What happened
On September 14, 2014, at Münster-Telgte airfield, two ultralight aircraft were involved in a fatal mid-air collision. The first aircraft, a W.D. Flugzeugbau D4 Fascination, departed at 17:57 for a local training flight with two occupants. Shortly after, at 18:03, a TL 96 Sting departed from the grass runway, towing a glider.
At approximately 18:13, both aircraft were on final approach to parallel runways. The D4 Fascination was executing a shortened base leg from the south toward the asphalt runway. Simultaneously, the TL 96 Sting was approaching the grass runway from the north via the north pattern. During the final approach, the tow rope from the TL 96 Sting struck the D4 Fascination. The impact caused the D4 Fascination to roll and crash from an altitude of approximately 120 to 150 feet into a cornfield, where it caught fire. The two occupants of the D4 Fascination sustained severe injuries and passed away in the hospital one week later.
The pilot of the TL 96 Sting reported feeling a sudden jerk during the approach, after which he completed the pattern, released the glider, and landed safely.
The investigation
The BFU investigation examined the flight paths, radio communications, and environmental conditions. Investigators reconstructed the flight paths using GPS and radar data from the TL 96 Sting. The investigation also reviewed witness statements from pilots and airfield personnel, as well as the status of the airfield's air traffic services.
Witnesses noted that while the pilot of the D4 Fascination had announced his direction changes via radio, the airfield controller and the glider takeoff leader did not perceive or hear these specific transmissions. Furthermore, the airfield controller was positioned in a location that prevented a clear view of the approach to runway 10 at the time of the accident.
Findings
Several contributing factors led to the collision:
- Inadequate visual lookout and lack of situational awareness by both pilots.
- Communication failures between the pilots and the airfield controllers, leaving participants uninformed about the traffic situation in both patterns.
- Unmanned air traffic services, as the airfield controller position was not occupied at the time of the accident, preventing active conflict resolution.
- Visual obstructions, including the TL 96 Sting turning from the north pattern into a short final, and the pilot of the TL 96 Sting being blinded by the sun.
- The position of the sun, which placed the D4 Fascination directly in the path of the TL 96 Sting's approach, making it difficult to detect.
- The tow rope strike, which served as the immediate physical cause of the loss of control of the D4 Fascination.