AIM Text
- For reasons peculiar to military or naval operations (unusual siting conditions, the pitching and rolling of a naval vessel, etc.) the civil VOR/Distance Measuring Equipment (DME) system of air navigation was considered unsuitable for military or naval use. A new navigational system, TACAN, was therefore developed by the military and naval forces to more readily lend itself to military and naval requirements. As a result, the FAA has integrated TACAN facilities with the civil VOR/DME program. Although the theoretical, or technical principles of operation of TACAN equipment are quite different from those of VOR/DME facilities, the end result, as far as the navigating pilot is concerned, is the same. These integrated facilities are called VORTACs.
- TACAN ground equipment consists of either a fixed or mobile transmitting unit. The airborne unit in conjunction with the ground unit reduces the transmitted signal to a visual presentation of both azimuth and distance information. TACAN is a pulse system and operates in the Ultrahigh Frequency (UHF) band of frequencies. Its use requires TACAN airborne equipment and does not operate through conventional VOR equipment.
Source: FAA Aeronautical Information Manual · current edition · paragraph 1-1-5.
The short answer
This AIM section is FAA advisory guidance on TACAN, a pulse navigation system developed by the military that operates in the UHF band and gives pilots a visual presentation of both azimuth and distance. Because VOR/DME was unsuitable for military and naval use, the FAA integrated TACAN with the civil VOR/DME program, creating the combined facilities called VORTACs that support Part 91 navigation.
Research Notes
Common Questions
What frequency band does TACAN use?
Why was TACAN developed instead of using VOR/DME?
Per the AIM, the civil VOR/DME system was considered unsuitable for military or naval use for reasons such as unusual siting conditions and the pitching and rolling of a naval vessel. TACAN was developed by the military and naval forces to better meet those requirements, and the FAA later integrated it with the civil VOR/DME program.
Can a standard VOR receiver use a TACAN signal?
No. The AIM notes that TACAN use requires dedicated TACAN airborne equipment and does not operate through conventional VOR equipment. The airborne unit works with the ground unit to present both azimuth and distance information.