The History of Memphis Center

In 1926 the United States Congress passed the Air Commerce Act which created the Bureau of Air Commerce. This agency had the responsibility of regulating air safety, establishing and maintaining airways, and making air traffic rules. By 1935, the airlines, fed by a thriving airmail business, were growing at a rapid pace. This success had drawbacks as well as benefits; traffic was severely straining the capacity of the nations rudimentary airway system. The problem lay in the fact that no one controlled enroute traffic. In order to stave off disaster, airline dispatchers began exchanging position reports and recording them.

Earl Ward ( former operations officer at American Airlines) approached the airlines operating out of Chicago with the idea of forming an airline air traffic control (ATC) consortium. While the airlines like and started the air route station, it still did not account for the private and military pilot. Obviously this was a job for the Federal Government, specifically the Bureau of Air Commerce. On July 6, 1936, the Bureau took possession of the three enroute stations the airlines had established.

During the first year of operation by the Federal Government, airway traffic control was expanded from the three original centers to eight. These centers operated an average of 12 hours a day and their control areas extended only for a distance of approximately 50 miles from the airport at which each center was located. Flight data was posted with chalk on a large blackboard, and the postions of aircraft were plotted with markers on a map table. The 35 persons employed in the eight airway traffic control centers controlled approximately 30,000 aircraft movements during the first 12 months of Federal operation.

No additional airway traffic control centers were established during the next fiscal year (1938). However, hours of operation were expanded to twenty-four daily and the control areas were extended so that by the end of the fiscal year, a total of 2,275 miles of civil airways were under control. Three additional centers were put in operation in fiscal year 1939, and control areas were increased to include a total of 11,000 miles of civil airways. Also a new type of flight progress board was designed, consisting of removable metal holders in which removable paper strips could be inserted. These new boards eliminated the old blackboard and table method of posting flight data and tracking aircraft. During fiscal year 1940 one additional center was established and the amount of civil airways under control totalled approximately 14,500.

The fiscal year 1942 saw the entry of the United States into World War II and a tremendous increase in the operation of Army and Navy aircraft. On December 18, 1941, the Secretary of War requested the Secretary of Commerce (the department to which the CAA belonged to) to expand the airway traffic control system with the least possible delay.

The addition to these nine new centers to the 14 already in operation raised the total employment of the airway traffic control centers from 306 to 471 with a corresponding increase in operating costs from $789,310 to $1,020,723 in 1941 dollars.

The original Memphis Airway Traffic Control Center was commissioned on January 15, 1942, and was located in the old terminal building at the Memphis Municipal Airport. The first complement consisted of 26 control personnel and was headed by Chief Controller Donald Tisdale. The actual staffing in addition to the chief was

• 1 senior controller
• 8 controllers
• 16 assistant controllers
• 1 secretary

In 1942, controllers did not talk directly to the pilots so there were no radio channels in the building. To issue clearances, controllers would communicate via Flight Service Stations (FSS) or airline company radio - thus the preface "ATC clears...". As the system continued to grow, Memphis Center outgrew it's location in the terminal building and moved to 1503 Union Ave. While located on Union, controllers recieved their first direct means of communication with pilots. This radio frequency was installed in 1949 and was located in Memphis. Outside the coverage of this frequency, controllers continued to use FSS and company radio.

By 1950 Memphis Center had increased its control personnel to 36, three of whom were senior controllers. The senior controller's primary responsibility was as a watch supervisor, but as the system grew more complex, they took on collateral duties: planning, military coordinator, training supervisor and anything else that was needed for the operation. By 1956, Memphis Center had again outgrownits home and had to move.

In March 1956, Memphis Center moved to the C & S Building at 2734 Winchester Pike located at the Memphis Airport. The need for direct pilot/controller communication continued to grow with the increase in traffic and in 1958, the first remote frequency was installed. In addition to the frequency located in Memphis, the Center now had a second frequency located in Little Rock, Arkansas. Also in 1958, Congress, realizing the need for a more modern air traffic control system, created the Federal Aviation Agency that took over all operations from the CAA. Along with this new agency came a new name: Memphis Air Route Traffic Control Center.

