What happened
On August 15, 2006, a Piper PA-18 150, registered as HB-PPJ, was conducting a mountain flight training session at the La Croix-de-Cœur mountain airstrip in Riddes, Switzerland. The flight involved a student pilot and an instructor. After an initial landing earlier in the day where the instructor flew the aircraft, the student took the controls for a series of circuits.
During the final approach, the student maintained an excessive airspeed. As the aircraft neared the runway, the student performed the flare too early. The instructor attempted to take control to rectify the situation but intervened too late to execute a go-around. To avoid hitting bystanders on the flight path, the instructor opted to land straight ahead. The aircraft struck the ground with great force beyond the runway, bounced, and spun approximately ninety degrees before coming to a halt 15 meters away. The student was uninjured, while the instructor sustained minor injuries.
The investigation
The investigation examined the aircraft's technical condition, the flight crew's experience, and the training procedures in place. Investigators found no mechanical or technical defects in the engine or airframe. The aircraft's weight, center of gravity, and fuel levels were all within prescribed limits. Meteorological conditions at the time were reported as good to excellent.
Review of the flight crew's records revealed that the instructor had not performed any mountain landings in the preceding three months. Furthermore, the investigation looked into the instructional sequence, noting that the student had not been provided with a demonstration of a mountain approach by the instructor during this session, as the instructor had been in the rear seat during the morning's landing.
Findings
- The primary cause of the accident was a hard landing resulting from the late intervention of the instructor.
- The instructional method used was inappropriate for the student's level of experience, as the student was left to manage the approach without a prior demonstration.
- The instructor lacked recent training in mountain landing techniques.
- The student's approach speed was too high, leading to an improper flare.