What happened
On September 24, 1965, at 15:29 local time, a private Beech 9/5-A-55 Baron, registration HB-GOZ, departed from Geneva Airport for a local VFR flight near the Mont-Blanc region. The aircraft was carrying two passengers at the time of the flight.
The flight proceeded without incident until the landing phase. At 16:21, the pilot touched down on runway 23 at Geneva-Cointrin under favorable weather conditions. Shortly after ground contact, the pilot attempted to retract the flaps. However, the pilot mistakenly operated the landing gear selector instead of the flap lever. This error triggered the immediate retraction of the landing gear. Although the pilot recognized the mistake and attempted to reset the selector to the "GEAR DOWN" position, the mechanism failed to extend. Consequently, the landing gear collapsed, causing the aircraft to slide on its belly before coming to a halt on the runway.
The investigation
The investigation focused on why the landing gear was able to retract while the aircraft was still in contact with the runway. Investigators examined the functionality of the safety switches installed on the main gear struts, which are designed to prevent accidental retraction while the aircraft is on the ground.
Findings
- The primary cause of the landing gear collapse was the inadvertent activation of the gear selector by the pilot.
- At the moment the selector was moved, the aircraft's wings were still generating enough lift to prevent the safety microswitches on the landing gear struts from engaging. Because the full weight of the aircraft had not yet settled on the wheels, the safety mechanism intended to block ground retraction was not operational.
- The investigation also noted that the pilot's decision to retract the flaps so early in the landing roll was unnecessary, as there was no risk of stone damage from the runway surface that would have necessitated such an action.