What is the purpose of TACAN?

• A. To determine the relative bearing and slant range distance to a TACAN ground station or a similar TACAN equipped aircraft.
• B. A source to keep aircraft present position and update the aircraft present position being kept by another source (INS or ADC)
• C. Determine altitude via barometric pressure
• D. Provide weather data to cockpit

Answer: (A)

TACAN is a navigation aid that provides two key pieces of information for navigation: the bearing to a TACAN ground station (or to another TACAN-equipped aircraft) and the distance to it. The bearing tells you the direction from your aircraft to the station, and the slant-range distance gives how far you are along the line of sight. With both pieces, you can plot your position relative to the station on a map or use it to navigate toward or away from the beacon. Altitude is read with the altimeter, weather data comes from weather radar, and position updates from INS or ADC come from separate navigation sources, but TACAN’s main purpose is to supply bearing and range information for navigation.