Mode S Technology
Project BeaconOn Dec. 16, 1960, a midair collision occurred over Staten Island, New York, when the pilot of a United Airlines DC-8 overshot his designated airspace and collided into a TWA Constellation, killing 128 passengers and 8 people on the ground. This collision brought the problem of air traffic control into the public eye, stirring the government into action and bringing to the surface many underlying problems with the national air traffic control system. Facing criticism from both the aviation community and the government, the Federal Aviation Agency (FAA) quickly began a reassessment of its existing system and research program.
Project Beacon Task Force
President John F. Kennedy issued an order on March 8, 1961 requesting the FAA to ``conduct a scientific, engineering overview of our aviation facilities and related research and development and to prepare a practicable long-range plan to insure efficient and safe control of all air traffic within the United States.'' A task force called ``Project Beacon'' was established that would report its findings to the FAA administrator.
Project Beacon was faced with two strong, competing factions in the choice of the next generation of air traffic control. The Research and Development Bureau of the FAA had been focusing on development of the most advanced equipment possible, a Data Processing Central computer and 3-D radar, neither of which had been completed. They believed that, once perfected, these technologies would revolutionize air traffic control. The air traffic controllers, who used the actual system on a day-to-day basis, pushed for the modernization and improvement of existing, proven technologies, especially radar. They felt that this solution would provide a more immediate fix to the problems facing air traffic control, while the engineers' new technology was still many years from completion.
The final recommendations of the Project Beacon task force agreed more strongly with the controllers than the engineers, concluding that an improved radar system would be the primary tool for air traffic control for at least the next decade. Whereas previously controllers kept track of airplanes on the radar screen with flight strips, plastic markers (``shrimp boats''), and grease-penciled markings on the radar screen, the system would now be upgraded to display altitude and identification visually in alphanumeric characters on the radar screen. The amount of controller workload would thus be reduced and help eliminate much of the confusion in air traffic control.
Project Beacon Deployment
The deployment of Project Beacon and the ATCRBS system did not go as planned. Although the FAA did begin to act on the plan, by 1965 it was clear that there was a wide separation between what the system promised and what it actually could do. Many controllers were still using the old manual ``shrimp boat'' system despite the fact that air traffic growth had jumped over 75% since the early 60's.
Project Beacon made a number of inherently wrong assumptions in its proposal for a new system, grossly underestimating the technical problems involved in the task. Estimates were based on the development of the military's SAGE system, which was designed to solve an entirely different, smaller class of problems than civilian air traffic control. The Beacon task force had also expected equipment and research development efforts to remain at the same level as in 1961. However, FAA budgets were cut through the 1960's, and funds originally intended for airspace programs were diverted into other areas. Thus, equipment for the new system was being deployed at a slower pace than had been originally planned. At the same time, the level of air traffic growth had not been predicted, and the new system was not prepared to meet the new level of demand.
By the late 1960's the air traffic control system was once again in disarray. With the budget so low, the FAA could only maintain the existing system, rather than improve it. At the same time, cutbacks were being made in personnel, and the main air traffic control training facility was closed down. By 1967, there was a shortage of air traffic controllers, and those who remained had to handle the rapidly-increasing traffic with outdated equipment. Congestion at airports was increasing nationwide, and flight delays skyrocketed. Although organized controller ``slowdowns'' and ``sick-outs'' prompted the FAA to accelerate its deployment of the automated systems recommended by Project Beacon, the FAA was still far behind its original schedule of deployment.