

Jun 30/94 737-53A1 166

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BOEING SERVICE BULLETIN 737.53A1166

Ill. ACCOMPLISHMENT INSTRUCTIONS

NOTES:

1. The paragraphs identified with letters give the general work instructions and the necessary tests. The instructions identified with numbers on the figures give the recommended sequence of steps.

2. Unless shown differently, these dimensions and tolerances are used:

- Linear dimensions are in inches - Tolerance on linear dimensions, other than rivet and bolt edge margins, is plus or minus 0.03 inch - Tolerance on rivet and bolt edge margin is plus or minus 0.05 inch - Angular tolerance is plus or minus 2 degrees - Hole dimensions for standard solid rivets are given in 737 Structural Repair Manual Chapter 51 - Torque limits to tighten nuts and bolts are given in 737 Structural Repair Manual Chapter 51 - Edge margins for fasteners are given in 737 Structural Repair Manual Chapter 51

3. Fastener installation is given in 737 Structural Repair Manual Chapter 51.

4. Alternative fasteners are given in 737 Structural Repair Manual Chapter 51.

5. Obey all of the warnings and cautions given in the specified manual sections.

Part I Flight Safety Insoection Proaram

A. Do the inspections that follow at the thresholds specified in the Compliance section.

B. Fully extend the trailing edge flaps. Get access to the outboard side of the frame at Body Station (BS) 727 through the opening in the flap fairing. At the operators option, for more access, remove the fairing for the inboard track of the inboard flap. Keep the fairing and all fasteners for installation.

C. Get access to the inboard side of the frame at BS 727 from inside the wheelwell. On the left side, at the operators option for more access, disconnect the connectors for the gauge and the detonator on the aft fire bottle.

D. Examine the outboard surface of the outboard chord of Stringer 18-A (refer to Figure 1). Look for cracks in the surface around the heads of the two fasteners immediately aft of BS 727.

E. If there are cracks in the outboard chord of Stringer 1 8-A, get repair instructions from Boeing.

F. Examine the edge of the forward flange of the outboard chord of the frame at BS 727 (refer to Figure 1). Look for cracks.

G. If there are no cracks in the forward flange of the outboard chord of the frame at BS 727, go to Step H. If there are cracks, go to Step L.

H. Use the Pulse Echo Shear Wave Inspection procedure in the area under the outboard chord of Stringer 18-A. Look for cracks in the area of the two lower fastener holes (refer to Figure 1).

I. If no cracks are detected by this procedure in the area of the two lower fastener holes in the outboard chord of the frame at BS 727 , go to Step J. If there are cracks, go to Step L

Jun 30/94 737-53A1 166

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BOEING SERVICE BULLETIN 737-53A1 168

NOTES:

1. Airplanes with 60,000 to 70,000 cycles can omit Steps J and K only at the initial inspection at 1500 flights after you get this bulletin.

2. Airplanes with more than 70,000 cycles can omit Steps J and K only at the initial inspection at 500 flights after you get this bulletin.

J. Get access to the two lower fasteners in the outboard chord of the frame at BS 727 where Stringer 1 8A is attached (refer to Figure 1).

K. Remove the two fasteners and inspect the fastener holes for cracks as shown in Figure 1.

L. If cracks are found in the outboard chord of the frame at BS 727, at the customers option install the time limited repair (refer to Part Ill of the Accomplishment Instructions) or go to Step M. The time limited repair is limited to a crack that extends from the forward edge of the chord, or from the forward fastener hole, but does not extend past the second fastener hole. At the time specified in Part C. Description, replace the chord (refer to Step M). The repair chord takes the place of the forward splice angle of the chord replacement kit per Service bulletin 737-53-1088. If the crack extends past the second fastener hole go to Step M.

M. Replace the chord as shown in Boeing Service Bulletin 737-53-1088 (refer to Part 11 of the Accomplishment Instructions). When you replace the chord, Boeing recommends that you also install the preventive modification. At the customers option, the preventive modification can be installed later. If you install the preventive modification, use the hole pattern shown for the chord replacement (refer to 737-53-1088) to install the 69-78770-1 splice plate. If the preventive modification is not installed, do the inspections again as specified in the Compliance section.

N. If no cracks are found, install the preventive modification as specified in Part II of the Accomplishment Instructions or do the inspections again as specified in the Compliance section.

0. If the preventive modification is not installed, replace the fasteners removed in Step K (refer to Figure 1). If necessary, drill 1/64 or 1/32 inch oversize to remove any damage (such as scratches, nicks, or ovality) in the fastener holes and install oversize fasteners (refer to Section II.A.2. Parts and Materials Supplied by Operator). Do the inspections again, as specified in the Compliance section, until the preventive modification is installed.

