What happened
On September 5, 2010, during an aviation event at the Lauf-Lillinghof airfield, a formation of three vintage biplanes attempted a takeoff. The formation consisted of a Bücker Jungmann Casa and two De Havilland DH82A Tiger Moth aircraft. The aircraft that subsequently crashed was positioned on the right grass strip of the runway.
As the formation began its takeoff roll, the DH82A Tiger Moth was operating in a three-point stance with the elevator pulled back. During the roll, the aircraft began to drift to the right. As the pilot applied full power, the aircraft lifted off before the tailwheel left the ground. This high angle of attack, combined with the engine's torque, caused the aircraft to enter an exaggerated flight state, banking sharply to the right. The aircraft veered off the runway and collided with spectators and event barriers. The accident resulted in one fatality, five serious injuries, and 3ered 33 minor injuries.
The investigation
The BFU investigation examined the aircraft's mechanical condition, the pilot's actions, the takeoff technique, and the event's organizational safety measures. Investigators reviewed video footage and witness statements, and performed a physical inspection of the wreckage. The investigation also reviewed the event's official permit and the briefing procedures used for the formation flight.
Findings
- The primary cause of the accident was that the pilot failed to apply corrective controls or abort the takeoff when the aircraft began drifting to the right during the takeoff roll.
- The use of a three-point takeoff stance contributed to the instability; at the high angle of attack required for this method, the ailerons experienced reduced effectiveness due to airflow shadowing, and the engine's torque induced a rightward yaw.
- The pilot was not sufficiently prepared for a potential malfunction or deviation during a formation takeoff.
- The formation takeoff itself was not included in the original event permit; it was added to the program on the day of the event.
- The safety distance between the runway and the spectators was significantly reduced because the formation's takeoff position and the presence of parked vehicles and spectators near the barrier narrowed the available margin.
- The briefing for the formation pilots was inadequate, as it was delegated to the lead pilot of the Bücker aircraft rather than being a coordinated briefing for all participants.
- Oversight of the event's safety requirements by the local event organizer was insufficient.