rtJ--BDE'NG 

DEC 2009 

747-400 MAINTENANCE PLANNING DATA 

747-400 

MAINTENANCE PLANNING DATA (MPD) DOCUMENT 

SECTION 9 

AIRWORTHINESS LIMITATIONS (AWLs) AND 

CERTIFICATION MAINTENANCE REQUIREMENTS (CMRs) 

D621U400-9 

DECEMBER 2009 

COMPILED AND PUBLISHED BY: 

MAINTENANCE PROGRAMS ENGINEERING 

COMMERCIAL AVIATION SERVICES 

BOEING COMMERCIAL AIRPLANE GROUP 

SEATTLE, WASHINGTON 

D621U40Q·9 

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!j}.-BOE'NG 747-400 MAINTENANCE PLANNING DATA 

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D621 U400-9 

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fJ--.BDE'NG 747-400 MAINTENANCE PLANNING DATA 

TABLE OF CONTENTS 

REVISIONS ..................................... ..................... ..... .. . . ...... 9.0-5 

LIST OF EFFECTIVE PAGES ................... _ .. ............. ... ....... . .. 9.0-17 

A. SCOPE ........................................................ . ........................................................................... . .................................................................... 9.0-19 

B. AIRWORTHINESS LIMITATIONS (AWl S)- SySTEMS ........................................................................................................................................................ 9.0-20 

C. PAGE FORMAT: FUEL SYSTEMS AIRWORTHINESS LIMITATIONS .................................................................................................................................. 9.0-22 

D. AIRWORTHINESS LIMITATIONS - FUEL SYSTEMS .. .............. . . .......................................................................... 9.0-23 

E. AIRWORTHINESS LIMITATIONS - NITROGEN GENERATION SYSTEM TASKS . . ............................................ ...... ................ 9.0-41 

F. AIRWORTHINESS LIMITATIONS (AWLS) - STRUCTURAL INSPECTIONS ............. . . ........ 9.0-45 

G. CERTIFICATION MAINTENANCE REQUIREMENTS (CMRs) ............................... .. . . .................................... .................. . 9.0-47 

H. CERTIFICATION MAINTENANCE REQUIREMENTS TASKS ................................... . . .. 9.0-50 

I. REPORTING UNCONTROLLABLE HIGH THRUST FAILURE CONDITIONS ................ . .9.0-55 

0621 U400-9 

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BDE'NG 747-400 MAINTENANCE PLANNING DATA 

REVISIONS 

APPROVAL 

REVISION AND REVISION DESCRIPTION MANAGER SEATTLE FAA AIRCRAFT 

CERTIFICATION OFFICE, ANM-100S 

Revision 0 - January 1989 D. l. Riggin 

Original Issue 

1Jt:~r Revision 1 - February 1989 O. l. Riggin 

Removed requirements to check for Operative bus between EEC and EIU one flight prior to 150 hour check and 

changed FADEC C2 check from 150 hours 10 500 flight hours. t!713r~ Revision 2 - June 1989 D. L. Riggin 

Added requirements to accomplish a 1000 hour operational test which checks that air conditioni ng pack 3 high tJ.t Ltr' flow mode is disabled with lower lobe cargo compartment conditioned air on. ¥y'!,J Added requirements to interrogate the CMC for engine position 2 turbine overspeed failure message every 

150 hours on RB211 ·524G or RB211·524G2. 

Revised requirements to check engine control system for Category 2 faults to 250 night hours on RB211·524G 

or RB211 ·524G2. 

Revision 3 - June 1989 D. L. Riggin 

Added requirement to Drain PW4000 Gearbox whenever cumulative oil addition totals 12 quarts. jJ ,b'Rt ,/.. . ~y--.- ~I 

Revision 4 • June 1989 D. L. Riggin 

Deleted CMR 22-lssue covered in FAA approved PW4000 Maintenance Manual via P&W Alert Service Bulletin iJf/2,r-r PW4 ENG A79-39. 

D621U400-9 

DEC 2009 BOEING PROPRIETARY - Copyright (c) - Unpublished Work · See title page for details Page 9.0·5 
r{;-HDE'NG 747-400 MAINTENANCE PLANNING DATA 

REVISIONS 

APPROVAL 

REVISION AND REVISION DESCRIPTION MANAGER SEATTLE FAA AIRCRAFT 

CERTIFICATION OFFICE, ANM·100S 

Revision 5 - August 1989 D. L Riggin 

Revised CMR 12 to include in operalionallesllhe E&E Cooling System Bypass Valve. -;:) r ~ 

Revised CMR 13 from an operational lesl of the E&E Cooling System Fan Check Valves to a detail visual u_ .. e'rrinspection of the lIapper doors and hinges. 

Added requirement to adjusVlest the main deck air distribution shutoff valves on the Combi main deck fire 

protection system. 

Revision 6 - February 1991 D. L. Riggin 

Revised CMR 3 RR effectivity to RR RB2 11-S24 Series engines. <;;.~_._t :1!""'h;1' .•. l "'I"" 

Revised CMR 21 RR effectivity to RR RB211-524 series engines and excluded requirement to interrogate CMC 

for engine 2 TOS on RB211 powered 747-400s equipped with EICAS Version RR004. 

Revision 7 - March 1992 D. l. Riggin 

Revised CMR 1 task description 10 Operational (Short) Test - 11 5-Volt Standby Power Generation. .Ae,,»;....u.., r 

Revised CMR 16 to limit applicability to 747-400's equipped with stabilizer fuel capability. 

Deleled CMR 21 because all RB211 powered 747-400s are now equipped with EICAS Software Version RR004 

or a later version. 

Revision 8 - November 1992 D. l. Riggin 

Revised CMR 3to change the 250 FH check for RR RB211 powered 747-400s to 500 FH in accordance with the 

updated Type Certificate Data Sheet (TeDS No. E30NE. Rev date: June 5, 1992). /tKf"'ff'~ f 

Revision 9 - January 1993 D. l. Riggin 

Revised CMR 3to change the 500 FH check for GE CF6-80C2B1F powered 747-4oos to 1000 FH in 

accordance with the FAA approved GE document GEK 98408. Rev. 6, dated September 1992. *~....e&f0621U400-9 

DEC 2009 BOEING PROPRIETARY - Copyright (c) - Unpublished Work - See tille page for details Page 9.0-6 
l?i-SDE'NG 747-400 MAINTENANCE PLANNING DATA 

REVISIONS 

APPROVAL 

REVISION AND REVISION DESCRIPTION MANAGER SEATTLE FAA AIRCRAFT 

CERTIFICATION OFFICE, ANM-100S 

Revision 10 - October 1993 D. L. Riggin 

Revised CMRs 9,10,12, 14, and 1510 exclude the 747-400F due to addition of an E&E cooli ng system self-test 

design feature . 0-j~rg: Revised CMR 18 and 20 to exclude 747-400F model appl icabi lity_ 

Revision 11 - January 1994 D. L. Riggin 

Revised CMR 6 to change the 1000 FH check for the E&E cool ing system override mode function to 20,000 FH 

for the 747-400F. CJL£~ Revised CMR 13 to exclude the 747-400F model applicability. 

Revised CMR 20 to change thel000 FH check 01 the lower lobe cargo compartment conditioned air system to 

7400 Fl-!. 

Added 747-400 CMR-MPDfTask Card correlation list for reference. 

Revision 12 - May 1994 D. L Riggin 

Revised CMR 3 to change the 500 FH check for the PW4000 engine to 1000 FH. :i~l/J- J?"'":rr 

Revision 13 - June 1995 D. L Riggin 

Revised CMR 18to revise the system description to note door #5 is not applicable on 747-400 Combi airplanes f;:t'£~ "4' in the cargo mode and to add a note to the task which specifies check is required immediately after conversion "t' 

to passenger mode. 

Revision 14 - February 1997 D. L Riggin 

Revised CMR 18 to change the interval of part of the functional check procedure relating to the escape slide/raft 

packs from 30 months to 36 months. The remainder of the check retains the interval of 30 months. ;)/;r1tt~ 

0621 U400-9 

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rtJ-aOEING 747-400 MAINTENANCE PLANN ING DATA 

REVISIONS 

APPROVAL 

REVISION AND REVISION DESCRIPTION MANAGER SEATTLE FAA AIRCRAFT 

CERTIFICATION OFFICE, ANM-100S 

Revision 15 - May 1998 D. L. Riggin 

Revised CMR 3 to change the 1000 FH check for GE CF6-80C2B1F powered 747-400'5 to 2000 FH in , "'/d 

accordance with the FAA approved GE document GEK 98408, Rev 10, dated March 1996. V f- , c<~ I 

Revised CMR 3 to change the 500 FH check for RR RB21 1 powered 747-400'5 to 560 FH in accordance with , 

, 

the updated Type Certificated Data Sheet (TeDS No. E30NE). 

Revision 16 - July 200 1 Liu-Nelson 

Revised CMR 88 to change the intelVal from 6000 FH to 10,000 FH based on revised High lifl System fault ).,: "!. !' ~ "---

tree analysis. ~ .,-

Revised CMR 9 and 10 to exclude 747-400F model applicability since the freighter airplane has the EfE Cooling 

automatic system self test which occurs every tenth landing. 

Revision 17 - September 2002 Liu-Nelson 

Added requirements to replace door strike assembly at four-year intervals. 

f~ ,;.~ \ Q.,e, ... - > 

\ r.,.- ,'"u.> 

'S'/t.'I· ~ 

Revision 18 - October 2002 Liu-Nelson 

Added CMR 25 applicable only to airplanes incorporating any of Ihese Boeing Service Bulletins 747-25-3306 

andlor 747-25-3312. This amended type certificate complies with the new 14 CFR 25.795 and the amended " .1UL. ' 14 CFR 25.772 as issued under Federal Register Docket No. FAA-2001-11 032. \ Io(~/~ 

Revision 19 - February 2003 Liu-Nelson 

Added CMR 26 applicable for line numbers 1320 and on except freighter models. This amended type certificale 

complies with the new 14 CFR 25.795 and the amended 14 CFR 25.772 as issued under Federal Register I 

~ :C'--

Docket No. FAA-2001 ·1 1032. ~A- ,.. ~JI<IIJ. 

D621U400-9 

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(I)..J~OE'NG 747-400 MAINTENANCE PLANNING DATA 

REVISIONS 

APPROVAL 

REVISION AND REVISION DESCRIPTION MANAGER SEATTLE FAA AIRCRAFT 

CERTIFICATION OFFICE, ANM-100S ; 

Revision 20 • March 2005 Jeffrey Duven , 

Revised the format of MPD Section 910 include the 747-400 Maintenance Planning Data (MPD) task references 

fjII'"'f£ Q ~.~ alongside each CMR task. 

Added standalone list of Effective Pages (LEP) to document. 

Added MPD Task Reference 52-051-08 to CMRs #24, #25 and #26. 0 4/0;-

Revised MPD Item Numbers to renect new ilem numbers as a result of transition to a new maintenance 

documentation publishing system. 

Revision 21 - August 2005 

Revised MPD Section 9 to add Airworthiness limitations section. 

Added Nitrogen Generation System AWL and COCeL. ~t ... l_Ll 

Revised Scope and CMR description section to explain and clarify. *1/'15 

Revision 22 • September 2005 Jeffrey Duven 

Revised MPD Section 9 to add Airworthiness Limitations Structures Inspection note for 

Revised 

747·400 

Ce

Specia

rtifica

l Freigh

tion Ma

ter. 

intenance Requirements section to reflect 747·400 Special Freighter incorporation. g~E~ Revised MPD item number for CMR 8 and 20 to correct reference. U/9/or 

Revi sed CMR 18, Note 2 to specify that the task be accomplished at 30 months rather than 36, whereas the 

remainder of the procedure can be performed at 36 months rather than 30. Revised procedure reference to 

remove E19 reference no longer required. 

