U.S. airspace is divided into classes that determine what authorization, if any, a drone pilot needs before flying.
Class B — major airport cores
Surrounds the busiest airports (major international hubs). Drone operations require prior air traffic control authorization; this is the most tightly controlled class.
Class C — mid-size airports
Surrounds airports with an operating control tower and radar approach control. Also requires prior authorization for drone flight, most often obtained through LAANC.
Class D — smaller towered airports
Surrounds smaller airports with an operating control tower but without the radar services of Class C. Still requires prior authorization for drone flight.
Class E — controlled airspace without a tower requirement
A broad category that exists in many forms (surface-level E near some airports, or starting at higher altitudes elsewhere). Where Class E extends to the surface, drone authorization is often required; check current sectional charts or an authorization app for your exact location.
Class G — uncontrolled airspace
The default class where none of the above applies — most rural and many suburban areas fall here. No prior ATC authorization is required for standard Part 107 operations, though all other Part 107 rules (altitude, VLOS, etc.) still apply fully.
How to check what class you're in
Use the FAA's B4UFLY app or a sectional aeronautical chart, or check within a drone-specific pre-flight app — never assume based on how the area "feels." Airspace boundaries frequently don't align with visible landmarks.