What happened
On 29 March 2006, an Airbus A320, registration EI-DIJ, was operating a scheduled passenger flight from Liverpool (John Lennon) Airport to Londonderry/Eglinton Airport. During the approach to Runway 26 at Londonderry, the crew reported issues with the ILS glideslope, believing the aircraft was too high. To avoid a missed approach, the commander requested and was granted a visual approach.
As the aircraft descended, the crew became convinced that the ILS signals were inaccurate. During the maneuver, the aircraft'ically entered a descending orbit that took it away from the intended destination. The crew subsequently touched down at Ballykelly Airfield, located approximately 5 nm east-north-east of Londonderry. The landing involved no injuries to the 39 passengers or 6 crew members, and no damage was sustained by the aircraft.
The investigation
The investigation examined flight recorders, radar data, and the cockpit voice recorder. It was established that the ILS transmitters at Londonderry were functioning correctly and that the perceived glideslope error was not a technical fault with the ground equipment. The investigation also reviewed the airfield charts used by the crew, which lacked specific warnings to prevent the confusion between the two nearby airfields.
Investigators found that the crew's focus was divided by several factors, including the presence of a nearby helicopter and the need to land before a scheduled train crossing the runway at Ballykelly. Additionally, the EGPWS triggered a "terrain ahead" warning during the descent, which the co-pilot attempted to silence, further distracting the crew.
Findings
- The crew misidentified Ballykelly as Londonderry due to the similar runway configuration and the lack of clear distinguishing information on their commercial approach charts.
- The crew's belief that the ILS glideslope was incorrect led them to commit to a visual approach that diverted them to the wrong airfield.
- The commander had been unable to obtain updated Londonderry airfield charts prior to the flight, relying instead on a brief provided by the operator.
- The presence of a nearby Army Gazelle helicopter and the pressure to land ahead of a train movement contributed to the loss of situational awareness.
- The EGPWS "terrain ahead" and "glideslope" warnings provided significant distractions during the final stages of the flight.