Airspace classes: B, C, D, E, G

Every sectional chart divides the sky into named blocks of airspace, and each block carries its own rule for whether a Part 107 remote pilot can fly there freely, needs authorization first, or cannot fly there at all. Reading a sectional chart correctly, meaning identifying which class you are looking at from its boundary line alone, is consistently one of the sections candidates report struggling with most on the Part 107 knowledge test. This page walks through each class specifically for what it means to a drone operator, not a manned-aircraft pilot; for the full symbol-by-symbol reference table, including obstructions and NOTAM (Notice to Air Missions) types, see the sectional chart symbol reference. To drill this material hands-on against original illustrative charts, use the free sectional chart drill.

How the classes stack, visually

Class B: the busiest airports, always needs authorization

Class B airspace surrounds the nation's busiest airports (think major hubs like Los Angeles International or Chicago O'Hare) in a shape often described as an upside-down wedding cake: several stacked rings, each with its own floor and ceiling tailored to that airport's traffic pattern. On a sectional chart, Class B is drawn as solid, heavy blue boundary lines, with each ring labeled by its floor and ceiling in hundreds of feet.

For Part 107 purposes, a remote pilot may never operate inside Class B without prior air traffic control authorization, obtained through LAANC where the facility participates, or a manual authorization request where it does not. There is no altitude inside Class B where authorization is not required, even down at the surface, because the surface at a Class B primary airport is typically within the innermost ring.

Class C: medium-traffic airports, same authorization rule

Class C airspace surrounds medium-activity airports with an operating control tower and radar approach control, usually a two-tier structure: a surface area out to roughly 5 nautical miles and a shelf extending out to roughly 10 nautical miles. On a chart, it is drawn as solid, heavy magenta boundary lines, tiered and labeled the same way as Class B.

The Part 107 rule is the same as Class B: authorization (LAANC or manual) is required before flying anywhere inside the Class C footprint, at any altitude within it.

Class D: smaller towered airports, still needs authorization

Class D airspace surrounds smaller airports that have an operating control tower but no radar approach service, typically a single cylinder roughly 4 to 5 nautical miles in radius. It is drawn as a thin, dashed blue boundary line, the same color family as Class B but visually lighter and segmented rather than solid, with the floor and ceiling numbers shown near the line.

A Part 107 remote pilot needs authorization before flying inside Class D, same as B and C. Class D airspace usually reverts to the airspace underneath it (often Class E or G) outside the tower's operating hours, but the safest default for test purposes and for real flight planning is to treat the boundary as active and check current status before assuming otherwise.

Class E: mostly irrelevant to Part 107, except one variant

Class E is controlled airspace that is not A, B, C, or D, and it comes in several floor variants that matter for manned aviation far more than they matter for a drone capped at 400 feet AGL:

• Class E surface area: Class E that extends all the way down to the ground around certain airports without a full-time tower, drawn as a thin, dashed magenta line. This is the one Class E variant that matters directly to a Part 107 pilot: because it reaches the surface, it behaves like Class D for authorization purposes, and a LAANC or manual authorization is needed to fly inside it while it is in effect.
• Class E with a 700 foot AGL floor: shown as a soft magenta shaded fade (a vignette) rather than a hard line. Below 700 feet, the airspace is typically Class G, which does not by itself require authorization. Since Part 107 flights stay under 400 feet AGL, this variant on its own does not trigger an authorization requirement.
• Class E with a 1,200 foot AGL floor: the nationwide default floor for Class E away from airports, and for that reason it usually is not specially outlined at all. Where a blue shaded fade does appear, it marks the edge of an area (common in parts of the western United States) where there is no Class E at 1,200 feet and Class G instead extends up to 14,500 feet MSL. Because Part 107 flights are capped at 400 feet AGL, this variant almost never affects a drone flight either.

The practical takeaway for the knowledge test: when you see a dashed magenta line around an airport, that is Class E reaching the surface, and it needs authorization exactly like Class D. The two shaded-fade variants are mostly a distractor for a low-altitude operator: know them for the test, but do not expect them to change your authorization plan on an actual flight.

Class G: uncontrolled, the default for most Part 107 flights

Class G is uncontrolled airspace, the default classification for anything not designated A, B, C, D, or E. It carries no boundary line of its own; it is simply the absence of every other airspace symbol on the chart. A Part 107 remote pilot may operate in Class G up to 400 feet AGL with no air traffic control authorization required, subject to the rest of Part 107's operating rules (visual-line-of-sight, right-of-way to manned aircraft, and so on). Most Part 107 flights in the United States, away from airports, take place in Class G.

The one rule that ties it together

For a Part 107 flight, the practical question is not "which of the five classes is this" in the abstract, it is "does this specific spot require authorization before I fly." Class B, C, D, and any Class E surface area: yes, always. Class E at 700 or 1,200 feet, and Class G: no, not on the airspace-class basis alone, though other restrictions (a Temporary Flight Restriction, a restricted area, or a waiver requirement) can still apply on top of the class. Checking LAANC coverage and current airspace status directly before flight remains the operational step; this page and the chart symbol reference exist to make the chart itself, and the knowledge-test questions about it, legible.

For the how-to on getting LAANC authorization itself, see the LAANC authorization guide.

Sources

• FAA Aeronautical Chart User's Guide, faa.gov/air_traffic/flight_info/aeronav/digital_products/aero_guide/
• 14 CFR Part 107 (Small Unmanned Aircraft Systems), law.cornell.edu/cfr/text/14/part-107

Cross-checked against one independent secondary source on 2026-07-30 (see the site's data provenance file); primary source confirmation against the current FAA Aeronautical Chart User's Guide is the launch-week gate above.

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