D621 U400·9 

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rti-0DEfN& 747-400 MAINTENANCE PLANNING DATA 

REVISIONS 

APPROVAL 

REVISION AND REVISION DESCRIPTION MANAGER SEATTLE FAA AIRCRAFT 

CERTIFICATION OFFICE, ANM-100S 

Revision 23 • March 2006 A. J. Pasion 

Added new Fuel System Airworth iness limitations which include inspections and design limitations to satisfy 

~~ SFAR88 requirements. 

Revised AilWorthiness limitation 47-AWL-Ol to add missing Step 3, and AWL 47-AWL-03 to correct 

ATA reference. 

3/~ I/Oh Revised CMR 10 AMM reference from 21-058-02 to 21-058-00 to correci reference. 

Revised CMR 20 MPD lIem Number from 21-028-01 to 21-028-00 to correct reference. 

Revision 24 - June 2006 Jeffrey Duven 

Revised lasks 47-AWl -Ol, 47-AWL-02, 47-AWL-03, 47-AWL-04 , 47-AWL-05, 47-AWL-06 to correct airplane 

Revised 

applicabi

bonding meaSurements. 

28-AWL-9 

lity, 

and 28-AWl-10 to clarify the intent of the inspection and to clarify the location of the /

'/I 7 ,/ ~ 

'7/2 '7/0 6 Deleted 28-AWl-21, because production incorporation and service bulletin release have been postponed 

indefinitely. 

Added 28-AWL·24 which mandates an inspection for th e horizontal stabilizer fuel boost pump auto 

shutoff system, 

Added new reserve tank fueling valve COCCl AWL Number 28·AWl·25, 

Revised 47-AWl-05 and 47-AWl·06 to add Interval Note. 

November 2006 Jeffrey Duven 

Added a new operational check of the Main 2 and Main 3 override/jettison fuel pump uncommanded on system 

AWL Number AWL 28-AWL-26. 'DfMn;~ 

f" 

D621U400-9 

DEC 2009 BOEING PROPRIETARY - Copyright (c) - Unpublished Work - See title page for details Page 9.0-10 
rti-BOE'NG 747-400 MAINTENANCE PLANN ING DATA 

REVISIONS 

APPROVAL 

REVISION AND REVISION DESCRIPTION MANAGER SEATTLE FAA AIRCRAFT 

CERTIFICATION OFFICE, ANM-100S 

December 2006 Jeffrey Duven 

Revised CMR-24. CMR-25. and CMR-26 intervals from 4 years to 6 years to renect improved reliabil ity data for 

the Flight Deck Door Strike Assembly. 

~L6~ lG c.~"''1 ~ e.,~' 

December 2006 R1 Jeffrey Duven 

Revised to add Airworthiness limitation Structures Inspection Note for 747-400 large Cargo Freighter (lCF). 

~y~4O- Revised CMRs 15, 16, 20. 23. 24. 25, 26 to exclude 747-400 LCF derivative. Revised CMR 2 to exclude cargo 

and APU fire/overheat detection system for 747-400 LCF. Revised CMR 18 to -only applicable to door 1 UH- for 

747-400 lCF. 

In Paragraph 1 of Section F, changed reference to 747 Supplemental Slruclural lnspeclion Document, 06-

35022, Revision H 10 Revision G due to unknown release date for Revision H. 

Revised Airworthiness Limitations-fuel system section introduction to include revisions recommended by the 

Seattle FAA Flight Standards group. 

Revised airworthiness limitation number 28-AWL-24 to correct AMM procedure number from 28-22-00 to 

28-17-00 and to revise line number in the applicability column from 1342 to 1343. 

Added Motor Opera ted Valve actuator Airworthiness Limitation. This AWL is applicable to airplane Line Position 

1382 and on, and airplanes modified per Service Bulletins 747-28A2292. and 747-28A2294. 

May 2007 Jeffrey Ouven 

Added new CMR 27 10 periorm a functional check of the ReseNe Tank 2 and 3 VTO Secondary Shut-off System 

for the 747·400 Large Cargo Freighter (LCF). fj¥h~ (0.-. 

0621U400-9 

DEC 2009 BOEING PROPRIETARY - Copyrighl (c) • Unpublished Work - See title page for details Page 9.0-1 1 
rzi-HDEfNC 747-400 MAINTENANCE PLANNING DATA 

REVISIONS 

APPROVAL 

REVISION AND REVISION DESCRIPTION MANAGER SEATTLE FAA AIRCRAFT 

CERTIFICATION OFFICE, ANM-100S 

October 2007 Dorr Anderson for Jeffrey Duven 

Revised Section B. Airworthiness Limitations (AWLs)· Systems paragraph on Exceptional Short-Term 

Extensions for AWLs to clarify notification requiremenls. 

Revised 

' Page Format: 

the litle 

Fue

of 

l 

Sect

Tank 

ion 

System 

C to read 

Airworlh

"Page 

iness 

Forma

limitatio

t: Fuel 

n

Systems 

". 

Airworthiness Limitations ~ instead of '[j"" Vtf ~ 

Revised AWL Number 28·AWL·1 9 to add Ground Faull Interrupter (GFI) relays to the limitation thai restricts 

resetting of fuel pump circuit breakers. 

Add ed AWL Number 28·AWL·28, a yearly check of the Main Fuel Tank Boost Pump GFI, applicable to airplane 

Line Numbers 1394 and on and airplanes thai have incorporated Service Bulletin 747·28A2261. 

Added AWL Number 28-AWL-29, a yearly check of the Center Wing Tank Electric Scavenge Pump GFI, 

applicable to airplanes with Electric Center Wing Tank Scavenge Systems, airplanes prior to Line Numbers 972 

that have incorporated Service Bulletin 747-2BA2261. 

Added Section G Certification Maintenance Requirements (CMRs) - Exception Short· Term Extensions to clarify 

notification requirements. 

Revised CMR-24, CMR-25 and CMR-26 task interval from 6 years to 9 years to reflect improved reliability data 

for the Flight Deck Security Door. 

Added Paragraph "I" to incorporate "Reporting Uncontrolled High Thrust Failure Conditions" per FAR 121.703 

and FAR 135.415. 

November 2007 Philip Forde for Jeffrey Duven 

Revised 28-AWL-25 bonding resistance value from 0.015 ohms to 0.001 5 ohms to correct a typo. 

S~ (The correct value is 1.5 milliohms). 

Revised CMR-27 to include Main Fuel Tanks 1 and 4 in VTO secondary shut-off system task for the 747-400 

Large Cargo Freighter. 

~~ZL 

D621U400-9 

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fJ-aOE'NG 747-400 MAINTENANCE PLANNING DATA 

REVISIONS 

APPROVAL 

REVISION AND REVISION DESCRIPTION MANAGER SEATTLE FAA AIRCRAFT 

CERTIFICATION OFFICE, ANM-l0DS 

FEBRUARY 2008 Robert Breneman for Jeffrey Duven 

Revised Paragraph F. AIRWORTHINESS LIMITATIONS (AWLs)· STRUCTURAL INSPECTIONS \0 add L restriction for 747-400 Special Freighters delivered after January 11, 2008, 

v I'O~ 

MARCH 2008 Dorr Anderson for Jeffrey Duven 

Revised Paragraph F. AIRWORTHINESS LIMITATIONS (AWl s) - STRUCTURAL INSPECTIONS to add 

restriction 

December 

for 

1, 

747-400 

200710 May 

Large 

30, 

Car

2008 

go Fre

and add 

ighter 

the 

(LCF) 

text-appendix

delivered after 

" per 

Janu

FAA 

ary 

lette

11

r 

,

dated 

2008 and 

July 

to 

16, 

change 

2007. 

end date of i!P"",}I17 ~ 

Revised 2a-AWL-01 by removing the 36000FH task inteNallimitation based upon engineering review and 3//1/08 

operator maintenance practice. 

Revised 28-AWl-03 to reflect the new maximum loop resistance values associated with the lightning protection 

of the unpressurized FalS wire bundle installations so as to satisfy the Airworthiness limitation Instructions 

required by SFAR 88. Also removed the joint resistance values and 36000FH task interval limitation based upon 

engineering review and operator maintenance practice. 

Revised 28-AWl-1D by removing the 36000FH task interval limitation based upon engineering review and 

operator maintenance practice. 

Revised 28-AWl·16 to change the term "grease" to "Corrosion Inhibiting Compound (CIC)" in Step 2 to reflect 

correct consumable type. 

Added AWls 28·AWl-3D, 28·AWl·31 , and 28·AWl·32 to add the Electronic Fuel levellndicalion System 

(EFLt) CoCel requirement for the 747-400 (910K). 

0621U400·9 

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!l1-DDE'NC 747-400 MAINTENANCE PLANNING DATA 

REVISIONS 

APPROVAL 

REVISION AND REVISION DESCRIPTION MANAGER SEATTLE FAA AIRCRAFT 

CERTIFICATION OFFICE, ANM-100S 

APRIL 2008 Philip Forde for Jeffrey Duven 

Revised the Procedure Reference for CMR 27 to remove incorrect Task number and reflect the correct Page 

Block number. I , 9/ 1.. L. It/Ie 

f\,,'JiV 

MARCH 2009 Jeffrey Duven 

Revised Paragraph E , AIRWORTHINESS LIMITATIONS (AWLs) * STRUCTURAL INSPECTIONS to remove 

opera

Supplemental 

compliance 

tional l

to 

im

S

14 

its 

tru

on 

CFR 

ctu

7

r

4

a

§ 

7-

l I

26

4

ns

00 

.

p

45 

ec

airplanes 

(c

tio

)

n 

, and 

Document, 

converted 

confer standards 

06-35022. 

to the Special 

for continued 

Freight

comp

er config

liance 

urat

to 

io

the 

n. as 

sp

es

eci

tablis

ficatio

hed 

ns of 

for 

747 ~J~ ;e;;tL SH7 

~}~o~ 

--- .. __ .. _-----

DECEMBER 2009 

Revised 28-AWL-03 by adding maximum loop resistance values, associated with the lightning protection of the 

FQtS wire bundle installations. specific to the 747-400 LCF derivative. Also specified that the existing va lues are 

appl icable to all 747-400 airplanes except 747-400 LCF. and clarified the wire bundle references as supplier part 

numbers. Also added conditional dependency of installation for resistance measurements of Connectors SIGNATURE ON FILE X01014 and X01015, and listed additional wire bundles associated with Connector X01 014. 

1/1212010 

Revised 28-AWl-11 to clarify component of concern as FOtS processor unit and identify the component 

manufacturer (Goodrich). 

Revised 28-AWL-12. 2B-AWl-13, 2B-AWl-1B, and 2B-AWl-32 to identify the component manuracturers. 

(Continued on next page) 

0621U400-9 

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Il'J.-HOEING 747-400 MAINTENANCE PLANNING DATA 

REVISIONS 

APPROVAL 

REVISION AND REVISION DESCRIPTION MANAGER SEATTLE FAA AIRCRAFT 

CERTIFICATION OFFICE, ANM·100S 

DECEMBER 2009, Continued 

Revised 28-AWL-14 to identify the component manufacturer (Goodrich) and correcl Revision identification for 

Component Maintenance ManuaI 2S-40-59 from ~ to ·E . 

Revised 28-AWL-20 by adding note sialing Ihallhe maintenance requirements are only applicable to areas that 

have been disturbed. Also clarified airplane applicability. 

Revised 28-AWL-22 by changing terminology in item references from "bonding strap" to "bonding jumper" to 

clarify the item of concern. 

