Fr: circulation en vol rasant
air-to-ground communication
One-way communication from aircraft to stations or locations on the surface of the earth.
.  see also: ground-to-air communication and air-ground communication
Fr: communications dans le sens air-sol
air traffic
All aircraft in flight or operating on the manoeuvring area of an aerodrome.
Fr: circulation aérienne
air traffic advisory service ICAO: A service provided within advisory airspace to ensure separation, in so far as practical, between aircraft which are operating on IFR flight plans. Fr: service consultatif de la circulation aérienne
air traffic clearance Other expression for: air traffic control clearance
air traffic control clearance An authorization issued by an ATC unit for an aircraft to proceed within controlled airspace in accordance with the conditions specified by that unit.
. also called: air traffic clearance, ATC clearance and clearance
Fr: autorisation du contr.le de la circulation aérienne
air traffic control instruction
A directive issued by an ATC unit for ATC purposes.
Fr: instructions du contr.le de la circulation aérienne
air traffic controller
A person holding a valid licence to control air traffic.
. also called: controller
Fr: contr.leur de la circulation aérienne
air traffic control operations support specialist
An employee assigned to perform non-control functions in an ATC unit.
. also called: operations support specialist (OSS)
Fr: spécialiste technique d’exploitation du contr.le de la circulation aérienne
air traffic control service
A service provided for the purposes of
(a)
preventing collisions between

(i)
aircraft;

(ii)
aircraft and obstacles; and

(iii) aircraft and vehicles on the manoeuvring area; and

(b)
expediting and maintaining an orderly flow of air traffic.

. also called: ATC service
Fr: service de contr.le de la circulation aérienne
air traffic control specialist
U.S.: Expression for: air traffic controller
. abbreviation: ATCS
air traffic control unit
As the circumstances require, this may be
(a)
an area control centre (ACC) established to provide ATC service to IFR and CVFR aircraft;

(b)
a terminal control unit (TCU) established to provide ATC service to IFR and CVFR aircraft arriving at, or departing from, one or more airports; or

(c)
an airport control tower unit established to provide ATC service to airport traffic.

. also called: ATC unit
Fr: unité de contr.le de la circulation aérienne