What happened
On 21 May 2022, a Jodel D140 C, registration F-HJLB, crashed in the commune of Les Adrets, France, during an introductory sightseeing flight. The aircraft, operated by Aéroclub du Daungphiné, was carrying a pilot and four passengers.
After taking off from Grenoble Le Versoud aerodrome, the pilot turned into the Les Adrets valley, flying alongside a mountain slope. Witnesses observed the aircraft flying at a low altitude and a slow speed. Shortly after, the aircraft struck a line of trees and crashed into a field, where a post-impact fire destroyed much of the wreckage. The accident resulted in five fatalities.
The investigation
The investigation focused on the aircraft's performance capabilities under the specific conditions of the day. The aircraft was equipped with skis, which were still attached at the time of the accident. The investigation noted that the aircraft's weight was approximately 1,125 kg, near its maximum takeoff weight of 1,200 kg, and the ambient temperature was 32°C.
Investigators compared the accident flight to a previous sightseeing flight performed earlier that afternoon in a different aircraft, a DR401/155 (F-GNXT). Unlike the accident aircraft, the DR401/155 was equipped with a turbocharged engine, providing significantly better climb performance. Analysis of the wreckage and flight path data indicated that the aircraft was flying at a ground speed that was steadily decreasing, suggesting a loss of airspeed.
Findings
Several factors contributed to the fatal collision:
- The pilot likely overestimated the climb performance of the Jodel D140 C, potentially due to the recent experience of flying a more powerful, turbocharged aircraft earlier that day.
- The aircraft was operating with an insufficient safety margin relative to the terrain; the climb performance, hampered by the high temperature, heavy weight, and the presence of skis, was inadequate to clear the nearby ridge.
- The aircraft likely entered the backside of the power curve. In the mountainous terrain, the lack of a natural horizon may have led the pilot to increase the pitch attitude, causing a gradual reduction in airspeed and climb rate until the collision occurred.