What happened
On 1 June 2022, a Pegasus Quik microlight, registration G-CCPC, was undergoing engine start-up procedures at East Fortune Airfield. Following several unsuccessful attempts, the engine started but immediately accelerated to a high RPM. This sudden surge caused the aircraft to accelerate across the grass area, striking a runway marker sign. The impact caused the aircraft to bounce and become airborne.
During the flight, the aircraft performed a tight, low-level turn before descending behind a hangar. The aircraft struck the ground in a field, cartwheelling before coming to rest. The pilot sustained fatal injuries, specifically a severe rotational head injury, and passed away eight days after the accident.
The investigation
Investigators examined CCTV footage, which showed the engine accelerating rapidly and the aircraft's path across the airfield. The investigation established that the aircraft's base bar remained tethered to the front strut during the ground run and the initial flight.
Examination of the aircraft revealed that the manufacturer's optional starter inhibitor switch, which prevents the engine from starting if the throttle is not closed, had not been installed on G-CCPC. Furthermore, the investigation found that the pilot was wearing only the lap strap; the diagonal shoulder strap had been routed under the seat cushion and was not in use. The pilot's helmet, while meeting existing standards, lacked protection against the rotational forces sustained during the impact.
Findings
- The primary cause of the accident was the aircraft becoming airborne while the base bar was still tethered to the front strut.
- The engine runaway was likely caused by the pilot setting the hand throttle to a high RPM setting to clear a suspected flooded engine.
- The lack of a starter inhibitor switch on the hand throttle allowed the engine to reach high RPM during start-up.
- The pilot's lack of upper body restraint, due to not wearing the shoulder strap, allowed for excessive head movement during impact.
- The pilot had not practiced the practical skill of using the ignition switches to shut down the engine while the aircraft was in forward motion.