What happened
On 1 August 2007, a Tipsy Nipper T.66 Series 2, registration G-ARBP, was performing a flight test of a new propeller at Seighford Airfield in Staffordshire. The pilot was conducting an approach at a speed of 55 mph using 1,900 rpm. During the approach, the aircraft encountered sudden and severe turbulence, which caused the wing to rise. This led to the aircraft striking the final approach path and subsequently hitting an earth bank. The impact resulted in substantial damage to the propeller, the landing gear, and the right wing. The pilot was not injured during the event.
The investigation
The investigation examined the environmental conditions and the positioning of ground objects near the runway. At the time of the accident, weather conditions were reported as CAVOK with winds from 250° at 4 to 12 kt. Investigators noted that a large Heavy Goods Vehicle (HGV) was positioned on the extended centerline of Runway 31, near the approach end. This area is a paved section used for HGV training. The pilot, who possessed significant flying experience, suggested that the turbulence was a result of the aircraft passing over this large vehicle.
Findings
- The aircraft, a small single-seat monoplane with a 6 m span and a maximum takeoff weight of only 329 kg, has a very limited tolerance for turbulent air.
- The presence of a large HGV positioned under the flight path was identified as a major factor in generating the turbulence encountered by the aircraft.
- The aircraft's nose and left wing were affected as it passed over the vehicle, leading to the loss of control and subsequent impact with the earth bank.