What happened
On 17 December 2000, a Gardan GY80-160, registration G-ASZS, was conducting a private training flight at Wellsbourne Mountford Airport. After performing pre-flight inspections and removing ice from the wings and tailplane, the pilot departed from Runway 18R. The flight proceeded normally through the climb and into the circuit pattern.
During the downwind leg, the pilot lowered the flaps and landing gear. While the aircraft made a gentle touchdown, the pilot continued the landing roll into a right turn toward Runway 05. During this maneuver, a loud bang occurred, and the main landing gear collapsed. The nose gear remained extended, allowing the pilot to shut down the engine and exit the aircraft without injury. Subsequent recovery efforts using a forklift truck caused additional damage to the aircraft's tail fin.
The investigation
Investigators examined the aircraft's landing gear mechanism and the failed torque tube lever. The investigation focused on the manual retraction system, which utilizes a screwjack and a control bellcrank to move the gear. The system is designed so that the drag braces become rigid once the gear is fully extended, providing a physical cue to the pilot via increased resistance in the gear handle.
Post-accident photographs revealed that the lever on the main landing gear torque tube had fractured, and the housing for the operating handle had been partially ripped from the centre console. Metallurgical analysis of the lever confirmed an overload failure but found no evidence of prior defects.
Findings
- The main landing gear torque tube lever failed due to excessive loading.
- The failure was consistent with the landing gear not being fully extended and locked into position.
- Bright sunlight through the windscreen likely prevented the pilot from clearly seeing the green 'gear down' indicator light.
- The pilot could not confirm if they had felt the characteristic stiffening of the handle that signals the gear is locked.