What happened
On 30 October 2006, a Raytheon Beech Bonanza A36, registration N4VQ, was performing a private flight from Fenland Airfield in Lincolnshire. The aircraft, carrying the pilot and three passengers, was departing from the grass Runway 18. During the takeoff roll, the pilot maintained the nosewheel off the ground for an extended period. This caused the aircraft to become airborne much earlier than anticipated.
As the aircraft reached a height of approximately 15 to 20 feet, it began to roll heavily to the left, reaching a bank angle of roughly 45 degrees. Fearing the proximity of the ground, the pilot immediately reduced power, leveled the wings, and deployed full flaps. While the aircraft briefly touched the ground again, it subsequently climbed to a similar height before a left-hand roll developed. The pilot eventually brought the aircraft to a halt in a field beyond the runway, where it struck a dyke. All four occupants escaped the wreckage, though the pilot sustained one minor injury.
The investigation
The investigation examined the aircraft's performance capabilities and the runway conditions. The takeoff roll and distance to 50 feet were calculated using the Pilot’s Operating Handbook, which assumes paved runways and specific atmospheric conditions. At the time of the accident, the runway was soft, and a wind of 220 degrees at 15 knots was reported.
Technical consultation with the manufacturer revealed that the aircraft is prone to leftward yaw and roll if insufficient right rudder is applied to counteract propeller slipstream effects. Furthermore, the use of right aileron instead of rudder to correct the turn can exacerbate the issue through adverse aileron yaw. The investigation also reviewed the takeoff distances required for soft ground, noting that the aircraft's early liftoff left it with insufficient airspeed and a potentially high angle of attack.
Findings
- The aircraft became airborne prematurely because the pilot held the nosewheel off the ground for too long.
- The early liftoff resulted in the aircraft being at an insufficient airspeed and potentially a high angle of attack, leading to a wing stall.
- The runway surface was soft, which necessitated increased takeoff distance calculations.
- The pilot had limited experience on this specific aircraft type, with only 20 hours recorded.