The near collision, which was averted by a pilot’s quick thinking, is now under investigation by the National Transportation Safety Board and the Federal Aviation Administration.
The near miss occurred on June 9 after both jets had been wrongly cleared for near-simultaneous takeoff at intersecting runways.
The incident was only made public late last week.
The Shannon-bound Aer Lingus plane, which had twelve crewmembers on board in addition to the passengers, had just taken off as the U.S. Airways plane was heading down the other runway and about to do the same.
The difference between the near miss and what would have been a calamitous collision was only a few seconds.
The U.S. airways plane, a Boeing 737, was bound for Philadelphia with 103 passengers and six crewmembers.
Investigators immediately pointed to an “operational error” by air traffic controllers as the cause of the incident.
The closest that the two aircraft came to each other has not been properly determined and will be a primary issue for investigators. Reported estimates vary from 200 to 1,000 feet.
Pilots must file a near miss report if planes come to within 500 feet of each other. The Boston Globe reported that the Aer Lingus pilot had filed such a report.
The paper quoted a Logan air traffic controller, speaking on condition of anonymity, as describing the distance between the two planes as being “exceptionally close.”
The source also stated that the control tower was two employees short on the evening of the incident.
In a preliminary report, the NTSB stated that both aircraft were “involved in a runway incursion at General Edward Lawrence Logan International Airport.”
The Aer Lingus plane was cleared for takeoff on Logan’s Runway 15R. According to the NTSB, the U.S. Airways Boeing was then cleared on the intersecting Runway 9.
The time lapse between the clearances, which were given by separate controllers, was just five seconds.
With the Aer Lingus plane gathering speed for takeoff, the U.S. Airways 737 began its acceleration.
The NTSB report stated that the U.S. Airways co-pilot had reported a “V1.” This is a reference to an aircraft’s runway speed at which point a decision to take off, or abort, must be made.
According to the preliminary report, the co-pilot at this juncture “noticed the Aer Lingus A330 rotating just prior to the intersection of runways 15R and 9.”
The term “rotating” refers to the point where a pilot pulls back on the stick and takes the plane into the air.
The U.S. Airways co-pilot told his captain to “keep it down” and pushed the control column forward to ensure that the Boeing stayed on the ground.
He subsequently stated to the NTSB: “The Airbus passed overhead with very little separation and once cleared of the intersection the captain rotated, and we lifted off towards the end of the runway. I reported to departure control that we had a near miss at which time Aer Lingus reported ‘we concur.'”
A statement from Aer Lingus, issued from its North American headquarters on Long Island, said that after take-off the Aer Lingus flight crew had contacted Logan tower to report the close proximity of a second aircraft.
Following strict guidelines, the Aer Lingus Safety Unit in Ireland had then reported the incident to Irish Aviation authorities and the National Transportation Safety Board in the U.S.
“Directly following the events of June 9th and through the present time, Aer Lingus is cooperating fully with both agencies as they carry out their investigations.
“The Aer Lingus aircraft did not make any evasive maneuvers and continued on to Shannon and Dublin under a normal flight plan,” the statement said.
“Because of the investigation we can’t comment beyond the fact that what we did was correct. Aer Lingus followed procedures to the letter,” said Aer Lingus spokesman Brian Murphy.
On Monday, FAA spokesman Jim Peters told the Echo that there have been seven “runway incursions” so far this year at Logan Airport, with the June 9 incident being by far the most serious.
An incursion involves the improper entry of a vehicle, worker or other aircraft onto a runway that has been cleared by a controller for take-off or landing.
Only two of the seven incursions involved “operational error” by an air traffic controller, with most stemming from “pilot deviation,” Peters said.
Peters confirmed that the two air traffic controllers who had simultaneously directed the Aer Lingus and U.S. Airways planes down intersecting runways were now being subjected to corrective action by the FAA.
“They are being de-certified until a retraining plan has been implemented,” he said. “They have been relieved of any local control positions while they are undergoing the retraining, but they do continue to work in other positions in the tower.”
Peters said that it is unlikely that the controllers would be fired under these circumstances.
“Under the collective bargaining agreement, termination could be an outcome if there were several such incidents involving operational error,” he said.
The National Transportation Safety Board is expected to issue a final report in several months. The report will examine in detail the causes of the near-collision.