Revised 2B-AWL-23 by changing terminology in item references from "bonding strap" to "bonding jumper" to 

clarify the item of concern. Also corrected resistance limit from 0.25 milliohms to 2.5 milliohms and clarified 

airplane applicability. 

Revised 28-AWL-24 to nole conditional dependency of Horizontal Stabilizer Fuel Boost Pump Automatic Shutoff 

System installation for AWL applicability. Also clarified airplane applicability. 

Revised 28-AWL-31 to correct spelling of the acronym for Electronic Fuel Level Indication System (EFLI) and 

identify the component manufacturer (Parker). 

Revised 28-AWL-05. 28-AWL-25, 28-AWL-26, 2B-AWL-27, and 26-AWL-28to clarify the airplane applicability. 

Revised Section F., AIRWORTHINESS LIMITATIONS (AWLs) - STRUCTURAL INSPECTIONS to include notice 

of the additional and revised inspection requirements for 747-400 Large Cargo Freighter (LCF) airplanes 

imposed by Service Bullelins 747-00-2120 and 747-53A2817, respectively; updated the document reference for 

the 747-400 LCF Supplemental Structural Inspection Document, and removed operational limits on 747-400 

LCF airplanes delivered after January 11, 2008, originally established for compliance to 14 CFR § 26.45 (c). 

0621U400-9 

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LIST OF EFFECTIVE PAGES 

Section Page Date Section Page Dale Section Page Date Section Page Dale Section Page Date 

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fl-OOEING 747-400 MAINTENANCE PLANNING DATA 

A. SCOPE 

The scheduled maintenance requirements described in this section result from Model 747-400 airplane certification activities with the U.S. Federal Aviation 

Administration (FAA). Accordingly, this FAA approved Airworthiness Limitations (AWLs) and Certification Maintenance Requirements (CMRs) document is 

cross-referenced in the Model 747-400 Type Certificate Data Sheet. These maintenance actions are mandatory. 

This Airworthiness Limitations Section is FAA-approved and specifies maintenance required under 43.16 and 91.403 of the Federal Aviation Regu lations. 

unless an alternative program has been FAA approved. 

AIRWORTHINESS LIMITATIONS (AWLs) 

The Airworthiness Limitations may only be revised with the approval of the Seattle FAA Aircraft Certification Office (ACO). 

If the inspections cannot be accomplished due to repairs and/or modifications, an alternate inspeclion acceptable to the Seattle FAA ACO must be used. 

CERTIFICATION MAINTENANCE REQUIREMENTS (CMRs) 

These scheduled maintenance tasks may only be revised by the Seattle FAA ACO. Principal Airworthiness Inspectors (local regulatory authority) may not 

change these requirements or the intervals associated with these requirements. 

D621U40Q-9 

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~DEINC 747-400 MAINTENANCE PLANNING DATA 

B. AIRWORTHINESS LIMITATIONS (AWLs) - SYSTEMS 

AIRWORTHINESS LIMITATIONS - FUEL SYSTEMS 

This section contains an FAA. approved program of Airworthiness Limitations (AWLs) for operators to incorporate into their maintenance program for Ihis 

type design. There are two sets of AWLs in this section; the first secHon is to meet the new standards and assumptions introduced by § 25.981 and 

Special Federal Aviation Regulation SFAR No. 88, and the second section is to meellhe requirements for [he introduction of the Nitrogen Generation 

System (NGS). An AWL may be an Airworth iness limitation Instruction (AU) or a Critical Oesign Configuration Conlrollimilation (GOCeL). 

CDCCLs are a means of identirying certain design configuration features intended to prectude a fuel tank ignition source for the operational life of the 

airplane, GDCCLs are mandatory and cannot be changed or deleted without the approval of the Seattle FAA AGO or applicable regulatory agency. A 

critical fuel tank ignition source prevention feature may exist in the fuel system and its related installation or in systems that, if a failure condition were to 

develop, could interact with the fuel system in such a way that an unsafe condition would develop without this limitation. Strict adherence to configuration, 

methods, techniques, and practices as prescribed is required to ensure compliance with the GOGGL. Any use of parts, methods, techniques or practices 

not contained in the applicable COCCl must be approved by the Seattle FAA ACO or applicable regulatory agency. 

AUs identify inspection tasks related to fuel tank ignition source prevention which must be done to maintain the design level of safety for the operational 

life of the airplane. These AUs are mandatory and cannot be changed or deleted without the approval of the Seattle FAA ACO or applicable regulatory 

agency. Strict adherence to methods, techniques and practices as prescribed is required to ensure the All is complied with. Any use of methods. 

techniques or practices not contained in these Alis must be approved by the Seattle FAA ACO or applicable regulatory agency. 

USE OF ALTERNATE TOOLS 

For AWlslCDCGLs which require use of certain tools, use of alternate tools requires prior approval from the Seattle FAA AGO. 

0621U400-9 

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!li-DDE'NG 747-400 MAINTENANCE PLANNING DATA 

DEVIATIONS FROM CMM OR AMM INSTRUCTIONS 

Any deviation from the Boeing published AMM Instructions or supplier CMM referenced within this section require prior approval from the Seattle 

FMACO. 

EXCEPTIONAL SHORT-TERM EXTENSIONS FOR AWLs 

Since AWL intervals are based on estimations of the probability of an event, an exceptional short-term extension for each fuel system AWL lis led in Ihis 

document may be made without jeopardizing safely. The local regulatory authorily (e.g. a Principal Maintenance Inspector) must concur with any 

exceptional short-term extensions before they take place using procedures established with the local regulatory authority in the operators' manuals. The 

"exceptional shorl-term extension" process is applicable to AWL intervals. It should not be confused with the operator's "shari-term escalation" program 

for normal maintenance tasks described in the operators' manuals and in the Flight Standards Handbook 8300.10. 

The Seattle FAA AGO has accepted that these exceptional short-term extensions may be granted without consultation with that office: 

1. The term "exceptional short-term extension" is defined as an increase in a fuel system AWL interval that may be needed to cover an uncontrollable or 

unexpected situation. All AWLs listed in this section have been approved with an exceptional short-term extension of 30 days. 

2. Repeated use of extensions, either on the same airplane or on similar airplanes in an operator's fleet, should not be used as a substitute for good 

management practices. Exceptional short-term extensions must not be used for fleet AWL extensions. 

After a fuel system AWL has experienced an exceptional shorl-term extension, the AWL interval will revert back to its interval listed in this document. The 

Seattle FAA ACO must approve, prior to its use, any desired extension not explicitly listed above. 

This exceptional short-term extension listed above applies to airlines that fall under the United States FAA jurisdiction only. Operators who are not under 

the U.S. FAA jurisdiction should obtain interval extension approvals from their local regulatory agency. 

AWL REVISION PROCESS 

In the event that an AWL is revised, Boeing will document it by preparing a revision to this document that will be approved by the Seattle FAA ACO. This 

revision will then be forwarded to all 747-400 operators and the Seattle FAA ACO offices. 

D621 U400-9 

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fl-SDE'NG 747-400 MAINTENANCE PLANNING DATA 

C. PAGE FORMAT: FUEL SYSTEMS AIRWORTHINESS LIMITATIONS 

COLUMN 

AWL NUMBER 

TASK 

INTERVAL 

APPLICABILITY 

DESCRIPTION 

OCT 2007 

EXPLANATION 

Each task is given a unique AWL Item Number. The first and second digits are the AlA Chapter Number. 

All = Airworth iness limitation Instruction. These tasks are inspections that should be performed al the listed intervals. 

COCel = Critical Design Configuration Controllimilalions 

Task frequencies are specified in terms of a usage parameter such as flight hours, cycles or calendar time. 

Airplane model applicability. 

Description of the task to be performed or critical design configurations aspects that cannot be changed without violating 

the intent of the design. 

0621 U400-9 

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rp...a0E'NG 747-400 MAINTENANCE PLANNING DATA 

D. AIRWORTHINESS LIMITATIONS - FUEL SYSTEMS 

The following lisl of AWLs contains FAA approved scheduled inspections for operators to incorporate into their maintenance program for this type design 

to meet the new standards and assumptions introduced by § 25.981 and Special Federal Aviation Regulation (SFAR) No. 88. SFAR 88 - Fuel Tank 

System Faull Tolerance Evaluation Requirements and Title 14 Code of Federal Regulations § 25.981 - Fuel Tank Igni\ion Prevention require maintenance 

instructions, and controllirnilations for certain fuel tank critical design configurations. 

Paragraph 2(a) of SFAR 88 and Paragraph (b) of the new standard introduced by § 25.981 require certain design approval holders of Type Certificates 

(TCs) and Supplemental Type Certificates (STCs) of large transport airplanes to conduct a safety review of the fuel tank systems. The purpose of the 

safety review is to identify design features that may result in development of ignition sources in the fuel tank systems. Fuel System Airworthiness 

Limitation Items (AWls) are mandatory maintenance actions required to ensure that unsafe conditions identified by the safety review do not occur or are 

not introduced into the fuel tank system as a result of configuration changes, repairs, alterations, or deficiencies in the maintenance program throughout 

the operational life of the airplane. 

0621 U400-9 

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rti-HDE'NG 747-400 MAINTENANCE PLANNING DATA 

AWL Number Tas k Interval Applic ability Description 

28-AWL-Ol ALI 12 YRS ALL External Wires Over Center Fuel Tank 

Concern: Potential for chafing and arcing through center Fuel Tank Upper Panel. 

Perform a detailed inspection of the bundles rouled on main deck over the center fuel tank and 

under the main deck floor boards per Boeing AMM 28-11-00 to detect damaged or loose 

clamps, wire chafing, and thai the wire bundle is not in contact with the surface of the center 

fuel lank. If discrepancies are found, ensure wires are installed per the applicable wire 

installation drawings and repair per the Boeing Standard Wiring Practices Manual 06-54446. 

28-AWL-02 CDCel N/A ALL External Wires Over Center Fuel Tank 

Concern: Potential for wire chafing and arcing to center Fuel Tank Upper Panel. 

If any maintenance is performed in the area under the main deck noor boards and over the 

center fuel tank, verify the following: 

1. Maintain the existing wire bundle routing and clamping. 

2. Installation of any new wire bundles must be per Boeing Standard Wiring Practices 

Manual 06-54446. 

3. All wire bundles over the center fuel tank are inspected per 28-AWL-01 . 

0621 U400-9 

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YJ--DDEfNG 747-400 MAINTENANCE PLANNING DATA 

AWL Number Task Inte rva l Applicability Descriptio n 

28-AWl-03 ALI 12 YRS ALL Fuel Quantity Indicating System (FQIS) - Out Of Tank Wiring Lightning Shield to 

Ground Termination 

Concern: Potential for Lightning induced voltages on the FQrS wiring to enter the fuel tank. 

Perform the following inspection to ensure the functional integrity of the FQIS wiring shield to 

ground termination per Boeing AMM 5-55-54: 

1. Visually inspect all connectors at the location being tested to ensure they are tight. This 

includes connector plugs and backshells. 

2. Use a Loop Resistance Tesler, PIN 906-10246-2 or 906-10246-3, to measure and 

verify the resistance of the shield to ground termination for the following items: 

The following applies to all 747-400 except 747-400 Large Cargo Freighter (LCF) 

Major Design Change: 

The loop resistance shall not exceed 40 mi!liohms for Connector X01021 and the wire 

bundle supplier part number CN1036-151(Wing LE UH Densitometer Main 1). 

The loop resistance shall not exceed 40 milliohms for Connector X01025 and the wire 

bundle supplier part number CN1 036-152 (Wing LE l/H Densitometer Main 2). 

The loop resistance shall not exceed 40 milliohms for Connector X01031 and the wire 

bundle supplier part number CN1036-152 or -172 (Wing LE RlH Densitometer Main 3). 

