What happened
On 29 May 2012, a Zenair CH 601HDS aircraft, registration G-CEZV, departed Swansea Airport for a flight to Haverfordwest. During the initial climb, which exceeded 1,000 feet per minute, the pilot encountered a sudden pocket of turbulence. Shortly after this encounter, at an altitude of approximately 1,200 feet, the pilot noticed a new sensation of draught and a clicking sound in the cockpit. Upon inspection, it was discovered that the passenger-side canopy hook had disengaged, causing the canopy to displace.
To manage the situation, the pilot attempted to re-engage the hooks and placed his left arm through the sliding window to hold the canopy in place. However, the remaining hook also failed, allowing the canopy to open by roughly 12 to 14 inches. The resulting aerodynamic drag significantly degraded the aircraft's performance, making it difficult to maintain altitude and requiring heavy back-pressure on the control column to prevent the nose from pitching down.
Due to the high drag and the presence of other traffic in the circuit, the pilot opted to perform a forced landing on a disused runway outside the airfield perimeter. During the landing, the aircraft struck a gorse bush and overturned. Although the pilot escaped without no injuries, a fire ignited in the engine compartment upon impact. Despite the arrival of the fire service, the aircraft was destroyed by the flames.
The investigation
The AAIB examined the circumstances surrounding the canopy failure and the subsequent forced landing. The investigation focused on the mechanical state of the canopy locking mechanism and the impact of the unlatched canopy on the aircraft's flight characteristics. The investigation also reviewed the pilot's actions during the emergency and the sequence of events leading to the engine fire during the landing on the disused runway.