What happened
On October 19, 1969, a Piper J3C, registration HB-OAK, was performing a training flight at Geneva-Crollin airport. During the landing phase on the grass runway, the student pilot executed a hard touchdown approximately 50 meters past the runway threshold. Due to excessive speed and insufficient pitch control, the aircraft bounced, reaching an altitude of between 2 and 5 meters.
In an attempt to stabilize the aircraft, the instructor took control and applied full power to mitigate the pitching motion. However, the left wing lifted abruptly, causing the aircraft to roll to a 45-degree angle relative to the runway centerline. The aircraft struck the ground in this oblique position, resulting in the failure of the left landing gear leg. The aircraft slid across the ground before coming to a halt near the aero club facilities.
The investigation
Investigators examined the wreckage and interviewed the instructor. The inspection of the aircraft's control surfaces, including the rudder, brakes, and stabilizer trim, revealed no mechanical defects. The aircraft's weight and center of gravity were found to be within prescribed limits. The investigation also noted that two large commercial airliners, an Air France Caravelle and a Swissair DC 9, had departed from the main runway only seconds before the accident occurred.
Findings
- The primary cause of the accident was a loss of control following a hard landing, triggered by an incomplete flare and excessive approach speed.
- The loss of control may have been further complicated by wake turbulence from the recent departures of two heavy commercial aircraft.
- There were no injuries to the instructor or the student pilot, though the aircraft sustained significant damage to the engine mount, the left wing leading edge, the fuselage structure, and the propeller.