Formal notification of the incident was transmitted to the USA National Transportation Safety Board (NTSB), the Irish Aviation Authority (IAA) and the aircraft Operator by the Irish Air Accident Investigation Unit (AAIU) on 20 September, 1999. Under the provisions of ICAO, Annex 13 (Aircraft Accident and Incident Investigation), State of Occurrence, the Chief Inspector of Accidents, Mr Kevin Humphreys, appointed Mr. Frank Russell and Mr. John Hughes, Inspectors of Accidents, to carry out an investigation into the circumstances of this incident and to prepare a Report for publication.
The incident followed an uneventful Trans-Atlantic flight and approach to Runway (RWY) 24 at Shannon Airport. On landing, the aircraft bounced a number of times and the ground spoilers did not deploy. While the pilot applied maximum thrust reverse and maximum manual braking, complete deceleration was not achieved in sufficient time to stop the aircraft departing the end of RWY 24 and rolling some 230 ft into the grass over-run area. Once stopped, the aircraft commander shut down the engines and the aircraft was evacuated in an orderly fashion through the normal entry/exit doors. Consequently, the airport was closed to commercial operations until 1245 hours, when the aircraft was towed back to the ramp.