Accident Sequence
The accident occurred when a Mitsubishi MU-2 airplane collided with a maintenance tug during takeoff. According to the pilot of the MU-2, he was cleared by the ground controller to taxi from his parking spot on the northeast side of the airport to runway 35. He taxied via taxiway A, taxiway D, across runway 26, to taxiway K. Approximately one minute after the MU-2 pilot was cleared to taxi, the same ground controller cleared a maintenance tug towing an MD-80 to taxi from the same northeast ramp to a ramp on the west side of runway 35. The taxi clearance included a clearance for the tug to cross runway 35.
After arriving at the runway, the MU-2 pilot contacted the tower controller and was cleared for takeoff from runway 35. The pilot initiated takeoff, and as the airplane reached an airspeed of 80 knots, the pilot observed an aircraft tug crossing the runway centerline. The pilot aborted the takeoff and maneuvered the airplane to the left side of the runway. However, the airplane contacted the tug at the intersection of runway 35 and taxiways "Golf" and "Echo."
Air Traffic Control
At the time of the accident, three full performance level air traffic controllers were working in the tower cab: a local controller (LCE), ground controller (GC), and clearance delivery controller. The LCE and GC positions were located next to each other in the northeast corner of the tower cab. FAA Air Traffic Control regulations required that a ground controller must obtain approval from a local controller before authorizing an aircraft or a vehicle to cross or use any portion of an active runway. Additionally, the standard operating procedures for the airport required all runway crossing authorization and runway crossing complete coordination to be accomplished via a recorded landline. Controller interviews and review of recorded voice communications revealed that the ground controller did not coordinate the runway crossing of the maintenance tug with the local controller.