What happened
On July 8, 2004, at approximately 09:17, a Robin DR 400-180R, registration HB-EXW, was performing a glider tow operation at Buochs Aerodrome. After completing the tow, the pilot commenced a landing on runway 07 R. Shortly after touchdown, the aircraft collided with a cyclist who was crossing the runway from a nearby path.
The cyclist, traveling at a low speed, entered the runway area from a track protected by barriers. An eyewitness noted that the cyclist was looking toward Ennetbürgen at the moment of impact and failed to notice the approaching aircraft. The collision resulted in one fatality (the cyclist) and caused substantial damage to the aircraft. The pilot escaped the accident without injury.
The investigation
Investigators examined the pilot's medical history and recent flight performance. It was discovered that the pilot's distance vision had significantly deteriorated due to age-related changes in the lens, a condition that had been noted during a medical exam two months prior. Furthermore, a check flight conducted the day before the accident had identified serious deficiencies in the pilot's flying performance, leading a flight instructor to recommend that the pilot no longer be used for towing operations.
The investigation also looked into the airfield's operational procedures. While the air traffic controller had closed the runway barriers shortly before the landing, it was unclear if the cyclist passed through the barriers while they were still open. The investigation also noted that the specific landing procedures used during glider training camps placed aircraft on the runway area in a location that was difficult for the control tower to monitor effectively.
Findings
- The primary cause of the accident was the collision between the landing aircraft and the cyclist.
- The pilot's impaired visual perception due to significantly reduced distance vision made it difficult to detect the cyclist in time.
- There was an inconsistent response to flight instructor feedback, as the pilot continued to perform towing duties despite failing a check flight the previous day.
- The cyclist's lack of attention to the runway environment contributed to the collision.
- Existing operational procedures for glider training camps were inadequate, as they allowed landings in areas with limited oversight from the tower.