What happened
On 9 September 2004, a Replica Campbell Cricket gyroplane, registration G-BVOH, was conducting a private flight along the Anglesey coastline. Approximately 30 minutes after departing from RAF Mona, while cruising at an altitude of roughly 800 feet, the aircraft's engine suffered a sudden failure. Prior to this event, the engine had been operating normally.
The pilot successfully transitioned the aircraft into an autorotative glide and selected a field for an emergency landing. As the aircraft approached the landing site, the pilot encountered a significant downhill slope that had not been visible from the air. During the flare, the aircraft' s flight path aligned with this downward gradient, causing the gyroplane to maintain a low forward speed. This resulted in the aircraft striking the ground and a hedge at the edge of the field simultaneously. The impact caused the rotating blades to hit the ground, which subsequently tore the rotor head assembly away from the mast. The aircraft sustained damage to the rudder assembly, rotor blades, and mast, but the pilot escaped the wreckage without injury.
The investigation
The investigation focused on the cause of the engine failure and the circumstances of the landing. Initial inspections of the engine by the pilot suggested the spark plugs were functioning correctly during rain; however, under dry conditions, no spark could be produced. The engine, a Rotax 532, utilizes a single alternator to provide power to the ignition coils of both cylinders.
Findings
- The engine failure was likely caused by an intermittent fault in the alternator, which provides power to the ignition system.
- The landing was complicated by a downhill slope in the chosen field that was not apparent during the initial approach.
- The impact with the ground and a hedge led to structural damage to the rotor head, mast, and rudder.