What happened
On 6 September 2001, a Hughes 269c, registration G-ZBHH, was engaged in a training flight at Redhill Aerodrome, Surrey. The flight was part of a solo consolidation session for a student pilot, following a period of dual instruction that included engine-off landing practice. After successfully completing two solo circuits, the student pilot commenced a third circuit, approaching runway 01 'H'.
During the approach, the student pilot noted what felt like rough engine running and observed a separation between the engine and rotor RPM indicator needles. In an attempt to maintain power, the pilot moved the throttle to the fully open position. However, the aircraft continued to lose altitude. As the helicopter neared the ground, the pilot performed a flare and attempted to cushion the impact using the collective pitch lever. The aircraft struck the ground heavily, subsequently bouncing and yawing to the left. The pilot performed emergency shutdown procedures before exiting the aircraft without assistance. There were no injuries to the crew.
The investigation
The investigation focused on the cause of the perceived power loss and the subsequent heavy landing. An examination of the Lycoming HIO-360-D1A engine following the accident revealed no mechanical faults or malfunctions. The investigation also considered the pilot's actions regarding the throttle control. The student pilot suggested that the apparent loss of power might have been caused by the mishandling of the twist grip throttle.
Findings
- The aircraft sustained damage beyond economical repair, including bent rotor blades, a damaged tail rotor, and bent skids.
- The pilot may have mishandled the twist grip throttle, leading to the perceived loss of engine power.
- No mechanical defects were found in the engine following the occurrence.