Terminal Control Area

A terminal control area (TMA, or TCA in the U.S. and Canada), also known as a terminal manoeuvring area (TMA) in Europe, is an aviation term to describe a designated area of controlled airspace surrounding a major airport where there is a high volume of traffic. TMA airspace is normally designed in a Concentric circular configuration centered on the geographic coordinates of the airport, and differs from a control area in that it includes several levels of increasingly larger areas, creating an "upside-down wedding cake" shape.
Each of these circles has a certain radius and height, and they are categorized accordingly.