BOEING 737-900ERDelta Air Lines

the local controller’s incorrect assumption that the Southwest Airlines (SWA) airplane would depart from the runway before the Federal Express airplane arrived on the same runway, which resulted in a loss of separation between both airplanes. Contributing to the controller’s incorrect assumption were his expectation bias regarding the SWA airplane’s departure, his lack of situational awareness regarding the SWA airplane’s position when the flight crew requested takeoff clearance, and the air traffic control tower’s…

The air traffic controller's failure to ensure the runway surface area was clear of vehicles before clearing an aircraft for takeoff. Also causal was the flight crew's decision to initiate a takeoff while the Runway Status Lights (RWSL) Takeoff Hold Lights (THLs) were activated. Contributing to the incident was the lack of a standard procedure for vehicle operators to request runway clearances and resultant "hear back/read back" error between the vehicle operator and the air traffic controller.

The flight crew's failure to manage cockpit tasks during taxi resulting in a loss of situation awareness and subsequently taxiing past a required turn point and onto an active runway without clearance. Contributing to the runway incursion was the ground controllers ineffective monitoring to ensure issued taxi instructions were followed.

The flight crew’s failure to identify the correct landing surface due to fatigue. Contributing to the cause of the incident were (1) the flight crew’s decision to accept a late runway change, (2) the unavailability of the approach light system and the instrument landing system for the runway of intended landing, and (3) the combination of numerous taxiway signs and intermixing of light technologies on the taxiway.

The air traffic controller’s failure to properly scan the runway and local area, and their general loss of situational awareness, resulting in a near midair collision. Contributing to the incident was the Cessna 337 pilot's poor decision making when he failed to fly the standard downwind leg distance from the runway and to maintain the standard traffic pattern altitude.