What happened
On 4 June 2011, an EC120B Colibri, registration G-FEDA, was performing a private flight at Redhill Aerodrome in Surrey. While the pilot was hover taxiing toward a designated landing pad near a hangar, the aircraft entered a turn to the left. During this maneuver, the helicopter's tail was caught by gusting winds, causing the aircraft to rotate more rapidly than the pilot intended.
In an attempt to arrest the increasing rate of turn, the pilot applied right yaw pedal; however, the rotation continued to accelerate. The right skid eventually made contact with the ground, leading the helicopter to roll onto its side. The impact caused the main rotor blades, tail section, skids, and floats to detach, resulting in general damage to the fuselage. Following the impact, the pilot engaged the rotor brake and fuel shutoff lever, then jettisoned the front left door to assist the two passengers.
The investigation
The investigation focused on the sequence of control inputs and the environmental conditions at the time of the accident. The crew consisted of one pilot and two passengers, all of whom sustained minor injuries. The investigation examined the pilot's use of yaw pedals to compensate for wind effects and the impact of wind gusts on the aircraft's stability during the hover taxi. At the time of the incident, north-easterly winds were recorded at 9 knots, with gusts reaching 21 knots.
Findings
- The primary cause of the loss of control was the insufficient application of right yaw pedal to counteract the wind-induced rotation.
- Gusting wind conditions contributed to the rapid, unintended rotation of the aircraft's tail.
- The aircraft's right skid struck the ground, triggering the roll onto its side.