AN Aer Lingus aircraft with 340 people on board narrowly avoided a fatal collision during take-off because of a mistake by an air traffic controller, an official investigation has revealed.
An inquiry by the US National Transportation Safety Board has blamed the incident on human error for the “near miss” incident at Boston’s Logan Airport on June 9, 2005.
The incident involved an Aer Lingus Airbus A330 and a US Airways flight.
The Airbus aircraft, which was leaving Boston bound for Shannon Airport with 12 crew and 328 passengers on board, was on a collision course after both aircraft were cleared for take-off at the same time on intersecting runways.
The sharp observation of the co-pilot on board the US Airways Boeing aircraft that the two planes were on a collision course helped to avoid a fatal accident. The co-pilot instructed his flying officer to keep the US Airways flight down on the runway in order to allow the Aer Lingus to clear the intersection and prevent a crash.
The US Airways aircraft, which had five crew and 103 passengers on board, was also leaving Boston destined for Philadelphia.
The “near miss” incident was official classified as a Category A event, the most serious type of air proximity incident. It isdefined as a separation between aircraft that “decreases to the point that participants takeextreme action to narrowly avoid a collision, or the event results in a collision”.
The NTSB noted that the four aircraft runways in use at Boston were under the control of two different local air traffic control centres. The West controller was required to obtain a release from the East control centre before authorising departures for aircraft including the Aer Lingus flight from Runway 15R.
Flight control data showed that the East controller contacted his counterpart at 7.38pm to release the Aer Lingus aircraft for take-off. A minute later, the authorisation for take-off was confirmed to the pilot of the Airbus by the West control centre.
Five seconds later, however, the East controller, who was operating on a separate radiofrequency, cleared the US Airways flight for take-off on another runway that intersected with the runway being used by the Aer Lingus aircraft. The co-pilot of the US Airways flight told the NTSB that he noticed the Aer Lingus A330 rotating just prior to the intersection of the two runways and told his captain to “keep it down” and pushed the control column forward.
“The Airbus passed overhead our aircraft with very little separation. I reported to departure control that we had a near miss at which time Aer Lingus reported ‘we concur’.”
The East controller told investigators he had forgotten he had given the West controller authorisation to clear the Aer Lingus flight for take-off when he similarly cleared the US Airwaysaircraft for departure.
The NTSB concluded that the controller had breached standard operating procedures by not waiting for a flight using anintersecting runway to have taken off before clearing another aircraft for departure on one of the intersecting runways.