United Kingdom Flight Infomation Services
Any aircraft can fly outside of controlled airspace (Class G) and be provided with a service. There are four UKFISs - Basic, Traffic, Deconfliction and Procedural. These services can be provided by both civilian and military control positions.
A pilot can request one of these services when outside of controlled airspace, depending on their flight but the controller remains free to downgrade the pilots requested service if they have a high workload or if the area the pilot is in has poor radar coverage (in IVAO this isn’t simulated).
A basic service gives the pilot information regarding airspace activity that could affect their flight. This information could be a weather change or airfield status change, depending on the controller’s workload. Under a basic service, pilots remain fully responsible for terrain and traffic avoidance so having a good lookout is vital. IFR flights in class G and VFR flights in both classes E and G can receive this type of service.
A traffic service will give the pilot detailed traffic information on specific conflicting aircraft but will not tell the pilot how to avoid the traffic- that’s for the pilot to decide. This service can be given to IFR flights in class G airspace and to VFR flights in both classes E and G airspace.
A deconfliction service is only available to IFR flights in class G airspace. When under this service, air traffic control will give the pilot detailed traffic information on specific conflicting aircraft and advice on how to avoid them. The pilot, however, is still responsible for avoidance and can choose not to follow the controller’s advice. If the pilot is below the minimum terrain clearance level, this service can’t be provided unless it’s during the climb and descent to the controller-assigned level.
A procedural service can only be provided to IFR flight, this is a non-surveillance service where the controllers will provide deconfliction advice against any other aircraft that are also receiving the same service from the same controller. It is not derived from radar. Under this service, pilots are responsible for terrain and collision avoidance.