Control Area

(Abbrev: CTA). Airspace that has been promulgated by aviation documentation to be controlled. No aircraft may enter such airspace without the approval of Air Traffic Control. This approval is commonly called a Clearance. The dimensions of a Control Area are defined both laterally and vertically. In some areas, a system of airspace classification defines which aircraft require a clearance and what services are provided.

Control Area Steps

(Abbrev: CTA Steps) An arrangement of the Control Area around an airport in which the lower limit (base) rises in steps as distance from the airport increases. This is done to contain the climb and descent of aircraft from and to the runway within controlled airspace at all times

Control Instruction

A direction by the controller to the pilot that requires the latter to fly the aircraft in a manner necessary for Air Traffic Control purposes.