What happened
On April 28, 1999, a DG 500 ELAN TR glider, registered F-CHJD, was performing a dual instruction flight at Bailleau aerodrome. During the return from a training session, the instructor instructed the student pilot to execute an approach to runway 08, targeting a specific touchdown point near an aircraft positioned two-thirds down the runway.
The student pilot completed the circuit and the final approach, but the glider touched down slightly short of the intended target at an excessive speed. As the aircraft rolled approximately 50 meters along the unpaved runway, the instructor retracted the airbrakes in an attempt to extend the landing ground roll. Believing that the controls were no longer functional, the student pilot inadvertently allowed the glider to lift off the ground. The aircraft subsequently impacted the ground on its left wing, resulting in a ground loop and damage to the aircraft.
The investigation
Investigators examined the flight sequence and the actions of both occupants. The investigation established that the weather conditions at the time were challenging, characterized by strong, turbulent winds ranging from 20 to 35 knots. The instructor confirmed that, for pedagogical reasons, he had left the primary control of the aircraft to the student pilot during this phase of the flight. However, due to the sudden change in the aircraft's state following the retraction of the airbrakes, the instructor's corrective actions were delayed.