Class C airspace generally extends from the surface to what altitude above the airport elevation?

Class C airspace is designed to provide air traffic control services to aircraft operating within its vicinity while helping to ensure safe and efficient operations in busy airport areas. Generally, the vertical limits of Class C airspace extend from the surface up to 4,000 feet above the airport elevation.

This structure is crucial for maintaining safe separation between arriving and departing aircraft at these airports, as it allows for both incoming and outgoing flights to operate within a structured environment. The lower limit at the surface helps ensure that aircraft takeoff and landing do so within controlled airspace, while the upper limit provides adequate vertical separation for aircraft in the area.

Therefore, selecting 4,000 feet AGL as the upper limit of Class C airspace correctly reflects its defined structure and purpose within the National Airspace System.