What happened
On July 25, 2008, a Robin DR 400-160, registration F-GJZQ, was performing an instructional flight from Le Plessis-Belleville aerodrome. The student pilot was at the controls during the takeoff roll on runway 25. Upon reaching a rotation speed of 105 km/h, the aircraft experienced an immediate stall warning.
The instructor took control of the aircraft to manage the situation. Despite reducing the pitch angle to regain airspeed, the aircraft's speed failed to increase, and the stall warning continued to sound. Consequently, the instructor decided to perform an emergency landing back on the runway. During the landing, the aircraft veered left off the paved surface and slid into an adjacent wheat field. The impact caused the nose and left landing gear to collapse, and the left wing and forward fuselage sustained damage. There were no fatalities among the four occupants, which included the instructor, the student, and two passengers.
The investigation
The investigation focused on the flight dynamics during the rotation phase and the instructor's oversight of the student. Investigators confirmed that the aircraft's weight and balance were within legal limits, with the center of gravity positioned toward the rear. The flaps were found in the takeoff position at the time of the accident.
Evidence indicated that while the instructor had performed the weight and balance calculations with the student present, there was a lack of specific communication regarding how the increased load would affect control sensitivity. Specifically, the instructor had not informed the student that the elevator control response would be less pronounced due to the aircraft's mass configuration.
Findings
- The primary cause of the stall was excessive elevator input during rotation, which was performed at a speed not recommended by the flight manual.
- The instructor provided insufficient supervision and awareness regarding the student's handling of the aircraft under the specific loading conditions.
- The instructor failed to adequately communicate that the elevator's effectiveness would be reduced due to the aircraft's weight and balance state.