NOTE: Check the fastener holes before they are oversized to see if they are already oversize by the incorporation of another service bulletin. If another service bulletin has been installed, use the same size and type of fastener used in the other service bulletin. If necessary, drill 1/64

or 1/32 inch oversize to remove any damage (such as scratches, nicks, or ovality) in the fastener holes and install oversize fasteners.

P. If disconnected in Step C, install the connectors for the gauge and the detonator on the aft fire bottle.

Q. If removed in Step B, Install the fairing for the inboard track of the inboard flap.

R. Return the airplane to serviceable condition.

Jun 30/94 73743A1 166

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BOEING SERVICE BULLETIN 737-53A1166

S. Send a report of the inspection to Boeing (refer to Paragraph C. Description and the Flight Safety Section in the Addendum).

Part II Preventive Modification

A. Get access to the outboard side of the outboard chord at Body Station (BS) 727 between Stringers S-17 and S-20. Also, get accesstotheoutboard side of Stringers S-18A and S-19 from BS 709 to BS 747 (for 737 -100 airplanes) or 727A (for 737-200 airplanes). Refer to Figure 2.

To get the access, remove the parts that follow: .The wing-to-body fairings (refer to AMM 53-51-21). .The fairing support structure at 8S 727 (refer to View A-A in Figure 2).

B. Get access to the inboard side of Stringer S-1 9 between BS 729 and 747 (for 737 -100 airplanes) or 727A (for 737-200 airplanes). To get the access, remove the cargo liner at the forward end of the cargo compartment in the aft lower lobe.

NOTE: On some airplanes there may be an auxiliary fuel tank installed. If installed, remove the auxiliary fuel tank to get access to the cargo liner (refer to 737 AMM 53-23-1).

C. In the wheel well, get access to the inboard side of Stringer S-18A between BS 709 and 727.

D. In the wheel well, get access to the inboard side of the outer chord at BS 727. To get the access, remove the engine fire extinguisher bottles (refer to 737 AMM 26-21 -11).

CAUTION: TO INSTALL THE PREVENTIVE MODIFICATION, SKIN PANEL ATTACHMENT FASTENERS ARE REMOVED. THIS SKIN PANEL AND FASTENERS ARE THE SUBJECT OF AIRWORTHINESS DIRECTIVES 88-22-11 Ri, 89-09-03, 91-08-12 AND 92-25-09. MAKE SURE THAT THE INCORPORATION OF THIS SERVICE BULLETIN DOES DIRECTIVES. NOT CHANGE THE COMPLIANCE WITH THESE AIRWORTHINESS

NOTE: Airworthiness Directives 88-22-11 RI and 89-09-03 refer to Boeing Service Bulletins 737-53-1039 and 737-53-1089. Airworthiness Directive 91-08-12 refers to Boeing Service Bulletin 737-53-1124. Airworthiness Directive 92-25-09 refers to Boeing Service Bulletin 737-53-1076.

E. Install the preventive modification as shown in Drawing 65C37277.

NOTES:

1. At the customers option make the external strap, 69-78770-1, -2 opposite, from 4130 150-170 KSl or 15-5PH 150-170 KSI steel.

2. Service Bulletin 737-53-1077 installs a repair patch at BS 727 and Stringer 18A. If the repair patch is installed, then the 69-78773-10 filler is not needed. If necessary, install an additional filler forward of BS 727 to match the thickness of the repair patch. If necessary, also use a tapered filler forward of BS 727, same as the 69-78773-7 tapered filler, but with the thickness increased to match the repair patch. Keep the same taper ratio.

F. install the cargo liner if that was removed in Step B. If removed in Step B. install the auxiliary fuel tank (refer to 737 AMM 53-23-1).

G. install the engine fire extinguisher bottles removed in Step D (refer to 737 AMM 26-21-11).

Jun 30/94 737-53A1 166

23
BOEING SERVICE BULLETIN 737-53A1 166

H. Install the wing-to-body fairing that was removed in Step A (refer to AMM 53-51-21).

NOTE: The preventive modification installs new structure to replace most of the fairing support structure that was removed in Step A (refer to Figure 2).

I. Return the airplane to serviceable condition.

Part Ill Time Umited Reoair

A. In the wheel well, get access to the inboard side of the outer chord at BS 727. To get the access,

remove the engine fire extinguisher bottles (refer to 737 AMM 26-21 -11).

B. Get access to the aft side of the bulkhead at BS 727. To get the access, remove the cargo liner at the forward end of the cargo compartment in the aft lower lobe.

NOTE: On some airplanes there may be an auxiliary fuel tank installed. If installed, remove the auxiliary fuel tank to get access to the cargo liner (refer to 737 AMM 53-23-1).

