What happened
A private aircraft came dangerously close to colliding with Pan Am flight N656PA while both were cruising at Flight Level 370. The incident occurred approximately 200 miles east of Miami in an area where radar coverage was not available. At the time, the two planes passed each other with only about 300 feet of vertical separation.
Both aircraft were operating on routes that had been approved and issued by the Miami Air Route Traffic Control Center (ARTCC). Each plane was also at its assigned flight level when the near collision took place. Despite being on authorized paths, the lack of radar monitoring in that specific sector meant that controllers relied heavily on procedural coordination to maintain safe distances between traffic.
The investigation
The National Transportation Safety Board examined the actions of several air traffic controllers involved in the incident. The primary controller for sector 72 (D72) failed to coordinate the altitude of Pan Am flight N656PA with the controller responsible for sector 81 (D81). This lack of communication was critical because the D72 controller also approved Flight Level 370 for the private aircraft, identified as N82NA, without recognizing the potential conflict.
Furthermore, the D72 controller placed the flight progress strip for N82NA in the wrong bay at the sector 72 position. This procedural error likely contributed to the confusion regarding the private aircraft's status and location. Additionally, controllers for sectors 81 (D81) and radar 81 (R81) failed to detect the developing conflict between the two aircraft before they reached each other.
When the R72 controller eventually located the misplaced flight progress strip, he did not read it carefully enough to identify the issue in time. The Board also determined that quality assurance efforts at the Miami ARTCC were deficient, suggesting systemic issues in monitoring and correcting these types of procedural failures.
Findings
The investigation highlighted a chain of human error and procedural breakdowns rather than mechanical failure or weather conditions. The core issue was the failure of air traffic control personnel to maintain proper separation standards through effective communication and adherence to strip management protocols. The absence of radar in the area placed a higher burden on controllers to coordinate altitudes manually, a task that was not executed correctly by the involved staff.
The Board concluded that the lack of coordination between sectors 72 and 81, combined with the misplacement of flight progress strips, created an environment where the conflict went undetected until it was too late. The deficiency in quality assurance at the Miami ARTCC further allowed these procedural lapses to persist without adequate oversight.
Safety message
The incident underscores the critical importance of strict adherence to air traffic control coordination procedures, particularly in nonradar environments. Effective communication between sectors and accurate management of flight progress strips are essential for preventing mid-air collisions when radar assistance is unavailable.