What happened
On February 26, 2009, a Piper J-3C-65/L-4, registration HB-OWO, was conducting a training flight at Lausanne-La Blécherette aerodrome. The flight involved an instructor in the front seat and a student pilot in the rear. During the second circuit of the training session, the crew encountered a wind component from the rear right.
The landing was characterized by a high flare, resulting in a firm contact with the runway approximately 100 meters past the threshold. Following touchdown, the aircraft experienced significant pitch and roll oscillations. The aircraft suddenly veered to the left, exiting the paved surface and striking a snowbank located just outside the runway. The impact caused the aircraft to trip over a pylon and ultimately come to rest on its back. Both occupants were able to exit the aircraft uninjured.
The investigation
Investigators examined the aircraft's technical condition, the meteorological environment, and the operational decisions made by the crew. The investigation confirmed that the engine, instruments, and flight controls were fully functional at the time of the accident. Meteorological data indicated a light wind of approximately 5 knots from the southeast.
The investigation also focused on the aircraft's weight and balance. It was determined that the aircraft was operating significantly above its maximum allowable takeoff weight. Additionally, the investigation looked into the roles of the two pilots and the decision-making process during the unstable landing phase.
Findings
- The aircraft was overweight, with a takeoff mass of 615 kg exceeding the manufacturer's limit of 580 kg. The crew had chosen to carry extra fuel for increased autonomy at the expense of weight limits.
- The aircraft experienced a loss of control during the landing roll, exacerbated by the rear-right wind component and the high-energy impact of the firm touchdown.
- The instructor's decision to remain passive to allow the student to manage the situation was inappropriate given the challenging wind and weight conditions.
- The collision with a snowbank, which was roughly 20 to 30 cm high, was the direct cause of the aircraft capsizing.