What happened
On 3 February 2011, a Magni M24C, registration G-CGRT, was involved in an accident at Rufforth Airfield in Yorkshire during a private flight. The pilot had been conducting a series of short takeoff and landing maneuvers in clear weather with a 20 kt headwind. During the fourth takeoff attempt, while performing the standard rotor pre-rotation procedure, the aircraft's nose lifted and the tail castor made contact with the ground.
As the rotor RPM reached 230 rpm, the aircraft began rolling to the left. The pilot attempted to recover the aircraft by applying full right stick and full power while pushing the stick forward. However, the aircraft gained roughly 10 kt of forward speed and continued its left roll, eventually impacting a ploughed field adjacent to the runway. The aircraft came to rest on its side, sustaining damage to the rotors, rotor head, propeller blades, engine cover, pilot door, and composite body. The pilot, who was wearing a helmet and full harness, sustained no injuries.
The investigation
The investigation examined the environmental conditions and the aircraft's behavior during the pre-rotation phase. It was noted that while the pilot was experienced in flying gyroplanes in high winds, this was his first time operating the M24C in such conditions.
An instructor's assessment highlighted that the combination of the pilot's rearward stick movement, the specific rotor RPM, and the wind strength contributed to the instability. Furthermore, the investigation established that at 220 rpm, directional control from the main rotor is inherently limited, which likely reduced the effectiveness of the pilot's corrective inputs.
Findings
- The accident was caused by a sudden increase in wind speed during the main rotor pre-rotation.
- The aircraft's nose lifted and the tail castor struck the ground because the aircraft weight would have caused lift-off at that specific rotor speed under the prevailing conditions.
- The pilot's ability to recover was hampered by limited directional control from the main rotor at the low RPM reached during the incident.