What happened
On 12 July 2020, a collision occurred between two aircraft at a private airstrip in Birdsedge, Yorkshire. The first aircraft, a Bristell NG5 Speed Wing, registration G-COLF, was performing a backtrack on Runway 08. During this maneuver, the pilot observed a section of undulating, soft ground spanning the runway.
After turning around at the runway threshold, the pilot taxied past the soft area to a position further down the runway before attempting takeoff. As the aircraft crossed the soft ground, the wheels became bogged down. In an attempt to overcome the resistance, the pilot increased engine power significantly. This high power setting led bystanders to believe a takeoff roll was underway. During the maneuver, the nosewheel castor deflected to the left, causing the aircraft to veer off the runway. The G-COLF then collided with a DH82A Tiger Moth, registration G-BAFG, which was parked on the grass area adjacent to the runway edge.
There were no injuries to the pilot of the Bristell or the pilot of the Tiger Moth. The G-COLF sustained damage to its wing and tailplane, while the G-BAFG suffered damage to its wing.
The investigation
The investigation examined the ground conditions and the sequence of the taxi maneuver. It was established that the pilot of the G-COLF likely became stuck in a rut on the runway. This caused the left wheel spat to dig into the earth, which induced a pivot under the high power being applied. The investigation also noted the proximity of the parked G-BAFG to the runway edge, which left the pilot of the Bristell with minimal time to correct the deviation.
Findings
- The primary cause of the accident was the aircraft becoming bogged down in soft ground while taxiing.
- The application of high power to overcome ground resistance contributed to the loss of directional control.
- The presence of parked aircraft near the runway edge and the specific hazards of the unlicensed airfield acted as contributing factors.