US officials have announced a safety investigation after two passenger jets taking off from Reagan National Airport, across the river from the White House, came dangerously close to an incoming plane.
The incident on Tuesday recalled another back in March 2011 when two jets carrying a total of 165 people were forced to land unassisted at the same airport because the lone controller on the night shift had fallen asleep.
On this occasion, three jets, reportedly carrying a total of 192 passengers and crew, came well within the recommended safe distance after a mix-up by air traffic controllers.
Responding to bad weather south of the airport, which is located near residential areas, air traffic controllers decided to change the runway and direction from which planes were landing and taking off.
"At no point were the three aircraft on a head-to-head course. They were not on a collision course," stressed Michael Huerta, administrator of the government's Federal Aviation Administration (FAA).
"The two departing aircraft came within these margins in relation to a plane that was landing. But, at no point were any of the planes headed directly for one another."
The closest that departing Chautauqua Airlines flight 3071 and arriving Republic Airlines flight 3329 got was 0.82 nautical miles (1.52 kilometers) laterally and 800 feet (244 meters) vertically, the FAA said.
Another Republic Airlines flight came within 2.07 nautical miles of the incoming flight and, again, 800 feet vertically, the agency said in a statement.
"We will get to the bottom of this," US Transportation Secretary Ray LaHood said. "And we will take all appropriate action to prevent similar miscommunications in the future."
The FAA explained that during the switchover of operations, there was a miscommunication between a manager at the radar control system and two traffic coordinators at the airport tower.
"The miscommunication should not have happened. FAA safety officials are investigating why the miscommunication occurred and will take action as appropriate," its statement said.
A Washington Post report said the aircraft involved in the incident had been US Airways commuter jets carrying 192 passengers and crew.
Republic Airlines and its subsidiary Chautauqua both operate flights for US Airways and other groups.
"We are currently investigating and working with the FAA to determine what occurred," US Airways said in a statement sent to AFP. "The safety of our customers and employees is always our top priority."
The FAA said an air traffic controller at the tower at Reagan "immediately realized that a loss of separation was occurring and acted quickly to correct the situation.
"The loss of separation should not have occurred. However, at no point were the three aircraft on a head to head course," the statement said.
US officials announced new shift rules for air traffic controllers in April 2011 as part of a "zero tolerance" policy to stop alarming numbers of staff from falling asleep on the job.
The head of US air traffic control resigned and the FAA vowed a major shake-up to win back public trust in its safety.