What happened
On 28 May 2017, a Pegasus Quantum 15, registration G-MYPY, was engaged in a private flight near Friskney, Lincolnshire. The pilot had departed from Skegness and was navigating toward the home airfield at Boston under favorable weather and visibility conditions. While flying at an altitude of approximately 2,300 ft, the pilot increased the throttle to accelerate while maintaining straight and level flight. The pilot reported that a wing failure occurred above the cockpit, causing the aircraft to enter a spiral descent. The impact resulted in serious injuries to the pilot and extensive damage to both the engine and the airframe.
The investigation
The investigation examined the pilot's account alongside physical evidence and flight dynamics. While the pilot initially suggested a structural failure occurred during a period of level flight, investigators found evidence suggesting the aircraft was actually undergoing a stall manoeuvre. This manoeuvre likely triggered a 'tumbling' departure from controlled flight, which is a known phenomenon in certain flexwing configurations. An independent inspection of the aircraft's structure by a qualified third party found no evidence of any pre-existing structural defects or failures prior to the event.
Findings
- The aircraft entered a state of uncontrolled flight characterized by a tumbling motion.
- The primary cause of the accident was the unintentional entry into a tumbling departure during a stall manoeuvre.
- There was no evidence of prior structural weakness in the airframe or engine components.