Which class of airspace is classified as uncontrolled?

Class E airspace is indeed classified as uncontrolled; this is because it does not have the same level of air traffic control (ATC) services that are required in controlled airspace classes like A, B, C, and D. In Class E airspace, pilots are responsible for their own separation from other aircraft unless they choose to operate under ATC clearance. This class allows for a mix of IFR (Instrument Flight Rules) and VFR (Visual Flight Rules) operations without the strict oversight of controllers that is present in more regulated classes.

This setup allows for more flexibility in operations, particularly for general aviation pilots flying under VFR who may not always want or need to interact with ATC. It's commonly found in various altitudes and includes airspace from the surface up to the overlying controlled airspace. Understanding the nature of Class E airspace is crucial for pilots to navigate safely, especially in areas where they may encounter other aircraft without ATC guidance.