In which airspace does ATC have no responsibility for air traffic?

In uncontrolled airspace, such as Class G airspace, Air Traffic Control (ATC) does not provide any services or have responsibility for managing air traffic. Pilots operating in this airspace are responsible for maintaining their own visual separation from other aircraft and for adhering to visual flight rules (VFR).

Class G airspace typically extends from the surface up to a specified altitude, primarily in rural or less congested areas where the need for ATC services is minimal. Since there are no ATC services provided, pilots must be vigilant and aware of their surroundings as they operate without the guidance or traffic advisories that are available in controlled airspace.

Class E airspace, Class A airspace, and Class D airspace are all controlled airspace, where ATC maintains responsibility for air traffic. In Class E airspace, ATC provides some level of service, especially when it intersects with controlled airspace. Class A airspace is entirely under ATC jurisdiction, as it covers high-altitude operations, while Class D airspace requires pilots to communicate with the tower for guidance and traffic advisories.