14910-13-P)

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. FAA-2010-0042; Directorate Identifier 2009-NM-OIO-AD)

RlN 2120-AA64

Airworthiness Directives; 8aab AB, Saab Aerosystems Model SAAB 340A

(SAAB/SF340A) and SAAB 340B Airplanes Mbdified in Accordance with Supplemen

Type Certificate (STC) SA00224WI-D, STOOI416WI-D,or SA984GL-D

AGENCY: Federal Aviation Administration (FAA), DOT.

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ACTION: Supplemental notice of proposed ruJemaking (NPRM); reopening of comme

period.

SUMMARY: We are revising an earlier proposed aiIViorthiness directive (AD) for

.

certain Saab AB, Saab Aerosystems Model SAAB 340A (SAAB/SF340A) and SAAB

340B airplanes. The original NPRM would have required inspecting the fuselage sUTfae o;w.H

for corrosion and cracking behind the external aoapter plate of the antennae installation, OOU1''''' SY~5O<-

and repair if necessary. The original NPRM resJlted from a report ofa crack found tNm~LSlSIG"~rU~£

behind the external adapter plate of the antennaJ during inspection. Similar cracking wa c~Te

found on two additional airplanes, and extensiv1 eorrosion was found on one airplane.

This action revises the original NPRM by correiting an STC Dumber, which would

expand the applicability of the original NPRM. We are proposing this supplemental

NPRM to detect and correct corrosion and cracking behind the external adapter plate of

the antennae of certain damage-tolerant structure, which could result in reduced structur

integrity and consequent rapid depressurization of the airplane.

DATES: We must receive comments on this supplemental NPRM by [INSERT DATE

• U.S,GPQ, ,1190-<I- 768-0' 2120 I 0 1

25 DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER].

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

I

OFFICIAL FILE C0PY FAA Form 1360-14.1 (6-89)
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Federal A\'iation Administration

14 CFR Part 39

[Docket No. FAA-20tO-0042; o;rCCloratc Idc1ntificr 2009·NM-OIO-ADJ

IUN 2120-AA64

DEPARTMENT Of TRANSJ'ORT-AnON

Ain\'orthincss Directives; Saab AS, Saab Acrasystems Model SAAB 340A

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(SAAB/SF340A) and SAAB 3408 Airplanes Modified in Accordance with Supplemc; ~~~

Type Certificate (STC) SA00224WI-D, STOOI46WI-D, or SA984GL-D o.o.n -

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?-1JV'""7e 2iJ/D

AGENCY: Federal Aviation Administration (FfA), DOT. l:~€O;

ACTION: Supplemental notice of proposed rulcmaking (NPRM); reopening of com~WltfuAu

period. \.-.l:

SUMMARY: We are revising an earlier propostd airworthiness directive (AD) for """''''''Sno __

certain Saab All, Saab Acrosys,[.cllls Model SA1B 340A (SAAB/SF340A) ,nd SAAIl! "

340B airplanes. The original NPRM would have required inspecting the fuselage surf; ~e2k-1£Q

for corrosion and cracking behind the external JaPlcr plate of the antennae installatio :]5)

and repair if necessary. The onginal NPRM resulted from a report ora crack found

bch;nd [he ex[e""l adapter pl,[e of [he 'ntennJ during ;nspectwn. S;ntil,r crock;ng \ ;:;"

found on two add;[;on,i ,;rplanes, and ex[eos;vcicorros;on was found on one a;rpi,nel<;=,,,"~

This action revises the original NPRM by correClting an STC number, which would

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expand the applicability of lhe original NPRt•••.. 1. We are proposing this supplemental

. I - .."'" SYloISOI.

NPRM to detect and correct corrosion and ctacking behind the external adapter plate ,.. 0"

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the antennae of ceria in d,'llH1gc-lolerant strllCltlr~, which could result in reduced strue! mll

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integrity and consequenL rapid depressurization of the airplane.

DATES: We must receive commenlS on this SU~Plemel~(a( NPRM by [INSERT Dl~:rE.

25 DA YS AFTER DATE OF PUBLICATION fN THE FEDERAL REGfSTERj.

ADDRESSES: You may send comments by any of the foJlowing methods:
DEPAR.TMENT OF TRANsrOR11A TION

Federal Aviation Administration

]4 CFR Pnrt 39

IDocket No. FAA-201 0-0042; Dirceloflllc Idcntifie:r 2009*NM~OIO-AD[

R1N ZlZO*AA64

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Airworli.incss Dirceti,'cs; Saab AI3, Saab ;\erosystcllls Model SAAB 340/\ """"•••.•,,'00<.

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(SAAB/SF340A) and SAAB 340B Airplanes Modified in Accordance with Supplemcllm--'="'-.:

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Type Certifi,calc (STC) 8A00224\\'I-O, STOOI16W1-D, or SA9S4GL-D "'''.

AGENCY: Federal Aviation Administration (FrA), DOT.

AcnON: Supplemental noticc of proposed rulcmaking (NPRlvf); reopening of comn;tttrt:r1

period. \ ,"""" ...1..-I D

SUMMARY: We arc revising an earlier proposed ail"\'1onhiness directi\'c (AD) lor """""'~•.•-

I I ~

certain Saab AB, Saab Aerosys.\ems ModeJ SAtB 340A (SAA13/SF340A) and SAAI3- .•••••••.•.• ..,.....,,.,;

34013 airplanes. The original NPRM would have required inspecting the fuselage surt: "el(

for corrosion and cracking behind the external a~aPlcr plate of the· antennae illstallatio 115"0<>.

and I """""""""""""'" repair jf necessary. The original NPRM resulted from a report of a crack found nd

behind lhe exlcrnal ndaptcr platc of the amellnad during illspccti~n. Sim iJar cracking \ ,1S"

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found 011 two additional nirplanes, and extensive corrosion W(1S found on om.: airplane'l

I . ·~rw"",.,,•.""""

This action revises the original NPRM by correcting nn STC number, which would

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expand the applicability of Ihe original NPRM. \IVe me proposing this supplemelltal

NPRM to dctecl and correct corrosion and cr"ad~j,ngbchind the exlernal adapler plate f

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I "~="""""'" the antennae of cerl,lin damage-tolcr<nll structure, which could res\lJ[ ill reduced slruct tral

. "d "dd" " If I " I .,. 1Il1cgmyan consequent rapl cpresSUrJ7.<l.llOll0 tIC UlfP ,me. .

DATES: We must receive- eommcll!~ Oilthis sU~PICmCnla[NPRM by [INSERT DJ.l.Tl::

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25 DAYS AFTER DATE Or: PUBLICATION IN Ti-IE FEDEHAL REGISTER].

ADDRESSES: YOLI JI1<1Y send commenls by anJ orllle following methods:

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