Incident Overview
On September 12, 2007, at 3:13 am, a runway incursion occurred at Dulles International Airport involving a Learjet 35, registration N66NJ, and an airport vehicle, CV11. Conditions were night visual meteorological. Runway 19R had been closed for surveying at 2:56 am, and its lights were off. The closure was advertised on ATIS information G, indicated by an X on the tower's ASDE display, and shown on the IDS 5 status display, though it was not entered in the Tower's Daily Log.
Sequence of Events
A survey crew was working at the south end of runway 19R, with weighted cones placed about 2,000 feet from the south end. The crew entered their truck and began driving northbound on the runway to retrieve something. As they approached the north end, the controller cleared N66NJ into position and hold on runway 19R—a maneuver prohibited with only one controller in the tower—and then cleared the aircraft for takeoff. The survey crew, hearing the clearance, advised the controller that they were still on the runway. Instead of canceling the takeoff clearance, the tower controller asked the survey crew if they could clear the runway. The crew drove off the runway into the grass near taxiway Y1 and reported themselves clear, with the Learjet's engine noise heard in the background.
Aftermath
AMASS data was requested; the FAA estimated that the aircraft missed colliding with the vehicle by approximately 600 feet. The departure controller at Potomac TRACON noticed the departure off runway 19R and asked the tower controller if the runway was open, and was told "no." There were two controllers assigned to the shift; at the time of the incident, one controller was working all positions in the tower cab, responsible for one aircraft, while the second controller was on break.