A chartered flight with 112 passengers and five crew on board went off course as it approached Dublin airport, a report has found.
The 1990 McDonnell Douglas DC 9-83 was en route from Lisbon when it was involved in the serious incident on August 16 thlast, a preliminary report by the Air Accident Investigation Unit (AAIU) of the Department of Transport said today.
The flight was approaching Dublin airport at 11.34pm with the co-pilot in control.
Weather conditions were good, but as a result of maintenance on the main runway at Dublin airport, runway 34 was the active runway.
At about five nautical miles from touchdown, the aircraft began to deviate left off the approach course, the AAIU report said. It continued to descend below the minimum descent altitude "without proper visual identification of the runway in use".
Air traffic control ordered the pilot to turn right and climb to a safe altitude. The pilot was then given guidance to approach on a different runway and "landed without further incident".
Subsequently, investigators found that lighting from a 16-storey building at Santry Cross appeared at night to resemble the red and white lights of a runway approach system.
The building has four fixed red obstacle lights on its roof, the AAIU report said.
The AAIU investigators said the Irish Aviation Authority should inform pilots and operators of "the possibility of confusing the obstacle at Santry Cross with the approach lighting of runway 34". The IAA has begun issuing such a warning to pilots.
They also asked the IAA to review the suitability of the lighting installed on the 52-metre high Santry building.
A full report into the incident will be published in due course.