What happened
While flying at an altitude of 3,000 feet, the pilot and passenger were reportedly discussing the practice of stalls. Witnesses observed the aircraft performing maneuvers when they heard a sequence of engine power fluctuations: an initial loss of power, followed by an increase in power, and then a subsequent loss of engine power.
Following this final loss of power, the aircraft was seen with its nose down, entering tight clockwise spins. One witness noted the aircraft appeared to be attempting to recover from the maneuver but lacked sufficient altitude before striking trees and the ground. Another observer described the aircraft transitioning into a flatter spin as the nose rose before descending out of control. The aircraft struck several trees prior to the final ground impact.
The investigation
During the field examination of the wreckage, investigators removed the fuel flow divider cover to check for available fuel; no fuel was found. A subsequent examination of the engine revealed that the upper fuel divider diaphragm was ruptured. Metallurgical analysis identified two tears within the diaphragm, though investigators could not determine exactly when the rupture occurred.