Service difficulty report · Support · Bell 407

Difficulty date
February 10, 2010
Submitted
February 19, 2010
Operation
General aviation
Aircraft
N40RX
Make and model
Bell 407
Aircraft serial
53872
Engine
Allsn 250C47B
Part
Support
Part number
23051106
Part serial
348664
Condition
Damaged
Location
Compressor
Part time
534 hours
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

ON 1/17/2010, THE PILOT, FLIGHT CREW, AND BASE MECHANIC REPORTED AN UNUSUAL NOISE COMING FROM THE ACFT/ENG. AFTER FLIGHT CKS, GROUND RUNS, AND TROUBLESHOOTIING OF THE ENG AND COMPONENTS, A DECISION WAS MADE TO REMOVE THE ENG FOR INSP AND REPAIR. ON 1/2/2010, THE ENGINE REPAIR VENDOR NOTIFIED US THAT THE SUSPECT ENG SUFFERED METAL TO METAL RUBBING CONTACT AND FAILED NR 1 COMPRESSOR BRG DUE TO IMPROPER INITIAL BUILD UP BY THE MFG. THIS NEW ENG (534 HRS TIS) WAS INSTALLED AS A NEW COMPONENT, AND HAD VERY LOW TIME ACCUMULATED. AS A PRECAUTION, WE REMOVED ANOTHER ENGINE FROM SERVICE ( 2 SERIAL NRS AWAY FROM THE DAMAGED ENGINE) UNTIL A VISUAL INSP BY REP WAS PERFORMED TO VERIFY THE INITIAL BUILDUP INSTALLATION, WHICH WAS CORRECTED. MFG HAS APPROVED THE REPAIRS TO THE DAMAGED ENG UNDER WARRANTY. MFG SHOULD VERIFY WHY THE IMPROPER BUILD UP OF THIS ENG OCCURRED, AND ASSURE NO OTHER UNITS WERE IMPROPERLY ASSEMBLED.

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