Primary finding
Probable cause
The pilot's inadequate preflight inspection of the aircraft which resulted in a loss of engine power during cruise flight. Related factors are the loose oil filler cap, and the short, wet grass strip used for the emergency landing.
Investigator assessment
Analysis narrative
The pilot reported he was in cruise flight at 3,000 feet when the engine began to run rough and he noted a drop in oil pressure. He performed a forced landing on a grass airstrip at an uncontrolled airport. The airplane ran off the departure end of the runway, across a road and came to rest inverted in a ditch. Post-accident examination of the wreckage revealed the presence of engine oil all over the wings, tail section, and the sides and bottom of the fuselage. The oil filler cap was loose in the engine compartment, attached by its chain.
Source record
Factual narrative
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