C. Get access to the forward side of the bulkhead at BS 727. Remove the flap right angle gearbox and associated brackets (refer to Figure 3).

D. On the forward side of the bulkhead at BS 727, find the horizontal stiffener at approximately Water Line189. Trim the outboard part of the vertical side of the horizontal stiffener to allow installation of the repair angle (refer to Figure 3).

E. Trim the aft part of the outboard vertical side of the Stringer S-18A Shear Beam to allow installation of the repair angle (refer to Figure 3).

F. Drill a stop crack hole at the end of the crack (refer to 737 Structural Repair Manual 51-10-1).

NOTE: To prevent damage to the skin or S-18 structure, put a thin steel shim between the outer chord at BS 727 and the skin.

G. Make the repair parts (refer to Figure 4).

H. Install the repair parts (refer to Figure 5).

I. Install the flap right angle gearbox and associated brackets removed in Step C (refer to Figure 5).

J. Install the cargo liner removed in Step B. If removed in Step B, install the auxiliary fuel tank (refer to 737 AMM 53-23-1).

K. Install the engine fire extinguisher bottles removed in Step A (refer to 737 AMM 26-21 -11).

L. Return the airplane to serviceable condition.

Jun 30/94 737-53A1 166

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BOEING SERVICE BULLETIN 737-53A1166

Illustration Table of Contents

Title Page

FIGURE 1. INSPECTION ................................................. 26

FIGURE 2. ACCESS FOR THE PREVENTIVE MODIFICATION ................... 29

FIGURE 3. ACCESS FOR THE REPAIR ..................................... 32

FIGURE 4. MAKE THE REPAIR PARTS ..................................... 36

FIGURE5. INSTALL THE REPAIR ....................................... 39

Jun 30/94 737-53A1 166

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BOEING SERVICE BULLETIN 737-53A1166

° / < EE DETAIL I

LEFT SIDE SHOWN

RIGHT SIDE OPPOSITE

(WINE-TO-BODY FAIRING NOT SHOWN)

FIGURE 1. INSPECTION

Jun 30/94 SHEET 1 OF 3 737-63A1 166

26
BOEING SERVICE BULLETIN 737-53A1166

STRIN6ER 18-A STA

(ON SOME AIRPLANES 727

THE OUTER CHORD OF I

STRIS6ER 18-A IS 0T RI N 18-

A FLAT STRAP) O 0o°

S DETAIL CIEE I

00

So o

Ju 3/4 HETOF 77531A6

F7 27

INBID0 P--- - DETAIL I ) O 0

STRIH6ER 18-A---

TYPICAL O O 0

CRACK /

o o

a DETAIL II

FIGU RE 1. INSPECTION

Jun 30/94 SHEET 2 OF 3 737-53A1 166
BOEING SERVICE BULLETIN 737-53A1166

The step number shown below agree with the numbers shown inside the circle symbols in the figure.

STEP TASK NAME PROCEDURE REFERENCES NOTES

1 Examine Outboard chord High Frequency NDT Part 6, 51-00-00, Examine the outboard of Stringer 18-A Eddy Current Figure 4 surface of the outboard Inspection chord around the

fastener head. Look for

cracks.

2 Examine Outboard chord Close Visual Examine the edge of the of frame Inspection forward flange of the

outboard chord. Look for _ _ _ _ _ I__ _ _ _ _ _ _ _ cracks.

3 Examine Outboard chord Pulse Echo NDT Part 4, 53-10-01 Examine the area under of frame Shear Wave the outboard chord of Inspection Stringer 18-A. Look for -_ - cracks.

If there is no indication of a crack, go to Step 4.

STEP TASK NAME PART NUMBER QTY NOTES

4 Remove / Lockbolt BACB30GW8() 2 Measure the grip length of the Discard Collar BACC3OK8 2 fastener that was removed.

STEP TASK NAME PROCEDURE REFERENCES NOTES

5 Examine Fastener Holes High Frequency NDT Part 6. 51 -00-00, Examine the fastener Eddy Current Figure 1 holes in the forward Inspection flange of the outboard

chord. Look for cracks

If you do not install the preventive modification, go to Step 6.

STEP TASK NAME PART NUMBER CTY NOTES

6 Examine Hole 2 Look for damage.

Drill Oversize 2 If necessary, drill oversize hole hole to remove damage. Make sure that

the edge margin is not less than 1.5D

Install Hi-Lok BACB30MB8A() (a) 2 Use the same grip length as the

or fastener that was removed in Step 4. BACB30MC8A() (b) 2

or

BACB30MD8A() (c) 2

or equivalent.

(a) Standard size.