The loop resistance shall not exceed 40 milliohms for Connector X01037 and the wire 

bundle supplier part number CN1 036-151 or -171 (Wing LE RlH Densitometer Main 4). 

The loop resistance shall not exceed 40 milliohms for Connector X01019 and the wire 

bundle supplier part number CN1 036-116 or -316 (Wing LE UH Main Tank 1). 

The loop resistance shall not exceed 40 milliohms for Connector X01023 and the wire 

bundle supplier part number CN1 036-117 or -317 (Wing LE UH Main Tank 2). 

The loop resistance shall not exceed 40 milliohms for Connector X01030 and the wire 

bundle supplier part number CN1036-117, -317 or -327 (Wing LE R/H Main Tank 3). 

The loop resistance shall not exceed 40 milliohms for Connector X01036 and the wire 

bundle supplier part number CN1036-116. -316 or -326 (Wing lE R/H Main Tank4). 

The loop resistance shall not exceed 40 milliohms for Connector X01028 and the wire 

bundle supplier part number CN1036-111 or -113 (Wing LE UH Main 2 Single Point 

Sensor). 

The loop resistance shall not exceed 40 milliohms for Connector X01034 and the wire 

bundle supplier part number CN1 036-111 (Wing LE R/H Main 3 Single Point Sensor). 

(Continued on next page) 

0621 U400-9 

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((;J .. J IDE'NG 747-400 MAINTENANCE PLANNING DATA 

AWL Number Task Interval Applicability Descri pti on 

28-AWL-03 ALI 12 YRS ALL Fuel Quantity Indicating System (FOIS) - Out Of Tank Wiring Lightning Shield to 

(Continued) Ground Termination (Continued) 

The loop resistance shall not exceed 40 milliohms for Connector X0100B and the wire 

bundle supplier part number eN 1 036-118, -318 or -518 (Center Wing Tank). 

The loop resistance shall not exceed 40 milliohms for Connector X01012 and the wire 

bundle supplier part number CN1036-112 or -312 (Center Tank Single Point Sensor). 

The loop resistance shall not exceed 40 milliohms for Connector X01009 and the wire 

bundle supplier part number CN1036-153 or -353 (Center Tank Densitometer). 

The loop resistance shall not exceed 40 milliohms for Connector X01040 and the wire 

bundle supplier part number CN1036-115, ·315 or -325 (Wing LE UH Reserve Tank 2). 

The loop resistance shall not exceed 40 milliohms for Connector X01042 and the wire 

bund!e supp!ier part number CN1036-115. ·315 or 325 (Wing LE RfH Reserve Tank 3). 

The !oop resistance sha!! not exceed 61 milliohms for Connector X01015 and the wire 

bundle supplier part number CN1036-154, -354 or -554 (Horizontal Stab Densitometer, 

if installed). 

The loop resistance shall not exceed 59 milliohms for Connector X01014 and the wire 

bundle supplier part number CN1036-119. -319. -519 or -719 (Horizontal Stab Fuel Tank, 

if installed). 

The fo llowing appl ies only to 747-400 Large Cargo Freighter (l CF) Majo r Design 

Change: 

The loop resistance shall not exceed 24 milliohms for Connector X01021 and the wire 

bundle supplier part number CN1036-351{Wing LE LfH Densitometer Main 1). 

The loop resistance shall not exceed 22 milliohms for Connector X01025 and the wire 

bundle supplier part number CN1036-352 (Wing LE LfH Densitometer Main 2). 

The loop resistance shall not exceed 22 milliohms for Connector X01Q31 and the wire 

bundle supplier part number CN1036-355 (Wing LE RfH Densitometer Main 3). 

The loop resistance shall not exceed 24 milliohms for Connector X01037 and the wire 

bundle supplier part number CN1036-356 (Wing LE RfH Densitometer Main 4). 

The loop resistance shall not exceed 17 milliohms for Connector X01019 and the wire 

bundle supplier part number CN1036-S16 (Wing LE LlH Main Tank 1). 

The loop resistance shall not exceed 15 milliohms for Connector X01023 and the wire 

bundle supplier part number CN1036-517 (Wing LE LlH Main Tank 2). 

(Continued on next page) 

D621U400-9 

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f). .. J!i'DEfNG 747-400 MAINTENANCE PLANNING DATA 

AWL Number Task Interval Applicability Descri ption 

28-AWl-03 ALI 12 YRS ALL Fuel Quantity Indicating System (FOtS) - Out Of Tank Wiring lightning Shield to 

(Continued) Ground Termination (Continued) 

The loop resistance shall not exceed 29 milliohms for Connector X0100B and the wire 

bundle supplier part number CN1036-718 (Center Wing Tank). 

The loop resistance shall not exceed 15 milliohms for Connector XQ1030 and the wire 

bundle supplier part number CN1036-522 (Wing LE RlH Main Tank 3). 

The loop resistance shall not exceed 17 milliohms for Connector X01036 and the wire 

bundle supplier part number CN1036-S21 (Wing LE RlH Main Tank 4). 

The loop resistance shan not exceed 34 miHiohms for Connector XQ1028 and the wire 

bundle suppl ier part number CN1036-31 1 (Wing l E UH Main 2 Single Point Sensor). 

The loop resistance shall not exceed 34 milliohms for Connector X01034 and the wire 

bundle supplier part number CN1036·313 (Wing lE R/H Main 3 Single Point Sensor). 

The loop resistance shall not exceed 27 milliohms for Connector X01009 and the wire 

bundle supplier part number CN1036-557 (Center Tank Densitometer). 

The loop resistance shall not exceed 28 milliohms for Connector X01040 and the wire 

bundle supplier part number CN1036-515 (Wing lE LlH Reserve Tank 2). 

The loop resistance shall not exceed 28 milliohms for Connector X01042 and the wire 

bundle supplier part number CN1036·520 (Wing lE RlH Reserve Tank 3). 

28-AWl-04 CDCCl NfA ALL FQIS - Out Of Tank Wiring Lightning Shield to Ground Termination 

Concern: Potential for l ightning induced voltages on the FQIS wiring to enter the fuel tank. 

If any maintenance is performed on the FQIS wire bundle in the un-pressurized zone at the 

spar pressure seal, verify the following: 

1. Verify presence of shielded wiring. 

2. Verify the shield ground is terminated per Boeing SWPM 20-10-15. 

3. The installation is checked per 28-AWl -03. 

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r;;J.-aDEING 747-400 MAINTENANCE PLANNING DATA 

AWL Number Task Interval Applicability Description 

28-AWL-05 COCeL N/A 747-400 airplanes Lightning Protection - Hydraulic Line Fuel Tank Penetration 

Line Numbers 1272 Concern: Potential for arcing or sparking inside the tan k at the interface between the bulkhead and on; 

or airplanes that fitling and th e spar during a lightning strike event. 

have incorporated The following design features must be maintained per Boeing AMM 29-11-22. If the bulkhead 

Service Bulletin fitting is removed and replaced: 

747-29A2104. 1. Verify electrical fay surface bond between the hydraulic fitting flange and the spar must 

be 0.001 ohms or less. 

2. Inslall fillet seal on the fitting to the tank wall interface ou tside the tank. 

3. Install full bodied fillet seal encapsulating the filting to the tank wall interface inside 

the tank. 

4. Verify an electrostatic bonding jumper exists between the structure and the Hydraulic 

Heat Exchanger inside the tank . 

S. Verify electrical bond from structure to the Hydraulic Heat Exchanger inside the tank is 

0.005 ohms or less. 

28-AWL-06 CDCCL N/A ALL AC Pump and DC Pump Maintenance 

Concern: Potential for maintenance error during pump overhaul. Fuel pump designs contain 

ignition source prevention means (i.e., flame arrestor, thermal fuses, materials, leadwire 

retention means, etc.) that must be maintained if pump is overhauled. 

Repair and overhaul of Fuel Pumps must be per the current manufacturer Component 

Maintenance Manual (CMM) Numbers 28-22-07 Revision Number 1, 28-31 -03 Revision 

Number 3, 28-26-12 Revision Number 0, 28-26-14 Revision Number 0, 28-20-02 Revision 

Number 9, or later revisions of these CMM s that have been approved by the Seattle FAA ACO. 

28-AWL-07 CDCCl N/A ALL lightning, Fault Current or Hot Short Protection - Fuel Tank Penetrations 

Concern: Potential for arcing or sparking inside the tank at a conductive metal-to-ground 

structure interlace as a result of electrical fault currents or lightning strike events due to 

insufficient bonding within the ground electrical path. 

Addition of any new penetrations to the fuel tanks (such as adding a bracket or bulkhead fitting 

or equipment) or change to the design features of the existing equipment penetrations (such as 

fuel measuring sticks. sump drain va lves, fueling manifold, fuel temperature sensor, and motor 

operated fuel shutoff valve adaptor plate) requires approval by the Seattle FAA ACO. 

D621U400-g 

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I{J-DDE'NG 747-400 MAINTENANCE PLANNING DATA 

AWL Number Task Interval Appli cability Description 

28-AWL-08 COCCl NfA All Fuel Quantity Indicating System (FOIS) - Oul Of Tank Wiring Installation Separation 

Requirement 

Concern: Potential for hot shorts and EMI induced voltages on the FQIS wiring outside of the 

lank to enter the fuel tank. 

Routing and installation of any new wiring must use wire types BMS 13-48, BMS 13-60 or 

8MS 13 58, and not be with in a 2-inch radius of the FQIS wiring. When a single clamp fails, a 

separation greater than Y. inch must be maintained from FQIS wiring. 

28-AWL-09 COCel NfA All Center Wing Tank Fueling Valve-Fault Current Bond 

Concern: Potential for arcing or filament heating inside the center wing fuel tank. 

The following design features must be maintained per Boeing AMM 28-21 -1 3 when the center 

wing tank fueling valve is removed and replaced: 

1. Bonding jumper between the valve body and structure inside the tank. 

2. Measure the resistance from the valve body to the adjacent structure. Resistance 

must be 0.010 ohms (10 milliohms) or less. 

The following design features must be maintained per Boeing AMM 28-21 -02 when the center 

wing tank refuel valve control unit is removed and replaced: 

1. The bonding resistance from the exposed threads on the valve unit mounting stud 

(one location). to the refuel valve control unit AND the bonding resistance from the 

exposed threads on the valve unit mounting stud (one location). to structure (spar) 

must not be more than 0.010 ohms (10 milliohms). 

This installation is checked per 28-AWL-10. 

28-AWL-10 ALI 12 YRS ALL Center Wing Tank Fueling Valve-Fault Current Bond 

Concern: Potential for arcing or filament heating inside the center wing fue l tank . 

This installation includes the following checks per Boeing AMM 28-21-13: 

1. The bonding resistance from the exposed threads on the valve unit mounting stud 

(one location). to the refuel valve control unit AND the bonding resistance from the 

exposed threads on the valve unit mounting stud (one location). to structure (spar) 

must not be more than 0.010 ohms (10 milliohms). 

0621 U400-9 

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fi-BDE'N& 747-400 MAINTENANCE PLANN ING DATA 

AWL Number Task Interval Appl icability Description 

28-AWL-11 eOCe l NfA ALL Fuel Quantity Indicating System (FQIS) - Fuel Quantity Processor Unit (FQPU) Repair 

Concern: Potential for maintenance error during FQPU repair. The FQPU is designed to limit 

the levels of energy, voltage, current, and power allowed within the FQIS circuit to intrinsically 

safe levels in order to preclude the potential of an ignition source within any fuel tank. 

I Repair and overhaul of FQIS processor units must be per Goodrich (V8930S) CMM 28-41-62 

Revision 4, or later revisions of this CMM that have been approved by the Seattle FAA ACO. 

