Service difficulty report · Cylinder · Beech 95C55

Difficulty date
April 11, 2003
Submitted
April 11, 2003
Operation
General aviation
Aircraft
N621G
Make and model
Beech 95C55
Aircraft serial
TE214
Engine
Cont IO520*
Part
Cylinder
Part number
655470A3
Condition
Worn
Location
Nr 2 & 6
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

CYLINDERS NR 2 AND 6 HAD LOW COMPRESSION WITH LEAKAGE PAST THE EXHAUST VALVES. REMOVEAL AND TEARDOWN OF THE CYLINDERS REVEALED THE FOLLOWING: CONDITION OF CYLINDER HEAD WAS NORMAL FOR TIME. EXHAUST VALVES EXHIBITED EXTREME WEAR FOR TIME IN SERVICE. CYLINDER BARREL EXHIBITED STEP WEAR IN THE BORE OF .003 INCH, AND PITTING. EXHAUST VALVE GUIDES WERE WORN PAST SERVICE LIMITS. HALF OF THE VALVE SPRINGS WERE OUT OF LIMITS, AND HALF WERE AT SERVICE LIMITS. HAVE BEEN FINDING NUMEROUS EXAMPLES OF FACTORY NEW AND OVERHAULED CYLINDERS THAT FAIL WITH APPROX 300 HOURS SINCE NEW OR OVERHAUL.

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