What happened
On 7 June 2002, a Rotax 447 powered ultralight, registration G-MYTA, was involved in an accident during a private flight near Headon, Nottinghamshire. Following a period of extensive maintenance that included the installation of a new engine and exhaust system, the pilot had been experiencing exhaust fumes entering the cockpit. To address this, the pilot had been sealing various gaps in the fuselage and had recently applied PVC tape to the wing root joint.
On the day of the event, the pilot intended to perform fast taxi runs to verify that the cockpit remained free of fumes. During one of these maneuvers, the aircraft unexpectedly lifted off the ground. Because the canopy had not been properly secured, it opened during the unplanned climb. Attempting to manage the situation, the pilot tried to close the canopy with his left hand, which inadvertently released the secondary safety catch, causing the canopy to fly open completely. In the process of trying to secure the canopy with his right hand, the pilot released the control column. This led to a sudden pitch-down motion. Despite an attempt to pull back on the controls, the aircraft struck the ground approximately 15 feet before the runway terminus. The impact destroyed the aircraft, and the pilot sustained minor injuries to his ankle.
The investigation
The investigation focused on the sequence of events leading to the loss of control and the presence of exhaust fumes. It was noted that the new exhaust system extended further back along the fuselage than the previous version, ending under the wing. While the pilot had attempted to seal the cockpit, the investigation looked into why fumes were still detectable. It was determined that the new engine and exhaust components, being recently installed, would likely produce more noticeable odors as coatings heated up during the running-in period. Furthermore, the investigation examined the physical state of the aircraft, noting that the unsecured canopy and the pilot's subsequent loss of control inputs were critical factors in the crash.