Primary finding
Probable cause
the loss of engine power due to the failure of a cylinder. The road's soft surface was a factor.
Investigator assessment
Analysis narrative
The pilot reported that he took off and flew for about 1/8 mile. During the flight the engine became very rough, he was unable to maintain altitude, and he made a forced landing on a dirt road. The road had a soft surface, and during rollout the airplane nosed over. The operator reported that the airplane's total time was 9,749 hours, and it was used in agricultural work. The engine had been operated for 750 hours since last being overhauled. The No. 3 cylinder head had failed upon separating from the barrel.
Source record
Factual narrative
On August 8, 1996, at 0750 hours Pacific daylight time, a Grumman G-164A, N8598H, owned and operated by Kennys Crop Dusting, Inc., experienced a partial loss of engine power while cruising about 1 mile south of Caruthers, California. The pilot made a forced landing on a soft dirt road, and the airplane nosed over during rollout. Visual meteorological conditions prevailed at the time of the work related (positioning) flight, and no flight plan was filed. The airplane was substantially damaged, and the commercial pilot received a minor injury. The flight originated from Caruthers at 0749. According to the pilot, the engine became very rough after he took off and flew for about 1/8 mile. Unable to maintain altitude, the pilot made a forced landing. According to the operator, the Pratt & Whitney R-1340 engine had been operated for 750 hours since last being overhauled. The restricted category airplane had a total time of 9,749 hours, and it was used in agricultural work. The Federal Aviation Administration (FAA) responded to the accident site and examined the wreckage. The FAA reported that the engine's No. 3 cylinder head had failed. It was found separated from the barrel. -