ATS services
ATS services
This domain tests the services provided by air traffic services, the difference between control and information, and how to use ATC, AFIS and UNICOM correctly.
Core rules
- ATS includes air traffic control (area, approach, tower), flight information service (FIS), alerting service, and aerodrome flight information service (AFIS). ATC provides separation; FIS and AFIS provide information, not separation.
- Control services include clearances, traffic information, sequencing and separation in controlled airspace. You must comply with ATC instructions and read back safety-related items.
- FIS provides weather, traffic and aerodrome information; it does not clear you into controlled airspace.
- AFIS provides aerodrome information and traffic information at some uncontrolled aerodromes; it is not a control service.
- UNICOM is an aerodrome advisory frequency, often shared; use standard broadcasts.
Worked example
You are VFR in Class G and request 'flight following' from Christchurch Information. The controller replies: 'ZK-ABC, traffic 2 o'clock, 5 miles, opposite direction, Cessna 172, 3,500 feet.' You reply: 'Traffic sighted, ZK-ABC' or 'Negative contact, ZK-ABC.' The controller is providing traffic information, not separating you. You remain responsible for see-and-avoid and terrain clearance.
Traps
- Expecting ATC to separate VFR from VFR in Class G.
- Treating an AFIS or UNICOM call as a clearance.
- Not listening out on the correct frequency.
- Failing to advise ATC when a traffic conflict develops.
ATS services
Know which unit you are talking to and what it can and cannot provide; that determines how much responsibility remains with you.