Definition
A datalink system operating on 978 MHz used by ADS-B Out and ADS-B In equipment in U.S. airspace below 18,000 feet MSL. UAT broadcasts an aircraft's GPS-derived position, altitude, and identity to ATC and other aircraft, and can also receive Flight Information Service-Broadcast (FIS-B) weather products and Traffic Information Service-Broadcast (TIS-B) traffic data.
Plain English
A radio-and-data system, used only in the United States and only below 18,000 feet, that lets an aircraft broadcast where it is and also receive free weather and traffic information from the ground.
Context Anchor
You may see UAT mentioned in discussions of ADS-B equipment, cockpit traffic and weather displays, and FAA diagrams showing how aircraft exchange position and flight information.
Derivation
‘Universal Access’ reflects the original design intent: one frequency (978 MHz) carrying many services — position reporting, weather uplink, and traffic uplink — open to general aviation users. ‘Transceiver’ is short for transmitter-receiver, meaning the unit both sends and receives.
Why Pilots Care
It supplies real-time traffic and weather data directly in the cockpit, supporting safer decision-making when radar coverage is limited or unavailable.
Intuition Check
UAT is not a navigation aid by itself. It is a data radio link that supports systems such as ADS-B by sending and receiving aircraft information.
Example Sentence 1
The aircraft was equipped with a UAT, giving the pilot free weather and traffic on the cockpit display while flying at 8,500 feet.
Example Sentence 2
Weather imagery from the ground station reached the cockpit display through the UAT.