Plain English Meaning

The little box on the cockpit display that shows which navigation radio frequency you are using right now, and the next one you have lined up ready to switch to.

Full Definition

The display field on an electronic flight display (EFD) or navigation radio that shows the currently tuned VHF navigation frequency, typically used for VOR, ILS, or localizer reception. It usually shows both an active frequency and a standby frequency, allowing the pilot to pre-select the next frequency before swapping it into use.

Context Anchor

Seen on an electronic flight display when a pilot tunes or checks the airplane’s navigation radio during instrument flying.