Precursors

The 1950s were a time of growth in the commercial aircraft industry. U.S. air traffic had more than doubled since the end of World War II; however, little had been done to expand the capacity of air traffic control systems, or to increase safeguards against midair collisions. Eighty mid-air collisions occurred in the United States in the period from 1950 through 1955. (Report of Midair Collisions in U.S. Civil Aircraft Operations 1938-1960). However, none of these collisions were between two large air transports. As the number of large transport flights increased, concern was growing about the inability of the ATC system to segregate VFR traffic from instrument flight rules (IFR) traffic, or slow moving flights from faster ones. Many experts recognized the need to institute positive control, requiring instrument flight over certain portions of the airspace irrespective of weather conditions. In February 1956, James Lederer, director of the Flight Safety Foundation said, "No greater evil could befall aviation than a fatal collision between two large air transports."

1936 photos of air traffic controllers tracking aircraft with shrimp boats (left), the Chicago airway traffic center (right)
1936 photos of air traffic controllers tracking aircraft with shrimp boats (left), the Chicago airway traffic center (right)
Photos from "The FAA a Historical Perspective," copyright Terry Kraus - used with permission

The air traffic control (ATC) system of 1956 was not able to keep up with the growth of the airline industry. A program to modernize ATC was launched in the late 1940s, but its progress was slowed by a number of factors. In 1947 a special committee (SC-31) was established to study and develop recommendations for the safe control of expanding air traffic. In 1948 the SC-31 report was accepted by the Executive Committee of the Radio Technical Commission for Aeronautics. The recommendations included implementation of very-high frequency omni-directional range (VORs) and distance measuring equipment (DME). The report's recommendations were accepted by Congress. In 1950 the CAA began to designate its Victor airways, which were marked for VOR navigation. Pilots would use individual stations as waypoints, flying from one to another.

Photo of 1950's era Air Traffic Controllers
Photo of 1950's era Air Traffic Controllers
Photo copyright Michael McComb - used with permission

The CAA was under the Department of Commerce, which had a wide variety of responsibilities. Further slowing modernization was a 1950 reorganization of the Department of Commerce which placed the CAA in the hands of an undersecretary, giving it less status. CAA appropriations fell in the early 1950s, and these budget cuts, as well as differences between civilian and military aviation on the direction of ATC, slowed completion of the VOR program.

While the navigational modernization was progressing slowly, ATC centers were struggling. Centers had been relying on table maps to depict the airspace and shrimp boats to depict aircraft. With the increase in air traffic, controllers were increasingly relying on visualization. ATC methods transitioned to flight-plan data written on slips of paper, noting each airplanes course, speed, altitude, and estimated time of arrival over checkpoints. Radar began to catch on in the areas near airports in the 1950s, but there were no long-range radars to control en route traffic.

Photo of 1950's era radio operators
Photo of 1950's era radio operators
Photo copyright Michael McComb - used with permission

In the mid 1950s, the Air Navigational Development Board (ANDB) established a committee to study the military tactical air navigation system (TACAN) and the civilian VOR/DME to determine which system would be best in the development of a common civilian/military system of air navigation. A series of congressional hearings were held when the committee reported that it was not able to reach a unanimous decision in 1955.

The Harding Report, commissioned in 1955, reported that the need to improve air traffic management had reached critical proportions. President Eisenhower, following the report's recommendations, appointed Edward P. Curtis as his special assistant for aviation facilities planning. His assignment was to develop a plan for meeting the needs disclosed by the Harding Report.

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