28-AWL-12 eOCeL NfA ALL Single Point Sensor (SPS) Conlrol Card Repair 

Concern: Potential for maintenance error during SPS control card repair. The SPS control card 

is designed to limit the levels of energy, voltage, current, and power allowed within the SPS 

circuit to intrinsically sa fe levels in order to preclude the potential of an ignition source within 

any fuel ta nk. 

Repair and overhaul of Single Point Sensor Control Card must be per Ragen Data Systems 

(V58880) CMM 28-21-02 Revision 2. or later revisions of this CMM that have been approved by 

the Seattle FAA ACO. 

Note: Ragen Data Systems is now Vibro-Meter Inc. 

28-AWL-1 3 COCCl NfA All 747-400 with HST Remote Electronic Unit (REU) Repair 

Concern: Potential for maintenance error during REU repair. The REU is designed to limit the 

levels of energy, voltage. current, and power allowed within the REU circuit to intrinsically safe 

levels in order to preclude the potential of an ignition source within any fuel tank . 

I Repair and overhaul of REU must be per Goodrich (V89305 ) CMM 28-41 -63 Revision 4, or later 

revisions of this CMM that have been approved by the Seattle FAA ACO. 

28-AWL-14 COCel NfA ALL Fuel Quantity Indicating System (FaIS) - Repair of In-Tank Hardware (Tank Units, 

Densitometers, and Compensators) 

Concern: Potential for maintenance error during repair of in-tank hardware (tank units, 

compensatOfs and densilometers). Arc gaps may develop that could result in an ignilion 

source inside the fuel lank. 

I Repair and overhaul of FQIS tank units, compensators, and densitometers must be per 

Goodrich (V8930S) CMM 28-40-55 Revision 6. 28-40-56 Revision 4, 28-40-59 Revision E, or 

later revisions of these CMMs that have been approved by the Seattle FAA ACO. 

0621U400-9 

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([i.JIDE'NG 747-400 MAINTENANCE PLANNING DATA 

AWL Number Task Interval Applicabi lity Description 

28~AWl 15 COCel NfA ALL Fuel Quantity Indicating System (FOIS) - Repair of In-Ta nk Wire Harness 

Concern: Potential for error during repair or replacement of in-tank wire harness. Arc gaps may 

develop that could result in an ignition source inside the fuel lank. 

Repair and overhaul of FQIS in-tank wire harness must be per SWPM 20-14-12. 

Installation of FQIS in-tank wire harness must be per Boeing AMM 28-41-09. 

Verify the following when installing spar penetrations per Boeing AMM 28-41-09: 

1. A new O-ring is installed in the groove of the FOIS wire bundle connectors. 

2. The spar connector and the mating surface are clean 

3. The connector jamnut is lightened to a torque of 200-250 inch-pounds. 

Verify the following when installing the applicable airplane wire bundle connector to the in-tank 

wire harness spar penetration: 

1. The coupling connector is tightened to a torque of 60-70 inch-pounds. 

2. The between the bonding jumper on the airplane wire bundle and the airplane spar 

structure is not more than 0.0005 ohm (0.5 milliohms) for HST tank and 0.010 ohm 

(10 milliohms) for all other tanks. 

28-AWL-16 COCCl NfA ALL Fuel Tank Access Doors Configuration 

Concern: Potential for arcing or sparking inside the tank at the interface between the door and 

the tank structure as a result of a direct strike or conducting currents through the wing skin. 

The following must be maintained during fuel lank access door installation (Boeing AMM 

28-11-02,28-11 -03): 

NOTE: Not applicable to center wing tank access door. 

1. Verify presence of a molded rubber seal positioned around the outermost periphery of 

the door that mates with the wing skin inside the tank. 

2. Apply Corrosion Inhibiting Compound (CIC) 10 both sides of the knitted aluminum 

mesh gasket, and 

3. Install the knitted aluminum mesh gasket between the outside face of the door and the 

wing skin to establish the electrical conductivity betveen the access door and the 

wing skin. 

0621 U400-9 

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~DE'NG 747-400 MAINTENANCE PLANN ING DATA 

AWL Number Task Interval Applicability Desc ription 

28-AWL-17 ALI 18 months ALL Fault Current Detector for CWT and Inboard Main Tank Override/Jellison Pumps and 

HST Transfer Fuel Pumps 

Concern: Potential burn through of pump case in the event of electrical ground fault in 

fuel pumps. 

Verify the following per Boeing AMM 28-31-14 for CWT and inboard main tank pumps, 

28-17-14 for HST transfer pumps. 

The ground fault detector for each pump is working properly. 

Use Fault Current Detector Test as specified in AMM. 

28-AWL-18 COCel NIA ALL Faull Current Detectors Repair CMM 

Concern: Potential for maintenance error during Fault Current Detector repair. Faull current 

may be introduced to pumps creating an ignition source. 

Repair and overhaul of Fault Current Detectors must be per Autronics (V03972) CMM 28-31-22 

Revision 4, or later revisions of this GMM that have been approved by the Seattle FAA ACO. 

28-AWL-19 GDGGL NIA ALL Resetting Tripped Fuel Pump Circuit Breakers or Ground Fault Interrupters (GFls) 

Concern: Potential for arcing or sparking inside the tank between fuel pumps and fuel pump 

housings and outside Ihe tank between pump wiring and structure in flammability leakage 

zones. 

Verify it is safe to reset the circuit breaker(s) or GFI{s) by following the applicable OEM 

troubleshooting procedures. Fault(s) that resulted in circuit breaker or GFI{s) relay trip must 

be isolated and corrected prior to reset. 

0621 U400-9 

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f:5-HOE'N& 747-400 MAINTENANCE PLANNING DATA 

AWL Number Task Interval Applicability Description 

28-AWL-20 COCCl N/A 747-400 airplanes Lightning Protection - Engine Fuel Feed Line Fuel Tank Penetration 

line Numbers 1284 Concern: Potential for arcing. sparking or fi lament healing inside the lank at the interface and on; 

or airplanes modified between the bulkhead fitling and the spar during a lightning strike event. 

per Service Bulletin The following must be maintained per Boeing AMM 28-22-07 if the bulkhead fitting or attached 

747-28A2239 or tubing are removed and replaced (Nole: Each of the following is only applicable if the subject 

747 -28A2245. area has been disturbed): 

Verify electrical fay surface bond between the bulkhead fitting and the fronl spar structure 

inside the tank must be 0.0005 ohms (0.5 milliohms) or less. 

Install full-bodied fillet seal encapsulating the bulkhead fitting to the tank wall interface inside 

the tank . 

Install full-bodied fillet seal encapsulating the first coupling interface inside the tank. 

Verify an electrostatic bonding jumper presence between the structure and the first tube mating 

with the bulkhead fitting inside the tank. 

Verify the electrical bond from structure to first tube mating with the bulkhead fitting is 

0 .010 ohm (10 milliohms) or less. 

28-AWL-21 Reserved for fu ture SFAR 88 AWL. 

I 

, 

D621U400-9 

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~OE'N& 747-400 MAINTENANCE PLANNING DATA 

AWL Number Task Interval Applicability Description 

28·AWl·22 COCCl NfA All AC Fuel Pump Fault Current Bonding Path 

Concern: Potential for fault current path through the pump housing to structure inside the tank. 

Electrical faults inlernal to the fuel pump motor impeller are by design routed through the motor 

impeller assembly to the bonding jumpers on the front face of the molor impeller assembly to 

structure outside the tank. The bonding jumpers ensure thai fault currents are conducted to 

structure outside the tank until the circuit breaker andfor GFI has had ti me 10 remove power 

from the pump. 

The following features must be maintained during pump replacement per Boeing AMM 

28·22·03: 

For Hydro-Ake Pumps: 

I 1. The presence of two bonding jumpers. 

2. The motor impeller bonding resistance across the jumpers to structure for Center tank 

is not more than 0.0002 ohms (0.2 milliohms). The molor impeller bonding resistance 

across the jumpers to structure for horizontal stabilizer tank pumps and main tank 

boost pumps is not more than 0.0004 ohms (0.4 miltiohms). 

For FR-HITEMP Pumps; 

I 1. The presence of one bonding jumper. 

2. The motor impeller bonding resistance across the jumpers to structure for Center tank 

is not more than 0.0002 ohms (0.2 milliohms). 

3. The motor impeller bonding resistance across the jumpers to structure for main tan k 

boost pumps is not more than 0.0005 ohms (O.S milliohms). 

D621U400-9 

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rtJ.-BOEING 747-400 MAINTENANCE PLANNING DATA 

AWL Number Task Interval Applicability Description 

28-AWL-23 CDCCL N/A 747-400 airplanes Fuel Quantity Indicating System (FOtS) - Installation of Center and HST Fuel Tank Hot Short 

Line Numbers 1368 Protector (HSP) 

and on; Concern: Potential for wire to wire hot short voltages on the center lank fuel quantity or airplanes that densitometer wiring to enter the fuel tank. This is applicable to airplanes with optional have incorporated densitometer installed. Service Bulletin 

747-28A2266 and The FQtS HSP is designed to prevent wire to wire external hot short voltages from entering the 

(if applicable) fuel lank where it may cause an ignition. 

747-28A2267. The following features must be maintained during replacement of the HSP per Boeing 

AMM 28·41·24: 

1. Verify the bonding jumpers are installed per AMM task. 

2. Verify the bonds from the HSP to stiffeners where the bonding jumpers are terminated 

are equal to or less than 0.0025 ohms (2.5 milliohms). 

3. A new unit must be used. 

The Hot Short Protector unit is not repairable. 

28·AWL·24 All 1 YR 747·400 airplanes Horizontal Stabilizer Fuel Boost Pump Automatic Shutoff System (If Installed) 

Line Numbers 1343 Concern : Dry running the horizontal stabilizer tank fuel pumps has the potential for single and on with HST 

installed; failure ignition sources developing at the pump inlet due to either frictional heating or sparking 

or airplanes modified as a result of FOD contacting the pump rotating elements, rotating elements contacting 

per Service Bulletin stationary parts, or hot journal bearings due to bearing contamination or failure. 

747·28A2262. The automatic shutoff system is installed and designed to limit continuous dry running condition 

to 15 seconds. 

The following test is required in order to protect against latent faults: 

Functionally check the horizontal stabilizer tank fuel boost pump automatic shutoff system per 

Boeing AMM 28· 17·00. 

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~OE'NG 747-400 MAINTENANCE PLANNING DATA 

AWL Number Task Interval Applicability Description 

28·AWL·25 COCCL NA 747-400 airplanes Reserve Tank Fueling Valve-Induced Lightning Protection Bond 

line Numbers 1378 Concern: Potential for arcing or filament heating inside the center left/Righ i wing Reserve and on; 

or airplanes that fu el tank. 

have incorporated The following design features must be maintained per Boeing AMM 28-2 1-02 when the reserve 

Service Bulletin tank fueling valve controller is removed and replaced: 

747-28A2291 . 1. Two bonding jumpers between the valve controller and structure outside the tank. 

2. The bonding resistance from the mounting boll to structure (spar) must nol be more 

than 0.0015 ohms (1.5 milliohms). 

28-AWL-26 ALI 1 YR 747-400 airplanes Main Tank 2 and Main Tank 3 Override/Jettison Fuel Pump Uncommanded on System , 

Line Numbers 1380 Concern: Dry running the main 2 and main 3 tank fuel overridefJettison pumps has the potential and on: 

or airplanes that for single failure ignition sources developing at the pump inlet due to either frictional healing or 

have incorporated sparking as a result of FOD contacting the pump rotating elements, rotating elements 

Service Bulletin contacting stationary parts. or hot journal bearings due to bearing contamination or failure. 