(b) 1/64 oversize.

(c) 1/32 oversize.

FIGURE 1. INSPECTION

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BOEING SERVICE BULLETIN 737-53A1166

STA STA STA 7509 STA 727 71672 71 ASTA

II l747 (737-100)

Se -i 727A (737-200)

< b0 >|B-518

5~~~-18^ i~9

5-20

SLEFT SIDE SHOWN

RIGHT SIDE OPPOSITE

(WING-TO-BODY FAIRING NOT SHOWN)

FIGURE 2. ACCESS FOR THE PREVENTIVE MODIFICATION

Jun 30/94 SHEET 1 OF 3 737-53A1 166

29
BOEING SERVICE BULLETIN 737-53A1166

iS-`17

-i-t

+2.)

*e t

>: I NOD

VIEW A-A

Jun 304 SHEET 2 OF 3 73753A1166

30
BOEING SERVICE BULLETIN 737-53A1166

The step numbers shown below agree with the numbers shown inside the circle symbols in the figure.

STEP TASK NAME REFERENCES CITY NOTES

1 R emove / Stiffener 1

Discard

2 

_ 

Remove/ Tee Chord 1 Keep the tee chord to use _Keep _ __ _ _ _ _ _ _again.

3 Remove/ Web 1

Discard

4 Remove/ Angle 1

Discard

5 Remove/ Attach Angle 1

Discard

6 Remove/ Filler 1 Keep the filler to use again. Keep

7 Remove/ Filler 2

Discard

FIGURE 2. ACCESS FOR THE PREVENTIVE MODIFICATION

Jun 30/94 SHEET 3 OF 3 737-53A1 166

31
BOEING SERVICE BULLETIN 737-53A1166

SEE DETAIL II

SEE DETAII

DETAIL I

FLAP RIGHT ANGLE GEARBOX

RIGHT GEAR BOX SHOWN

LEFT GEARBOX SIMILAR

FIGURE 3. ACCESS FOR THE REPAIR

Jun 30/94 SHEET1 OF4 737-53A1 166

32
BOEING SERVICE BULLETIN 737-53A1166

SEE DETAIL III X ~,,, ,/X

|-,--,--,--,- ,- '- '- '' 'f }/// S-18A

( 4 1- /s-19

SE DI ,SEE DETAIL I

I ~ ~ ~ ~ ~ -I I ~ I~ ' I,--t-X

J, C-

<g S-ZO

INBD< D

DETAIL II

LEFT SIDE SHOWN

RIGHT SIDE SIMILAR

FIGURE 3. ACCESS FOR THE REPAIR

Jun 30/94 SHEET 2 OF 4 737-53A1 166

33
BOEING SERVICE BULLETIN 737-53A1166

D ;I an/ A190

>S-18A

-191

--------------- '----'II- ~ ------

STA

727

-r VIEW B-B

VIEW A-A

FIGURE 3. ACCESS FOR THE REPAIR

Jun 30/94 SHEET3OF4 737-63A1166

34
BOEING SERVICE BULLETIN 737-53A1166

The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

STEP TASK NAME PART NUMBER Qy NOTES

1 Remove/ Flap Right Angle Keep Gearbox 1 Keep the parts to use again. Refer to AMM 27-51-261.

2 Remove/ Tee 65-48692-5 Left Side 1 Keep the tee to use again. Keep 65-48692-12 Right Side

3 Remove/ 

Keep 

Bracket 69-39436-2 Left Side Keep the bracket to use again. 69-39437-2 Right Side

4 Trim Shear Beam Web 65-46877-() 1 Trim the aft part of the outboard

vertical side of the Shear Beam

Web to allow for the installation

of the Repair Angle.

Apply Chemical Film Apply to cut area. Refer to 737 Treatment Structural Repair Manual (Alodine) 51-10-2

Apply Primer BMS 10-11, Type 1 Apply one layer to cut area

5 Trim Horizontal 

Stiffener 65-46547-() 1 Trim the outboard part of the vertical side of the Horizontal

Stiffener to allow for the

installation of the Repair Angle.

Apply Chemical Film Apply to cut area. Refer to 737 Treatment Structural Repair Manual (Alodine) 51-1 0-2

Apply Primer BMS 10-11, Type 1 Apply onelayertocut area.

