What happened
On June 2, 2019, at approximately 10:49 UTC, a collision occurred above the Hirschpleiskopf in the municipality of St. Anton am Arlberg, Austria. A DG-400 motor glider, flying from Altenrhein, Switzerland, was performing a soaring flight and utilizing an updraft near a mountain ridge. During this maneuver, the aircraft was in a banked position of approximately 60 degrees, climbing at a rate of 1.5 m/s with a forward speed of 110 km/h.
Simultaneously, a paraglider was flying westward at an altitude of approximately 2,700 meters. The motor glider pilot reported seeing a red canopy appearing from the lower left before the impact occurred. The collision caused the motor glider to pitch forward by about 45 degrees, though the pilot was able to regain control and land safely at Altenrhein airport.
The impact caused significant damage to the motor glider's wings and destroyed the Gin Carrera S paraglider. The paraglider pilot sustained serious injuries to the upper body, resulting from the compression forces experienced when the reserve parachute was deployed. The pilot managed to perform an emergency landing at approximately 2,300 meters near the Leutkirchner Hütte.
The investigation
The investigation examined the flight paths of both aircraft, the mechanical condition of the equipment, and the meteorological environment. Investigators reconstructed the sequence of events using statements from both pilots and data from local police. The investigation also reviewed the presence of collision avoidance technology on both aircraft and analyzed the visibility conditions at the time of the accident.
Findings
- The primary cause of the accident was the late detection of the collision risk.
- Visual limitations contributed to the accident, as the motor glider's banked position restricted the pilot's field of view, and the paraglider's position above the motor glider limited upward visibility.
- The motor glider was equipped with a FLARM collision warning device, but the paraglider was not equipped with a FLARM device, as such equipment is not mandatory for paragliders.
- Meteorological conditions were found to be a contributing factor, but weather alone was not the cause of the accident.