High Quality Content by WIKIPEDIA articles! TACtical Air Navigation, commonly referred to by the acronym TACAN, is a navigation system used by military aircraft. It provides the user with bearing and distance (slant-range) to a ground or ship-borne station. It is a more accurate version of the VHF omnidirectional range/distance measuring equipment (VOR/DME) system that provides bearing and range information for military aviation. At VORTAC facilities where a VOR is combined with a TACAN, the DME portion of the TACAN system is available for civil use. Aircraft equipped with TACAN avionics can use this system for enroute navigation as well as non-precision approaches to landing fields.