FIGURE 3. ACCESS FOR THE REPAIR

Jun 30/94 SHEET 4 OF 4 737-53A1 166

35
BOEING SERVICE BULLETIN 737-53A1166

A]

,-,

1 11

0

VIEW A-A Aj

FIGURE 4. MAKE THE REPAIR PARTS 0

Jun 30/94 SHEET 1 OF 3 737-S3A1 166

36
BOEING SERVICE BULLETIN 737-53A1166

S

I

05

*

r

0 FIGURE 4. MAKE THE REPAIR PARTS

Jun 30/94 SHEET 2 OF 3 737-53A1 166

37
BOEING SERVICE BULLETIN 737-53A1166

The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

NOTE: Make the repair parts shown in the table that follows. Trim the repair parts to match the existing equivalent airplane parts. Make sure that the fastener hole edge margin is not less than the equivalent airplane part.

STEP TASK NAME MATERIAL OTY NOTES

1 Make Repair Angle AND1 01 34-2008 x 20.8 1

7075-T6,

or equivalent.

2 Make Shim 1.25 x 4.25 x 0.032 inch thick 1

7075-T6 Aluminum Alloy Sheet.

3 Make RepairStrap 1.25 x 6 x 0.18 inch thick 1

7075-T6 Aluminum Alloy Sheet.

4 Make Filler 1.4 x 8.2 x 0.18 inch thick 1

7075-T6 Aluminum Alloy Sheet.

5 Make Filler 1.2 x 1.4 x 0.82 inch thick 1

7075-T6 Aluminum Alloy Sheet

6 Make Repair Angle 4 x 8.2 x 0.15 inch thick 1 Refer to 737 Structural 7075-TO Aluminum Alloy Sheet. Repair Manual 51-20-1.

Use a minimum bend radius

of 0.44. Chamfer the aft

vertical edge 0.10 x 45

degrees to match the

Repair Angle made in Step 1 .

Bend Vertical Wall Also, bend the vertical wall

so it will align with the filler

made in Step 4 and the

Repair Angle made in Step 1. Heat Treat Repair Angle Heat treat to T-6.

7 Make Shim 2.1 x 11.4 x 0.18 inch thick 1

7075-T6 Aluminum Alloy Sheet.

8 Make Shim 1.2x8.7x 0.18inchthick 1

7075-T6 Aluminum Alloy Sheet.

FIGURE 4. MAKE THE REPAIR PARTS

Jun 30/94 SHEET 3 OF 3 737-53A1 166

38
BOEING SERVICE BULLETIN 737-53A1166

IW I~

DETAIL I

FLAP RIGHT ANGLE GEARBOX

RIGHT GEAR BOX SHOWN

LEFT GEARBOX SIMILAR

IFIGURE 5. INSTALL THE REPAIR

Jun 30/94 SHEET 1 OF 6 737-53A1 166

39
BOEING SERVICE BULLETIN 737-53A1166

/ (t (a i~ w lL 90

SS-20A

INBD C

DETAIL II

LEFT SIDE SHOWN

RIGHT SIDE SIMILAR

FIGURE 5. INSTALL THE REPAIR

Jun 30/94 SHEET 2 OF 5 737-63A1 166

40
BOEING SERVICE BULLETIN 737-53A1166

STA

727

I -_-1 . I I __

X I a r I 12rt3

--------------------------

FWD

VIEW A-A

- 1

FIGURE 6. INSTALL THE REPAIR

Jun 30/94 SHEET 3 OF 6 737-53A1 166

41
BOEING SERVICE BULLETIN 737-53A1166

STA

727

S-19-

-S-20

<> FWD

VIEW B-B

LOOKING OUTBOARD

FIGURE5. INSTALL THE REPAIR

Jun 30/94 SHEET 4 OF 5 737-53A1 186

42
BOEING SERVICE BULLETIN 737-53A1166

The step numbers shown below agree with the numbers shown in the circle symbols in the figure.

STEP TASK NAME PART NUMBER TY NOTES

1 Install Repair parts Temporarily install repair parts.

Drill Fastener holes

Remove Repair parts

Deburr Fastener holes Remove sharp edges.

Apply Chemical film Refer to 737 Structural Repair treatment (Alodine) Manual 51 -1 0-2. Apply Primer BMS 1 0-11, Type 1

2 Install Repair Angle (refer to Figure 4, Step 1) 1 Install parts with BMS 5-95 fay Isurface sealant. Refer to 737 3 Install Shim (refer to Figure 4, Step 2) 1 Structural Repair Manual

51-20-4. 4 Install Repair Strap (refer to Figure 4, Step 3) 1 Install with BACB30 MB

5 Install Filler (refer to Figure 4, Step 4) 1 fasteners the same size as - was removed. If necessary, 6 Install Filler (refer to Figure 4, Step 5) use oversize fasteners.

Frnwfastener locations, use 7 install Repair Angle (refer to Figure 4, Step 6) 1 BACB30MB8-( ) fasteners.

