Primary finding
Probable cause
The failure of valve springs in the number two engine cylinder which resulted in a total loss of engine power during initial climb. The unsuitable terrain encountered during the subsequent forced landing was a factor.
Investigator assessment
Analysis narrative
The pilot reported that at approximately 1,000 feet above the ground during takeoff climb, the airplane's engine lost total power. The pilot made a forced landing in a soft field, and the airplane nosed over. Postaccident examination of the engine revealed that the two intake valve springs in the number two cylinder had failed. The valve spring fracture surfaces were 'corroded and pitted.' the engine had accumulated 13.7 hours since it received a major overhaul.
Source record
Factual narrative
On May 13, 1995, at 1050 eastern daylight time, a Piper PA-28- 140, N9672W, lost total engine power during takeoff climb from runway 25 at the Dubois-Jefferson County Airport, Dubois, Pennsylvania. A forced landing was made in a field near the airport. The pilot and passenger were seriously injured. The airplane was substantially damaged. Visual meteorological conditions prevailed. The local personal flight was conducted under 14 CFR Part 91. The pilot reported that shortly after takeoff, at an altitude of about 2,800 feet mean sea level, the engine lost power. The pilot wrote, "Heard a loud 'pop' then the engine went from full power to idle. Was going back to (N97). Picked out a farmer's field and went for it. Hit plowed area [and] turned over." Witnesses stated that they heard the airplanes engine "sputtering" and "cutting out" prior to its touchdown on the field. Postaccident examination revealed the airplane touched down on a soft, soil field. The airplane nosed over damaging the outboard section of the left wing, vertical fin, rudder, nose gear, nose gear cowling, engine mount, and fuselage skin. Fuel was found throughout the airplane's fuel system. The airplane and engine were transported to a storage facility for further examination. According to a Federal Aviation Administration Safety Inspector, "Postaccident examination of the engine revealed that the two intake valve springs in the number two cylinder had failed." The inspector stated that the valve spring fracture surfaces were "corroded and pitted." According to the airplane's owner, the engine had accumulated 13.7 hours since it received a major overhaul. -