[49IO-13-P)

W\I

INII'IM.S.'SIG

-1

C~

hftt 1'0

"OUT,,,G 'YMR"l.

ROUTING S\'MHOL

IWfE

[Docket No. FAA-20IO-++++; Directorate Ide[tifier 2010-NM-095-AD]

RlN 2120-AA64

Airworthiness Directives; Learjet Inc. Model 4 Airplanes

AGENCY; Federal Aviation Administration (FtA), DOT.

ACTION; Notice of proposed rulemaking (NPRM).

SUMMARY: We propose to adopt a new airwokhiness directive (AD) for certain

I

Learjet Inc. Model 45 airplanes. This proposed tD would require replacing aluminum "OUT"aSYMBOL

fire extinguisher discharge tubes with new, impTved tubes; checking the fire INITIALS'SIG

extinguisher container for certain serial numbers; replacing fire extinguisher containers I,; j)/~

I o,;~o

that have affected serial numbers; inspecting thelpressure indicator on certain fire RO~,(:;'.,nJD

extinguisher containers for discrepancies; and pf(rforming corrective act~on ifnecessary. _ ov

,I I I ].5'".

This proposed AD results from a report of aCCidfntal discharge of a fire extinguisher

container and damage to an aluminum dischargl tube. Investigation revealed that .,~,'3;y,

following the discharge an inaccurate pressure inI dicatioll, due to the indicator dial being

f h

'N[TLAlqIG incorrectly staked_ showed that the contamer war Ully c arged. We are proposing this

AD to prevent inaccurate pressure readings and fubsequent damage to the discharge tub :sm

during operation, which could result in failure of the fire extinguisher system and an ROun~\""M"OI,

14 CFR Part 39

Federal Aviation Administration

DEPARTMENT OF TRANSPORTATION

uncontained fire in an emergency situation. INITIM"/jIG

DATES: We must receive comments on this priPosed AD by [INSERT DATE 45

DAYS AFTER DATE OF PUBLICA nON IN THE FEDERAL REGISTER].

ADDRESSES: You may send comments by anJ of the following methods:

• Federal eRulemaking Portal: Go to httJ://Vo."Nw.regUlations.gOv.Follow the

D.HE

instructions for submitting comments.
DEPARTMENT OF TRANSPORTATION

/491O-13-Pj

14 CFR Part 39

Federal Aviation Administration

IDocket No. FAA-2010·++++j Directorate IdCrtifier 2010-NM-095-ADI

RIN 2120-AA64 "'" I

;'6 oK lD

Airworthiness Directives; Lemjet Inc. Model 4$ Airplanes n,1 , .~ -. "~l. pn.

AGENCY: Federal Aviation Administration (Fr)' DOT. "".~o.,,"~£,

ACTION: Notice of proposed rulcmaking (NPRM). ['""m I "Y·/~

SU~MARY: We propose to adoPt.anew airworthiness directi~e (AD) ~orcertai~ '4~<

Learyet Ine. Model 45 airplanes. This proposed ~D would reqUIre replaemg alummum ,.fr~;.,£

fire extinguisher diseharge tubes with new, imprLed tubes; ebecking the fire ""'0- _If)

extmb'Uisher cuntainer for certain serial numbers! replacing fire extinguisher containers l[r' ,-,

that have affeeted senal numbers; inspectmg the rressure indicator on eertain fire

extinbruisher containers for discrepancies; and performing corrective achon if necessa

This proposed AD results from a report of accidJntal discharge of a fire extinguisher

eontainer and damage to an aluminum diseharge rUbe. Investigation revealed that

following the discharge an inaccurate pressure in(lication. due to the indicator dial bein

incorrectly staked, showed that the container wJ fully charged. Weare proposing this "o;'''''JS'''''(;(lL

AD to prevent inaccurate pressure readings and SlbSeqUent damage to the discharge tu es"".L3!S'[,"'''L'~E

during operation, which could result in failure oJthe fire extinguisher system and an

uncontained fire in an emergency situation.

DATES: We must receive comments on this proposed AD by [fNSERT DATE 45

I

DAYS AFTER DATE OF PUBLICA nON IN jHE FEDERAL REGISTER].

ADDRESSES: You may send comments by any ofthe following methods:

• Federal eRulemaking Portal: Go to http.//www.rcgu1<llioIlS.goV. Follow the

"'''''r''3 SV""Cl

"""1' '..""""'"

"'1

n''''rr. :;,",'OO[

.",,,",-~.,$;(""""" ,

instructions for submitting comments.

\ (l.S. GOVEflNMUJr PAIUTING onlC( 1m 169·~11

FAA Form 1360-14.1 (6-89)