Control zone
A control zone (english control zone, internationally as CTR for short) is the reaching to the ground airspace in the immediate vicinity of an aerodrome, the air traffic is managed by an air traffic controller.
A control zone for the purpose of coordinating the on -, off - and by flying VFR traffic with the ( already managed by air traffic control ) IFR traffic in areas of high traffic density. With control zones therefore especially airfields with a high volume of IFR traffic feature.
Legally, control zones in Germany classified as air spaces of category D ( CTR). International also airspace Classes A, B or C can be found. To the CTR is also established in Germany at least a so-called terminal area.
Shapes and sizes
The lateral extent of a control zone according to local requirements. Many have rectangular shape with about 10-15 km wide and 25-35 km in length. But even circular shapes, combinations or irregular polygons occur, depending on the arrangement of the start and runways of the airfield and on the expected flight paths for arriving and departing traffic.
In the height range control zones according to ICAO standard until at least 1500 ft AGL ( above ground level ). The upper limit is always specified as height above sea level (MSL, mean sea level ). In Germany the highest control zones ranging up to 4500 ft MSL, for example at Memmingen airport.
The limits of a control zone are listed in the VFR charts officially valid.
Visual flight control zones
A test flight under visual flight rules in a control zone is permitted only with approval of the appropriate air traffic controllers and is generally designated in the VFR charts compulsory reporting points. These often coincide with distinctive soil features that are clearly visible from the air ( eg freeway crosses or striking buildings) and are usually named by the direction in which they are located, for example, is " WHISKEY " (see ICAO alphabet ) a compulsory reporting point, which is approximately west of the airfield.
Within the control area of each pilot on tower frequency must be listening watch as the traffic management is responsible for the air traffic controller that assigns each aircraft flight paths and heights.
For the visual flight (VFR ) in a control zone following VFR minima apply
If the conditions 1 or 2 is not a given, single exhaust and approaches can be performed by the control zone with the release of the air traffic control for special VFR.