The Visual Aural Radio Range (VAR) was a short range radio navigation aid, used from about 1940 until 1960, that provided four-course visual and aural track guidance signals at a range of about 100 miles. The VAR bridged the technological gap between the

Low-Frequency Radio Range The low-frequency radio range, also known as the four-course radio range, LF/MF four-course radio range, A-N radio range, Adcock radio range, or commonly "the range", was the main Radio navigation, navigation system used by aircraft for instrument ...

(LFR) radio navigation system and the VHF omnidirectional range (

VOR VOR or vor may refer to: Organizations * Vale of Rheidol Railway in Wales * Voice of Russia, a radio broadcaster * Volvo Ocean Race, a yacht race Science, technology and medicine * VHF omnidirectional range, a radio navigation aid used in a ...

) navigation system. VAR provided four courses for navigation, two using visual instrument signals functionally and technically similar to the modern

localizer An instrument landing system localizer, or simply localizer (LOC), is a system of horizontal guidance in the instrument landing system, which is used to guide aircraft along the axis of the runway. Principle of operation In aviation, a localiz ...

and backbeam components used in the ILS system and two using audio signals similar to the LFR system. VAR also used marker beacons similar to the ILS.

History

In the United States

The

Bureau of Air Commerce The Air Commerce Act of 1926 created an Aeronautic Branch of the United States Department of Commerce. Its functions included testing and licensing of pilots, certification of aircraft and investigation of accidents. In 1934, the Aeronautics Bran ...

created a demonstration version of the VAR in 1937 at an

Indianapolis Indianapolis (), colloquially known as Indy, is the state capital and most populous city of the U.S. state of Indiana and the seat of Marion County. According to the U.S. Census Bureau, the consolidated population of Indianapolis and Marion ...

research center. A demonstration version of the VAR system was built in 1941 between Chicago and New York. Initially, war shortages of VHF radio equipment prevented the system from being widely deployed. The first operational installation of a VAR was in

Matawan, New Jersey Matawan is a borough in Monmouth County, in the U.S. state of New Jersey. A historic community located near the Raritan Bay in the much larger Raritan Valley region, the borough is a commuter town of New York City within the New York Metropol ...

in 1944. By 1948, the

Civil Aeronautics Authority The Civil Aeronautics Board (CAB) was an agency of the federal government of the United States, formed in 1938 and abolished in 1985, that regulated aviation services including scheduled passenger airline serviceStringer, David H."Non-Skeds: T ...

had built 68 VAR installations on various federal airways across the United States. Quickly overtaken by the more advanced VOR system, VARs never replaced LFR as the primary airway navigation system of the United States. The last VAR was decommissioned in 1960.

References

Radio navigation {{aviation-stub