What happened
On August 3, 2024, a GLASER DIRKS DG800 B glider, registration F-CHYD, was conducting a local flight near Blesle, France. After departing from the Issoire - Le Broc aerodrome, the pilot spent approximately 75 minutes searching for thermal uplifts. Due to unfavorable aerological conditions and a low cloud ceiling, the pilot entered a valley to find better conditions but was unable to regain altitude.
Seeking a suitable location for an off-aerodrome landing, the pilot identified a field and began a landing circuit. As the pilot completed a left turn and transitioned to the final approach, the propeller was extended while the aircraft was at an altitude of approximately 20 meters. Eight seconds after the extension sequence began, the glider struck the tops of a tree line before falling into the field. The aircraft sustained significant damage, including a torn wing and a ruptured tail fin.
The investigation
Investigators analyzed data from the onboard OUDIE flight computer and examined the wreckage. The investigation confirmed that the engine pylon was in the extended and locked position at the time of impact, and the propeller blades were damaged, though there were no signs of rotation.
The investigation also reviewed the pilot's flight manual and established that the procedure for extending the propeller and starting the engine was initiated at an altitude far below the manufacturer's recommended safety margins. The pilot's strategy involved extending the propeller first and then attempting to start the engine during the final approach to a field, a technique intended to allow for a go-around if the engine failed to start.