14910-13-U]

m,PARTMENT OF TRANSPORT ATlON

Federral Aviation Administration

14 CFR 1'•• 139

2.010- 0/73

[flocket No. FAA_' , , , '; Ilirectorate Identifier 2009-NM-076-AJ:l]

iUN 2120-AA64

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that applies to all Boeing Model 737-100, -200, -200e, -300, -400, and -500 series

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

ACTION: Notice of proposed ru!emaking (NPRM).

Airworthiness J!)irectives; Boeing Model 737-19°, -200, -20De, -300, -400, and -500

any new or serviceable carriage spindle installed per the requirements of the existing AD

to meet minimum allowable diameter measurements taken at three locations. TIris

airplanes. The existing AD currently requires repetitive inspections to find cracks,

fractures, or corrosion of each carriage spindle of the left and right outboard mid-flaps; ATE

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and corrective action, if necessary. The existing AD also currently requires repetitive gap

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

checks of the inboard and outboard carriage of the outboard mid-flaps to detect fractured

carriage spindles; and corrective actions, ifne,cessary. This proposed AD would require

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Series Airplanes

of the carriage spindles, and applicable corrective actions. In addition, this proposed AD

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proposed AD also would require new repetitive inspections, measurements, and ovcrhau G

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would require replacing any carriage spindle when it has reached its maximum life limit. lAA.- (D(

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'Ibis proposed AD results from reports of fractures that resulted from stress corrosion an

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pitting along the length of the spindle ana spindle diameter, and additional reports of /'"

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corrosion on the outboard flap carriage spindles. We are proposing this AD to detect and ~-lO /)

correct cracked, corroded, or fractured carriage spindles, and to prevent severe flap
14910-13-lJ]

DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 eFR Part 39

[Docket No. FAA-2009-+++t+; Direetorate Identifier 2009-NM-076-AD)

:R1N 2120-AA64

Airwortbiness Directives; Boeing Model 737-100, -200, -200C, -300, -400. and -500

Series Airplanes

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

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ACTION: Notice of proposed rulemaking (NPRM).

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fractures, or corrosion of each carriage spindle ofthe left and right outboard mid-flaps; AU

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o 0 Of Th 0 0 AD I tl 0 00 12 I

an corrective actIOn, I necessary. e eXlstmg a so curren y reqUires repetItive gap , OL

checks of the inboard and outboard carriage of the outboard mid-flaps to detect fractured ;;ffi-lG

airplanes. The existing AD currently requires repetitive inspections to fmd cracks,

carriage spindles; and corrective actions, if necessary. This proposed AD would require ATE

r

SUM:MARY: The FAA proposes to supersede an existing airworthiness directive (AD) 0"""

any new or serviceable carriage spindle installed per the requirements of the existing AD

to meet minimlliIl allowable diameter measurements taken at three locations. 'l1ris -

that applies to all Boeing Model 737-100, -200, -200e, -300, -400, and -500 series

proposed AD also would require new repetitive inspections, measurements, and overhau

of the carriage spindles, and applicable corrective actions. In addition, this proposed AD

would require replacing any carriage spindle when it has reached its maximum life limit. -

This proposed AD results from reports of fractures that resulted from stress corrosion an

pitting along the length of the spindle ana spindle diameter, and additional reports of

corrosion on the outboard flap carriage spindles. Weare proposing this AD to detect and

correct cracked, corroded, or fractured carriage spindles, and to prevent severe flap