History of the Flight
The aircraft, a Turbolet Let L 410 UVP-E registered OK-RDA, departed from Belfast City Airport at 0914 hrs on a scheduled commercial passenger flight to Ronaldsway, Isle of Man. The crew consisted of a commander (line training captain) and a co-pilot undergoing line training. Shortly after being handed over to Aldergrove approach at 0917 hrs, the right nose baggage door opened while the aircraft was near the south-west corner of Strangford Loch. The crew reduced speed to 120 kt and, observing no vibration and the door stable in the open position, decided to continue to their destination. They did not declare an emergency. At 0923 hrs they informed Aldergrove approach of the situation, stating that the unpressurised aircraft was stable at the reduced speed. The co-pilot monitored the open door during the remainder of the flight. Approaching Ronaldsway, the crew requested a wide vector for a long left-hand circuit and a runway inspection after landing. The airport fire service found no debris on the runway. The airport Duty Manager saw the open door and a holdall hanging out; one piece of baggage was later found missing.
Engineering Inspection
An operator's maintenance engineer inspected the baggage door and reported no defects with the door or its locking device that would have prevented locking. Photographs taken after landing showed that the locking device appeared locked from the outside, but the hook had not engaged with the catch (see Figure 2). The lack of damage indicated the hook did not engage.
Securing of Baggage Door
According to a report from Hungarian aircraft accident investigators, standard practice in the airline was to load baggage through the left baggage door, and it is the co-pilot's responsibility to check that the nose compartment doors are closed and locked before departure. The door did not open during the outbound journey, suggesting it was probably opened at Belfast City Airport. Although the locking mechanism appeared locked externally, the hook did not engage. A modification to fit a physical indicator to the front door locking mechanism was available but not installed on this aircraft.
Conclusion
The incident occurred because the right nose baggage door had probably been incorrectly closed prior to departure.