747-28A2280. Perform an operational lest of the main 2 and main 3 override/jettison fuel pump 

uncommanded on system per Boeing AMM 28-31-00 

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!{ia0E'NC 747-400 MAINTENANCE PLANNING DATA 

AWL Number Task Interval Applicability Description 

28-AWL-27 COCel NA 747-400 airplanes Fault Current Protection - Molor Operated Valve (MOV) Actuator 

Line Numbers 1382 Concern: Potential for arcing or sparking inside the fuel tank at a conductive metal-la-ground and on; 

or airplanes modified structure interlace as a result of electrical fau lt currenl event. 

per Service Bulletin The following design features must be maintained per Boeing AMMs: 

747 -28A2292 and 28-14-21, 28-14-31, 28-14-41, 28-14-61 , 28-16-01, 28-16-04, 28-17-01 , 28-21-11, 28-22-01, 747-28A2294. 28-22-02,28-25-02,28-31-04, and 28-31-05. 

I. If the MOV actuator is mounted to the spar with an adapter plate. 

1. Maintain the following if the adapter plate is removed and replaced: 

a. Verify electrical fay surface bond resistance between the adapter plate and the spar is 

0.0005 ohms (O.S milliohms) or less. 

b. Install fay surface seal between the adapter plate and the spar outside the tank. 

c. Cap seal the four bolts that attach the adapter plate to the spar inside the tank and fillet 

seal around the edge of the hole and on the stationary part of the adapter plate inside 

the lank. 

d. Install sealed electrical fay surface bond and fay surface seal between the serrated 

mating surfaces of the index plate and the adapter plate. 

e. Install sealed electrical fay surface bond and fay surface seal between the mating 

surfaces of the actuator and the index plate. 

f. With the bonding jumper not installed. verify electrical bonding resistance between the 

actuator mounting feet and the spar is 0.0025 ohms (2.5 milliohms) or less. 

g. Prior to attachment of the bonding jumper to the actuator, verify electrical bonding 

resistance between the loose end of the bonding jumper and the spar is 0.0015 ohms 

(1.5 milliohms) or less. 

h. Attach the bonding jumper to the actuator bonding tab using a sealed electrical fay 

surface bond. 

(Continued on next page) 

0621 U400-9 

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r{;-BOE'NG 747-400 MAINTENANCE PLANNING DATA 

AWL Number Task Interval Applicability Description 

28-AWL-27 COCel NA 747-400 airplanes Fault Current Protection - Motor Operated Valve (MOV) Actuator (continued); 

Line Numbers 1382 2. Maintain the following if the index plate is removed and replaced: and on; 

or airplanes modified a. Install sealed electrical fay surface bond and fay surface seal between the serrated 

per Service Bulletin mating surfaces of the index plate and the adapter plate. 

747-2BA2292 and b. Install sealed electrical fay surface bond and fay surface seal between the mating 747-28A2294. surfaces of the actuator and the index plate. 

c. With the bonding jumper not installed, verify electrical bonding resistance between the 

actuator mounting feel and the spar is 0.0025 ohms (2.5 milliohms) or less. 

d. Prior to attachment of the bonding jumper to the actuator, verify electrical bonding 

resistance between the loose end of the bonding jumper and the spar is 0.001 5 ohms 

(1.5 milliohms) or less. 

e. Attach the bonding jumper to the actuator bonding tab using a sealed eleclrical fay 

surface bond. 

3. Maintain the following If the MOV actuator is removed and replaced: 

a. Install sealed electrical fay surface bond and fay surface seal between the mating 

surfaces of the actuator and the index plate. 

b. With the bonding jumper not installed, verify electrical bonding resistance between the 

actuator mounting feet and the spar is 0.0025 ohms (2.5 mill iohms) or less. 

c. Prior to attachment of the bonding jumper to the actuator, verify electrical bonding 

resistance between the loose end of the bonding jumper and the spar is 0.0015 ohms 

(1.5 mi ll iohms) or less, 

d. Attach the bonding jumper to the actuator bonding tab using a sealed electrical fay 

surface bond. 

(Continued on next page) 

D621 U400-9 

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rti-HOEfNG 747-400 MAINTENANCE PLANNING DATA 

AWL Number Task Interval Applicability Description 

28-AWL·27 COCel NA 747-400 airplanes Fault Current Protection - Molor Operated Valve (MOV) Actuator (continued): 

Line Numbers 1382 II. If the MOV actuator is mounted without an adapter plate. and on; 

or airplanes modified 1. Maintain the following If the MOV actuator is removed and replaced: 

per Service Bulletin 

a. Install sealed electrical fay surface bond between the mating surfaces of the actuator 747-28A2292 and 

747-28A2294. and structure. 

b. With the bonding jumper not installed, verify electrical bonding resistance between the 

actuator mounting feet and the spar is 0.005 ohms (5 miliiohms) or less. 

c. Prior to attachment of the bonding jumper to the actuator, verify electrical bonding 

resistance between the loose end of the bonding jumper and the spar is 

0 .0015 ohms (1.5 milliohms) or less, 

d. Attach the bonding jumper to the actuator bonding tab using a sealed electrical fay 

surface bond. 

28·AWl-28 ALI 1 YR 747-400 airplanes Main Fuel Tank Boost Fuel Pump Ground Fault Interruption (GFI) Control Relay System 

line Number 1394 Concern; GFt is installed to protect against burn·through of the pump housing, and to protect and on; 

or airplanes that against overheating of the pump cavity andlor auto ignition temperature on the outside surface 

have incorporated of the housin9, due to electrical arcing. 

SeNice Bulletin Perform an Operational Test of all Main Fuel Tank Boost Pumps GFI Control relays per Boeing 

747·28A2261. AMM 28-22-00. 

28-AWL-29 ALI 1 YR 747·400 airplanes Center Wing Tank Electrical Scavenge Pump Ground Fault Interruption (GFt) Control Relay 

with Electric Center System 

Wing Tank Scavenge Concern; GFI is installed to protect against burn·through of the pump housing, and to protect Systems, airplanes 

prior to line Number against overheating of the pump cavity andlor auto ignition temperature on the outside surface 

972 that have of the housing, due to electrical arCing. 

incorporated Perform an Operational Test of all center wing tank scavenge system GFI Control relays per 

Service Bulletin Boeing AMM 28-22-00. 

747·28A2261 . 

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!tJ.-BOE'NG 747-400 MAINTENANCE PLANNING DATA 

AWL Number Task Interval Applicability Description 

28·AWL·30 COCel NA 747-400 (910K) Electronic Fuel Level Indication System (EFLI) - Out Of Tank Wiring Installation Separation 

with Auxiliary Requirement 

Fuel Tank Concern: Potential for hot shorts and EMI induced vo ltages on the EFLI wiring outside of the 

tank to enter the fuel tank. 

Routing and installation of any new wiring must use wire types BMS 13-48, BMS 13-60 or 

BMS 13-58, and not be within a 2-inch radius of the EFLI wiring. When a single clamp fails, a 

separation greater than liz inch must be maintained from AUX Fuel lank EFlI wiring. 

28-AWL-31 CDCel NA 747-400 (910K) Electronic Fuel level Indication System (EFU) Processor Display Unit (PDU) or AUX tank 

with Auxiliary EFU - Repair 

Fuel Tank Concern: Potential for maintenance error during PDU repair. The PDU AUX lank EFU is 

designed 10 limit the levels of energy, voltage, current, and power allowed within the EFU 

circuit to intrinsically safe levels in order to preclude the potential of an ignition source within a 

fuel lank. 

Repair and overhaul of PDU must be per Parker (V260SS) CMM 28-41-81, Revision 0, or later 

revisions of this CMM that have been approved by the Seattle FAA ACO. 

28-AWl-32 COCCl NA 747-400 (910K) Fuel Tank Electronic Fuel l evel Indication System (EFLI) - Repair of In-Tank Hardware 

with Auxiliary Concern: Potential for maintenance error during re pair of in-tank hardware. Arc gaps may Fuel Tank develop that could result in an ignition source inside the fuel tank. 

EFU probe repair and overhaul must be per Parker (V260SS) CMM 28-41 -70, Revision 1, or 

later revisions that have been approved by the Seattle FAA ACO. 

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rp..a0E'NG 747-400 MAINTENANCE PLANNING DATA 

E. AIRWORTHINESS LIMITATIONS· NITROGEN GENERATION SYSTEM TASKS 

The following list of AWLs contains FAA approved scheduled inspections for operators to incorporate into their maintenance program for this type design 

to meet the requirements for the introduction of the Nitrogen Generation System (NGS). The FAA Special Condition No. 2S-285-SC requires maintenance 

instructions and control limitations for certain NGS critical design configurations. § 25.981 (b) also requ ires AWLs to preclude ignition sources inside the 

fuel tank that may be introduced by the addition of NGS. 

Special Condition, Paragraph III (a), Maintenance, requires the applicant identify Airworthiness limitations for aU critical features identified under 

Paragraph II (a)(3) and for all maintenance and/or inspection tasks requ ired to identify failures of components within the NGS that are needed to meet 

Paragraphs II (a), (b), and (c)(2) of the special conditions. NGS Airworthiness Limitations (AWLs) are mandatory maintenance actions that ensure that 

unsafe conditions that arise due to NGS failures do not occur or are not introduced into the airplane as a resu lt of configuration changes, repairs, 

alterations, or deficiencies in the NGS maintenance program throughout the operational life of the airplane. 

AWL TASK INTERVAL APPLICABILITY DESCRIPTION NUMBER 

47-AWl-01 CDCCl NIA 747-400 airplane line Lightning Protection - NGS NEA Description Line Fuel Tank Penetration 

Numbers 1363, 1366 Concern: Potential for arcing, sparking of filament heating inside the tank at the interface 

between the bulkhead fitting and the spar during a lightning strike event. 

The following must be maintained per Boeing AMM 47-21 -06 if the bulkhead fitting or 

attached tubing are removed and replaced: 

1. Verify electrical fay surface bond between the bulkhead fitting and the front spar 

structure inside the tank is 0.0005 ohms or less, 

2. Install full-bodied fillet seal encapsulating the first coupling connecting the tube to the 

bulkhead fitting inside the tank , 

3. Install full bodied fillet seal encapsulating the first coupling interface inside the tank, 

a,d 

4. Verify electrical bond from structure to first tube mating with the bulkhead fitting is 

0.010 ohms or less. 

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~DE'NG 747-400 MAINTENANCE PLANNING DATA 

AWL TASK INTERVAL APPLICABILITY DESCRIPTION NUMBER 

47·AWl·02 CDceL NfA 747-400 airplane line Center Fuel Tank Vent System Auxiliary Tanks 

Numbers 1363, 1366 Concern: The addition of an Auxiliary Fuel Tank system via Supplemental Type Certificate 

may reduce the effectiveness of the NGS resulting in an increase in flammability exposure of 

the center tank. 

The NGS installation is designed to provide the proper level of nitrogen to the center wing 

lank in order to reduce the fleet wide average flammability exposure to levels equal to that of 

wing fuel tanks. Auxiliary fuel tank installations typically transfer fuel and ullage gases to and 

from the center wing lank. 

Any new Supplemental Type Certificate (STC) design auxiliary tank system that 

communicates ullage directly to or from the center wing tank must not significantly affect the 

performance of the FRS. All new STC auxiliary tank installations must be reviewed and 

approved by the Seattle FAA ACO. See Boeing AMM ATA 28 for a description of the Fuel 

System and Fuel Venting System. 

47-AWl -03 ALI 1200 Flight 747-400 airplane line Nitrogen Generation System Functional Check Performance Inspeclion 

Hours Numbers 1363, 1366 Concern : latent failure of the Hollow Fiber Membranes that make up the Air Separation 

Modules (ASMs) will reduce the percentage of nitrogen in the nitrogen enriched air entering 

the center wing fuel tank. 

