Air Traffic Services Outside Controlled Airspace

A review of Air Traffic Services Outside Controlled Airspace (ATSOCAS) was triggered following concerns about the lack of standardisation and the problems that this raised. As part of the Airspace and Safety Initiative, air traffic services in uncontrolled airspace were subject to a substantial review. As a result of this review, a complete revision of the flight information services in uncontrolled airspace (classes F & G) was made. These came in to effect on the 12th March 2009, and are detailed in CAP 774.

There are now 4 distinct services, summarised here for your convenience:

Type of Service Definitions of service (Source: CAP 774)
Basic Service 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.

A Basic Service relies on the pilot avoiding other traffic, unaided by controllers/FISOs. It is essential that a pilot receiving this service 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 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 avoidance of other traffic is ultimately the pilot’s responsibility.
Deconfliction Service A Deconfliction Service is a surveillance based ATS where, in addition to the provisions of a Basic Service, the controller provides specific surveillance derived traffic information and issues headings and/or levels aimed at achieving planned deconfliction minima against all observed aircraft in Class F/G airspace, or for positioning and/or sequencing. However, the avoidance of other traffic is ultimately the pilot’s responsibility.
Procedural Service A Procedural Service is an ATS where, in addition to the provisions of a Basic Service, the controller provides vertical, lateral, longitudinal and time instructions, which if complied with, shall achieve deconfliction minima against other aircraft participating in the Procedural Service. Neither traffic information nor deconfliction advice can be passed with respect to unknown traffic.

A Procedural Service does not require information derived from an ATS surveillance system. Therefore, due to the ability for autonomous flight in Class F/ G airspace, pilots in receipt of a Procedural Service should be aware of the high likelihood of encountering conflicting traffic without warnings being provided by ATC. Pilots flying in the vicinity of aerodromes, ATS routes, or navigational aids where it is known that a Procedural Service is provided, are strongly encouraged to attempt to establish RTF contact with the notified ATS provider.

References:

An interactive guide is available at http://www.airspacesafety.com/content/ATSOCAS.asp# (Well recommended!)

CAP 774 is available from http://www.caa.co.uk/docs/33/cap774.pdf

Atmospheric Picture

FL45, English Channel.