What happened
On 31 March 2007, a pilot operating an RAF 2000 GTX-SE, registration G-HOWL, performed a takeoff from Eddsfield Airfield in North Yorkshire. After landing and refueling, the pilot assessed the wind at approximately 020°/7 kt. To avoid a 15-foot hedge at the eastern end of the runway, the pilot opted for a downwind takeoff using Runway 27, accepting a slight tailwind component.
During the takeoff roll, the aircraft climbed to a height of roughly 160 ft. However, the aircraft then encountered a severe downdraft, causing a rapid descent. While the pilot initially suspected engine failure, instruments showed a normal engine speed of 5,220 rpm and an indicated airspeed of 50 mph. In an attempt to recover, the pilot turned the aircraft back toward a westerly heading. This maneuver, however, further increased the rate of descent. As the aircraft approached the end of the runway, the airspeed dropped to approximately 30 mph. The pilot lowered the nose to regain speed but instinctively partially closed the throttle. This action prevented the airspeed from recovering, leading to an almost vertical descent. The aircraft struck the ground on its left side in a shallow nose-down attitude, subsequently bouncing and rolling to the right. The pilot sustained superficial head injuries and was able to exit the aircraft.
The investigation
The investigation examined the aircraft's configuration and the pilot's actions during the emergency. It was noted that the pilot had failed to notice a low-speed warning light, which activates when airspeed drops below 46 mph. The investigation also reviewed the performance capabilities of the aircraft type, noting that for an RAF 2000 with a single occupant and full fuel, the minimum power required speed is approximately 60 mph. Furthermore, the investigation considered the impact of the tailwind and the airfield's terrain, noting that the runway used was subject to potential turbulence from nearby trees.
Findings
- The aircraft was operating at an airspeed significantly below the minimum power required speed for its weight configuration.
- The pilot's decision to turn into the wind during the descent reduced the vertical component of lift, exacerbating the rate of descent.
- The instinctive partial closure of the throttle prevented the pilot from increasing airspeed to a safe level.
- The takeoff configuration involved a tailwind, which reduced the aircraft's climb performance.