Air Traffic Control Instructions Directives issued by Air Traffic Control for the purpose of requiring a pilot to take a specific action. Air Traffic Control Radar Beacon System A surveillance radar system which uses transmitters/receivers (interrogators) and transponders.
See Secondary Surveillance Radar Air Traffic Control Sector A defined airspace region for which an associated controller (or controllers) has ATC responsibility Air Traffic Control Service Is a service provided for the purpose of : preventing collisions between aircraft and on the manoeuvring area between aircraft and obstructions and expedition and maintaining an orderly flow of air traffic. (Ref. ICAO Doc 9569 Definitions). Air Traffic Control Strategic Constraint An ATC constraint defined by the Airspace structure and associated operational rules. Such constraints are applicable to all flights and do not change very frequently. Air Traffic Control Tactical Constraint An ATC constraint coming from a controller’s guidance order (e.g. for conflict avoidance), or clearance. Such constraints concern individual flights, are very dynamic and unpredictable Air Traffic Control Task An operational ATC function or sub-function (e.g. clearance delivery, tower control, departure control). Air Traffic Control Unit A generic term meaning: Air Traffic Control Centre, Approach Control Office or Aerodrome Control Tower. Air Traffic Controller Usually meant to indicate the radar (executive) controller. The person having final responsibility in co-ordinating traffic in a sector. The radar controller (often simply called the controller) is assisted by a planner (advance planning) and assistant. Air Traffic Controller Licence A document that identifies a person as a qualified Air Traffic Controller and contains personal, medical and professional qualifications including details of ratings, endorsements and current competence/validity. (Ref. Developed by Licensing Work Group).
Note: For ATS purposes, the expression "licence" used throughout the licensing documentation has the same meaning as the expressions "certificate" and "licence" used in the ICAO Convention. Normally, the granted student or air traffic controller licence will authorise individuals to transmit on aeronautical wave bands. Where this is not the case, States should make appropriate arrangements.