Perform the inspection procedure listed in Boeing AMM 47-00-01. 

1. Measure the oxygen concentration of the NEA at the outpu t of the ASM per Boeing 

AMM 47-00-01. 

2. Verify the NEA purity is in the satisfactory zone (shaded area) of the ASM performance 

charts published in Boeing AMM 47-00-01. 

If the nitrogen conlent is not satisfactory, troubleshoot per Boeing Faull Isolation Manual and 

perform the recommended repairs per Boeing AMM 47·00-01. 

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r[iaDE'NG 747-400 MAINTENANCE PLANNING DATA 

AWL TASK INTERVAL APPLICABILITY DESCRIPTION NUMBER 

47-AWl-04 ALI 9675 Flight 747-400 airplane Line Nitrogen Generation System - Thermal Switch Functional and Operational Test 

Hours Numbers 1363, 1366 Concern: Latent failure of the Thermal Switch removes a layer of protection against fuel tank 

ignition by hot bleed air. 

The NGS uses engine bleed air from the bleed system cross-over manifold to generate 

nitrogen to reduce the flammability of the center fuel tank. The NGS has features to prevent 

direclly feeding hot bleed air into the fuel lank. The Thermal Switch provides a redundant 

backup to the NGS controller to protect the ASMs and prevent hot bleed air from entering the 

fuel tank. The Thermal Switch backup feature is a latent (not detected) failure and must be 

tested to maintain certification of the NGS. 

Perform a functional and operational test of the thermal switch per Boeing , 

AMM 47-43-02 to ensure the integrity of the thermal switch. , 

47-AWL-05 All 1500 Cycles 747-400 airplane Line Nitrogen Generation System - Thermal Control Unit (TCU) and Intercon nect Duct 

or 7500 Numbers 1363, 1366 ReplacemenUUpgrade 

Flight Hours 

Note Concern: The TCU pallet failed vibration testing during qualification. The interconnecl duct 

vibration analysis demonstrates limited life capability. The TCU and interconnect duct may fail 

in service if not replaced or upgraded. 

Replace the TCU Assembly PIN 5848740-1 or Duct Assembly PIN 5849522-1 (component 

ofTCU) 

Replace the interconnect duct PIN 5849599-1 . 

Interval Note: Whichever comes first. 

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rp. .. J IOE'NG 747 .. 400 MAINTENANCE PLANNING DATA 

AWL TASK INTERVAL APPLICABILITY DESCRIPTION NUMBER 

47-AWL-OB ALI 3000 Cycles 747-400 airplane Une Nitrogen Generation System - Air Separation Unit (ASU) ReplacemenUUpgrade 

or 15000 Numbers 1363, 1366 

Flight Hours Concern: The ASU pallet failed vibration lesting during Qualification. The ASU may fail in 

Note service if not replaced or upgraded. 

Replace ASU Assembly PIN 5848760-1 or the following combination of ASU components: 

- Overtemperature Shutoff Valve Bracket PIN 5849542-41 

- Nitrogen Enriched Air Bracket PIN 5849542-25 

- Two ASM Inlet Ducts PfN 5849548-1 (one on the primary ASM and one on the adjacent 

secondary ASM 

- Supply Air Primary Duct Assembly PIN 5849557-1. 

Interval Note: Whichever comes first. 

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~OE'NG 747-400 MAINTENANCE PLANNING DATA 

F. AIRWORTHINESS LIMITATIONS (AWLs)- STRUCTURAL INSPECTIONS 

The 747-400 passenger airplane can be operated in a 747-400 Special Freighter (SF) configuration if modified in accordance with specific Boeing service 

bulletins. These service bulletins are identified (with associated effectivity) in Boeing Service Bulletin 747-00-2004. Airplanes converted by incorporation 

of Boeing service bulletin(s) to the 747-400 SF configuration require existing supplemental structural inspections identified for the 747·400, and new 

supplemental structural inspections specific to the 747-400SF configuration. For the 747-400SF configuration, all of these supplemental inspections are 

shown in the 747 Supplemental Structural lnspeclion Document 06·35022, beginning with Revision G (and on) of that document. 

After reaching the threshold specified in the 747 Supplemental Structural Inspection Document, 06-35022, 747-400SF aircraft modified as noted above 

must limit all repeat inlervals in MPO Section 2, Structural Maintenance Program, to the values shown therein. 

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Il1--BDE'NG 747-400 MAINTENANCE PLANNING DATA 

Airplanes converted to a 747-400 Large Cargo Freighter (LCF) configuration by incorporation of Boeing Service Bulletins 747-00-0008, 747-00-0018, 

747-00-0033, or 747-00-2 120 require additional supplemental structural inspections specific to the 747-400 lCF configuration. These supplemental 

inspections are shown in the 747-400 LCF Supplemental Structural Inspection Documenl - Appendix A, 06-35022-1. dated January 2010, or later FAA 

approved revision. For these supplemental fatigue related inspections, after the airplane reaches the threshold specified in 06-35022-1, issued 

January 2010, or later FAA approved revision, the repeal intervals of the C-Checks and O-Checks specified by the MPD must be limited by flight cycles in 

addilion to the required limitation for flight hours and calendar time. For MPD Section 2, Structures Maintenance Program, and MPD Section 3, Zonal 

Inspection Program, the check intervals must not exceed the following: 

C-Check ~ 1,500 night cycles 

2C~Check ~ 3,000 flight cycles 

D·Check ~ 6,000 flight cycles 

2D-Check - 12,000 flight cycles 

Aircraft converted to the 747-400 l CF configuration also require the revised inspection and modification requirements listed in Boeing Service Bulletin 747-

53A2817 Rev. 00, or a later revision approved by the Manager of the Seattle Aircraft Certification Office, in order to adequately address differences in 

aircraft structure and internal loads/stresses. When Boeing Service 747-53A2817 states to contact the Boeing Company for modification data, that 

modification data must be approved by the manager of the Seattle Aircraft Certification Office. 

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fi--DDE'NG 747-400 MAINTENANCE PLANNING DATA 

G. CERTIFICATION MAINTENANCE REQUIREMENTS (CMRs) 

SELECTION OF CMRs 

In order to grant operators of the 747-400 airplane an opportunity to participate in the evaluation and selection of CMRs in an integrated process with MRB 

tasks and intervals, a Certification Maintenance Coordination Committee (CMCC) was convened to review all of the 747-400 CMRs. The CMRs listed in 

this document are the result of applying the CMCC process as described in AC 25-19. 

CMR DEFINITION 

As defined by AC 25-19. a CMR is a required periodic task, established during the design certification of the airplane as an operating limitation of the type 

certificate. CMRs usually result from a formal. numerical analysis conducted to show compliance with catastrophic and hazardous failure conditions. 

Additional notes concerning the definition of CMRs: 

1. A CMR is intended to detect safety-significant latent (hidden) failures that would, in combination with one or more specific failures or events, result in a 

hazardous or catastrophic failure condition. 

2. II is important to note that CMRs are derived from a fundamentally different analysis process than the maintenance tasks and intervals that result from 

the Maintenance Steering Group (MSG-3) Analysis associated with Maintenance Review Board (MRB) activities. MSG·3 Analysis activity produces 

maintenance tasks that are performed for safety, operational, or economic reasons, involving both preventative maintenance tasks, which are perfonned 

before failure occurs (and are intended to prevent failures), as well as failure-finding tasks. CMRs, on the other hand, are failure-finding tasks only, and 

exist solely to limi! the exposure to otherwise hidden failures. Although CMR Tasks are failure-finding tasks, use of potential failure-finding tasks, such 

as functional checks and inspections, may also be appropriate. 

3. CMRs are designed to verify that a certain failure has or has not occurred, and do not provide any preventative maintenance function. CMRs "restart 

the failure clock to zeron for latent failures by verifying that the item has not failed, or cause repair if it has failed. Because the exposure time 10 a latent 

failure is a key element in Ihe calculations used in a safety analysis performed to show compliance with FAR 25.1309, limiting the exposure time will 

have a significant effect on the resultant overall failure probability of the system. The CMR task interval should be designated in terms of flight hours, 

cycles, or calendar time, as appropriate. 

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HDE'NG 747-400 MAINTENANCE PLANNING DATA 

4. The type certification process assumes thai the airplane will be maintained in a condition of airworthiness at least equal to its certified or properly altered 

condition. The process described in AC 25-19 is not intended to establish normal maintenance tasks that should be defined through the MSG-3 

analysis process. Also, this process is not intended to establish CMRs for the purpose of providing supplemental margins of safely for concerns arising 

Jate in the type design approval process. 

5. CMRs should not be confused with requ ired structural inspection programs thai are developed by the type certificate applicant to meet the inspection 

requirements for damage tolerance, as required by FAR 25.571 or 25.1529, Append ix H25.4 (Airworthiness limitations section). CMRs are to be 

developed and administered separately from any structural inspection programs. 

EXCEPTIONAL SHORT-TERM EXTENSIONS FOR CMRs 

Since CMR intervals are based on statistical averages and reliability rates, an exceptional short·term extension of 90 days for CMRs 24, 25, and 26 listed 

in this document may be made without jeopardizing safety. The local regu latory authority (e.g. a Principle Maintenance Inspector) must concur with any 

exceptional short-term extensions before they take place using procedures established with the local regulatory authority in the operators' manuals. The 

"exceptional short-term extension" process is applicable to CMR intervals. II should not be confused with the operator's "short-term escalation" program 

for normal maintenance tasks described in the operators' manuals and in the Flight Standards Handbook 8300.10. 

The Seattle FAA ACO has accepted that these exceptional short-term extensions may be granted without consulta tion with that office: 

1. The term "exceptional short-term extension" is defined as an increase in a CMR interval that may be needed to cover an uncontrollable or unexpected 

situation. CMRs 24, 25, and 26 listed in this document have been approved with an exceptional short-term extension of 90 days. 

2. Repeated use of extensions, either on the same airplane or on similar airplanes in an operator's fleet, should not be used as a substitute for good 

management practices. Exceptional short-term extensions must not be used for fleet CMR extensions. 

After a CMR has experienced an exceptional short-term extension, the CMR interval will revert back to its interval listed in this document. The Seatlle FAA 

ACO must approve, prior to its use, any desired extension not explicitly listed above. 

This exceptional short-term extension listed above applies to airlines that fall under the United States FAA jurisdiction only. Operators who are not under 

the U.S. FAA jurisdiction should obtain interval extension approvals from their local regulatory agency. 

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fi.-HDE'NG 747-400 MAINTENANCE PLANNING DATA 

POST CERTIFICATION CHANGES TO CMRS 

Any post certification changes to CMRs should be reviewed by the 747-400 CMCC and approved by the Seattle FAA ACO: 

1. Since the purpose of a CMR is to limit the exposure lime to a given significant latent failure as part of an engineering analysis of overall system reliability, 

instances of a CMR task repeatedly finding that no failure has occurred may not be sufficient justification for deleting the task. 

2. The introduction of a new CMR should be reviewed by the same process used during initial certification. It is important that operators be afforded the 

same opportunity to participate thai they received during the original certification of the airplane, in order to allow the operators to manage their own 

maintenance programs. 

3. In the event that later data provide sufficient basis for relaxation of a CMR (less restrictive actions to be required), the change may be documented by an 

FAA-ACO approved change to this CMR document. 

4. If the requirements of an existing CMR must be decreased (more restrictive actions to be performed). it will be implemented by a change to this CMR 

document and enforced by an FAA Airworthiness Directive (AD). 

5. After initial aircraft certification, the only basis for adding a new CMR is in association with the certification of design changes. 

6. A new CMR created as part of a design change should be part of the approved data for that change and added to this CMR document. 

