What happened
On June 4, 1998, at approximately 15:43, two gliders were involved in a mid-air collision near the Géruen ridge in the Hautes-Duyes region of France. The first aircraft, a Schempp Hirth Ventus 2-B with registration F-CGLV, had departed from Saint-Auban earlier that afternoon for a local training flight. The second aircraft, a Rolladen Schneider LS 8 A registered D-3968, departed from the same airfield for a similar local flight.
At an altitude of approximately 2,100 meters, the two aircraft, which were flying on converging paths at an angle of about 40 degrees, collided. The impact caused the canopy of the D-3..'LS 8 A to shatter and the right wing of the F-CGLV to be severed. The pilot of the D-3968 managed to eject from the aircraft via parachute, sustaining only minor injuries. However, the pilot of the F-CGLV was killed when the aircraft struck the terrain.
The investigation
The investigation reconstructed the flight paths using data from GPS flight recorders and Zander SR 940 calculators recovered from both aircraft. The analysis established that the two gliders were flying at similar speeds, approximately 92–93 km/h, and were descending or fluctuating in altitude between 2,000 and 2,300 meters in the minutes leading up to the event.
Investigators examined the wreckage of both aircraft. The D-3968 was found overturned in a wooded area, while the F-CGLV was found in several pieces; its right wing had been broken off at the point of impact. Witnesses, including other pilots in the vicinity and observers on the ground, confirmed seeing the two aircraft collide and observed the subsequent debris and the pilot's parachute deployment.
Findings
- The primary cause of the collision was the failure of both pilots to perceive the other aircraft.
- The visibility of gliders is inherently difficult due to their small surface area and predominantly white color, which provides low contrast against the sky and mountainous terrain.
- The pilot of the F-CGLV was performing his first solo flight in this specific aircraft type, which may have impacted his situational awareness.
- The pilot of the D-3968 was focused on monitoring weather developments and other previously identified aircraft, which likely diverted attention from the approaching F-CGLV.
- The use of modern cockpit instruments, such as GPS and flight computers, may have increased pilot workload and reduced environmental scanning.