14 CFR Part 39

·14910-13

DEPARTMENT OF TRANSPORT AnON

Federal Aviation Administration

DlO'5

IDocket No. FAA-2010-+++++; Directorate Identifier 2009-NM-206-AD)

R1N 2120-AA64

Airworthiness Directives; McDonnell Douglas Corporation Model OC-9-14, DC-9-1

and DC-9-15F Airplanes; and Model DC-9·20, DC-9-30, DC-9-40, and DC-9-50 S

Airplanes

AGENCY: Federal Aviation Administration (FAA), Department of Transportation

(DOT).

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: The FAA proposes to supersede an existing airworthiness directive (

that applies to certain Model DC-9-14 and OC-9-15 airplanes; and Model DC-9-20,

OC-9-30, DC-9-40, and DC-9-50 series airplanes. The existing AD currently requires

repetitlve high frequency eddy current inspections to detect cracking in the vertical fadi

(also known as the "vertical leg") oflhe upper 1ap of the center wing rear spar, and rep

ifnecessary. This proposed AD expands the area to be inspected by including inspectio

to detect cracking orthe horizontal flange ofthi upper cap of the left and right center

wing rear spar, and repair if necessary. This prJposed AD also adds c~rtain airplanes to

the applicability. This proposed AD results frol reports of cracking in the horizontal

flange on the inboard side of the of the rear spar upper cap, which resulted from stress

DATf

corrosion. We are proposing this AD to detect and correct cracking in the vertical leg or

the horizontal flange of the upper cap of the le~ or right center wing rear spar, which

could cause a possible fuel leak, damage to the wing skin, and structural failure of the

upper cap, and result in reduced structural integrity of the airplane.

FAA Form 1360-14.1 (6-89) OFFICIAL FILE C0PY

* U.S,GPQ:' 990<1· 766-01 2!20' 0'
[4910-I3-P]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CPR Part 39

fDocket No. FAA~2009~+++++; Directorate IdcntifiC12009_NM-206-ADl

RIN 2120-AA64

Ain\'orfhiness Directives; McDonnell Douglas Carpar" tion Model DC-9~ 14 and

DC-9-15 Airplanes; and Model DC-9-20, DC-9-30, DC-~-40, and DC-9-50 Senes

Airplanes I

AGENCY: Federal AVlahon Admill1stration (FAA), Department of Transportation

(DOT).

ACTION: Notice of proposd rulemaking (NPRM).

SUMMARY: The FAA proposes to supersede an existirg airworthiness directive (AD)

that applies to certain Model DC-9-] 4 and DC-9-15 airplanes~ and Model DC-9-20,

DC-9-JO, DC-9-40, and DC-9-50 se,ies ai'planes. The +sting AD currently wqui,es

repetitive high frequency eddy current inspections to delfct cracking in the Vertical radius

of the upper cap of the center wing rear spar, and repair ilf necessary. This proposed AD

expands the area to be inspected by including inspection ofthe horizontal nange of the

upper cap of the left and right center wing rear spar, and repair if necessary_ This

proposed AD re~-ullsfrom reports of cracking in the horizontal flange on the inboard side

of the of the rear spar uppereap, which resulted from strtl 5S corrosion. We are proposing

this AD to detect and correct cracking in the vertical leg I r the honzontal flange of the

upper cap orthe left or right cent..::rwmg rear spar, Wlllclr could cause a possible fuel

leak, damage to the ",ing skin, and structural failure of tIe upper cap, and result in

reduced structural integrity of the airplane

DATES: We must receive comments on this proposed 0 by rInsert date 45 days after

date of publication in the FEDERAL REGISTER].

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FAA Form 13611-14.1 (6-89) OFFICIAL FILE COpy \,>U.$.GOVERNMLNTf'RINTINGOi'FICE: 1~'· 76~211

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