According to ICAO, AIR TRAFFIC SERVICE (ATS) is a generic term meaning variously, Flight Information Service, Alerting Service, Air Traffic Advisory Service, Air Traffic Control Service (Area Control Service, Approach Control Service or Aerodrome Control Service).
The components of services under ATS include:
- Flight Information Service
- Alerting Service
- Air Traffic Advisory Service
- Air Traffic Control Service
Flight Information Service – Flight Information service is a service provided for the purpose of giving advice and information useful for the safe and efficient conduct of flights. A flight information service may be provided on its own or in conjunction with an Air Taffic Control Service. Flight Information Service gives useful information and advice for the safe and efficient conduct of flight, such as the status of navigation aids, bad weather, closed airfields, etc.
Alerting Service – A service provided to notify appropriate organizations regarding aircraft in need of search and rescue aid, and assist such organizations as required. Alerting service being part of Air Traffic Service (ATS) is provided by ATS Units (e.g. Area Control Centres, Flight Information Centres, etc.). The main task is to promptly notify the appropriate organizations (e.g. Search and Rescue (SAR) Units) about the situation, and provide relevant information about the aircraft in distress. ATS Units themselves do not provide SAR service.
Alerting Service is provided to: i) All aircrafts provided with Air Traffic Control Service; ii) All other aircraft having filed a Flight Plan or otherwise known to the Air Traffic Services (as far as practicable); and iii) Any aircraft known or believed to be the subject of unlawful interference.
Air Traffic Advisory Service – Air Traffic Advisory Service is a service provided within advisory airspace to ensure separation, insofar as practical, between aircrafts which are operating on IFR Flight Plans. The objective of the Air Traffic Advisory Service is to make information on collision hazards more effective than it would be in the mere provision of Flight Information Service. As a rule, advisory service is only implemented where the air traffic services are inadequate for the provision of air traffic control, and the limited advice on collision hazards otherwise provided by flight information service will not meet the requirement. Where advisory service is implemented, this is usually considered as a temporary measure only until such time as it can be replaced by air traffic control service.
Advisory service does not afford the degree of safety and cannot assume the same responsibilities as Air Traffic Control Service in respect of collision avoidance, since information regarding the disposition of traffic in the area may be incomplete. Advisory service, according to ICAO, does not deliver “clearances” but only “advisory information”.
Air Traffic Control Service – This is a service provided for the purpose of: a) preventing collisions: between aircrafts, and on the manoeuvring area between aircrafts and obstructions; and b) expediting and maintaining an orderly flow of air traffic. To explain further, Air Traffic Control Service is offered to prevent collisions and to organize traffic efficiently: i) on taxiways, runways and in the airspace around the airfield or Control Zone (CTR) called Aerodrome Control service; ii) between arriving and departing aircrafts in a Terminal Control Area (TMA) to and from one or more aerodromes, called Approach Control Service; and iii) between en-route aircraft in Control Areas (CTA) and along Airways (AWY), called Area Control service.
REFERENCES
ICAO Annex 11
ICAO Doc 4444
www.wiki.ivao.aero
