The Federal Aviation Administration Thursday said it has ordered additional training for 10,000 air traffic controllers after a near mid-air collision over La Guardia Airport in New York in April.

James Washington, acting director of the FAA's Air Traffic Service, ordered all controllers working in airport towers to complete at least two hours of additional training after the incident, which could have been disastrous if the two planes had collided, a spokesman said."We're taking this incident very seriously," said FAA spokesman William Shumann.

The action followed a previously unreported incident April 3 in which an Air Canada Airbus-320 that been cleared for takeoff from the airport came as close as 40 feet to a US Airways DC-9 that was set to land.

The controller, after realizing the two planes would be too close, ordered the US Airways jet to abort its landing and circle the airport again, which it did. But the two planes still came dangerously close to colliding.