Service difficulty report · Bearing · Bell 407

Difficulty date
December 7, 2017
Submitted
December 13, 2017
Operation
Air carrier
Aircraft
N409GA
Make and model
Bell 407
Aircraft serial
53790
Aircraft time
5,255 hours, 12,255 cycles
Engine
Allsn 250C47B
Engine time
9,602 hours, 17,989 cycles
Part
Bearing
Condition
Leaking
Location
Compressor
Part time
6,495 hours, 7,952 cycles
Stage of operation
CL
How discovered
O
Nature of condition
K, B
Precautionary procedure
A

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

What was found

REPORTED SMOKE IN COCKPIT AND CABIN DURING BLEED AIR USE. PILOT RETURNED TO MAINTENANCCE BASE. INVESTIGATION SHOWS OIL GETTING INTO ENGINE COMPRESSOR AND BLEED AIR SYSTEM. SUSPECT FORM OVER OILING AFS FILTER. REPLACED AFS FILTER WITH A RECENTLY SERVICED FILTER AND CONTINUED TROUBLESHOOTING. FOUND OIL WAS COMING FROM #1 BEARING OF ENGINE COMPRESSOR. SUSPECT PROBLEM WAS TRIGGERED BY COMPRESSOR WASH COMPLETED JUST BEFORE FLIGHT .COMPRESSOR WASH WAS COMPLETED PER THE ROLLS ROYCE MM AND AMC AAIP SECTION 5099 AT TEMPERATURE CLOSE TO FREEZING. PERCAUTIONS MADE FOR COLD WEATHER COMPRESSOR WASH AND ENGINE RUN FOR 10 MINUTES TO COMPLETELY DRY SYSTEM. RESULT AND CORRECTION MADE BY REPLACING ENGINE COMPRESSOR WITH A RECENTLY REPAIRED UNIT FROM STANDARD AERO.

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