NTSB Factual Report

On April 22, 2001, at 1542 hours Pacific daylight time, a Piper PA-22-135, N75343, made an off field forced landing following a loss of engine power during climb out from Oxnard, California. The owner was operating the airplane under the provisions of 14 CFR Part 91. The private pilot and one passenger were not injured; the airplane sustained substantial damage. The personal, local flight departed Oxnard about 1515. Visual meteorological conditions prevailed, and no flight plan had been filed.

The pilot submitted a written statement. He filled the airplane with fuel and completed a preflight inspection. He practiced touch-and-go landings for over an hour and experienced no difficulties with the airplane. After a break, he completed another preflight inspection and practiced more landings. As the airplane climbed through 200 feet on the fourth takeoff, the engine made a clunking noise and stopped producing power. He steered the airplane to an open field and landed on soft dirt. The airplane dug into the soft dirt and sustained damage to the wings, stabilizer, landing gear, and propeller.

The engine was an O-290-D2, serial number 6571-21. An engine logbook entry on April 11, 1960, recorded a field overhaul at a tachometer time of 951 hours. An entry on August 1, 1970, recorded a "top overhaul" at a tachometer time of 1,603 hours, and noted that the exhaust valves were replaced. The tachometer read 1,861.57 at the time of the accident.

Textron Lycoming was a party to the investigation. An investigator from Lycoming examined the engine under the supervision of a Safety Board investigator. According to archived Lycoming records, the engine had been manufactured on November 9, 1953, and they had no record of it returning to the factory since that time.

The investigator removed the top spark plugs and examined the cylinders with a lighted bore scope. All cylinders were undamaged except cylinder No. 3, which exhibited extensive mechanical damage. The investigator removed this cylinder.

The exhaust valve for cylinder No. 3 fractured and separated where the valve stem transitions to the valve head. The fracture surfaces on the valve pieces were obliterated by the mechanical damage. The piston face exhibited mechanical damage over most of its surface, which contained two holes. The investigator observed that the corresponding push rod was slightly bent, but he did not observe evidence of the valve sticking. The valve stem measured approximately 13/32 inches, which met original factory specifications.

NTSB Probable Cause

The fracture and separation of the number 3 cylinder exhaust valve head resulting in a loss of engine power and a forced landing. A factor in the accident was the soft field where the forced landing occurred.