Definition
A feature in modern avionics, GPS units, and radios that automatically loads the correct frequency for a navigation aid, communication facility, or approach into the active or standby slot when the pilot selects it from a database, removing the need to look up and manually dial the frequency.
Plain English
The radio or navigation unit fills in the right frequency for you when you pick a station or approach from its database, so you don't have to find and type it in yourself.
Context Anchor
Seen when using GPS or flight management equipment to view airport information such as tower, ground, ATIS, or navigation frequencies.
Derivation
Combines 'auto' (Greek 'autos', meaning self) with 'tune,' which in radio use means setting the equipment to a specific frequency. Together: the equipment tunes itself.
Why Pilots Care
Lowers workload during busy phases of an instrument approach so the pilot can focus on flying the aircraft.
Intuition Check
Auto-tune does not mean the airplane decides which frequency is correct. It means the equipment loads the frequency you select into the radio.
Example Sentence 1
When she loaded the ILS approach into the GPS, the localizer frequency auto-tuned into the standby side of the nav radio.
Example Sentence 2
With auto-tune active the communication radio switched to the tower frequency without any manual input from the pilot.