Accident Overview
An aircraft experienced a power failure during flight, prompting the pilot to execute an emergency off-airport landing. During the landing sequence, the aircraft nosed over and sustained substantial damage. The pilot reported no injuries.
Post-Accident Investigation
Following the accident, investigators examined the engine and identified a valve sticking problem. During post-accident testing, the engine operated normally at high power settings but ceased operation when power was reduced to cruise settings.
Engine Condition Findings
Examination of the engine valves revealed that while valve stem clearances met manufacturer specifications, there were excessive carbon deposits at the base of the intake valve stems. The engine had been overhauled 350 hours prior to the accident and had undergone a 100-hour inspection 49 hours before the event.
Maintenance History
The engine's most recent overhaul occurred 350 flight hours before the accident, and a 100-hour inspection was performed 49 hours prior. No other maintenance issues were reported in the available records.