8 Install Shim (refer to Figure 4, Step 7 1 Install fasteners wet with BMS 5-95 sealant.

9 Install Shim (refer to Figure 4, Step 8) 1

1 0 Install Bracket 69-39436-2 Left Side 1 Install the bracket removed in

69-39436-2 Right Side Step 3 of Figure 3.

11 Install Tee 65-48692-5 Left Side 1 Install the tee removed in Step 65-48692-12 Right Side 2 of Figure 3.

12 Install Flap Right Angle 1 Install the Flap Right Angle Gearbox Gearbox removed in Step 1 of

Figure 3.

Refer to AMM 27-51-261.

FIGURE 5. INSTALL THE REPAIR

Jun 30/94 SHEET 5 OF 5 737-53A1 168

4:3
BOEING SERVICE BULLETIN 737-53A1166

ADDENDUM

FLIGHT SAFETY SECTION

INSPECTION TO ENSURE STRUCTURAL INTEGRITY OF AIRFRAME

A structural reassessment of the 737 airplane has been conducted under the requirements of Federal Aviation Administration (FAA) Advisory Circular 91-56 in accordance with Federal Aviation Regulation (FAR) 25.571, as amended in 1978, to ensure safe operation of 737 airplanes throughout their operational life.

Table I provides a summary of the inspections specified in Accomplishment Instructions, Part I - Flight Safety

their 

Inspection Program and the Compliance Section. that are recommended for the detection of cracks prior to reaching critical lengths. Failure to detect cracks prior to their reaching critical length may result in failure of the outboard chord of the frame at BS 727.

Any cracked structure should be replaced prior to further flight unless specifically approved by your cognizant regulatory agency.

described 

Please report any discrepancies to Boeing Customer Support Engineering using the reporting system in the addendum.

Jun 30/94 ADDENDUM

Page 1 of 6
BOEING SERVICE BULLETIN 737-53A1166

TABLE I - CHORD INSPECTION

Inspection Airplane Condition Inspection Threshold Repeat Inspection (See 737 Non (Flight Cycles) Interval (Flight Cycles) Destructive Test until Preventive Manual) Modification is installed

Close visual inspection Service Bulletin

of the the outboard Modification not chord of the frame at accomplished. 27,000 to 50,000 (a) 15,000 (e) BS 727. Examine the Service Bulletin

edge of the forward 737-53-1088 frame

flange. replacement not

accomplished. Pulse Echo Shear 50,000 to 60,000 (b) 7,500 (0 Wave inspection of the or

outboard chord of the

frame at BS 727. Service Bulletin

Examine area where Modification not 60,000 to 70,000 (c) 5,000 (g) Stringer 18A is accomplished.

attached. Lower part of frame

replaced per Service High Frequency Eddy Bulletin 737-53-1088. 70,000 (d) 3,000 Current inspection of

the outboard chord of Service Bulletin 30,000 (after the Use the intervals shown the Examine frame at BS 727. Modification not chord was replaced). above for flight cycles two fastener accomplished, after the chord was

holes (i) *f. Upper part of frame replaced.

High Fequenc Eddy replaced per Servicerelcd

Current inspection of ulletin 737-53-1088.

the outboard surface

of Stringer 18-A.

Examine around the

heads of two fastener

holes.

Close visual inspection Service Bulletin Next scheduled Use your Maintenance of the the outboard Modification structural inspection. Program Interval for chord of the frame at accomplished. Refer to the 737 scheduled structural BS 727. Examine the Maintenance Planning inspections. edge of the forward Data Manual Refer to the 737 flange. (h) D6-17594-2, Section Maintenance Planning 6-02. Data Manual

D6-17594-2, Section

65-02.

Jun 30/94 ADDENDUM

Page 2 of 6
BOEING SERVICE BULLETIN 737-53A1 166

(a) For airplanes at this threshold, do the inspection initially within 4.500 flights after you get this bulletin.

(b) For airplanes at this threshold, do the inspection initially within 2,500 flights after you get this bulletin.

(c) For airplanes at this threshold, do the inspection initially within 1,500 flights after you get this bulletin.

(d) For airplanes at or over this threshold, do the inspection initially within 500 flights after you get this bulletin.

(e) Use these intervals until the airplane collects more than 50,000 flights.

(f) Use these intervals until the airplane collects more than 60,000 flights.

(g) Use these intervals until the airplane collects more than 70,000 flights.

(h) Fully extend the trailing edge flaps. Get access to the outboard side of the frame at BS 727 through the opening in the flap fairing. Get access to the inboard side of the frame at 8S 727 from inside the wheelwell.

(i) Airplanes with 60,000 to 70,000 cycles can omit this step only at the initial inspection at 1500 flights after you get this bulletin.

