Definition
A separate, individually assigned radio frequency used by an air traffic control facility to communicate with a specific aircraft or small group of aircraft, distinct from the general frequencies used for broader traffic. Discrete frequencies reduce radio congestion by keeping a controller's communications with a particular aircraft off shared channels.
Plain English
A radio frequency set aside for one aircraft (or a small group) so the pilot and controller can talk without sharing the channel with lots of other traffic.
Context Anchor
Seen in instrument flying when a controller gives a pilot a specific frequency to contact approach control, departure control, tower, or another controller.
Derivation
‘Discrete’ comes from the Latin discretus, meaning ‘separated’ or ‘set apart.’ In radio use, it keeps its original sense: a frequency that has been set apart for a specific purpose, rather than shared with general traffic.
Why Pilots Care
Prevents frequency congestion and ensures clear, direct communication with the controller handling your flight segment.
Intuition Check
Discrete does not mean secret, private, or digital here. It means separate and specifically assigned for the communication you need.
Example Sentence 1
After departure, the tower handed the pilot off to a discrete radio frequency for radar vectors to the en route phase.
Example Sentence 2
The pilot switched to the discrete frequency to receive vectors without hearing other aircraft on the same channel.