What happened
On 14 May 2016, a Thruster TST Mk1, registration G-MTKA, was performing a private flight from Manchester/Barton Aerodrome. As the aircraft accelerated along the grass runway 26L, the pilot experienced a sudden loss of effectiveness in the rudder and aileron controls. This led to the right wing lifting and the aircraft yawing 90 degrees to the right. During this maneuver, the left mainwheel struck the ground and detached, causing the left wing to impact the runway surface. The aircraft then pitched nose-down until the propeller struck the ground, before eventually settling back onto its tailwheel and right mainwheel. There were no injuries to the two occupants, who were able to exit the aircraft without assistance.
The investigation
The investigation examined the aircraft's mechanical condition and local meteorological data. The aircraft sustained damage including a distorted wing spar, a detached left mainwheel, and propeller damage. While the pilot initially believed a moderate crosswind was present, airport records showed the wind was predominantly northerly at 10 knots or less, with gusts reaching 15 knots. Just prior to takeoff, the pilot had been informed of a wind from 030 degrees at 7 knots. The pilot noted that the wind felt extremely variable and suspected a sudden wind shift contributed to the loss of control.
Findings
- The aircraft's control surfaces became ineffective during the takeoff roll.
- The left mainwheel detached upon impact with the ground.
- The pilot experienced a sudden change in wind conditions during the takeoff sequence.