0) Airplanes 

you 

with more than 70,000 cycles can omit this step only at the initial inspection at 500 flights after get this bulletin.

Jun 30/94 ADDENDUM

Page 3 of 6
BOEING SERVICE BULLETIN 737-53A1166

Boeing requests that operators use the following Structural Significant Item (SSI) Reporting System to report any discrepancies that are found in accomplishing a Flight Safety Inspection.

1. Upon recognition of discrepancy, the following information should be telegraphed to Boeing:

Heading: ATTENTION - SSI DISCREPANCY - SERVICE BULLETIN RELATED

- Service Bulletin number

- Airplane serial number on which discrepancy was found

- Identification of structural item found damaged

- Flight cycles and hours on damaged item

- Location and description of damage including direction and size

- When discovered and inspection method used

Send telegram through Boeing Field Service Representative or directly to:

737 Customer Support Engineering

2. An Operators Follow-Up Report containing all available pertinent data, relative to the structural discrepancy, shall be sent to Boeing. A summary of the information that should be reported is shown in the DISCREPANT STRUCTURE REPORT form attached. Operators may use this form or any sutable alternative which contains the same information.

3. All data and reports dealing with the Flight Safety Inspection Program shall be submitted either through a Boeing Field Service Representative or directly to:

The Boeing Commercial Airplane Group P.O. Box 3707

Seattle, Washington 98124-2207, USA

Attn: 707/7271737 Service Engineering Director

Org. M-7201 Mail Stop 2H-84

4. All reports will be reviewed promptly.

5. The Boeing Company will summarize the results of all reported significant data for distribution semi-annually to operators and appropriate Airworthiness Authorities.

Jun 30/94 ADDENDUM

Page 4 of 6
BOEING SERVICE BULLETIN 737-53A1166

DISCREPANT STRUCTURE REPORT SIDE I

I REPORT DATA ATA. iNDEX REPORTINO.

AIRUNE/AGENCY_ - STATION MONTH DAY YEAR -

2 AIRCRAFT DATA MODEL SERIES TAIL NO.

MFG. SERIAL NO. FLIGHT HOURS FLIGHT CYCLES

3 COMPONENT DATA (AS APPLICABLE AND AVAILABLE):

NAME . . . . . . P/N __ _ SIN

IPC/DWG. REF. SRM REF.

COMPLETE THE FOLLOWING IF KNOWN AND DIFFERENT FROM SECTION 2:

COMPONENT FLIGHT HOURS SINCE NEW - SINCE OVERHAUL

COMPONENT FLIGHT HOURS SINCE NEW - SINCE OVERHAUL

4 REPAIR DATA [] PLANNED [] COMPLETED

4A ACTION

4B REFERENCE ASSOCIATED WITH INSPECTION/REPAIR (SPECIFY NO., PAGE. FIGURE. ETC):

S8 AD IPC SRM

MPD OTHER (E.G. SDR. MRR) RSIIA

STRUCTURAL SIGNIFICANT ITEM NO. SERIES 50 NO.

5 SERVICE BULLETINS INCORPORATED IN AREA OF DISCREPANCY

SERVICE BULLETIN APPLICABLE SECTION DATE OF TOTAL FLIGHT HOURS AND NO. OF SERVICE BULLETIN INCORPORATION CYCLESAT INCORPORATION

HOURS FLIGHTS

HOURS FLIGHTS

HOURS - FLIGHTS

6 INSPECTION DATA (COMPLETE KNOWN INFO., CHECKAPPROPRLATE ITEMS FOR DISCREPANT STRUCTURE):

CURRENT INSPECTION INTERVALS (FLIGHTS) CORRESPONDING INSPECTION LEVELS

6A WHEN DISCOVERED 68 INSPECTION LEVEL 6C DETECTION METHOD

0 SCHEOULEOMAINTENANCE [I WALK-AROUND [ VISUAL 0 TAP TEST [ OVERHAUL | GENERAL VISUAL [ MAG. ViSUAL SOUND j UNSCHEDULED ] EXTERNALSURVEIUANCE [DYE PENETRANT SMELL 0 SPECIALIDIRECTED (AD 58...) INTERNALSURVEILLANCE [ ULTRASONIC FEEL SYMPTOM (FUEL/PRESS LEAK..) DETAILED [ LOW X-RAY

0 RELATED FLEET EXPERIENCE SPECIAL FREQUENCY PRESS. LOSS 0 ACCIDENT INVESTIGATION EDDY CURRENT SSID 0 0 HIGH 0SERIES 60 [] SERES 50EDDY FREQUENCY CURRENT

0BORESOOPE

SMAGNETI

PARTICLE

Jun 30/94 ADDENDUM

Page 5 of 6
BOEING SERVICE BULLETIN 737-53A1166

DISCREPANT STRUCTURE REPORT I SIDE 2

7 DISCREPANCY DESCRIPTION:

AttAch sketch, photos and text as required to desicobe defect and specific location. When apIicable give detail. oi associated disaepances on the samre aeaft. reLated expenence wnth this discrepancy on any aircraft, and previous modifcation (s) to the d'sepant sfludure.

