The U.S. National Airspace System (NAS) makes use of computers for a great part of its data management and information transfer, however the air traffic control process itself is still an almost completely human operation performed by highly skilled air traffic controllers whose information is derived from processed radar data, voice communication with pilots, as well as printed flight data strips.
While ATC system automation is prehistoric compared to the advanced technology in the aircraft that it controls, the system is a really extraordinary human-machine system that has accommodated itself to huge demands on it.
In recent years, the system has been named on to handle traffic volume well beyond what a few years ago was thought to be its capacity. It has done so due to the creativity and flexibility of its operators and managers.
During this same period, the air transport system itself been beset by continuous change, completely unlike anything known during its seventy year history. In their former regulated environment, air carriers were capable to set operating standards at a level well above the minimums needed by regulations.
The same could be said of air traffic control; safety and conservatism were the superseding factors in its design and implementation. (Daniel J. Garland, John A. Wise, V. David Hopkin, 1999)
This state of affairs altered noticeably during the 1980s for numerous reasons, together with the air traffic controllers' strike in 1981 and a huge increase in discretionary travel brought about by airline deregulation also the emergence of unfettered competition.
The aviation system worked well regardless of these perturbations; however carriers found it essential to adopt radically different ways of doing business. A major change was the introduction of "hub-and-spoke" flying, in which carriers selected "hub" airports, flew long segments between them, after that shunted passengers onto shorter "spoke" flights to get them to their destinations.
This produced huge concentrations of traffic that had previously been more reasonably spaced, with resulting workload increases for controllers. The air traffic control system found itself handling considerable peak loads of traffic with outdated equipment, chronic understaffing, as well as less experienced controllers in lots of facilities.
As the early 1980s, the FAA has been working on plans for a radical upgrading of the ATC infrastructure concerning major increases in automation to develop controller productivity, eradicate airspace bottlenecks, and augment traffic throughput.
The first of the new equipment was planned to be installed in the Seattle Air Route Traffic Control Center (ARTCC) in late 1994, however the implementation schedule has slipped significantly and the costs have risen by nearly three billion dollars. (Paul R. Schulman, 2001).
History of ATC
Air traffic control started at airports during the late 1920s. The first controllers used flags and stood outside; later, control towers were built and controllers used light guns to present one-way communication with airplanes.
Radios started to be used during the middle 1930s, while smaller aircraft did not carry them until after World War II, and light guns continued to be used well into the 1950s.
Since all-weather transport flying increased and radar turned out to be available after the war, tower visual control of local aircraft was augmented by radar control of traffic in busier terminal areas. Terminal area controllers, attached to towers, were given separate radar facilities, which allowed them to offer departing air traffic with a transition to the en route environment and guide arrivals from that environment to a last approach to landing.
Terminal radar approach control (TRACCIN) facilities were prepared with broadband radar, afterward augmented by data-processing equipment and automated data communication with en route centers. Full-performance-level controllers functioned as both tower and TRACON controllers.
