What happened
On 11 August 2021, a Piper PA-2-2-150, registration G-ARDS, was conducting a private flight from Sherburn in Elmet to Beverley Airfield. The weather was good, with a 10-knot crosswind from 180 degrees. During the landing sequence on Runway 12, the pilot experienced significant turbulence at 150 feet above ground level, requiring immediate corrections to maintain wing level. While the approach remained stable following this initial disturbance, a sudden, violent gust occurred during the flare. This gust caused the right wing to lift, leading the aircraft to drift left and veer off the runway. Despite an attempt to apply power for a go-around, the aircraft missed a nearby ditch but eventually struck the ground in a field. The pilot sustained minor injuries, but the aircraft was damaged beyond economical repair.
The investigation
The investigation examined the aircraft's flight path and the environmental factors at Beverley Airfield. The pilot suggested that turbulence from a wind farm located south of the airfield might have contributed to the loss of control. Investigators noted that the aircraft was still equipped with a rudder/aileron interlink, which coordinates control inputs; the pilot noted this feature might have influenced the aircraft's response to the sudden gust.
Furthermore, the AAIB reviewed the proximity of the wind turbine installation to the runway. The most northerly turbine is approximately 1.4 km from the Runway 12 threshold. Investigators also consulted airfield management, who reported no previous issues with turbulence from the wind farm, though they noted potential shadowing from nearby trees.
Findings
- The aircraft experienced a sudden gust during the flare that caused the right wing to lift.
- The aircraft's movement off the runway was likely exacerbated by the presence of the rudder/aileron interlink during the corrective maneuvers.
- While the pilot suspected wake turbulence from the nearby wind farm, the distance from the turbines to the point of the upset exceeded the 16 rotor diameters identified in CAA guidelines as the furthest distance where turbulence might be expected.
- The possibility of encountering wake turbulence from the wind farm cannot be entirely dismissed, though it is considered remote based on current literature.