What happened
On 30 April 2008, a Beech 76 Duchess, registration G-OADY, was conducting a multi-engine rating training flight at Doncaster Sheffield Airport. The flight originated from Leeds Bradford Airport, where the student pilot and instructor departed at 0825 hrs. The training involved performing touch-and-go circuits under favorable weather conditions.
After successfully completing the first circuit, the aircraft touched down for a second circuit. Following the established company procedure, the instructor intended to clean up the aircraft by retracting flaps and resetting switches while the student maintained control. During the ground roll, the instructor announced the intention to tidy the aircraft. In response, the student pilot removed his hand from the throttles and moved the landing gear selector switch to the up position.
While the main landing gear remained locked, the nose gear retracted. This caused the aircraft's nose and propeller blades to strike the runway surface. The aircraft slid along the runway, veering slightly left of the centerline before coming to a stop. There were no injuries to the two crew members on board.
The investigation
The investigation focused on why the nose gear was able to retract while the aircraft was still on the ground. It was established that the student pilot, who had very limited experience on this specific type, performed the gear retraction as a reflex action. The investigation also examined the safety mechanisms of the Beech 76 Duchess.
It was found that the aircraft's landing gear safety switch, designed to prevent accidental retraction on the ground, was bypassed. This switch relies on pitot pressure; when airspeed is between 59 and 63 kt, the system deactivates the hydraulic pressure pump circuit. During this specific ground roll, the aircraft's speed remained above this threshold, meaning the safety protection was not active.
Findings
- The student pilot's selection of the landing gear up position was an inadvertent reflex action.
- The instructor's non-standard verbal callout may have acted as a trigger for the student's error.
- The aircraft speed remained above 63 kt during the ground roll, which prevented the landing gear safety switch from deactivating the hydraulic pressure pump.
- The student pilot's high mental workload, due to limited experience on the type, contributed to the error.