C10/2003L Taxiing incident at Helsinki-Vantaa Airport on 6 December 2003

On Wednesday 6 December 2003, an Airbus A319 airliner owned and operated by Finnair Ltd., registered OH-LVH, collided its left engine with passenger bridge 24 while taxiing to the docking station at Helsinki-Vantaa airport, Finland. The Finnish Accident Investigation Board (AIB) decided to investigate the case (decision no. C 10/2003 L). Heikki Tenhovuori was appointed as investigator-in-charge, and Arto Nissinen and Toivo Vitikka as members of the investigation commission.

The incident aircraft was arriving from Munich on scheduled flight AY804 and started taxiing towards the docking station, guided with the APIS system. At the same time, the gate officer on duty started to drive the passenger bridge, using automatic control, from its assumed basic position towards the bridge’s holding position for that particular aircraft type. However, the passenger bridge was actually not in its correct basic position, and it moved considerably beyond the programmed holding position towards the arriving aircraft. As a result, the aircraft’s left engine collided with the passenger bridge when the APIS display still showed two indicator bars, which corresponds to a remaining taxiing distance of about 1.2 metres.

The investigation revealed that the program logic of the passenger bridge automatic control was not sufficiently able to identify and indicate an error in longitudinal control. For this reason, the bridge was driven into its maximum position, which is about 4.2 metres further than it was supposed to be, according to the selected program.

The passenger bridge had extended to its maximum length, beyond the correct holding position, because of a malfunction in the automatic control system. Contributing factors to the incident were: 1) Double standards had developed in the passenger bridge operation, as well as for handling any faults and malfunctions with the passenger bridges. One procedure was in accordance with official training, and another was an established practice in daily operations. 2) There were shortcomings in the bridge operators’ training, operating instructions, and in the monitoring of faults and malfunctions. 3) The marshallers, who carried out malfunction analyses and made decisions about taking a passenger bridge back into service after a malfunction, had insufficient training for handling these malfunctions and identifying any safety risks. 4) The responsible organisations had not audited the operating procedures, instructions and practices for bridge 24. 5) The persons in charge had differing views about the technical characteristics and driving practices of bridge 24.

The investigation commission gave the following safety recommendations: 1) CAA Finland should develop an indicator system for monitoring the position of passenger bridges, based on the APIS system. 2) CAA Finland should examine any prospects for improving technical reliability of the passenger bridge drive system, so that position detection would remain under control despite any fault or malfunction. 3) Helsinki-Vantaa airport should update the operating instructions for bridge 24 and make them constantly available to personnel. Moreover, bridge operators should be provided with a checklist for quick revision of the driving procedures, including safety instructions for the gate in question. 4) Helsinki-Vantaa airport should develop a procedure for collecting any technical failures and operational problems of passenger bridges into a follow-up file, and analysing them at regular intervals. Bridge operations should also be included in internal auditing. 5) Helsinki-Vantaa airport should provide sufficient training for technical support personnel on managing any malfunctions of passenger bridges. 6) Finnair Ltd. should ensure that gate officials are assigned to bridge 24 driving duty in good time.

C10/2003L Report (pdf, 1.23 Mt)