What happened
On 25 June 2019, an EC120 B Colbri, registration G-RCNB, was involved in a ground accident at Enniskillen Airport, County Fermanagh. The aircraft, operated for a private flight, had recently been refuelled at a station adjacent to fuel storage tanks. Following standard pre-start and pre-takeoff procedures, the pilot raised the collective pitch lever to initiate takeoff.
As the aircraft became light on its skids, it began to yaw toward the left. In an attempt to avoid the nearby fuel installation, the pilot applied left cyclic control. However, the leftward yaw continued, eventually completing a full 3ered rotation. During this movement, the left skid struck the apron, causing the helicopter to roll. The main rotor made contact with the ground, scattering debris across the area. The aircraft continued to rotate an additional 90 degrees before settling on its right side. The pilot successfully exited the aircraft through the left door without injury.
The investigation
The investigation focused on the pilot's control inputs and the mechanical behavior of the aircraft during the takeoff roll. Investigators examined the pilot's recent flying history, noting that during the previous weekend, the pilot had been operating a Robinson R44. Unlike the EC120 B Colbri, the Robinson R44 features a main rotor that rotates anticlockwise, whereas the EC120 rotates clockwise. This difference in rotation direction fundamentally alters the direction of torque-induced yaw and the required pedal inputs.
Findings
- The pilot had recently been flying an aircraft with an opposite rotor rotation direction.
- Insufficient right yaw pedal application during the initial increase of collective pitch allowed the aircraft to yaw left.
- The pilot's attempt to use left cyclic to move away from the fuel tanks did not prevent the continued rotation.
- The accident resulted in no injuries to the crew, though the aircraft sustained damage to the rotor blades, head, tailboom, horizontal stabiliser, fenestron, and skid gear.