What happened
On 21 August 1999, a Pegasus XL-Q, registration G-MYBR, was performing a private flight from a prepared field near Radwell, Hertfordshire. The pilot had recently adjusted the wing batten profiles and intended to use the flight to assess the aircraft's trim. The flight included one passenger, who was also a microlight pilot.
Following takeoff from a strip orientated 040°, the aircraft climbed rapidly. In an effort to align the flight path with the prevailing wind, the pilot initiated a right-hand turn. At an altitude of approximately 30 to 40 feet, a strong gust of wind struck the left wing. This caused a significant increase in the right bank angle, leading to a rapid loss of height. The aircraft struck a ditch and subsequently crashed into trees and dense undergrowth. The pilot sustained fatal injuries, while the passenger suffered serious injuries.
The investigation
Investigators examined the wreckage and the flight conditions. The engine and mechanical systems showed no signs of malfunction prior to impact; the fuel selector and ignition were both in the ON position, and the engine sounded normal to the passenger during the flight. While the pilot had recently modified the outermost wing battens, measurements showed the camber deviation was within the manufacturer's allowable limits and unlikely to cause adverse handling.
The investigation also reviewed the takeoff site. The field used for operations did not meet the British Microlight Aircraft Association's recommended criteria, as the boundary obstructions (trees) exceeded the recommended height for a runway of that length. Additionally, the aircraft was operating in a direction (040°) that was unusual for the site, as prevailing winds typically come from the southwest.
Findings
- The aircraft was in excellent condition with no evidence of technical failure.
- The pilot's rapid climb may have been an attempt to clear the trees at the end of the field.
- A strong wind gust struck the aircraft while it was at a low airspeed, a condition where the aircraft's roll authority is significantly reduced due to its design.
- The loss of roll control following the gust prevented the pilot from recovering the aircraft before it struck the ground.