This glossary is written for virtual airline and flight simulation use within Virtual Air Canada Airline. It is not intended as a real-world aviation reference.
VOR
VHF Omnidirectional Range
VOR is a type of short-range radio navigation beacon that allows aircraft to determine their magnetic bearing from the station. VOR transmitters broadcast on frequencies between 108.0 and 117.95 MHz and produce two radio signals simultaneously - an omnidirectional reference signal and a directional signal that rotates at 30 revolutions per second. The aircraft’s VOR receiver compares the phase difference between these two signals to compute the radial on which the aircraft is located, measured from the station. From this, the pilot or FMS can determine bearing to or from the VOR and track any of 360 radials outbound from the beacon.
VOR has been a cornerstone of IFR navigation since the 1950s and forms the basis of the airways system still used worldwide. Many airways are defined by VOR radials, and instrument approach procedures are built on VOR courses. A VORDME station combines a VOR with a Distance Measuring Equipment (DME) transponder, allowing the aircraft to obtain both bearing and distance simultaneously - enough information to determine a precise position fix without GPS. While GNSS has replaced VOR as the primary navigation source on most modern flights, VOR remains an important backup and is still used for approach and en-route navigation in regions where GNSS coverage is insufficient. ICAO has approved reducing the number of VOR stations globally through VOR Minimum Operational Network (MON) programmes.