Airspace Classification, Operating Requirements, and Flight Restrictions
The Airspace Ladder
Know Class A through G. Class A begins at 18,000 ft MSL and is irrelevant to sUA. Class B is the busy terminal airspace (solid blue lines on sectionals), Class C surrounds airports with radar service (magenta), Class D is airport traffic areas (dashed blue), Class E is controlled airspace that can extend to the surface (dashed magenta), and Class G is uncontrolled. For sUA, authorization is required in Class B, C, D, and surface-area Class E. Class E that does not reach the surface is generally not a barrier at 400 ft, but always check the chart's floor.
Reading the Chart
Sectional charts show maximum elevation figures (MEF) in each quadrangle, airport data, and special use airspace. Prohibited areas (P-) forbid flight entirely. Restricted areas (R-) are hazardous when active and require permission when hot. Warning areas (W-) sit over water. Military operations areas (MOA) and alert areas require extra vigilance but not authorization. Temporary flight restrictions (TFRs) can appear with little notice - check before every flight. National security areas, stadium TFRs, and designated wilderness restrictions also matter.
Traps
Questions often present a charted airport and ask whether authorization is needed at a specific altitude - read the Class E floor. Another favorite: confusing a MOA (fly with caution) with a restricted area (do not enter when active). LAANC covers many but not all airports and not all altitudes.
Rule of Thumb
"Solid = ask." Solid blue, magenta, or dashed-blue rings around an airport mean get authorization before launch; dashed magenta reaching the surface means the same.