7A TYPE OF DISCREPANCY:

|]BENT []CONTAMINATEO nDENTED []LOOSE []WRINKLED BROKEN (]CORRODED [J DETACHED MISSING [ BUCKLED 

BURNED 

[]CRACKED I] IMPROPERLY OUTOF-TOUERANCE U []DEFORMED ADJUSTED STUCK I] [i CLOGGED [J DELAMINATED LEAK [WORN __ -

78 SIE OF DISCREPANCY: D INCHES. OR [ CENTIMETERS

AREA X DEPTH -

CRACK LENGTH INITtALLY DETECTED D DATE -

FINAL MEASUREMENT (IF DIFFERENT) DATE

7C DISCREPANT PART:

[ FRAME/BUUKHEAD 0 SKIN ] JOINT/SPLICE [J PRESSURE BULKHEAD i PLATE/PANEL I] LUG O FRAMEAROUNDOPENING ] CHORD [ WELD WINDOW FORGING ]STRINGER NO. BOND KEELBEAM fiBEAM OPENHOLE ] FLOOR STRUT/BRACE ] FASTENER HOLE ] WING CENTER SECTION [UNK/ROD 1 CUT-OUT WIG DRY-BAY AREACOMPT. LONGERON ACCESS/LIGHTENING HOLE [ SPAR 0 FITTING NOTCHAGROOVE [ RIB I] BRACKETICUP j DISCONTINUITY O LANDING GEAR BEAM [j STOP - ] BASIC MATERIAL ] FLAP TRACK [j FASTENER BUSHING F PAIRING [ PIN O O__ _ _ _ I]_ _ _ _ __ _ _ _

7D LOCATION OF DISCREPANT PART:

GENERAL LOCATION (E.G.. BILGE. UNDER GALLEY)

n BODY STA. NO. DOR/ACCESS PANEL INTERIOR ] EXTERIOR o WING STA NO- RUDDER INBOARD OUTBOARD [ VERT. STAB. STA[ ELEVATOR ULEFT RIGHT [] HOR12STAB.STA [ AILERON FORWARD ] AFT f] NACELLE/PYLON FLAP UPPER L LOWER DNOSE COMPARTMENT 

LANDING GEAR _ _ SLAT LEADING EDGE TRAILING EDGE SPOILER MIDDLE [ SIDE

MAIN LANDING GEAR TAB (ALSO CHECKASOVE) SPECIFIC LOCATION WING LANDING GEAR

BODY LANDING GEAR j

INSPECTIED BY | E~RED BY

ORIGWATEO BYDAI

Jun 30/94 ADDENDUM

Page 6 of 6
D - M n - O Commercial 737 Airplane

Group Service Bulletin

Number 737-53A1168 Date: June 30, 199 Evaluation Form

ATA System: 5311

Prepared By: Maurice Chatwin

SUBJECT: FUSELAGE - FRAMES - BODY STATION 727 OUTBOARD CHORD AT STRINGER 1 8A, INSPECTION AND PREVENTIVE MODIFICATION

Use this evaluation form to tell us what you think of the quality of this service bulletin. We will use the data that you give us to improve the quality of our service bulletins. Please include data about these or other items:

- Did this service bulletin meet your estimate of quality? - How easy is this service bulletin to understand? - Are the Planning Information, Material Information and Accomplishment Instructions satisfactory? - Will you do this service bulletin fully? If not, please tell us why. - Is the Manpower estimate satisfactory?

NOTE: Please do not use this evaluation form to tell us to make changes to your manuals. To make these changes, please use a Publication Change Request (PCR) form.

Please give us this data:

OPERATOR: TODAY'S DATE:

PREPARED BY: TITLE:

ORGANIZATION: TELEX CODE:

TELEPHONE NUMBER:

COMMENTS:

If you have other comments please use the other side. Thank you for the time you used to complete this form.

Give 

directly 

the 

to 

completed evaluation form to your Boeing Field Service Representative or send the evaluation form this address:

T. J. Taylor, Manager Service Bulletin Engineering Boeing Commercial Airplane Group P.O. Box 3707, Mail Stop 2L-02

Seattle, WA 98124-2207

BOEING GOMMERCIALAIRPLANE GROUP P.O. BOX 3707 SEATTLE WASHINGTON 98124-2207 Page 1 of I