Class C Airspace for Drones: Core and Shelf
Class C has a core from the surface and a shelf 1,200 feet up or higher. Where a Part 107 drone needs ATC authorization, with the FAA's Savannah example.
Class C surrounds airports with an operating control tower, radar approach control, and enough traffic to justify it. The AIM says it usually has two parts: a core with a 5 NM radius from the surface up to 4,000 feet above the airport, and a shelf with a 10 NM radius that starts no lower than 1,200 feet and goes up to the same ceiling. For a Part 107 drone, the core is what matters. Under 14 CFR §107.41, flying inside Class C needs prior ATC authorization.
How does Class C look on a sectional chart?
Class C is drawn with solid magenta lines. The Chart User's Guide says each sector's ceiling and floor are printed as solid magenta MSL figures with the last two zeros dropped. A ceiling of "T" means the Class C goes up to, but not including, the floor of an overlying Class B.
The FAA's own test figure shows a textbook case. On Figure 23, Savannah/Hilton Head International is labeled 41 over SFC in the core and 41 over 13 in the shelf.
| Label | Meaning |
|---|---|
| 41 over SFC | Core: surface to 4,100 ft MSL |
| 41 over 13 | Shelf: 1,300 ft MSL to 4,100 ft MSL |
The FAA's sample question on this asks for the floor of the shelf. The answer is 1,300 feet MSL, not AGL, because Class C altitudes are always MSL.
5 NM / 10 NM
the usual radius of the Class C core and shelf, per the AIM
Can you fly under the Class C shelf?
Usually, yes, without Class C authorization. The shelf floor is at least 1,200 feet above the airport, so a drone at 400 feet AGL under the shelf is in whatever airspace lies below it, typically Class E with a higher floor or Class G. The Class G post covers what still applies there.
Two checks before you rely on that:
- Terrain. Floors are MSL. Over high ground, a shelf at 1,300 MSL may be much closer to the surface than the 1,200-foot rule of thumb suggests.
- Other surface areas. A satellite airport under the shelf may have its own Class D or Class E surface area that starts at the ground.
Some Class C airports are not full-time. The chart then shows a note such as "See NOTAMs/Directory for Class C eff hrs". The FAA's AIM says a part-time surface area may revert to Class E or Class G when the tower closes, and the Chart Supplement states which.
What the FAA sample questions ask
Two of the FAA's sample questions ask how a remote pilot may operate in Class C. In both, the answer is prior authorization from ATC, not monitoring the frequency, calling after launch, filing a flight plan, or using a visual observer. The sample questions post walks through all three Class C questions, and the handbook element is UA.II.A.K1, sub-element b.
In the Class C core, authorization comes first. Under the shelf, check the floor and what lies beneath it.
Class C sits between Class B and Class D in size, and the airspace classes overview compares all five.
Shelf floors are MSL, which the AGL vs MSL post shows how to convert.
Find the Savannah core and shelf yourself on the same chart excerpt the test uses.
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