In the event that a CMR is revised, Boeing will document it by preparing a revision to this document that will be approved by the Seattle FAA ACO. This 

revision will then be forwarded to all 747-400 operators and the Seattle FAA ACO offices. 

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(lJ .. J~OE'NG 747 .. 400 MAINTENANCE PLANNING DATA 

H. CERTIFICATION MAINTENANCE REQUIREMENTS TASKS 

NUMBER SYSTEM INTERVAL TASK PROCEDURE MPDITEM 

REFERENCE NUMBER 

1 Standby Power System Daily Operational (Short) Test - 115-Volt AC Standby Maintenance Manual 24 -029-01 

Power Generation D633Ul 0 1 

Subject 24-29-00 

Page Block 500 

2 Cargo, Engine and APU Fire/Overheat Daily Operational Test for Fire/Overheat Detection Maintenance Manual 26-010-00 

Detection System. Systems D633U101 

(Only applicable to Engine Fire/Overheat Subject 26-10-00 

Detection System for 747-400 LCF) Page Block 500 

3 FADEC C2 Failures 2000 FH Check Engine Control System for Category 2 Maintenance Manual 73-121-00 ' 

(GE CF6- Faults using the CMC D633U101 

80C2B1 F) Subject 73-21-00 

Page Block 200 

1000 FH 73-221-00 

(PW4000) 

560 FH 73-321-03 

(RR RB211 -524 ) 

4 Generator Control Unit and Bus Control Uni 500 FH Operational Test - Generator and Bus Control Unit Maintenance Manual 24-023-01 

D633U101 

Subject 24-23-01 

Page Block 500 

5 lavatory Waste Compartment 1000 FH lavatory Waste Compartment Inspection Check Maintenance Manual 25-040-01 

D633U101 

Subject 25-41 -00 

Page Block 600 

D621U400-9 

APR 2008 BOEING PROPRIETARY - Copyright (c) - Unpublished Work - See title page for details Page 9.0-50 
r{;-BDE'NG 747-400 MAINTENANCE PLANNING DATA 

NUMBER SYSTEM INTERVAL TASK PROCEDURE MPDITEM 

REFERENCE NUMBER 

6 E&E Cooling System Override Mode 1000 FH Override Mode Operational Test Maintenance Manual 21-058-03 

Function (Not Applicable D633U101 

to 747-400F or Subject 21-58-00 

747-400SF) Page Block 500 

20,000 FH 

(Applicable to 

747-400F and 

747-400SF) 

7 High lift Control System 1200 FH Primary Electric Operational Test of LE and TE Maintenance Manual 27-081-01 

A. Trailing Edge Electric Control 1200 FH Flap Systems. D633Ul 01 

B. leading Edge Electric Control Subject 27-51-11 

Page Block 500 

8 High Lift Control System 1200 FH Alternate Electrical Operational Test of l E and Maintenance Manual 27-051-01 

A. Alternate Arm Switch 10,000 FH TE Flap System. D633U1 01 

B. Altemate Control Subject 27-51 -11 

Page Block 500 

9 E&E Cooling System Flow Detectors 2000 FH Remove Clean and Install Low Flow Detectors. Maintenance Manual 21-058-22 

(Not Applicable to 747-400F or 747-400SF) D633U101 

Subject 21 -58-00 

Page Block 200 

10 E&E Cooling System Smoke & Flow 2000 FH Equipment Cooling Detector Ground Test Maintenance Manual 21-058-04 

Detection D633U101 

(Not Applicable to 747-400F or 747-400SF) Subject 21-058-00 

Page Block 500 

11 E&E Cooling System E30-2 Shelf 2000 FH System Test-E30 Rack Pressure Maintenance Manual 21-058-16 

(Equipment Cooling System) 0633U1 01 

Subject 21-58-00 

Page Block 500 

12 E&E Cooling System Fans & Bypass Valve 2000 FH Fan and Bypass Valve Operational Test Maintenance Manual 21-058-01 

(Not applicable to 747-400F or 747-400SF) (Normal Mode) D633U1 01 

Subject 21-58-00 

Page Block 500 

D621U400-9 

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fl--aOEfNG 747-400 MAINTENANCE PLANNING DATA 

NUMBER SYSTEM INTERVAL TASK PROCEDURE MPDITEM 

REFERENCE NUMBER 

13 E&E Cooling System Fan Check Valves 6250 FH Check Valve - Detail Visual lnspeclion Maintenance Manual 21-058-23 

(Not Applicable to 747-400F or 747-4QOSF) D633U101 

Subject 21 -58-03 

Page Block 600 

14 E&E Cooling System Clean Mode 6250 FH Clean Cycle - Operational Test {Equipment Maintenance Manual 21-058-02 

(Not Applicable to 747-400F or 747-400SF) Cooling Card CMC initialed BIT) D633U101 , 

SubjecI21-SB-DO I 

Page Block 500 

15 E6JE9 Equipment Cooling Valve 6250 FH Cargo Fire Switch Test Maintenance Manual 21-058-19 

(Not applicable to 747-400F, 747400SF or 0 633U101 

747400 l CF) Subject 21-58-00 

Page Block SOD 

16 Horizontal Stabilizer Fuel Tank Installation 6250 FH Inspection of Horizontal Stabilizer Bonding Maintenance Manual 55-010-04 

(Only applicable to 747-400's equipped with Jumpers (Applicable only to airplanes with D633U101 

horizontal slabilizer fuel capability.) horizontal stabilizer fuel quantity gage and controls Subject 55-10-04 

(Not applicable to 747-400 LCF) on Fuel Control Panel) Page Block 600 

17 Upper Rudder System 6250 FH Test Upper Rudder Hinge Bearing and Rudder Maintenance Manual 27-021-02 

Power Control Package Bearing Play D633U101 

Subject 27-21 -02 

Page Block 600 

D621 U400-9 

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1{') .. J i'DE'NG 747-400 MAINTENANCE PLANNING DATA 

SYSTEM INTERVAL TASK PROCEDURE MPDITEM 

REFERENCE NUMBER 

18 Main Entry Door Escape System (Not 30 months! Main Entry Door Escape System Functional Check I Service Letter 52~O 1-18 

Applicable to 747-400F, 36 months - SL-747~SL52-44 

747-400SF or Door #5 on Combi Airplanes See Note (2) 

in Cargo Mode. See Note (1). Note (1): On Combi airplanes. the check is also Maintenance Manual 

(Only applicable to Door #1 LlH for required on Door #5 immediately after conversion D633U101 

747-400 LCF) to passenger mode Subject 52-11-07 

Page Block 600 -

Para 2 

Emergency Linkage 

Inspection 

Note (2): The reference functional check Maintenance Manual 

procedure covering examination of the escape D633U101 

slide or slide/raft packs, may be accomplished at Subject 52-11-07 

30 month intervals, (the remainder of the procedure Page Block 600 -

at 36 month intervals) Emergency Linkage 

Inspection - Para 2. 

Examine the escape 

slide or slide/raft pack. 

19 I Engine Strut Spring Beam 12500 FH I Spring Beam Bearing Movement Check Maintenance Manual 154-051-03 

0633U101 

Subject 54-51-03 

Page Block 600 

20 Lower Lobe Cargo Compartment 7400 FH Check 

Conditioned Air System (Non-Standard, if Control Valve High Flow Disable with Lower Lobe 0633U101 

installed) Cargo Compartment Conditioned Air On Subject 21-28-00 

(Not Applicable to 747-400F, 747-400SF or Page Block 500 

747-400 LCF) 

0621U400-9 

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rt1-SDE'NG 

SYSTEM 

747-400 MAINTENANCE PLANNING DATA 

INTERVAL TASK PROCEDURE 

REFERENCE 

flI1 r ~ p'-~ !~! :lf~-' t1~ I "~~,,~r I.J" ~" _~"~~~~b~~ ~;t~' :!pag~e ~loJ:k OO'}4Ai ' til"" I ~ 

Combi Main Deck Fire Protection System 6250 FH Main Deck Air Distribution Flapper Va lve Maintenance Manual 26-024-10 

24 

25 

26 

Zones 0 and E Air Distribution Shutoff AdjustmentiTesl. D633U101 

Valves, V532 and V533. Subject 26-24-05 

(Not applicable to 747-400 lCF) Page Block 500 

Flight Deck Security Doors Installed per 

Service Bulletin 747-25-3302 

(Not applicable to 747-400 lCF) 

Service Bulletin 747-25-3306 and/or 

747-25-3312. 

(Not applicable to 747-400 LCF) 

pec 

Flight Deck Security Doors Installed 

beginning al the line number 1320 and on 

(except freighter models). 

(Not applicable to 747--400 LCF) 

reserve 

2 & 3 VTO secondary shut-off system 

(Applicable to 747-400 LCF only) 

9 Years 

9 Years 

15000 FH 

the 

Discard the Adams Rile strike mechanism. 

Discard the Adams Rite strike mechanism. 

Functional Check of the fuel main tanks 1 & 4 and 

fuel reserve tanks 2 & 3 VTO secondary shut-off 

system. 

D633U101 

Subject 52-51-02 

Page Block 400 

Maintenance Manual 

D633U101 

SubjecIS2-S1-02 

Page Block 400 

Maintenance Manual 

D633U101 

Subject 52-51-02 

Page Block 400 

Maintenance Manual 

D633U101 

Subject 28-21 -00 

Page Block 500 

NOTE: SHADED CMRs HAVE BEEN DELETED. 

0621 U400-9 

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" 

rfJ-.-BOEING 747-400 MAINTENANCE PLANNING DATA 

I. REPORTING UNCONTROLLABLE HIGH THRUST FAILURE CONDITIONS 

Title 14 Code of Federal Regulations Sections 121.703 and 135.415 state that "each certificate holder shall report any failure, malfunction, or defect in an 

aircraft, system, component, or powerplant that occurs or is detected at any time if, in its opinion. thai failure, malfunction, or defect has endangered or 

may endanger the safe operation of an aircraft", Section 125.409 also requires reporting of failures, malfunctions or defects. In many cases a reportable 

failure or malfunction will be obvious, but there are some failure modes related to uncontrolled high thrust that are reportable but may nol be obvious. The 

following information is provided, as required by FAA Exemption No. 8518, to assist the operators in identifying reportable malfunctions related to 

uncontrolled high thrust. 

The FAA has concluded that the loss of capability to control thrust due to a failure of the engine thrust control system may endanger the aircraft. This 

includes any malfunctions having one or more of the following characteristics: 

• Auto-acceleration or uncommanded thrust change to higher power 

• Stuck Ihrust lever above idle power 

• Inability to reduce thrust 

Although some of these incidents may not appear to be safety related, documenting the events is important to ensure the present level of safety is 

maintained andlor 10 identify failure conditions that must be corrected. 

When filing a report of such an event with the FAA, the operator is requested to include in the description of the event one or more of the following 

phrases: 

• "thrust contror 

• "no response to thrust lever'" 

• aulo-acce rat ion~ 

• ·uncontrolled high thrust" 

D621U4QO·9 

OCT 2007 BOEING PROPRIETARY - Copyright (c) - Unpublished Work - See title page for details Page 9.0-55 
!l5--BOEfNG 747-400 MAINTENANCE PLANNING DATA 

In addition, the following information should be included in the report: 

• Event description 

• Flight Crew action 

• Maintenance action 

• list of affected or removed components 

Reports should be submitted to the local representative of the FAA Administrator that handles the appropriate reporting responsibility for §§ 121.703, 

125.409, and 135.4 15. In addition to filing reports wHh the FAA. it is recommended that a copy be sent to Boeing and to the engine manufacturer. 

0621U40Q-9 

OCT 2007 BOEING PROPRIETARY - Copyright (c) - Unpublished Work - See tille page for details Page 9.0-56