History of the flight
The aircraft was operating a scheduled passenger service from Saint Brieuc to Guernsey. Shortly after takeoff, after climbing to approximately 200 ft agl, a loud bang was heard. The commander could not identify the cause but confirmed that all three engines were operating normally and the aircraft was under control. He returned to Saint Brieuc. The landing was uneventful, and neither the air traffic control officer nor the airport fire and rescue service reported anything unusual about the aircraft's appearance. After disembarking the passengers, the commander inspected the aircraft and found that the baggage door, though still attached, had been forced inward into the baggage compartment.
Aircraft information
The Trislander is a stretched derivative of the Britten-Norman Islander twin-engined aircraft, differing primarily in having a longer fuselage and an additional engine mounted on the vertical stabiliser. It is unpressurised. The outward-opening rear baggage door, mounted on the left side of the rear fuselage, is constructed of glass-reinforced plastic and attached by two hinges on its forward edge. When closed, it is secured by a plain latch operated from the outside by rotating a lever. Neither the lever nor the latch is sprung. No warning light in the cockpit indicates if the baggage door is not shut; only the passenger doors have such a device.
Damage
An engineer who inspected the aircraft at Saint Brieuc judged that the door had not been secured prior to flight and had been forced through its aperture by aerodynamic forces when the aircraft became airborne. The door lip, which normally rests against the door frame, was deformed sufficiently to allow the door to move inward. One of the three rivets attaching each hinge to the fuselage had been loosened by lever action. The hinges were considered sufficiently secure to fit a new door for the non-revenue return flight to Jersey Airport, where the rivets were replaced before the aircraft returned to service.
Previous occurrences
Several Trislanders are in service with three operators in the United Kingdom and have been exported widely. None of the four documented instances of baggage doors opening in flight were attributed to failure of the door or its locking mechanism.
Ground handling procedures
The operator provides ground handling staff at all airports except Saint Brieuc, where the airport provides the service. Handling staff have access to the company Ground Handling Manual. At the time of the incident, the procedure was to place a trestle under the tail and embark passengers before baggage to avoid tipping the aircraft on its tail. The commander, following company policy, did not leave the cockpit to check the baggage door; responsibility for checking its security was delegated to a ground handler, who was to report that all doors were secure before engine start.
Follow-up action
Another Trislander operator, after a similar incident several years ago, introduced a procedure requiring ground staff to walk clockwise around the aircraft, checking each door in turn, starting from the starboard side. The operator of G-LCOC stated its intention to introduce a similar procedure. The organisation holding the type design authority for Trislander aircraft is considering restarting production and would equip future Trislanders with a baggage door warning system including a cockpit light. Retrofitting such a system to existing airframes has proved complex and uneconomic.
Conclusion
The baggage door was probably serviceable prior to the flight but was not secured prior to departure. During the short flight, aerodynamic forces shut the door with sufficient violence to push it into the fuselage aperture.