Reading airspace on sectional charts

Once you know the color and line-style code, airspace on a sectional becomes readable at a glance:

• Class B — solid blue lines forming the upside-down-cake shelves. Each segment shows a fraction like `100/30` meaning ceiling 10,000 / floor 3,000 ft MSL.
• Class C — solid magenta lines, usually two rings, with fractions for each ring's top and bottom (e.g. `42/SFC` = 4,200 to surface).
• Class D — dashed blue line; the ceiling appears as a bracketed number like `[25]` = 2,500 ft MSL. Active only when the tower is open.
• Surface Class E — dashed magenta around some non-towered airports with instrument approaches.
• Class E floors — faded magenta shading = Class E starts at 700 ft AGL; faded blue = 1,200 ft AGL. A zipper-edged blue line with a number marks where a Class E floor changes (e.g. Class E starting at a specific MSL altitude).
• Special-use airspace — blue (prohibited/restricted/warning) or magenta (MOA/alert) hatched boundaries with a P-/R-/W-/MOA label; details (altitudes, times, controlling agency) in the chart margin.

The single most useful skill is reading the altitude fraction: top over bottom in hundreds of feet MSL, with `SFC` meaning surface. That tells you whether you'll clip the airspace at your planned altitude. Trace your course line and resolve every boundary it crosses before you fly it.

*Reference and training only. Use current charts for navigation.*