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DEPARTMENT OF TRA<'lSPORTATION

Federal Aviation Administration _<lNC\I~"I.~CES

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14 eFR Part 39 , _

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[Docket No. FAA-~·++++; Directorate Identifier 2010-NM-.104-ADJ

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R1N 2120-AA64

Ainvorthiness Directivcs; The Boeing Company Model 777-200 and -300 Series

Airplanes Equipped with Pratt and Whitney Engines

AGI£NCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: We :r:ropose to adopt a new airwOltbincss directive (AD) for cert

Model 777-200 and -300 series airplanes. This proposed AD would require doing

repetitive inspections for hydraulic nuid contamination of the interior of the strut

disconnect assembly; repetitive inspections for discrepancies of the interior of the strut

disconnect assembly, if necessary; repetitive inspections of tbe exterior of the strut

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compromise of the engine firewall. A cracked fire\vall can allow fIre in tht: engine are

enter the strut and can lead to an Wlcontained engine strut fire if flammable fluid is

cause cracking of titanium parts in the system disconnect assembly, resulting in

disconnect assembly for cracks, jf necessary; and corrective action if necessary. This

are proposing this AD to detect and correct hydraulic fluid cont.umination, which can

contaminated with hydraulic fluid and, in one incident, led to subsequent cr<Jcking. W

present. Cracking of the disconnecl box may also compromise the effectiveness of the

fire extinguishing system in the engine compartment and could contribull:: to an

proposed AD also provides an optional terminating aClion for the inspections. This

proposed AD results from reports of system disCOllllcct boxes that have been

uncontained engine tire. ln addition, a cracked disconnect box can leak l1ammable ftui

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into (he engine core, which can initiate au engine tir~ ~ vJl. "h\ ~

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(4910-13-PI

DEPARTMENT OF TRANSPORT AnON

Federal Aviation Admin.istration

14 CFR Part 39

IDocket No. FAA-2010~++++j Directorate Identifier 20JO-NM-I04-ADJ

R1N 2120-AA64

Ainyorthine5s Directives; The Boeing Company Model 777-200 and -300 Series

Airplanes Equipped with Pratt and Whitney Engines

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ACTION: Notice of proposed rulemaking (NPRM).

AGENCY: Federal Aviation Administration (FAA), DOT.

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SUMMARY: We propose to adopt a new airworthiness directive (AD) Jor cert in SeeModel 777-200 and -300 series airplanes. This proposed AD would requi.re doing P~clttJ

repetitive inspections for hy_draulic fluid contamination of the interior of the strut

disconnect assembly; repetitive inspections for discrepancies of the interior of the strut

disconnect assembly, if necessmy; repetitive inspections of the exterior of the strut

disconnect assembly lor cracks, if necessary; and corrective action if necessary. This

proposed AD also provides an optional terminating action for the inspections. This

proposed AD results from reports of system disconnect boxes that have been

contaminated with hydraulic fluid and. in one incident, led to subsequent cracking. W·

are proposing this AD to detect and correct hydraulic fluid contamination. which can

cause cracking of titanium parts in the system disconnect assembly, resulting in

compromise of the engine firewall. A cracked firewall can allow fire in the engine are.

enter the strut and can lead to an uncontalled engine strut fire if flammable fluid is

present. Cracking of the disconnect box may also compromise the effectiveness ofthe

fire extinguishing system in the engine compartment and could contribule to an

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uncontained engine fire. In addition, a cracked disconnect box can leak flammable Qui 1

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into the engine core, which can initiate an engine fir~ ~ ~ -t:\. c::t& ~~.-- _

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