On December 5, 1958, Memphis Center had the distinction of becoming the first Air Route Traffic Control Center to inaugurate radar service with the FAA's second region (now Southern Region). The first site was located in Byhalia, MS, and remoted to the Center by microwave link. This first site was to provide radar service to aircraft within an 85 nm distance from Memphis, and to follow civil air carrier jet flights operating within a 200 nm radius of the radar antenna site. In conjunction with the introduction of radar, the first class to qualify controllers to use of radar began in 1958.

A second radar site was commisioned on March 20, 1961. The antenna for this system is located near Joelton, TN. Today, Memphis Center uses 11 radar sites to provide radar coverage over its entire area and long gone are the days of, "ATC Clears...". Each sector ( Memphis Center now has 38 sectors ) now has radio contact with all users.

Since the first center was established at Newark, NJ in 1936 the ability to display information to the controller for analysis of traffic situations has been a problem. First blackboards and plotting maps were used, and later flight progress strips. As traffic grew, the need for more data grew as well. This explosion of information required additional manpower to prepare it for use by the controller. In 1958, Memphis Center was selected for installation of the IBM 858 Cardatype machine. This actually was a programmable accounting machine, that would print flight progress strips and make simple calculations as to the estimated time over a fix.

From this simple beginning began the era of automation for air traffic control. The FAA was planning for a modern ATC system that would include the use of computers. This, along with the continued growth of Memphis Center, necessitated a fourth move to 3229 Democrat Rd. on the northeast corner of the Memphis International Airport. Dedication of this new facility was May 5, 1962, and it was one of standard design that which 20 were built around the country. Centers were consolidated to make way for the next round of automation. In November 1972 Memphis Center commissioned its new computer system, the IBM 9020. This system, would prepare all flight progress strips, store flight plans, and pass revisions to flight plans between controllers within the facility and to adjacent facilities.

The 9020 marked the complete automation of the clerical activities controllers accomplished in "working" an aircraft. But, just as automation was growing, so was the use of radar as the primary means to seperate aircraft. Controllers identified targets on radar by using "shrimp boats". On these little pieces of plastic, controllers wrote the aircraft call sign, altitude, and other information (headings, speed, etc.). The controllers moved the shrimp boat as the target moved throughout the sector and then call the next sector to "hand-off" the aircraft. These repeated mechanical actions were to be automated. On September 16, 1974 Memphis Center commisioned its radar data processing (RDP) system. This brought automation into the radar realm of the controller. The entire radar display was computer generated. Shrimp boats were replaced with computer generated "data blocks" and hand-offs were accomplished by the computer.

In 1981 the Professional Air Traffic Controllers Organization ( PATCO ) staged an illegal strike against the FAA. Memphis Center was not immune from this and lost approximately 80% of its control room workforce. Through the efforts of those who remained and the newly hired controllers, Memphis Center rebuilt and continued its reputation of excellence to the flying public.

As the ATC system continued to grow, so did its demand for automation, and the 9020 was no longer able to keep up with the demand. To move air traffic control into the 21st century, the FAA developed the Advanced Automation System (AAS). While much of this system is still in developement, the first phase has been completed. On November 19, 1987, Memphis Center commisioned the HOST computer system. This new computer replaced the 9020 and allows the growth needed to meet the automation needs for ATC.

In 1996 Memphis Center commisioned its Voice Switching Control System ( VSCS ) to replace the aging Western Electric 300 switching system ( WECO 300 ). This state of the art communication system replaced thousands of manually operated swithches and countless amounts of wire with "touch screen" monitors and computers.

1997 brought more new technology into the control room. Thermal printers replaced the aging ( and quite noisy ) 9 pin printers. Controllers were no longer required to "tear" flight data strips before inserting them into the strip holders. Construction is started on the new DSR ( Display Service Replacement ) control room. A temporary support building is erected adjacent to the main building to facilitate renovation of the main building.

In 1998 while construction on the DSR room nears completion, renovation, including asbestos removal continues. New technology again appears in Memphis Center, this time in the form of a prototype computer sytem designed to aid and alert the controller to possible conflicts and help plan resolutions. Named URET (User Request Evaluation Tool) this system probes ahead for conflicts and displays the information directly to the controller thus relieving them from the task of doing a "traffic search" on flight data strips. Memphis Center, along with Indianapolis Center continue to test and develop the URET system that will one day be incorporated in the DSR console. Planning and development continues on HOST computer replacement.