Service difficulty report · Stud · Bell 430

Difficulty date
January 20, 2010
Submitted
March 1, 2010
Operation
General aviation
Make and model
Bell 430
Engine
Allsn 250C40B
Part
Stud
Part number
AN154720
Condition
Loose
Location
Gearbox
Part time
3,319 hours
Component
Gearbox · C40B
Stage of operation
IN
How discovered
V
Nature of condition
O
Precautionary procedure
K

As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.

What was found

(CAN) QTY (2) STUDS PARTIALLY BACKED OUT OF THE THREADED HOLES OF THE 2-1/2 BRG CAGE MOUNTING BOSS. STUDS BACKED OUT APPROX 1 AND 2 THREADS RESPECTIVELY. NUTS ON THESE STUDS DID NOT HAVE ANY REMAINING TORQUE ON THEM. NUTS ON THE REMAINING STUDS WERE ALSO LOOSE. SIGNIFICANT FRETTING NOTED ON GEARBOX COVER UNDERNEATH BRG CAGE AS A RESULT OF VIBRATION/LOOSENESS. TWO PREVIOUS OCCURRENCES OF THIS CONDITION HAVE BEEN NOTED ON C47 ENGINES. C47B CAE847306 (TSN 4095.4, CSN 11987) NOVEMBER 2008 AND C47B CAE847611 (TSN 2863.7, CSN 8003) 5 JUN 2009. THE OEM HAS BEEN PROVIDED THIS SDR INFORMATION.

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