Accident Summary
On November 11, 2022, at about 1207 mountain standard time, a Cessna C-150 airplane, N3131J, was substantially damaged when it collided with terrain near Star Valley, Arizona. The pilot sustained serious injuries. The flight was conducted under Title 14 Code of Federal Regulations Part 91 as a personal flight.
The airplane was the second of two aircraft that departed Phoenix Deer Valley Airport (DVT) at 1115 with a planned destination of Gallup Municipal Airport (GUP), Gallup, New Mexico.
Pilot Statement
The pilot reported that while climbing over rising terrain at about 1,000 ft above ground level, the engine began running rough. He applied carburetor heat and manipulated the engine controls, but the engine did not respond and the engine rpm continued to decrease. He attempted to land in a clearing but collided with trees before reaching the intended landing area. The airplane came to rest inverted.
Engine Examination
Post-accident examination of the engine revealed that both the top and bottom spark plugs of the No. 1 cylinder exhibited damage consistent with metal-to-metal contact after their removal. The No. 1 cylinder was removed, and the exhaust valve and a portion of the intake valve were found to have separated from their respective valve stem and valve face. The exhaust valve was embedded in the piston face, which was cracked. A portion of an intake valve was recovered inside the heat exchanger. The extent of damage to the exhaust valve and piston precluded further examination to determine the failure mode of either valve.
Maintenance History
At the time of the accident, the engine had accumulated approximately 993 hours since overhaul and about 32 hours since its last annual inspection, which was completed on May 13, 2022.