What happened
On May 23, 1965, a Piper PA-18-150 Super Cub, registration HB-OVZ, was engaged in a glider towing operation near Delsberg, Switzerland. The pilot was tasked with retrieving a glider from a meadow at La Deute, located approximately one kilometer south of Dels．berg, and transporting it back to Grenchen.
During the approach to the landing site, the pilot attempted to land on a slightly ascending meadow. While the pilot identified only one viable landing direction due to the terrain, the aircraft encountered a tailwind. The pilot underestimated the strength of this wind, causing the aircraft to overshoot the intended landing area. As the aircraft continued its roll, it entered a depression in the ground, resulting in damage to the propeller and the right side of the landing gear.
The investigation
The investigation established that the landing took place on a field that had been previously scouted by the glider pilot. Although the pilot was experienced in both powered and glider flight, the investigation noted that the landing was an unauthorized field landing, as no permission had been obtained from the Federal Office of Civil Aviation.
Investigators examined the wind conditions and the terrain, noting that the pilot's decision to land in a specific direction was constrained by the upward slope of the meadow. The investigation also considered the operational context, noting that the pilot was acting under a written instruction from the head of the glider group to perform the retrieval.
Findings
- The primary cause of the accident was that the pilot underestimated the strength of the tailwind during the field landing, leading to an excessive landing roll.
- The aircraft sustained damage to the propeller blade and the right landing gear assembly.
- There were no injuries to the pilot during the occurrence.