14910-13-U]

m,PARTMENT OF TRANSPORT ATlON FederralAviation Administration 14 CFR 1'•• 139 

## 2.010- 0/73 [flocket No. FAA_' , , , '; Ilirectorate Identifier 2009-NM-076-AJ:l] iUN 2120-AA64 >ATE 

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that applies to allBoeing Model 737-100, -200, -200e, -300, -400, and -500 series SUMMARY: The FAA proposes to supersede an existing airworthiness directive (AD) ACTION: Notice ofproposed ru!emaking (NPRM). Airworthiness J!)irectives; Boeing Model 737-19°, -200, -20De, -300, -400, and -500

any new or serviceable carriage spindle installed per therequirements ofthe existing AD to meet minimum allowable diameter measurements taken atthree locations. 

### TIris airplanes. The existing AD currently requires repetitive inspections to find cracks, fractures, orcorrosion ofeach carriage spindle ofthe left and right outboard mid-flaps; ATE 

### 12 and corrective action, 

### ifnecessary. The existing AD also currently requires repetitive gap AGENCY: Federal Aviation Administration (FAA), Department ofTransportation

checks ofthe inboard and outboard carriage ofthe outboard mid-flaps to detect fractured carriage spindles; and corrective actions, ifne,cessary. This proposed AD would require (DOT). Series Airplanes

ofthe carriage spindles, and applicable corrective actions. In addition, this proposed AD 1'1 ,A~Sl proposed AD also would require new repetitive inspections, measurements, and ovcrhau 

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# '-1-/0) would require replacing any carriage spindle when ithas reached its maximum life limit. 

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- (D( '1mA1.SISIG 'Ibis proposed AD results fromreports offractures that resulted from stress corrosion an 

### ., pitting along the length ofthe spindle ana spindle diameter, and additional reports of /'" O\/TUIG SfMllOL corrosion on the outboard flap carriage spindles. We areproposing this AD to detect and 

## ~-lO /) correct cracked, corroded, orfractured carriage spindles, and toprevent severe flap14910-13-lJ]

DEPARTMENT OF TRANSPORTATION Federal Aviation Administration 14eFR 

### Part 39 [Docket No. FAA-2009-+++t+; Direetorate Identifier 2009-NM-076-AD) :R1N2120-AA64 Airwortbiness Directives; Boeing Model 737-100, -200, -200C, -300, -400. and -500 Series Airplanes AGENCY: Federal Aviation Administration (FAA), Department ofTransportation 

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## t2J'\V'l (DOT). ACTION: Notice ofproposed rulemaking (NPRM). 

# S, fractures, orcorrosion ofeach carriage spindle ofthe left and right outboard mid-flaps; AU do 0 Of Th 0 0 AD I tl 0 00 12 

## I an corrective actIOn, I necessary. eeXlstmg a so curren y reqUires repetItive gap , OL checks ofthe inboard and outboard carriage ofthe outboard mid-flaps to detect fractured 

# ;;ffi-lG airplanes. The existing AD currently requires repetitive inspections to fmd cracks,

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

# r SUM:MARY: The FAA proposes to supersede anexisting airworthiness directive (AD) 0"""

any new or serviceable carriage spindle installed per therequirements ofthe existing AD to meet minimlliIl allowable diameter measurements taken atthree 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 ofthe carriage spindles, and applicable corrective actions. In addition, this proposed AD would require replacing any carriage spindle when ithas reached its maximum life limit.
- This proposed AD results fromreports offractures that resulted from stress corrosion an pitting along the length ofthe 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, orfractured carriage spindles, and to prevent severe flap