What happened
On May 9, 1999, at 14:40, a single-seat SZD 48-1 Jantar Standard II glider, registration OO-ZWJ, was participating in a local reconnaissance flight near Château-Arnoux-St Auban. The flight involved three gliders scouting potential takeoff and landing sites. While flying along the southwest slope of the Montagne de la Blanche at an altitude of approximately 1,700 meters, the pilot entered a thalweg positioned perpendicular to the slope.
In an attempt to exit the thalweg, the pilot pitched the aircraft up. During the subsequent turn, the glider lost airspeed, became uncontrollable, and struck the terrain. The impact resulted in the destruction of the aircraft and one injury to the pilot.
The investigation
Investigators examined the flight circumstances and the pilot's actions during the maneuver. The investigation established that the aircraft was operating under CAVOK conditions with a 12-knot wind from 200 degrees. The pilot, who held a Belgian license with 420 total flight hours, had performed the maneuver to navigate out of the valley feature, but the resulting loss of energy led to the impact.