What happened
On 12 June 2010, a Pegasus XL-R microlight, registration G-MTOO, was being used for ground testing at a playing field near Newbridge, Gwent. The owner, who was undergoing pilot training, had intended to perform untethered ground runs to test the aircraft following recent maintenance to the wing battens.
After completing two successful 400-metre runs, the pilot rigged the wing and began a third run to determine the speed at which the wing would produce lift. As the aircraft reached approximately 24 mph, the pilot felt the wing generating lift. In an attempt to stop the aircraft, the pilot reported that the foot throttle had become stuck in the open position. While attempting to reach the ignition kill-switch to shut down the engine, the pilot inadvertently pushed the A-frame forward. This action caused the aircraft to become airborne, leading to a collision with goalposts at the site.
The investigation
The investigation examined the mechanical state of the throttle system and the circumstances of the ground run. The aircraft's throttle mechanism uses a splitter box with a nylon piston to manage both foot and hand throttle inputs. While the owner reported the foot throttle was stuck, no such malfunction could be replicated during subsequent inspections. The investigation also noted that the owner had recently performed maintenance on the wing battens and was conducting the tests without an instructor present.
Findings
- The pilot's selection of a test site containing obstructions contributed to the severity of the accident.
- The aircraft became airborne due to the pilot pushing the A-frame forward while attempting to reach the engine kill-switch.
- Although the foot throttle was reported as stuck, no mechanical faults were found in the throttle system following the accident.
- The possibility that the hand throttle was left partially open from a previous run could not be entirely ruled out, though the pilot could not confirm this.