What happened
On the afternoon of October 8, 1972, a Fuji FA-200-180, registration HB-ESW, departed Beromünster for Ascona with a pilot and three passengers. During the approach to Ascona airfield, the aircraft encountered another plane, a HB-OZU, which was also on final approach.
While the two aircraft were in close proximity, the pilot of the HB-ESW initiated a sharp left-hand turn toward a nearby mountainside. During this maneuver, the aircraft entered an uncontrolled descent. The plane struck tree branches and severed high-voltage power lines before crashing into a chestnut forest near Solduno. The impact resulted in four fatalities, as all occupants of the aircraft were killed. The aircraft was destroyed in the crash.
The investigation
An investigation conducted by the Swiss authorities examined the flight paths of both aircraft and the environmental conditions at the time. Investigators noted that the approach pattern at Ascona is non-standard due to the local topography, requiring a specific eight-shaped pattern.
Witnesses and the pilot of the other aircraft, HB-OZU, provided accounts of the sequence. The investigation looked into whether the pilot of HB-ESW was aware of the proximity of the other aircraft and why the approach was not aborted. Technical analysis of the wreckage confirmed that the aircraft's weight and center of gravity were within limits and that no pre-existing mechanical failures were responsible for the accident.
Findings
- The pilot was flying a valid route and was familiar with the specific approach requirements for Ascona.
- Both aircraft were simultaneously on final approach, creating a high-risk situation.
- The pilot of the HB-ESW failed to abort the approach when the aircraft came into dangerous proximity with the other plane.
- Instead of abandoning the landing, the pilot executed a steep turn toward the terrain.
- During this tight turn, the aircraft's airspeed dropped below the minimum flight speed, leading to an aerodynamic stall and subsequent uncontrolled descent into the hillside.