What happened
On September 10, 1970, a private flight departed from Sitterdorf airfield carrying a pilot and two passengers. The flight was destined for Pruntrut, where the aircraft approached runway 07. During the approach, the aircraft overshot the 550-meter grass runway, touching down approximately 3 meters beyond the end of the paved surface.
As the Cess0172 rolled for about 60 meters, it encountered a bump in the terrain that caused the aircraft to lift off the ground. In an attempt to recover, the pilot initiated a go-around. However, during this maneuver, the pilot attempted a right-hand turn to avoid a line of trees but failed to retract the landing flaps from their fully extended position. This resulted in insufficient airspeed, causing the aircraft to bank sharply to the left and crash at approximately 16:01.
The investigation
The investigation examined the flight parameters, the aircraft's mechanical state, and the pilot's experience. The pilot held a valid private pilot license with specific authorization for the Cessna 172 and was well-acquainted with the Pruntrut airfield. At the time of the accident, the pilot had approximately 115 total flight hours.
Investigators also analyzed the meteorological conditions, noting that while visibility was good at 20 km, the area was experiencing gusty winds between 15 and 20 knots due to approaching thunderstorm activity. The investigation focused on the sequence of the landing attempt and the subsequent aerodynamic behavior of the aircraft during the aborted landing.
Findings
- The aircraft touched down significantly past the runway threshold due to an overly long approach.
- The pilot delayed the decision to execute a go-around until after the aircraft had already left the runway surface.
- The pilot failed to retract the landing flaps from the fully extended position during the go-around maneuver.
- The combination of high flap settings and a turning maneuver led to a loss of airspeed and an uncontrolled left bank.