What happened
On September 10, 2011, a Boeing Stearman PT 17 took off from the grass runway 11 at Backnang-Heiningen airfield as part of an aviation event. At approximately 16:04 local time, the aircraft was in the initial climb phase at an altitude of about 50 feet when the engine began to sputter and lose power.
In an attempt to avoid a group of parked aircraft, the pilot initiated a right turn. However, the sudden loss of power caused the aircraft to lose altitude, eventually striking the ground. The impact caused the aircraft to flip onto its back. The pilot sustained one minor injury, while the aircraft suffered heavy damage. The wreckage was located on a field immediately south of the airfield.
The investigation
The BFU examined the wreckage and the circumstances surrounding the flight. The investigation confirmed that the aircraft was operating within its permitted takeoff weight and center of gravity. The engine, a Pratt & Whitney P 985-AN-3, had been in operation for 203 hours since its last overhaul.
Investigators also analyzed the fuel used for the flight. The aircraft had been refueled using Mogas from canisters sourced from a local gas station. Samples taken from both the aircraft's tanks and the canisters showed no visible abnormalities during inspection. The investigation found no evidence of mechanical defects in the aircraft's structure or systems prior to the engine failure.