What happened
On 17 May 1998, an ARV1 Super 2, registration G-BMWM, was performing a private flight from Little Snoring Airfield. After an initial successful leg, the aircraft prepared for a short 15-minute return flight from Cromer (Northrepps) Airfield. The aircraft lined up on Runway 18, which is the standard departure runway at this location and was positioned downwind at the time.
During the takeoff roll, configured with one stage of flap, the aircraft reached a rotation speed of 50 kt. At this moment, a loud noise was heard and the entire canopy detached from the airframe, moving rearwards. The pilot identified that the canopy had not been locked before departure. While the aircraft had become airborne, it lacked the necessary climb performance to clear the obstacles at the end of the runway, which included a farm track and a 45-metre drop into a cornfield.
To avoid the track and the drop, the pilot maintained full engine power to ensure sufficient altitude before reducing power to perform an emergency landing in the cornfield. The landing was successful, with the aircraft following the alignment of the corn rows. The pilot avoided using brakes and held the nose up to ensure a smooth touchdown. The aircraft came to a stop approximately 100 metres into the field with the propeller still rotating. Aside from some superficial damage to the upper aft fuselage, the aircraft remained largely intact.
The investigation
Investigators examined the wreckage and the circumstances of the flight. Debris from the canopy frame and perspex was recovered from the latter portion of the runway. The pilot noted that there had been no unusual wind noise during the initial part of the takeoff roll, suggesting the slipstream had temporarily held the unsecured canopy in place until the aircraft reached rotation speed.