US investigators probing a conflict at Washington National airport have revealed that a Beechcraft King Air was 0.9nm from touchdown when an American Airlines Airbus A319 was cleared for take-off on an intersecting runway.
While the A319 was ordered to abort its take-off roll, and the King Air was instructed to go around, the crew of the King Air was unable to comply because the aircraft had already landed.
Both aircraft exited their respective runways without further incident following the occurrence on 29 May.
The King Air had been conducting a visual approach to runway 33, says the National Transportation Safety Board in preliminary findings.
Its crew had been advised, at 6nm final, of an aircraft lining up on the same runway which would depart ahead of the King Air’s arrival.
The A319, bound for Boston, was subsequently cleared to hold short of runway 1 – which intersects runway 33 – then instructed to line up, while being advised of an inbound flight on 6nm final to the same runway.
At this point the King Air was 2nm from landing on runway 33, and had closed to 0.9nm when the A319 was cleared for take-off.
Just under 30s later the tower controllers were alerted to a conflict by the ASDE-X surface-movement detection system.
The A319 crew was immediately told to cancel the departure and the crew of the King Air was ordered to execute a go-around.
While the A319 crew responded that they were rejecting take-off, the King Air crew responded that that they were unable to go around, having already landed. None of the occupants of either aircraft was injured.
The inquiry says traffic volume was “moderate” at the time, with “routine complexity”.
Final conclusions over the incident have yet to be reached, but the inquiry says it is analysing ADS-B surveillance data and a particular focus has been placed on human performance aspects.
