USAF Academy Alert Area A-260 and Colorado Springs Class C · Denver Sectional, 3 Sep 2026 – 29 Oct 2026 · Denver.pdf (FAA current sectional, not redistributed), p. 1 · Not for navigation
Refer to the current Denver sectional excerpt, which includes the chart's own "Examples of Class C Altitudes" box showing "70" over "30." According to this legend, what does a Class C shelf printed this way mean?
Why: Just like the Class B altitude legend elsewhere on this same chart, the "Examples of Class C Altitudes" box states: "Ceiling in hundreds of feet MSL" and "Floor in hundreds of feet MSL." For "70" over "30," that's a ceiling of 7,000 feet MSL and a floor of 3,000 feet MSL — both referenced to mean sea level.
Mixes reference frames — the chart's legend states the floor, like the ceiling, is in MSL, not AGL.
Confuses the altitude shelf numbers with the Class C ring's lateral radius (typically shown separately as a distance on the chart, not as part of this ceiling/floor fraction).
UA.II.A.K1 · Source: Denver.pdf, current edition sectional chart excerpt, "Examples of Class C Altitudes" legend box (gitignored full-resolution source; not redistributed — see sources/README.md) · Reviewed 2026-10-22