SDR 2009F00026

Service difficulty report · Compressor Wheel · Agusta A109C

Difficulty date
April 7, 2009
Submitted
April 9, 2009
Operation
General aviation
Aircraft
N70NM
Make and model
Agusta A109C
Aircraft serial
7664
Aircraft time
5,625 hours
Engine
Allsn 250C20R1
Engine time
4,030 hours, 4,155 cycles
Part
Compressor Wheel
Part number
23032624
Part serial
KR64387
Condition
Damaged
Location
Nr 1 Engine
Part time
4,030 hours, 4,155 cycles
Stage of operation
CR
How discovered
O
Nature of condition
J
Precautionary procedure
E

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

What was found

PILOT REPORTED NR 1 ENG LOW WARNING LIGHT AND NR 1 ENG LOW AURAL ACTIVATED WITH CORRESPONDING DECREASE IN ENG SOUND. NR 1 ENG N1 WAS AT 28 PERCENT AND TOT WAS RISING, REACHING APPROX 1000 DEGREES C. PROCEEDED TO PULL NR 1 ENG THROTTLE TO IDLE AND THEN TO OFF. CONTINUED TO DESTINATION AND PERFORMED SINGLE ENG LANDING. UPON INSP, MX VERIFIED THAT ENG OIL RESERVOIR WAS FULL, NO SIGNS OF EXTERNAL DAMAGE OR LEAKAGE, N2 AND ROTOR SYS TURNED FREELY, COMPRESSOR INTAKE CLEAN AND FREE OF FOD. N1 SYS WAS LOCKED UP, COMPRESSOR WOULD NOT TURN. FOUND SMALL CHUNKS OF METAL IN ENG BAY, BELIEVED TO BE COMPRESSOR BLADES. AFTER REMOVAL OF LWR COMPRESSOR CASE HALF FOUND THAT 4TH STAGE COMPRESSOR BLADES WERE SHEARED OFF AT ROOT/DISK. REMOVED COMBUSTION CHAMBER AND FOUND 1ST STG TURBINE BLADES DAMAGED, OUTER 3RD OF BLADES BROKEN OFF.

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