> and pilots must be very sure they have clearance before entering a runway
The word "clearance" is used uniquely in the context of landing and departing exactly to avoid mistakes and has to be repeated again by the aircraft before ATC confirms.
The word "clearance" is used uniquely in the context of landing and departing exactly to avoid mistakes and has to be repeated again by the aircraft before ATC confirms.
The word "cleared" is often used for IFR clearance delivery as well which gives you permission to navigate via a planned route to a particular point, so it's much more common than just takeoffs and landings.