Casualties unknown

Piper Cub J3C HB-OUO Incident on 23 May 1965 at a Military Airfield

Militärflugplatz, CH

On May 23, 1965, a PIPER AIRCRAFT CORPORATION J3C-65/L-4. (registration HB-OUO) was involved in an aviation accident near Militärflugplatz, CH. Investigators recorded the probable cause as: The flight instructor allowed the aircraft to lose speed while correcting a student's failed landing approach, causing a stall and subsequent damage. This summary draws on records from the Swiss Transportation Safety Investigation Board (STSB / SUST).

Sourcesthe Swiss Transportation Safety Investigation Board (STSB / SUST)Primary reportUpdated 2026-09-13Data APIEditorial standards

During a training flight, a Piper Cub J3C stalled after the instructor corrected a student's landing approach, resulting in landing gear damage; no injuries.

Incident Overview

On 23 May 1965, a Piper Cub J3C with registration HB-OUO was involved in an incident at a military airfield. The aircraft was being used for flight training under the supervision of a flight instructor. During a landing approach, the student pilot executed an unsuccessful landing attempt. The flight instructor intervened to correct the approach. However, the corrective action led to a loss of airspeed, causing the aircraft to stall. The aircraft then sank abruptly and sustained heavy damage to its landing gear.

Aircraft Information

The aircraft was a Piper Cub J3C, a light two-seat training monoplane. The registration HB-OUO identifies it as a Swiss-registered aircraft. The damage to the landing gear was assessed at 30% of the aircraft's value, indicating substantial but not total loss.

Sequence of Events

The incident occurred during a training exercise. The student pilot was conducting a landing approach but failed to execute it properly. The flight instructor took control to rectify the situation. During the correction, the aircraft's speed decreased below a safe threshold, leading to an aerodynamic stall. The aircraft descended rapidly and impacted the runway with sufficient force to damage the landing gear.

Damage and Injuries

The landing gear suffered heavy damage, quantified as 30% of the aircraft's value. The two occupants—the flight instructor and the student pilot—remained uninjured. No other injuries or damage were reported.

Probable cause

The flight instructor allowed the aircraft to lose speed while correcting a student's failed landing approach, causing a stall and subsequent damage.

Investigation report by the Swiss Transportation Safety Investigation Board (STSB / SUST). Original record: https://www.sust.admin.ch/inhalte/AV-berichte/253.pdf. This page is a structured re-presentation; facts and quotes are in the Swiss Transportation Safety Investigation Board (STSB), Switzerland.