On 11 July 2020, a tragic accident occurred near Dülmen in which two gliders, an LS4-b and a DG-300, collided and crashed while approaching an upwind area. Both pilots, aged 25 and 29, suffered fatal injuries and both gliders were destroyed.
At the time of the accident, visual flight conditions prevailed and the sun was almost behind the pilots, which meant that weather conditions could be ruled out as a contributing factor. The collision occurred because neither pilot could see the other glider and was therefore unable to initiate an evasive manoeuvre.
A contributing factor was the DG-300's non-functioning collision warning system due to a missing firmware update. Another contributing factor could have been the open harness of the LS4-b pilot's reserve parachute, possibly due to distraction while using a urinal. Both gliders were equipped with a collision warning system, but the lack of function in the DG-300 and possibly an over-reliance on the system in the LS4-b contributed to the accident. The BFU refrained from making its own safety recommendations, but referred to existing recommendations from other national aviation accident investigation authorities on the introduction of collision warning systems in general aviation.
Source references:
Federal Bureau of Aircraft Accident Investigation
