What does the term "controlled airspace" refer to?

Controlled airspace refers to airspace where air traffic control (ATC) services are provided to ensure the safe and orderly flow of air traffic. This type of airspace is typically associated with busy airports and major flight routes where aircraft operations are more complex.

In controlled airspace, pilots must comply with ATC instructions, which help to prevent mid-air collisions, manage the flow of traffic, and facilitate a safe flying environment. This type of airspace is categorized into different classes (A, B, C, D, and E), each with varying levels of control and requirements for pilots and aircraft operating within them.

The other options describe aspects of airspace that don’t match the definition of controlled airspace. For instance, uncontrolled airspace does exist without ATC services, and while commercial aircraft operate in controlled airspace, it is not exclusive to them—general aviation and other aircraft types also use these airspace classifications. Additionally, while there are areas designated for recreational flying, they do not constitute the entirety of controlled airspace.