Service difficulty report · Valve · Cessna 172N

Difficulty date
July 17, 2000
Submitted
August 2, 2000
Operation
General aviation
Aircraft
N4822G
Make and model
Cessna 172N
Aircraft serial
17273370
Engine
Lyc O320H2AD
Part
Valve
Part number
SL54017
Condition
Failed
Location
Cylinder
Stage of operation
IN
How discovered
V
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

MAJOR DAMAGE TO THE ENGINE CAUSED AS A RESULT OF THE VALVE KEEPERS BREAKING AND ALLOWING THE EXHAUST VALVE TO FALL INTO THE COMBUSTION CHAMBER FOR CAUSE APPEARS TO BE KEEPERS BROKE WHILE WEARING ON THE VALVE UNTIL RELEASE. THE VALVE BROKE AWAY FROM THE HEAD OF THE VALVE AND WAS DRIVEN THROUGH THE TOP OF THE CYLINDER AND ENDED UP INSIDE THE MUFFLER ALONG WITH LARGE CHUNKS OF THE PISTON WHICH BROKE OFF AND EXITED THROUGH THE NOW EMPTY EXHAUST PORT.

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