Accident Sequence
During a training flight, a student pilot and a certified flight instructor (CFI) were practicing stalls. According to the student pilot, the flight was normal until the throttles were advanced to recover from a practice stall, at which point a violent right yaw developed. The CFI assumed control and attempted recovery, but a substantial loss of power occurred on both engines. A forced landing was executed in a field. During the landing, the left wing struck trees, and the aircraft was subsequently engulfed in flames.
Post-Accident Examination
Examination of the left engine revealed no discrepancies. However, the right engine exhibited two discrepancies: a crack extending approximately 50% of the circumference of the fuel controller fuel line tee fitting, consistent with ductile overload, and a leakage covering about 70% of the inlet-side turbocharger gasket. The aircraft had a history of fuel vaporization symptoms that subsided with use of the auxiliary fuel pump, as recommended by the engine manufacturer. It is unknown whether the auxiliary pump was used during the accident flight.
Investigation Findings
The official investigation identified multiple occurrences. Occurrence #1: Loss of engine power (total) due to mechanical failure/malfunction, with findings including a fuel system line leak, improper maintenance/installation (manufacturer), turbocharger leak, cracked fuel line fitting, fuel starvation, and temperature extremes. Occurrence #2: Loss of engine power (total) non-mechanical, due to fuel starvation and temperature extremes. Occurrence #3: In-flight collision with trees during descent. Occurrence #4: In-flight collision with terrain during landing.