Definition
A military navigation system that provides aircraft with both bearing (direction to the station) and slant-range distance from a ground transmitter, using ultra-high frequency (UHF) signals. TACAN stations are commonly co-located with civilian VOR stations to form a combined VORTAC facility, allowing civilian aircraft to use the VOR azimuth signal and the TACAN distance-measuring signal (DME) from the same site.
Plain English
TACAN is a ground-based navigation station, used mainly by the military, that tells an aircraft which direction the station is and how far away it is. When paired with a VOR, civilian pilots can use it to get their distance reading.
Context Anchor
Seen in discussions of navigation aids, especially around military airfields and some combined civil/military navigation facilities.
Derivation
From 'tactical,' meaning related to military operations, plus 'air navigation.' The name reflects that it was developed for military aircraft to navigate during operations, but its distance-measuring component became widely useful to civilian aviation as well.
Why Pilots Care
Provides precise navigation data for military operations and can supplement civilian systems where compatible receivers are installed.
Intuition Check
Do not read “tactical” as meaning a flying tactic or maneuver here. In TACAN, it identifies a military-style radio navigation system.
Example Sentence 1
The pilot tuned the VORTAC and used the TACAN portion of the signal to display distance to the station on the DME.
Example Sentence 2
During the approach the aircraft used TACAN signals to track the correct radial while monitoring distance to the airfield.