What does "controlled airspace" refer to?

Controlled airspace refers to airspace within which air traffic control (ATC) provides services to aircraft and establishes specific operational rules and regulations that pilots must follow. This includes managing the flow of traffic to ensure safety and efficiency in overcrowded regions and at busy airports. Within controlled airspace, there are designated classes, such as Class A, B, C, D, and E, which have varying requirements regarding pilot qualifications, aircraft equipment, and communication with ATC.

The distinction between controlled and uncontrolled airspace is crucial for pilots, as it dictates the level of air traffic services available and the protocols they must adhere to. Controlled airspace is designed to provide a framework that enhances safety and order during flight operations, particularly in areas with higher traffic density.