Which airspace class is generally uncontrolled?

• A. Class E is uncontrolled
• B. Class B is uncontrolled
• C. Class C is uncontrolled
• D. Class G is uncontrolled

Answer: (D)

Uncontrolled airspace means ATC isn’t providing separation or clearance services for flights inside it. In the United States, the only general example of uncontrolled airspace is Class G. This space starts at the surface and goes up to the base of the overlying controlled airspace, which is typically the base of Class E (often at 700 or 1200 feet AGL depending on location). Above that base, the airspace becomes controlled (Class E and higher), and pilots must follow ATC procedures and, for IFR, obtain clearances.

So, Class G is the airspace where you can operate without ATC intervention for VFR, whereas the other classes (A, B, C, D, and E) are controlled and involve some level of ATC coordination.