Within 5 miles of Barnes County Airport, airspace from the surface to 700 ft AGL is classified as which class?

• A. Class G from the surface to 700 ft AGL
• B. Class E from the surface to 700 ft AGL
• C. Class B from the surface to 700 ft MSL
• D. Class A from the surface to 700 ft AGL

Answer: (A)

Airspace that's not controlled ends at the base of the overlying controlled airspace. In many areas around airports, the base of Class E begins at 700 ft above the surface, so the airspace from the surface up to 700 ft AGL is Class G. That means within five miles of Barnes County Airport, the airspace from the surface to 700 ft AGL is uncontrolled, i.e., Class G. Above 700 ft AGL, you enter Class E. The other options don’t fit because Class A starts at 18,000 ft MSL, and Class B/C/D are associated with larger, towered airports with different surface areas, not this surrounding pattern.