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ADDRESSES: You may send co ents by any of the following methods:

[4910-13-P]

Ajnvorthiness Directives; The loeLng Company Model 737-600, -700, -70De, -800,

and -900 Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

ACTION: Notice of proposed ruJemaking (NPRM). .

SUMMARY: We propose to sUPfrsede an existing airworthiness directive (AD) that

applies to the products listed abOr' The existing AD currently requires replacement of

the power control relays in the P9

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1 and P92 power distribution panels for the fuel boost

and override pumps with new, improved relays having a ground fault interrupter (GFI)

feature, or installation and maintcrance of universal fault interrupters (UFls) using a

certain supplemental type certificate. Since we issued that AD, we have determined that

we need to clarify which relays nJay be replaced by installation ofUFIs. This proposed

AD would continue to require th1 actions of the existing AD and also specify which

relays may be replaced by GFls or UFls. We are proposing this AD to prevent pump

housing burn-through due to ele+ical arcing, which could create a potential ignition

source inside a fuel tank. This condition, in combination with flammable fuel vapors,

could result in a fuel tank exPlosihn and consequent loss of the airplane.

DATES: We must receive comn+lts on this proposed AD by [INSERT DATE 45

DAYS AFTER DATE OF PUBL CATION IN THE FEDERAL REGISTER].

DEPARTMENT OF TRANSPiRTA TION

Federal Aviation Administratior

14 CFR Part 39 I \Cf il

[Docket No. FAA-10lO-++++; directorate Identifier 2010-NM-225-AD]

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[4910-13-P[

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

(Docket No. FA....o\-2010-++++; Directorate Identifier 2010-NM-225- ..:\.Dj

RlN 2120-AA64

Airworthiness Directives; The Bleing Company Model 737-600. -700, -700C, -800,

and -900 Series Airplanes

AGENCY: Federal Aviation Administration (F.M), DOT.

ACTION: Totice of proposed ruliaking (NPRM).

SUMMARY: We propose to supe!Sede an existing airworthiness directive (AD) that

applies to the products listed abovd. The existing AD currently requires replacement of

the power control relays in the P91 and P92 power distribution panels for the fuel boost

and override pumps with new, Ilnproved relays having a ground fault interrupter (GFI)

feature, or installation and maintenrce ofun;versal fault inlCnUjlters (UFls) using a

cCltain supplemental type certi ncar, Since we issued that AD, we have determined that

we need to clarify which relays m be replaced by installation of UFIs. This proposed

AD would continue to require the clions orthe existing AD and also specify which

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housing bum-through due to electr cal arcing, which could create a potential ignition

source inside a fuel tank. This COlllitlon, in combination with nammable fuel vapors,

could result in a fuel tank eXPIOSiOr and consequent loss of the airplane.

DATES: We must receive comments on this proposed AD by [L"JSERT DATE 4S

DAYS AFTER DATE OF PUBLI~A nON [N THE FEDERAL REGISTER].

ADDRESSES: You may send COl~Jl1enlSby any orthe following methods:

,

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relays may be replaced by GFrs or Is. We are proposing this AD to prevent pump