What happened
On 25 June 2024, a Spitfire IXT, registration G-BMSB, was conducting a passenger experience flight from London Biggin Hill Airport. During the takeoff roll on Runway 03, the forward cockpit canopy began to slide backward as the aircraft accelerated. As the aircraft entered a left turn during the initial climb, the canopy moved further back and eventually detached from the airframe.
The pilot notified air traffic control and requested an immediate return to the airfield. A full airport emergency was declared, and the airport's Rescue and Fire Service (RFFS) met the aircraft upon its arrival. The return, approach, and landing were completed without further incident. There were no injuries to the pilot or the passenger. While the aircraft sustained no further damage, the detached canopy fell into nearby fields and was not recovered at the time of the report.
The investigation
The investigation established that the cockpit side door had been left open prior to departure. Because the left side canopy rail sits atop the edge of this door, the open position prevented the canopy from engaging correctly with the rail. This allowed airflow to get underneath the canopy, causing it to slide and eventually detach.
The pilot noted that they were relatively inexperienced on this specific aircraft type, having only 12 hours of flight time on the model. During pre-flight preparations, the pilot was distracted by a talkative passenger, which led to the omission of closing the side door. The pilot also suggested that they may have instinctively followed procedures from other aircraft types where a side door does not exist, simply sliding the canopy closed as a final action.
Findings
- The primary cause of the canopy detachment was the failure to close the cockpit side door prior to takeoff, which prevented the canopy from latching into its rail.
- The pilot's limited experience on the aircraft type contributed to the oversight.
- Distractions during the pre-flight phase, specifically interaction with a passenger, contributed to the error.