There were no navigational aids, during the beginning days of flying, to help the pilots navigate. The pilots flew watching their window of the cockpit or visual cues with map in hand. These visual cues also called as maps were acceptable for the day flights, but airmail would operate at all hours.
In July 1923, windsocks enlightened place, and beacons rotating on the tower had taken root. During 1923, the Postal Service has been working to finish a transcontinental air tag on towers that are spaced between 15 and 25 miles from each other, bright enough to be noticed from 40 miles away in the clear weather.
The postal service began regular operations by the first week of July, 1924, through parts of the route. The Departments of Aeronautics and Commerce had taken the responsibility to build airways with lights in 1926. By June, 1927, approximately 4,121 miles of runways had lights. In 1933, 18000 miles (28968 kilometers) of runway and 1500 beacons had been placed.
In October of1928, the Department of Aeronautics installed a new group of radio stations in order to accompany the seventeen they had acquired from Postal Services. There were sixty eight different stations, which would enable pilots get navigation application by radio contact. The Department of Standards had also developed radio navigation beacons.
During 1929, the Department of Aeronautics standard four during which pilots range radio would listen to the audio signals in order to determine whether they are on track. The Directorate of Aeronautical accelerated the ability to install four ranges of radio-race; this technology had become the standard for public aviation through the Second World War.
In May of 1941, the CAA (Civil Aeronautics Administrations) opened the first radio-frequency ultra-high range for the air navigation system planned, possibly extending the use of this type of equipment at thirty five thousand miles of federal airspace. In 1944, during the war with the progress of radios, the CAA has tested static-free and very-high -frequency (VHF) omni-directional radio ranges (VOR), which has allowed the pilots that navigate watching the dial on the dashboard rather than listening to radio signals.
By mid-1952, 45000 miles (72420 kilometers) of airways and VHF VOR, called Victor airway, supplements the 70000 miles (112654 km) of the Federal Act has remained at low frequency airway. The CAA has begun to close the low frequency and medium radio frequencies over four bands.
In October of 1969, the 16 waterways surfaces have been developed. Before, pilots flew straight toward or retreated from the radio that was on the ground. This aid has sent a journey along the lines called radial invisible. In 1973, almost one hundred fifty six high-altitude navigation zone legs were available.
In October of 1994, the Federal Aviation Authority (FAA) has asked the government and industrial studies of the concept of Free Flight, which may enable pilots, would pick the most effective routes needing to fly routes between aids to navigation. The FAA and the industries partners had begun to limit the applications of some functions associated with this concept.
More navigation technologies were partial for use or development, to include Global Positioning Systems at the same time to help locate and control aircraft satellite, for prospective Air Navigation Systems for flights ocean and distant, and communications, navigational and surveillance systems to help air traffic control.
Read also: National Advisory Committee for Aeronautics