What happened
On July 30, 2013, a Jodel D140 Mousquetaire, registration F-PMGV, was engaged in a training session at the La Tovière altisurface in France. The flight, operated by Aéroclub de Megève, was being conducted by an instructor and a student pilot to obtain a mountain flight qualification.
After completing four successful landings, the student pilot aligned the aircraft on the upper platform to begin a takeoff roll on runway 12. As the aircraft transitioned through the change in gradient between the platform and the runway, it suddenly deviated to the left. The student pilot attempted to correct the course by applying right rudder, but the maneuver was unsuccessful. The aircraft veered off the side of the unpaved runway and struck metal fence posts located immediately adjacent to the runway edge. The aircraft sustained heavy damage, but there were no injuries to the two occupants.
The investigation
The investigation focused on the aircraft's handling during the transition between the different runway gradients and the presence of obstacles near the takeoff area. The runway at La Tovière, situated at 7,350 ft, features a significant slope change, dropping from 18% to 16% and then to 9% along its length.
Investigators examined the aircraft's mechanical condition and found no technical failures that contributed to the deviation. The instructor, a highly experienced pilot with 1,600 total flight hours, noted that the lateral deviation occurred so abruptly that there was insufficient time to intervene effectively. The investigation also noted that the metal posts, which were 2 meters high, had been installed as part of a fence to prevent livestock from entering the runway.
Findings
- The primary cause of the excursion was the delayed and insufficient reaction of the instructor to the aircraft's lateral deviation. This delay was attributed to the instructor's high level of confidence in the student pilot's performance during the preceding successful takeoffs.
- The presence of the metal posts at the immediate edge of the runway contributed to the extent of the damage sustained by the aircraft.
- The student pilot's attempt to correct the deviation using the right rudder pedal was ineffective in maintaining the centerline during the gradient transition.