The normal vertical limit of Class C airspace above the primary airport is what?

• A. 2,000 ft AGL
• B. 4,000 ft AGL
• C. 6,000 ft AGL
• D. 8,000 ft AGL

Answer: (B)

The important idea is how Class C is structured around a primary airport. It has an inner core from the surface up to 4,000 ft above the airport’s elevation, plus a surrounding shelf that typically starts at 1,200 ft above the airport and rises to the same top of 4,000 ft above the airport. So the highest point of Class C above the primary airport is 4,000 ft above the field—i.e., 4,000 ft AGL. The other options would place the top too low or too high relative to the field. If you’re operating in the Class C airspace, staying within that 4,000 ft AGL ceiling is part of what defines the airspace you’re in.