What happened
On 28 November 2010, a Thruster TST Mk 1, registration G-MVIU, was performing a private flight from RAF Mona Airfield in Anglesey, Wales. After completing standard warm-up procedures, the pilot lined up on Runway 04, which offered roughly 4,700 feet of available distance.
During the takeoff roll, the pilot applied full power. However, shortly after lift-off at an altitude of about 10 feet, the pilot sensed a lack of climbing performance and suspected insufficient engine thrust. Consequently, the pilot reduced power to abort the takeoff. As the aircraft returned to the runway, it passed the intersection with a disused runway and landed to the left of the centerline.
Despite attempts to use the rudder to maintain the path, the aircraft drifted off the paved surface and entered heavy mud. The sudden deceleration caused the aircraft to tip forward onto its nose. While the aircraft sustained significant damage—including a cracked cabin floor, a bent wing strut, and a sheared mainwheel—the two occupants escaped without injury.
The investigation
The AAIB investigation focused on the aircraft's performance and weight configuration. The investigation established that the aircraft had been modified in 2001 with an enclosed cockpit, which increased its weight. This modification required more careful monitoring of the takeoff weight, as the zero fuel weight had increased.
Post-accident calculations revealed that the aircraft was approximately 13 kg above its maximum takeoff weight of 360 kg. The total takeoff weight was determined to be 373 kg, as the two occupants and the full fuel load exceeded the permitted limits. The pilot noted that the runway surface was slippery, which may have impacted control during the aborted maneuver.
Findings
- The aircraft was operating above its maximum takeoff weight.
- The pilot was unaware of the specific weight restrictions imposed by the enclosed cockpit modification.
- The pilot's decision to reduce power during the aborted takeoff may have resulted in insufficient rudder authority to counteract the aircraft's deviation on the slippery runway surface.