14910-13-P] DEPARTMENT OF TRA<'lSPORTATION Federal Aviation Administration _<lNC\I~"I.~CES oun"G S'/M50l 14eFR 

### Part 39 , _



### 'lb\\-OO'2lP [DocketNo.FAA-~·++++; Directorate Identifier 2010-NM-.104-ADJ '''''''lS{SI(; 

## A 

# z..'£if1
n 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 ofproposed rulemaking (NPRM). SUMMARY: We 

### :r:ropose to adopt anew airwOltbincss directive (AD) for cert Model 777-200 and -300 series airplanes. This proposed AD would require doing repetitive inspections for hydraulic nuid contamination ofthe interior ofthe strut disconnect assembly; repetitive inspections for discrepancies ofthe interior ofthe strut disconnect assembly, ifnecessary; repetitive inspections oftbe exterior ofthe strut j~ I /0 «lUl1;C; S'1'IIl<ll 

# 4'u",-{'-ID~ NffiAUlSlli 

### k..l< 

### \7./'/10

NJIlJ';L.5{Slti • TIHG S't>IOOI. 

# 4-

~ DUnNli S'fMllOl 

# -7 l"!noeSlS'" 

## C.Ct.r.-- compromise ofthe engine firewall. A cracked fire\vall can allow fIreintht:engine are enter the strut and can lead to anWlcontained engine strut fire ifflammable fluid is cause cracking oftitanium parts inthe system disconnect assembly, resulting in disconnect assembly for cracks, jf necessary; and corrective action ifnecessary. 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 ofthe 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 ofsystem disCOllllcctboxes that have 

### been

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

### '" into(heengine core, whichcaninitiateauenginetir~ ~ 

# vJl. "h\~ -'~ ",,'.JU9. \<>..<J. b O~ <>/ 

## b, ~\-

## fir-c:.. 

# '-<:>~.;v, 

# &.,~ e..u.._,A ~.(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 ;ONC\J~~ElIrES OUTING sYMOOl 

### A~1>l-II<f ",mAI.5151G 

## A. Zat"

# Of,

'''It j 2. I ID

, 5'>'I!IOL 

### 4-,](h-,'I05 ~JTI.&lSIS1G 

### k
...1< 

# rtJ./, 0
ACTION: Notice of proposed rulemaking (NPRM). AGENCY: Federal Aviation Administration (FAA), DOT. l;'iU/..., •..•.. ~<...-- (,.....J.f.pJ~

z..~l"'-'O OOTIr SYMiIQI, 

## ...~,& INIl\AY"StG SUMMARY: We propose to adopt anew 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 ofthe interior ofthe strut disconnect assembly; repetitive inspections for discrepancies ofthe interior ofthe strut disconnect assembly, ifnecessmy; repetitive inspections ofthe exterior ofthe strut disconnect assembly lor cracks, ifnecessary; and corrective action ifnecessary. 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 oftitanium parts in the system disconnect assembly, resulting in compromise ofthe engine firewall. A cracked firewall can allow fire in the engine are. enter the strut and can lead to an uncontalled engine strut fire ifflammable fluid is present. Cracking ofthe disconnect box may also compromise the effectiveness ofthe fire extinguishing system in the engine compartment and could contribule to an OunNc; SYMBOL uncontained engine fire.

# Inaddition, acracked disconnect box can leak flammable Qui 1 'NI1\A1.SISlc; into the engine core, which can initiate an engine fir~ ~ ~ 

# -t:\. c::t& ~~.--

_ (,.Q'.~ \~ 

# b D~ 

## w- 

# )",,,1-',..f{r-.:... L.o~'D~

__ 

# &.,' UJ"M

..• ·~ 

## cJk. G'4~
..