What happened
On August 23, 2003, a Cessna 182H carrying a pilot and four passengers (two tandem skydivers and two passengers) was climbing through FL 36 after requesting clearance to FL 105. Simultaneously, an LS-4 glider had been flying a thermal flight since 13:22.
Radar data and witness accounts indicate that the aircraft were on a collision course. The Cessna was climbing toward a heading of 295°, while the glider was traveling approximately 195°. The collision occurred near Marxheim-Leᆻchend, resulting in the destruction of both aircraft. Witnesses reported hearing a loud bang followed by the cessation of engine noise and debris falling from the sky. The impact caused the Cessna to crash into a field and catch fire, while the glider's fuselage and wings were scattered across the area. The collision resulted in six fatalities, including the glider pilot.
The investigation
The BFU examined radar data from the DFS and the Bundeswehr, as well as radio communications between the Cessna pilot and Munich Information. The investigation analyzed the wreckage distribution, which showed that the aircraft broke apart at a significant altitude before hitting the ground. Physical evidence, including red paint and oil transfers, confirmed the contact point between the Cessna's right wing strut/propeller and the glider's left wing and cockpit area.
Investigators also calculated the theoretical visibility of the aircraft. Based on the aircraft dimensions, the glider was theoretically detectable by the Cessna pilot approximately 70 seconds before impact, and the Cessna was detectable by the glider pilot approximately 88 seconds before impact. The investigation also considered the cockpit design of the Cessna, noting that the instrument panel and engine cowling could obstruct the pilot's view.
Findings
- The primary cause of the accident was that the pilots failed to recognize the other aircraft or the impending collision risk in time.
- While aviation regulations dictate that the aircraft approaching from the left (the glider) should yield, the investigation found that the Cessna pilot's view was likely obstructed by the engine cowling and instrument panel due to the aircraft's climbing attitude.
- The glider pilot likely overlooked the Cessna because it was initially positioned well below the glider's flight path, and a small, constant-bearing target is difficult to detect during routine scanning.
- Weather conditions were clear with excellent visibility, meaning environmental factors did not contribute to the lack of detection.