Air Traffic Control is an all-embracing term and on occasion there is some doubt about its scope. For the present purpose it will be as defined within the internationally agreed principles set out in Annex 11 to the International Civil Aviation Convention. Here it is set out that the Air Traffic Control service is for:–

1. (i) Expediting and maintaining an orderly flow of air traffic.

2. (ii) Preventing collision between aircraft.

3. (iii) Providing advice and information useful for the sake of efficient conduct of flights.

4. (iv) Preventing collision on the manoeuvring area between aircraft and obstructions.

5. (v) Notifying the appropriate organisations regarding aircraft in need of search and rescue and to assist such organisations as required.