United Kingdom Division

The UK's ATC is split into the following categories; Delivery, Ground, Tower, Approach, and Centre (En-Route). These are also called positions. The idea behind these positions are to ensure that controllers do not deal with more aircraft than required, and each positions its own responsibilities.

Depending on traffic levels and airspace complexity, some airports may have more than one of each of the positions. In fact, it is common practice for busy airports, such as Manchester or Heathrow, to have more than one Tower, Approach and even Ground controllers.

Some airports might not even have one of these positions, such as Leeds which does not have a Ground controller, or Doncaster which does not have either Delivery nor Ground. In such a case, the position above will take-over the responsibilities for the underlying position. This is also called top-down controlling.

In OCAS, the airspace is not directly controlled by ATC. However, that is not to say that ATC is not present at all. In fact, it is common small, uncontrolled airports have an Information controller during specified hours. For example, Sandtoft Airfield, a small uncontrolled airfield used for General Aviation in the North of England, has an Information controlled online usually between the hours of 09:00-17:00 local time.

These Information units will usually provide a Basic Service to aircraft, which provide information such as general activity (e.g. glider activity, current circuit height and direction) or weather information (e.g. current pressure setting). These units do not have the ability to provide any clearance or give instructions to aircraft, but instead provide advisory's based on the information reported to them.

When looking at Approach and Centre ATC units, there will often be multiple positions to consider. Approach is often broken-down into Intermediate approach and Final approach. Intermediate approach will deal with arriving aircraft after taking them from the en-route controller, and then hand them off to final approach once the aircraft is nearer the airport, and below the Transition Altitude. It is common practice for busy aerodromes to have more than one intermediate approach position, with one final approach position.

The idea behind this split of traffic is to ensure that controllers are able to focus on a smaller area of responsibility, especially during high levels of traffic. Sometimes, final approach will only be open when the traffic levels are at their highest, to aide with workload distribution. Intermediate controllers take on the responsibilities of final approach where the final approach controller is not present. 

On POSCON, it is requested members only log onto final approach positions where an intermediate approach position is filled.