Incident Overview
A certificated flight instructor (CFI) was serving as pilot in command, according to the aircraft owner. The CFI was flying from the right front seat. During an en route descent, the CFI was instructed to descend to 3,000 feet. To avoid shock cooling the engine, he reduced manifold pressure by approximately 2 inches every 2 minutes.
Sequence of Events
As the descent continued, the CFI noted that the manifold pressure dropped from 18 inches to 10 inches, and the engine ceased responding to his inputs. At the time, the fuel selector valve was positioned to the left tank, and the fuel indicator showed one-quarter tank remaining. At about 2,500 feet MSL, the CFI handed control of the airplane to the owner.
The owner estimated the altitude at approximately 1,500 feet above ground level and began searching for a suitable field for a forced landing. The subsequent landing was made in a freshly plowed field. During the rollout, the airplane flipped over.
Post-Accident Examination
Following the accident, the fuel selector switch was found in the left tank position. No fuel could be drained from the left tank, while 11 gallons of fuel were drained from the right tank. Investigators found no mechanical problems with the airframe or engine.