Air to Ground
The History of Air Traffic Control
Part one – Flight Service
Did you know that what is now the FAA started out as a division of the Post Office? After World War I, the US Post Office decided these newfangled air machines could provide a faster method of delivering important documents nationwide than anything else available in that era. During the war, the Army used aircraft for reconnaissance, so they worked with the Post Office to create schedules, routes, and decide what equipment was needed for cross country mail delivery. Thus was “Air Mail” created.
A key component in the plan was to provide landing sites for aircraft that were manned by personnel equipped with another WWI innovation – the field radios. Named Air Mail Radio Stations (AMRS), these were the precursors to today’s Flight Service Stations. When a pilot called inbound, he called the site name followed by “Radio”, that practice has not changed in a hundred years.
The first AMRS station was built in 1920 at Bellefonte, PA. The AMRS specialists were mainly ex-military radio operators. Their duties included the maintenance of their radios, fueling, loading the aircraft, and pushing oil soaked logs in a metal wheelbarrow out to the field to mark the ends of the “runway”. They took weather observations on the field to give to incoming pilots. Their primary function was to watch for incoming scheduled aircraft, and if it did not show up on time, to begin search and rescue. This is still one of Flight Service’s primary functions.
In those days an airfield was any flat area with relatively predictable winds; meadows, county fairgrounds, racetracks etc. These first airfields became magnets for local kids and ex-military pilots who could watch the aircraft and dream of flying. The AMRS stations became hangouts for people who just loved airplanes could sit and discuss their passion. “Radio” specialists became an intricate part of the general aviation community. This type of camaraderie would exist well into the 1980’s.
The Trancontinental Airway boasted 17 landing sites, each with its own AMRS station. Flights began on February 22, 1921. Industry leaders of the day were quick to realize the commercial potential of aviation and began investing in corporate aircraft. It was quickly determined that with beacons set up enroute the aircraft could fly at night, so in 1926 the Air Commerce Act transferred the AMRS’s and airway maintenance to the Bureau of Lighthouses under the Department of Commerce. In 1927 the Airways Division of the Commerce department was created and AMRS stations were renamed “Airways Radio Stations” or ARS.
During this time the basics of today’s ATC requirements were being created. Short range radios still only allowed the ARS’s to communicate over a local area and the quality of the transmission was poor. The language of aviation took form to allow both pilots and radio operators better communication. Flight and weather information was transmitted to/from the ARS by telegraph. As full words were expensive to transmit, only absolutely relevant information was sent. Airfields were assigned three letter identifiers.
As now, the pilot filed a flight plan. As he departed the field, the ARS specialist sent a message to the destination airfield that only gave the Aircraft ID, type, departure point, destination point and ETA. If the aircraft failed to arrive, the destination airport would request all the flight plan information, but otherwise the rest of the flight plan data was filed away.
“Q” signals further shortened the need for long messages. QRUQ N3RK means “do you have any information on N3RK?”. QALQ N3RK means “This aircraft is overdue please send the full flight plan.” Although there was a list of about 20, only the QALQ is still widely used by flight service. In 1928 teletype replaced the telegraph service as the primary method for disseminating information.
By the end of the 1920’s there were 145 municipally owned airports in the US. Radio technology was improving, but was still generally local in nature. The first air traffic control tower opened in 1929 – more details on the tower system will be in next month’s column.
Beacon lights and searchlights had replaced wheelbarrows full of firewood on dedicated airfields by now and commercial airlines had come into existence. On Oct 1, 1929 the Federal Radio Commission allocated frequencies to air transport companies, who began maintaining communication with their aircraft in flight.
With the opening of the first Air Traffic Control Center in 1935, the ARS station’s duties broadened. Pilot’s would file their flight plans with the ARS, who teletyped it to the Centers. Remember, there was no radar and no long distance radio. As planes flew over designated spots or ARS stations they would give a position report that was sent to the Center. ARS specialists would receive back instructions or “clearances” from the Centers to relay to the pilots.
In 1938 the Civil Aeronautics Act created an agency independent of the Commerce Bureau – The Civil Aeronautics Authority or CAA. The government also gave itself the power to regulate the airlines and to determine what routings were created in the sky. ARS stations were renamed Airway Communications Stations or ACS.
In 1940 VOR technology dramatically changed how planes could navigate cross country. By picking up the radio signals, aircraft could fly at night or in the clouds and still remain on course. The ACS Radio operator no longer repaired their own radios or helped pilots load their planes. They were required to have certification from the National Weather Service for giving pilots their preflight briefings and updating enroute weather.
Flight plans began to be separated into those that were followed by the Centers (IFR) and those who wanted to fly where they choose (VFR). In 1960 the Federal Aviation Authority was created and ARS stations were renamed Flight Service Stations (FSS). FSS stations were set up at airfields with a significant amount of traffic – eventually growing to over 400 across the country. FSS specialists were trained in how to help lost pilots using pilotage, VOR orientation or using basic Direction Finder (DF) equipment.
Pilots began demanding more updated weather enroute, so in 1970 the FAA and NWS created the En Route Flight Advisory Service, aka “Flight Watch”. Computer systems and special phone lines had replaced the teletype, and radio signals could be relayed from local airports hundreds of miles via microwave links.
In 1981 the FAA announced a plan to reduce the number of FSS’s to 61 within 10 years. FSS specialists were now responsible for multiple airports and had to monitor as many as 75 frequencies instead of only one or two. They were required to memorize more airport information, larger scale weather patterns and larger geographic areas.
In 2003 the FAA decided it could privatize the management of Flight Service and the contract was award to Lockheed Martin in the spring of 2005. Part of the requirements of the contract was for the 61 legacy sites to be further consolidated. As of 2009 there were three major FSS Hubs at PRC, FTW and DCA, and three smaller briefing sites.
Flight Service today is still is the FAA’s primary and most immediate line of communication with the General Aviation community. When 9-11 grounded every aircraft in the nation, the 1-800-WXBRIEF phone number was alive with pilots all asking the same question “When can I fly?”
Flight Service still briefs pilots, handles flight plans, performs lost aircraft orientations, coordinates clearances with Centers, and initiates search and rescue on lost aircraft. When you call, they will answer 24 hours a day.
Rose Marie Kern has worked in ATC since 1983. For more ATC information contact her at author@rosemariekern.com.