NATS provides air traffic navigation services to aircraft flying through UK controlled airspace and at several UK and international airports. So how do we move over 6,000 flights every day through the busy skies around the world safely and efficiently?
The guiding principle of air traffic control is that safety is paramount. Controllers must keep the aircraft they handle safely separated using internationally agreed standards. They achieve this by allocating different heights to aircraft or by arranging minimum horizontal distances between them. These distances vary according to circumstances, but aircraft flying along the airways under radar surveillance, for example, are kept five nautical miles apart horizontally or at least 1,000 feet vertically.
UK airspace contains a network of corridors, or airways. These are usually ten miles wide and reach up to a height of 24,000 feet from a base of between 5,000 and 7,000 feet. They mainly link busy areas of airspace known as terminal control areas, which are normally above major airports. At a lower level, control zones are established around each airport. The area above 24,500 feet is known as upper airspace.
All of these airways are designated “controlled airspace”. Aircraft fly in them under the supervision of air traffic controllers and pilots are required to file a flight plan for each journey, containing details such as destination, route, timing and height.
Within controlled airspace, pilots must follow controllers’ instructions. Outside controlled airspace they take full responsibility for their own safety, although they can ask for help.
Military controllers work closely with their civilian colleagues to provide a fully integrated service to all users. They offer an air traffic service to aircraft in uncontrolled airspace. Military personnel also provide services to aircraft crossing airways and for those flying above 24,500 feet. A priority task for them is helping aircraft in distress.