What is the upper boundary of Class G airspace at Tomlinson Airport?

• A. Surface
• B. 1,200 ft AGL
• C. 18,000 ft MSL
• D. 700 ft AGL

Answer: (B)

The key idea is that Class G airspace is uncontrolled and ends at the base of the overlying Class E airspace. If the Class E floor in the Tomlinson area is 1,200 feet above ground level, then Class G extends from the surface up to 1,200 feet AGL. So, the upper boundary being 1,200 ft AGL means you’re flying in Class G up to that height, and above that becomes Class E.

In many places the base of Class E is 700 ft AGL, 1,200 ft AGL, or higher depending on local procedures and terrain. On sectional charts, 1,200 ft AGL Class E floors are shown with a blue shading, while 700 ft AGL floors are shown with magenta shading, helping you identify the boundary. The option of ending at the surface would apply only where Class E begins at the surface, which isn’t the case here, and 18,000 ft MSL is beyond where Class G typically ends in this region.