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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration O~CUI\I\E'lCES

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[Docket No. FAA-2010-++++; Directorate Identifier 2009-NM-214-ADJ

Airworthiness Directives; The Boeing Company Model 747-100, 747-100B,

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747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747SR, and 747SP 1.li

14 CFR Part 39

: RIN 2120-AA64

Series Airplanes 2-2 -\0

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instructions for submitting comments.

DATES: We must receive corrunents on this proposed AIDby [INSERT DATE 45

DAYS AFTER DATE OF PUBLICATION IN THE FEDF.RAL REGISTER].

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

• Federal eRulemaking Portal: Go to http://www.lgulations.gov. Follow the

AGENCY: Federal Aviation Administration (FAA), DOl'

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: We propose to adopt a new airworthiness drrective (AD) for certain Mod I 5 \ U

747-100, 747-100B, 747-100B SUD, 747-200B, 747-200G:, 747-200F,747-300, 747-40 ;1J\£6

747SR, and 747SP series airplanes. This proposed AD wolld require repetitive detailed Nmi\l.Sf51G

inspections of certain overwing intercostal webs, and rel'led investigative and correctiv A{lfl

actions if necessary. This proposed AD results from reports'.of cracks in overwing ,NG SYMBOL

intercostal webs. We are proposing this AD to detect and Lrrect such cracking, which

could grow and result in a severed, intercostal. If an intercbstal is severed, cracks could

develop in the adjacent frame structure and skin, reSUltinJ in a rapid loss of cabin

pressure.

• Fax: 202-493-2251.

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DEPARTMENT OF TRANSPORT ATION

Federal Aviation Administration

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14 CFR Part 39

[Docket No. FAA-201O-++++; Directorate Identifier 2009-NM-2I4-AD]

RIN 2120-AA64

Ain\'orthiness Directives; The Boeing Company Model 747-100, 747-100B, /.;cs· (HI747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-400, 747SR, and 747SP 1. l;

Series Airplanes

AGENCY: Federal Aviation Administration (FAA), DOT.

.2-2 -1 0

ACTION: Notice of proposed rulemaking (NPRM).

SUMMARY: We propose ~oadopt a new airv.rorthiness d~rective (AD) for certain Mod rn: I

I 5 \0

,- 747-100, 747-100B, 747-100B SUD, 747-200B, 747-200C, 747-200F, 747-300, 747-40 '5Qii'fq

747SR, and 747SP series airplanes. This proposed AD would require repetitive detailed

inspections of certain overwing intercostal webs, and relatld investigative and correctiv

I

actions if necessary. This proposed AD results from reports of cracks in overwing

intercostal webs. We are proposing this AD to detect and correct such cracking, which

could grow and result in a severed intercostal. If an intercoltal is severed, cracks could

develop in the adjacent frame structure and skin, resulting in a rapid loss of cabin

pressure.

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

DAYS AFTER DATE OF PUBLICATION IN THE FEDERAL REGISTER].

ADDRESSES: You may send comments by any of the fOllOWingmethods:

• Federal eRulemaking Portal: Go to http://www.regulations.gov.Fo(low the

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instructions for submitting comments .

• Fax: 202-493-2251.

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