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14 CFR Part 39

FAA Form 1360·14.1 (6-89)

DEPARTMENT OF TRANSPORT ATION Federal Aviation Administration



# OfbS5 (Docket No. FAA-2010-++++j Directorate Identifier 201O-NM-066-AD] RlN 2120-AA64 Airworthiness Directives; The Boeing Company Model 737-300, -400, and -500 Serie Airplanes AGENCY: Federal Aviation Administration (FAA), Department ofTransportation (DOT). ACTION: NotIce ofproposed rulemakllig (NPr) SUMMARY: The FAA proposes to supersede an existing airworthiness directive (AD) OATE~ that applies to all Model 737-300, -400, and -501 series airplanes. The existing AD 

# !.~:'"~ currently requires repetitive inspections for discrepancies ofthe fuse pins of the inboard 1~rw.t=IC~ATURE and outboard midspar fittings ofthe nacelle stTUtl and corrective actions ifnecessary. 'J.'TE This proposed AD would continue to require the[repetitive inspections required by the ~m.~ ""~. existing AD and add replacing the midspar fuse pins with new, improved fuse pins, 'NfTl.£l-StS'GM'W~E 

## I which would terminate the repetitive inspections!. This proposed AD results from arepo T" ofcorrosion damage ofthe chrome runout on thJ head side found on all four midspar fus ~~,,,,," .ruM pins ofthe nacelle strut. Additionally, alarge p+ion ofthe chrome plate was missing ,"m,~,"""'" from the corroded area ofthe shank. We are proposing this AD to prevent damage ofth DAle fuse pins ofthe inboard and outboard midspar fi~ings ofthe nacelle strut, which could I roUTING sruBOC result in reduced structural integrity ofthe fuse pins and consequent loss ofthe strut and



# 1 'HmAC=lGNATW~e separation ofthe engine from the airplane. DArt DATES: We must receIVecomments on this pr posed AD by [INSERT DATE 45 I DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER]. ADDRESSES: You may send comments by an)]]I, ofthe following methods:

• U.S.GPO: 19\1O-O-lll8·0 12120 101 OFFIClAL FILE COpy[4910-13-Pj

DEPARTMENT OF TRANSPORTATION Federal Aviation Administration -m'CURRE"CE$ OUTI"G S""BDL 14 CFR Part 39 

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### &9:1\1 0 Airworthiness Directives; The Boeing Company Model 737-300, -400, and -500 Series ROUTINGSY"BOL I 

# m"~ RlN 2120-AA64 (Docket No. FAA-2010-++++j Directorate Identifier 201O-NM-066-AD]

AGENCY: Federal Aviation Administration (FAA), Department ofTransportation

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### c"/,,) ACTION: NotIce of proposed rulemakmg (NPRM). [N~}mSISIC SUMMARY Th FAA : d I

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. : e' proposes to superse e an eXlshngaIrwo mess lrectlve DA~E I

.. . that applies to all Model 737·300, ADO, and -500 series airplanes. The existing AD G:2 '-I Ie- ·0" "'l $yo'llo) currently requires repetitive inspections for discrbpancies ofthe fuse pins ofthe inboard I !. AI, iSIG and outboard midspar fittings ofthe nacelle stru-d, and corrective actions ifnecessary. ' DAT~ 10 n,is proposed AD would continue to require tbe repetitive inspections required by the 

### .7 OUllNG YM60L existing AD and add replacing the midspar fuse pins with new, improved fuse pins, 

## '5Er-t I INmAl5/S1G which would telminate the repetitive inspections'. This proposed AD results from arepo t i<:{) I OAT" ofcorrosion damage ofthe chrome runout on the head side found on all four midspar fu ~ I

. aUnNG SYMBOL pins ofthe nacelle strut" Additionally, alarge portion ofthe chrome plate was missing Ht-..Jfh-"\OO:J from the corroded area of the shank. We are pr+oSing this AD to prevent damage ofth fuse pins oftbe inboard and outboard midspar fittings ofthe nacelle strut, which could 

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# )/'0 I aUnNG S~MOOL result in reduced structural integrity ofthe fuse pins and consequent loss ofthe strut and separation ofthe engine hom the airplane. DATES: We must receive comments on this prrposed AD by [INSERT DATE 45 DAYS AFTER DATE OF PUBLICATION IN ,HE FEDERAL REGISTER]. ADDRESSES: You may send comments by an); ofthe following methods: aunNG SYMBOL

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DEPARTMENT OF TRANSPORTATION Federal Aviation Administration ~ONCLJ"'R£"CE$ OUTING SYMBOL 14 CFR Part 39 [Docket No. FAA-2010-++++; Directorate Identifier 2010-NM-066-AD)

.RIN 2120-AA64 I 

### 6>9.'310 Ainvorthincss Directives; The Boeing Company Model 737~300, -400, and -500 Series ROLJW<GS<MBOL '1Y\~2lJ_ n Airplanes AGENCY: Federal Aviation Administration (F!A.A), Department ofTransportation (DOT). lNITIALSfSIG 

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~I ACTION: Notice ofproposed rulemaking (NPj)' 

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.. SUMl\1ARY: The FAA proposes to supersede an existing airworthiness directive (AD) DATE that applies to all Model 737-300, -400, and

# -506 series airplanes. The existing AD (,;:2 '/ 

### j lecurrently requires repetitive inspections for disc)epancies ofthe fuse pins of the inboard and outboard midspar fittings ofthe nacelle 5tmJ and corrective actions ifnecessary. This proposed AD would continue to require the repetitive inspections required by the 

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OUTING SYMBOL existing AD and add replacing the midspar fuse pins with new, improved fuse pins, which would terminate the repetitive inspectionSI This proposed AD results from arepo , ofcorrosion damage ofthe chrome runout on the head side found on all four midspar fu I

. OVTl~G SYM60~ pins ofthe nacelle strut. Additionally, a large portion ofthe chrome plate was missing 

## f1t'JrY\--i OO~ I j~IllAI.s/SIG from the corroded area ofthe shank. We are proposing this AD to prevent damage ofth I JI~ fuse Pi.nsofthe inboard and.outbO. ard midspar fitf.ings ofthe nacelle strut, which could



### I. QJJTING SYMBO~ result III reduced structural mtegnty ofthe fuse pr' ns and consequent loss of the strut and NmJllSiS1G separation of the engine from the airplane. , 

### "~ DATES: We must receive comments of!- this prlposed AD by [INSERT DATE 45 DAYS AFTER DATE OF PUBLICATION rN HE FEDERAL REGISTER]. ADDRESSES: You may send comments by any ofthe following methods: NmAl.5/S1G

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