What happened
On 2 January 2002, a Mainair Blade microlight, registration G-BYLK, was conducting a training flight from Abbey Farm, Norfolk. The flight involved an instructor and a student, intended to practice circuits at a nearby airfield. The landing strip was frozen with a light layer of snow, and the aircraft' and wing had been stored in a barn and garage overnight.
During pre-flight preparations, the instructor noted a light dusting of frost on the upper surface of the wing but believed it was too thin to affect performance. During the takeoff roll, the aircraft accelerated normally and lifted off the ground. However, once airborne, the aircraft failed to gain altitude. As the instructor attempted to establish a climbing attitude and subsequently initiated a left turn to avoid trees and power lines at the end of the field, the left wing tip struck the ground. The aircraft rolled over violently, resulting in 1 fatal and 1 serious injury.
The investigation
The AAIB examined the wreckage and reviewed video footage of the flight. The investigation focused on the aircraft's performance during the climb and the condition of the wing. While the engine and airframe were found to be structurally sound, the investigation looked into the impact of the frost observed on the wing's upper surface.
Investigators also analyzed the safety equipment, specifically the student's helmet. The examination revealed that the helmet was a communications-only model, not designed to meet modern impact protection standards. The investigation also reviewed the manufacturer's manual, which contained warnings regarding flight in ice and rain, though the specific risks of thin frost were not highlighted in a dedicated safety section.