What happened
On Saturday, June 19, 1999, at approximately 16:10, two gliders were involved in a mid-air collision near Châtлоillon-sur-Morin, France. The aircraft involved were a Rolladen Schneider LS 4, registered F-CFZG, and a DG Flugzeugbau DG 600, registered F-CGRO.
The flight began around 11:30 when three gliders departed from Coulommiers for a planned 500-kilometer circuit. A fourth glider joined the group during the flight. Due to weather conditions being less favorable than originally anticipated, the pilots decided to shorten their route.
During the return leg, at approximately 16:00, the pilots attempted to climb to 1,400 meters to facilitate their return to Coulommiers. A witness pilot observed the F-CFZG performing a right-hand spiral dive. As the F-CFZG leveled its wings to exit the spiral, its flight path converged with that of the F-CGRO, which was approaching from the left. The underside of the left wing of the LS 4 struck the upper surface of the right wing of the DG 600.
Following the impact, the pilot of the F-CFZG exited the aircraft by opening the canopy without jettisoning it and deployed a parachute. The pilot of the F-CGRO attempted to egress the aircraft, but the parachute lines became entangled in the fuselage, resulting in a fatal outcome for the pilot of the DG 600. The pilot of the F-CFZG sustained injuries, and both aircraft were destroyed.
The investigation
The investigation examined the flight circumstances, the meteorological conditions, and the physiological state of the pilots. Investigators noted that all four gliders in the group were operating on the same radio frequency. The investigation also reviewed the flight duration and the specific maneuvers performed by the aircraft immediately preceding the collision.