14CFR Part 39

(4910-13-V] DEPARTMENT OF TRANSPORTATION Federal Aviation Administration



# 1:::'·2.2- (Docket No. FAA.-2009-+++++; Directorate Identifier 2009-NM-153-ADj



## iL'lltO Amendment 39-**; AD 2008-10-06 Rl J 

# ·r RIN 2120-AA64 Ainvorthiness Directives; Boeing Model 747-400, -400D, and -400F Series Airplanes AGENCY: Federal Aviation Administration (FAA). Department ofTransportatioll (DOT). ACTION: Final rule; request forcomments. SUMMARY: The FAA is revising an existing airworthiness directive (AD), which applies to cCltain Boeing Model 747-400, -400D, and -400F series airplanes. That AD currently requires revising the FAA-approved maintenance program by incorporating
new airvvorthiness limitations (AWLs) for fuel tank systems to satisfy Special Federal

components. Thjs AD results from adesign review ofthe fuel tank systems. We are issuing thIs AD to prevent the potential for ignition sources inside fuel tanks caused by latent failures, alterations, repairs, ormaintenance actions, which, incombination with flammable fuel vapors, could result in a fuel tank explosion and consequent loss ofthe airplane. OATES: This AD is effective [insert date 15days after date ofpublication inthe FEDERAL REGTSTER]. On June 12,2008 (73 fR 25990, May 8, 2008), the Director ofthe Federal Register approved the incorporation by reference ofa certain publication listed inthe A 

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# m- TRANSPORTATION Federal Aviation Administration 14CFR Part 39 IDocket No. FAA-1009-+++++; Directorate Identifier 2009-NM-153-Allj Amendment 39_*"; AD 2UU8-1O-06 Rl( RlN 212U-AA64 Ain,'orthincss Directives; Boeing ModeJ 747-400. -4000, and -400F Series Airplanes AGENCY: Federal Aviation Administration (FAA), Department ofTranspoJ1atiol1 (DOT). ACTION: final rule; request for comments. SUMMARY: The FAA isrevising an existing airworthiness directive (AD). which applies to certain Boeing ModeJ 747-400, -4000, and -400F series airplanes. That AD currently requires revising the FAA-approved maintenance program by incorporating
new air\vorlhincss limitations (AWLs) for hlel tank systems to satisfy Special Federal U.~-f~
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Aviatian Regulation No. 88 requirements. That AD also requires the initial inspection 0 certain repetitive AWL inspections to phase inthose inspections, and repair ifnecessary Ir<rJ1Al$/SIt; This AD clarifies the intended effect ofthe AD on spare and on-airplane fuel tank SystCI ATE components. This AD results from a design review·ofthe fuel tank systems. Weare issuing this AD to prevent the potential for ignition sources inside fuel tanks caused by latent failures, alterations, repairs, or maintenance actions, which, incombination with nammablc fuel vapors, could result ina fuel tank explosion and consequeI1lloss ofthe airplane. DATES: This AD is effective [insert date 15days after date ofpublication inthe FEDERAL REGISTER]. On June 12, 2008 (73 FR 25990, May 8, 2008), the Director ofthe Federal Register approved the incorporation byreference ofacertain publication listed inthe A TI~G S"M£lOt

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