Definition
A radio transmission broadcast from a ground-based or satellite-based navigation aid that an aircraft's onboard equipment receives and interprets to determine position, course, or guidance information relative to that aid.
Plain English
A radio broadcast from a navigation station that tells the aircraft where it is or which way to fly to reach somewhere.
Context Anchor
Seen in autopilot discussions when the airplane is using navigation guidance instead of only holding a heading or attitude.
Derivation
‘Radio’ comes from the Latin ‘radius’ (ray or beam), reflecting that the signal travels outward like rays from the transmitter. ‘Navigation’ comes from the Latin ‘navigare’ (to sail or steer a ship). Together the phrase describes a broadcast beam used for steering — originally a maritime idea adapted to aviation.
Why Pilots Care
Enables the autopilot to track a desired course without constant manual input, reducing pilot workload on long flights.
Intuition Check
A radio navigation signal is not a voice radio call from air traffic control or another pilot. It is guidance information received by the aircraft’s navigation equipment.
Example Sentence 1
The autopilot was coupled to the radio navigation signal from the VOR, holding the aircraft precisely on the inbound radial.
Example Sentence 2
Interference with the radio navigation signal caused the autopilot to disengage from navigation mode.