Service difficulty report · Clamp · Bell 407

Difficulty date
June 8, 2012
Submitted
September 14, 2015
Operation
General aviation
Make and model
Bell 407
Engine
Allsn 250C47B
Part
Clamp
Condition
Missing
Location
Engine
Part time
182 hours
Stage of operation
NR
How discovered
9
Nature of condition
O
Precautionary procedure
O

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

What was found

(CAN) CUSTOMER TOOK THE ENGINE TO REPAIR STATION TO HAVE THE NR 2 BEARING UPGRADED TO THE LATEST PN. UPON ENGINE DISASSEMBLY THEY FOUND THE CIRCLIP HOLDING THE SPUR ADAPTOR GEARSHAFT INTO THE COUPLING WAS MISSING. THE TEFLON RING WAS THE ONLY ITEM KEEPING THE SHAFT IN PLACE AS IT HAD BECOME DEFORMED. THE CIRCLIP WAS FOUND IN THE BOTTOM OF THE GEARBOX AND WAS DAMAGED AS IF IT HAD BEEN UNWOUND BY THE GEARS ON THE GEARSHAFT. A PORTION OF THE CIRCLIP WAS FOUND IN THE CEFA FILTER. AT THE SAME TIME WHEN THE BEARING WAS REMOVED, THERE WAS SOME SPALLING NOTED ON ONE BALL. TCCA AND TSB WERE ONSITE FOR THE INVESTIGATION.

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