What happened
On August 31, 2008, a Stampe SV 4C biplane was participating in a flight festival at the Müllheim glider field. The pilot, intending to perform a formation flight with another Stampe SV 4C over the runway for spectators, departed from the grass runway 34 at 14:43 local time. The takeoff was conducted with a light tailwind.
Shortly after liftoff, the aircraft abruptly veered to the right. Witnesses observed a significant reduction in engine RPM and noted that the aircraft was flying at a high angle of attack without gaining altitude. The biplane began to oscillate and drifted northeast, away from the airfield area. Approximately 1.5 NM from the Müllheim glider field, the aircraft entered a right-hand turn and collided with the ground at a low forward speed.
The investigation
The BFU investigation examined the wreckage and the mechanical condition of the aircraft. The impact occurred on a meadow at an elevation of approximately 850 ft, where the lower wing struck the ground followed by the aircraft's nose. The investigation found that the interplane struts were broken and the upper wing had shifted forward.
Mechanical inspections of the Renault 4 PO3 engine revealed that the magnetos and fuel pumps were fully functional. The engine's valves operated correctly, and compression across all four cylinders was within normal parameters. The fuel system contained Avgas 100 LL, and the carburetor contained fuel. The investigation also noted that the throttle was found in the full-power position.
Findings
- The pilot and passenger sustained two serious injuries.
- The aircraft was destroyed in the crash.
- The primary factor in the loss of control was a sudden reduction in engine power and a high angle of attack immediately following takeoff, which led to the aircraft's inability to maintain altitude and its subsequent deviation from the flight path.