BOEING 737-79PSOUTHWEST AIRLINES CO

The controller's issuance of a landing clearance to an arriving aircraft while another aircraft was in position on the same runway. Contributing to the incident was the controller's non-compliance with traffic advisory procedures, and insufficient requirements for use of memory aids to track arrival and departure operations.

The American Airlines flight 106 (AAL106) crew’s surface navigation error due to distractions caused by their performance of concurrent operational tasks during taxi, which resulted in a loss of situational awareness. Contributing to the incident was the air traffic control tower team’s nondetection of the AAL106 crew’s deviation from taxi instructions while performing concurrent operational tasks; the timing of the runway status light system, which activated too late to prevent the AAL106 crew from crossing the ru…

The flight crew’s misidentification of the intended landing runway. Contributing to the incident were (1) the flight crew’s failure to perceive and correctly interpret visual and auditory indicators – including electronic guidance – that they were approaching the incorrect runway which was likely the result of a degradation in cognitive function brought on by working within their window of circadian low, increased workload, and fatigue, and (2) the air traffic controller’s failure to monitor the arriving flight af…

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 air traffic controller issuing the aircraft a clearance to land while there was a vehicle authorized to be on the same runway. Contributing to the incident was the air traffic controller's decision to not simulcast the local control and ground control frequencies, and, the reduced visibility at the airport as a result of the weather.