What happened
On 19 June 2005, a Cessna 172RG, registration HB-CLN, was attempting to land at Dittingen airfield in Switzerland. The flight, which included the pilot and one passenger, originated from Basle-Mulhouse airport. Prior to the approach, the pilot had been advised by the airfield's operations manager that weather conditions were unfavorable due to strong winds.
Despite this warning, the pilot proceeded with the approach. During the landing attempt, the pilot initiated a go-around over the runway. Eyewitnesses noted that the aircraft followed an unusual and low flight path, missing the runway centerline. As the aircraft attempted to climb, it encountered heavy turbulence and a significant tailwind. The aircraft failed to clear the terrain, colliding with the ground south of the airfield. The impact caused a fire that completely destroyed the aircraft, and both occupants sustained fatal injuries.
The investigation
The investigation conducted by the AAIB focused on the flight dynamics and the pilot's decision-making process. Investigators examined the aircraft's configuration during the critical moments of the go-around. They found that the landing gear was still extended and the flaps were set to 30°, which significantly increased drag and reduced the aircraft's climb performance. Furthermore, the pilot had not adjusted the propeller control to the minimum pitch for maximum RPM.
Environmental factors were also scrutinized. The investigation established that a strong 'Bise' wind was present, creating a substantial tailwind component and gusty conditions. The high air temperature of 27 °C further contributed to reduced engine and aerodynamic performance. Investigators also noted that the pilot did not utilize the established emergency departure paths, which were designed to avoid the tallest trees near the airfield.
Findings
- The pilot attempted the landing despite being explicitly advised against it due to adverse wind conditions.
- The final approach was unstabilized, characterized by an unusual flight path and centerline deviations.
- The decision to execute a go-around was made too late in the approach.
- The aircraft was in an improper configuration for climbing, with the landing gear down and flaps at 30°.
- The pilot underestimated the impact of the high air temperature and the strong tailwind on the aircraft's ability to climb.
- The pilot failed to follow the recommended departure paths that would have provided better obstacle clearance.