What happened
On 19 October 1998, a Cessna 172C, registration G-ARYI, was engaged in an aerial photography mission near Bishopstoke, close to Southampton Airport. During the flight, the aircraft's side window became detached from the airframe. The incident occurred at approximately 13:00 UTC as the photographer was attempting to close the window following the completion of a photographic task.
The investigation
The investigation established that the crew had adopted a specific procedure to manage the window during flight. To prevent the window from swinging shut during unbalanced turns, a wooden chock was typically placed in the hinge line whenever the window was left open.
Evidence suggested that earlier in the same flight, the photographer had attempted to close the window while this wooden chock was still positioned in the hinge line. It is believed that this specific action may have compromised the structural integrity of the window's attachment mechanism.
Findings
- The side window detached from the Cessna 172C while being closed by the photographer.
- The damage was limited to the loss of the side window.
- Mechanical failure of the hinges is the primary cause, likely resulting from the impact or pressure caused by attempting to close the window while a wooden chock was obstructing the hinge line.