NATS operates two area control centres at Prestwick in Ayrshire. The Scottish Area Control Centre (SACC) handles aircraft flying in the Scottish Flight Information Region, an area that stretches from north of a line from Carlisle to Newcastle to near the Faroe Islands, including Northern Ireland and the surrounding seas. The Oceanic Area Control Centre (OACC) provides air traffic management to aircraft flying over the eastern part of the North Atlantic from the south of Iceland to north of the Azores.
- Scottish Area Control Centre
- Oceanic Area Control Centre
- Military Control
- Engineering
Scottish Area Control Centre
Controllers at the Scottish Area Control Centre handle aircraft flying in (geographically) Europe’s largest flight information region. Each of the centre’s control suites is manned by two controllers – a planning controller and an executive or radar controller. They are supported by a flight progress board assistant.
The suites house a flight planning board to display the flight progress strips and a radar position containing two radar displays, as well as the necessary radio channel selectors, touch sensitive telephone keypads and visual display units providing a variety of operational information including weather conditions.
Factfile:
- SACC has 12 civil control suites.
- Controllers use high definition radar displays.
- The centre covers an area of over 190,000 square miles.
Oceanic Area Control Centre
As radar only has a range of some 200 miles, controllers in the Oceanic Area Control Centre use position reports and estimates passed from pilots to ensure aircraft are safely separated. This information is provided using high frequency radio and is transmitted and received via a radio communications station at Ballygireen, near Shannon in Ireland.
To take account of passenger demands, time zone differences and airport noise restrictions, most North Atlantic flights operate in two time blocks - westbound in the late morning and afternoon and east bound during the night and early morning. Because of this and the limited height band for economical jet operations the airspace is comparatively congested. To safely accommodate as many aircraft a possible an organised track structure is created every 12 hours. This allows aircraft to be handled in an orderly and efficient manner. The OACC is responsible for the day track system and the Gander Centre in Canada provides the night track system.
After entering oceanic airspace, pilots are required to make position reports at every ten degrees of longitude. These reports are used to update the Shanwick Automated Air Traffic System (SAATS) which automatically updates the controllers’ traffic information displays. SAATS alerts the controller if a report is overdue, or if the situation is other than that expected. Based on the time of the last reported position and the forecast winds the computer will work out an estimate for the next position. It will also warn the controller if the separation between any two flights is approaching the minimum allowed.
Fact file:
- The centre covers an area of over 633,000 square miles.
Military Control
Military controllers provide services to civil and military aircraft operating outside controlled airspace in the Scottish FIR. The military controllers work closely with civilian controllers to ensure safe co-ordination of traffic.
Fact file:
Military services include:
- aid to aircraft in distress.
- radar control to aircraft in uncontrolled airspace flying above 24,500 feet.
Engineering
To ensure the highest levels of safety, controllers need highly reliable equipment. SCOACC engineers are responsible for providing this service operating to a comprehensive safety management system. System control ensures a 24 hours a day, 365 days a year radar and radio service.
Fact file:
- Engineers ensure controllers have access to over 40 VHF and UHF radio frequencies via 14 remote stations serving SCOACC.
- SCOACC receives radar information from remote radar sites including Lowther Hill in the Southern Uplands.
- Radar and radio information is continuously recorded for incident analysis.
- Engineers maintain over 800 telephone extensions, using digital telephone lines linking operational staff in the UK, Canada, France, Iceland, Ireland, Norway, Portugal and Spain.
