Figure 20 — Sectional Chart Excerpt · FAA-CT-8080-2H, p. 2-19
Near the Norfolk International Airport core on Figure 20, the Class C airspace is labeled with the numbers "40" over "SFC." What do these numbers mean?
Why: A number stacked over "SFC" on a Class C shelf gives the ceiling in hundreds of feet MSL above a surface floor; "40" over "SFC" means that segment runs from the surface up to 4,000 feet MSL, consistent with the FAA study guide's description of Class C as generally surface to 4,000 feet above the airport.
Swaps which number is the ceiling and which is the floor — "40" (4,000 ft) is the ceiling here, and "SFC" (surface) is the floor, not the reverse.
Misreads the airspace shelf numbers as unrelated airport data; they describe the Class C airspace's vertical limits, not the field elevation or a runway identifier.
UA.II.A.K1 · Source: sport_rec_private_akts.pdf, Figure 20, p. 2-19; remote_pilot_study_guide.pdf, p. 6 · Reviewed 2026-10-21