Aircraft: Cessna 152. Injuries: None. Location: Wimauma, Fla. Aircraft damage: Substantial.
What reportedly happened: According to the pilot, who was also the mechanic, shortly after takeoff at an altitude of 300 feet AGL, he heard a loud noise, followed by a loss of engine power. Attempts to restore power were unsuccessful and the pilot made a forced landing. During the landing roll the Cessna hit a fence and a pole.
According to the pilot, another pilot who flew the airplane previously reported a rough running engine, which made him perform an uneventful precautionary landing to an airstrip.
Examination of the wreckage revealed that the No. 2 top spark plug and its associated heli-coil had separated from the cylinder. Further examination revealed that the spark plug and cylinder threads were worn and an approximate 2-inch crack originated near the cylinder head threads. Additionally, the area around the top and bottom spark plug holes exhibited evidence of exhaust gas leakage, which would have most likely been visible during the most recent maintenance inspection.
At the time of the accident, the airplane had been operated about 77 hours since its most recent 100-hour inspection, which was completed about three months prior to the accident. The No. 2 overhauled cylinder had been operated for 832 hours since it was installed, about four years before the accident.
Probable cause: The mechanic/pilot’s failure to detect a visible exhaust gas leak and cracked cylinder head immediately prior to the accident flight, which resulted in a partial loss of engine power during initial climb. Contributing to the accident was an inadequate 100-hour maintenance inspection, which also failed to detect a visible exhaust gas leak.
NTSB Identification: ERA11LA103
This December 2010 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.