Types of CAA Air Traffic Services (ATS)

I have noticed, there is quite a bit of confusion within the Aviation community, on the different types of Air Traffic Services in the UK, so I am going to make it as simple as possible, so everyone has a brief idea on what the different types of ATS.

Basic Service

Introduction - The Basic Air Traffic Service (Basic Service), is surprisingly the most Basic of available the Services available from an Air Traffic Service Unit (ATSU). However, the Basic Service, is the most common Service requested by a Pilot to an ATSU.

What it provides - The Basic Service offers general advice, and information critical to the operation of the Aircraft, such as Weather and Airfield information. The ATSU that provided the Basic Service can also give Traffic Information, such as ‘Intense gliding with in the area’,’Traffic reported at 2,000 feet, overhead Garstang’, they usually will not, or can’t provide any further information.

CAA Definition CAP774(2.1)

A Basic Service is an ATS provided for the purpose of giving advice and information useful for the safe and efficient conduct of flights. This may include weather information, changes of serviceability of facilities, conditions at aerodromes, general airspace activity information, and any other information likely to affect safety. The avoidance of other traffic is solely the pilot’s responsibility.
Basic Service relies on the pilot avoiding other traffic, unaided by controllers/ FISOs. It is essential that a pilot receiving this ATS remains alert to the fact that, unlike a Traffic Service and a Deconfliction Service, the provider of a Basic Service is not required to monitor the flight.

Traffic Service

Introduction - The Traffic Air Traffic Service, is a surveillance based ATS, and is regularly used by VFR Pilots, in areas with LARS, or outside of controlled Airspace, where Radar Coverage is available.

What it provides - The Traffic Air Traffic Service provides information on traffic, that the ATSU believes would assist the Pilot in the safe operation of the Aircraft, specifically, to reduce the risk of Mid-Air collisions. ATSU who provides Traffic Services will provide Height information (if available) direction, and location of the traffic that may be a factor.

CAA Definition CAP774(3.1)

A Traffic Service is a surveillance based ATS, where in addition to the provisions of a Basic Service, the controller provides specific surveillance-derived traffic information to assist the pilot in avoiding other traffic. Controllers may provide headings and/or levels for the purposes of positioning and/or sequencing; however, the controller is not required to achieve deconfliction minima, and the pilot remains responsible for collision avoidance.

Radar Control Service

Introduction - A Radar Control Air Traffic Service, is a surveillance based Service, only provided inside controlled Airspace, with ATSU equipped with a Radar.

What it provides - A Radar Control Air Traffic Service, provides complete Radar Coverage inside of Controller Airspace, the key to a Radar Control Service, is the word control, the ATSU, is able to give instructions to Aircraft under the service. You can also request for a Radar Service in an AIAA (Area of Intense Aerial Activity).


Radar control is the term used to indicate that radar-derived information is employed directly in the provision of air traffic control service. (ICAO Doc 4444: PANS-ATM)

Radar control is employed where available within controlled airspace for traffic identification, control and separation in all phases of flight.

There are other forms of Radar Services, provided outside of controlled airspace, such as a Deconfliction and Procedural Service, but these shouldn’t really concern a pilot flying VFR.

Any questions or typos let me know.

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