What happened
At approximately 2045, Dixie Flight 06, a military aircraft, established contact with Birmingham Approach Control. The crew received clearance for a low approach maneuver, which was to conclude with a full-stop landing on Runway 05. By 2053, the flight reported being on a four-mile final approach segment for this low approach, communicating directly with the local controller.
Shortly thereafter, at 2054:19, the local controller issued instructions to another aircraft, Abex Flight 74, registered as N19T. The controller directed the pilot of N19T to taxi onto Runway 05 and hold short. The crew of Abex 74 positioned their aircraft on the runway and awaited further takeoff clearance.
While Dixie 06 was completing its approach, a collision occurred between the two aircraft on Runway 05. The incident took place during night operations when the tower was staffed by two air traffic controllers and one air traffic assistant. No supervisor or coordinator was present in the control cab to monitor workload or provide assistance.
The investigation
Post-accident analysis focused on the actions of the local controller responsible for sequencing arrivals and departures. Investigators determined that the controller had lost track of Abex 74, which was holding on Runway 05. The controller became preoccupied with managing other traffic utilizing Runway 36.
The controller described the volume of traffic at the time as busier than normal for a night operation. The absence of supervisory oversight meant that no one was available to detect the controller's overload or intervene to prevent the runway incursion.
Findings
The primary factor in this accident was the local controller's failure to maintain situational awareness of all aircraft on the active runway. By focusing on traffic on Runway 36, the controller forgot about Abex 74, which was cleared to hold but not cleared for takeoff. This oversight led directly to the collision with Dixie Flight 06 during its low approach.
The staffing configuration at the time contributed to the lack of redundancy. With only two controllers and one assistant, and no supervisor present, there was no mechanism to detect or mitigate controller fatigue or distraction during a period of increased traffic density.