Definition
The onboard avionics that allow a pilot to determine position and track courses (navigation radios) and to talk with air traffic control and other stations (communication radios). Navigation radios receive signals from ground-based or satellite sources such as VOR, ILS, GPS, and DME, while communication radios transmit and receive voice on assigned VHF frequencies, typically in the 118.000–136.975 MHz band.
Plain English
The radios in the cockpit that help the pilot find their way and talk to controllers. One set listens to navigation signals to figure out where the aircraft is and where it is going. The other set is used to speak with air traffic control and other aircraft.
Context Anchor
Seen in instrument flying when selecting frequencies, checking radio equipment, following a route or procedure, and making radio calls.
Derivation
Navigation comes from older words connected with ships and steering a course. Communication comes from words meaning to share or make common. Together, the phrase points to radios used both to find the way and to share flight information.
Why Pilots Care
These radios are the pilot's primary link to the airway system and to ATC. Without functioning nav radios, instrument navigation is not possible; without comm radios, the pilot cannot receive clearances, altitude assignments, or traffic advisories. Pre-flight checks of both are required for IFR operations.
Intuition Check
Do not read this as one single radio that always does everything. In an aircraft, this phrase usually means the group of radio equipment used for navigation signals and voice communication.
Example Sentence 1
Before departure, the pilot tested the navigation and communication radios to confirm both could be tuned and heard clearly.
Example Sentence 2
During the ILS approach the navigation and communication radios supplied both course guidance and ATC instructions without interruption.