On October 22, 2003, an American AA-1 (registration N5968L) operated by Michael D. White was involved in an aviation accident near San Martin, CA. Investigators recorded the probable cause as: The absence of compression in two of the airplane's four cylinders, and the pilot/mechanic's failure to maintain the engine in an airworthy condition, which resulted in a loss of engine power during takeoff-initial climb, and subsequent forced landing. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A student pilot reported losing engine power during initial climb after takeoff. The aircraft made a forced landing, colliding with a fence. Examination revealed compression loss in two cylinders, missing air cleaner, and spark plug issues.
Pilot Report
The student pilot, who also owned the airplane and held an aviation mechanic certificate, reported a loss of engine power after takeoff during the initial climb. He stated that the engine began running rough and subsequently lost power. Unable to maintain altitude, he performed a forced landing. During the landing roll, the airplane collided with a fence.
Engine Examination
A post-accident examination of the engine disclosed virtually no compression in two of the four cylinders. Additionally, the air cleaner was absent, all bottom spark plugs exhibited excessively wide gaps, and the number 4 top spark plug was heavily sooted and fouled.
Maintenance History
The engine was installed in July 1978 and had accumulated 2,157.5 total operating hours. It had never been overhauled.