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Class C airspace for drone pilots

Last updated 2026-11-14 · Published by Certloom Learning · Sources

Class C is drawn in solid magenta and generally runs from the surface to 4,000 ft above the airport elevation, with a 5 NM surface core and a 10 NM shelf that starts at 1,200 ft or higher. Any Part 107 flight inside it needs prior ATC authorization under 14 CFR 107.41.

What is Class C airspace and how big is it?

The AIM defines Class C as generally the airspace from the surface to 4,000 ft above the airport elevation (charted in MSL) around airports that have an operating control tower, are served by a radar approach control, and meet a threshold of instrument operations or passenger enplanements. Each area is custom, but it usually has two parts: a core of 5 NM radius that runs from the surface up, and a shelf of 10 NM radius that begins no lower than 1,200 ft and runs to the same ceiling.

There is also a procedural outer area, normally 20 NM from the primary airport, but the AIM notes that outer area is not charted and it is not Class C airspace itself. Do not treat the 20 NM ring as a boundary for 107.41.

Sources (checked 2026-11-14): AIM 3-2: Controlled Airspace; FAA Remote Pilot sUAS Study Guide (FAA-G-8082-22).

How does Class C look on a sectional chart?

Class C is drawn in solid magenta lines, usually as two concentric rings: an inner circle for the surface core and a wider ring for the shelf. The Chart Users' Guide says the MSL ceiling and floor of each sector are printed in solid magenta figures with the last two zeros dropped, and that a ceiling of T means up to, but not including, the floor of overlying Class B. A floor of SFC means the surface.

LabelReads asWhere it usually is
40 over SFC0 to 4,000 ft MSLThe core, around the airport
40 over 121,200 to 4,000 ft MSLThe shelf ring, outside the core
40 over 151,500 to 4,000 ft MSLA shelf sector with a higher floor

The free Norfolk, Virginia chart (Figure 20) has the first two labels: 40 over SFC in the core next to Norfolk International and 40 over 12 on the outer shelf. Norfolk's field elevation is 27 ft MSL. The Corpus Christi chart (Figure 69) has 40 over SFC, 40 over 12 and a western sector marked 40 over 15, with the field at 44 ft MSL. Open those lessons in the Norfolk lesson or the Corpus Christi lesson and tap the labels.

Sources (checked 2026-11-14): FAA Aeronautical Chart Users' Guide (effective 9 July 2026); AIM 3-2: Controlled Airspace.

How do I find the floor of a Class C shelf in feet AGL?

Take the floor number from the label, add two zeros, and subtract the ground elevation under the spot you plan to fly. The result is how many feet above the ground the shelf begins. If your planned altitude AGL is below that number, you are under the shelf. If it is at or above it, you are inside Class C.

Worked example

Corpus Christi shelf, using a chart obstruction

Near the 40 over 15 sector on Figure 69 there is an obstruction labeled 1037 (977). The first number is its top in MSL and the second is its height above ground, so the ground there is about 1,037 minus 977, or 60 ft MSL.

Worked example

Norfolk shelf with low ground

The Norfolk shelf 40 over 12 floors at 1,200 ft MSL. Say the ground below it is 20 ft MSL. A drone at 300 ft AGL is at 320 ft MSL, about 880 ft under the floor, so no Class C authorization applies at that altitude. Move the same drone inside the inner ring labeled 40 over SFC and it needs authorization at any altitude, even 50 ft AGL.

The rule is about lateral and vertical position together: 400 ft AGL is a legal altitude near the surface core, but it is still inside Class C there. The 400 ft AGL limit in 107.51 never exempts you from 107.41.

What does a Part 107 pilot need to fly in Class C?

Prior ATC authorization under 14 CFR 107.41, the same as for Class B and Class D. The AIM lists a two-way radio and a transponder for manned aircraft, and manned pilots must talk to ATC before entering; none of that is the remote pilot's requirement. You get permission through LAANC or FAADroneZone.

Part 107 gives you two routes to the authorization. LAANC works through an FAA-approved service supplier's app and usually answers in near real time when you ask for an altitude at or below the UAS Facility Map value for that spot. If you need more than the map allows, you can send a further coordination request for up to 400 ft AGL; the FAA asks for these at least 72 hours before the flight, and you can file up to 90 days ahead. Airports that are not LAANC-enabled go through FAADroneZone instead, where the FAA says processing historically takes up to eight weeks. Unless the authorization says otherwise, you do not call the tower before you fly.

Sources (checked 2026-11-14): FAA: Part 107 Airspace Authorizations; FAA: UAS Data Exchange (LAANC).

Two practical notes. First, an approval covers the location, time and altitude you requested, so fly exactly that. Second, an authorization only covers airspace. You still check TFRs and NOTAMs, weather, and the other Part 107 rules, as the FAA's LAANC page reminds you.

What about the area outside the shelf, and the 20 NM ring?

Outside the 10 NM shelf ring, the chart shows no Class C lines. The AIM's procedural outer area, normally 20 NM from the primary airport, exists so approach control can provide services to aircraft that have established contact. It starts at the lower limit of radio and radar coverage and is not charted. 14 CFR 107.41 names Class C airspace, so the boundary that counts for your authorization is the charted magenta line, not the 20 NM ring. The AIM also warns that pilots who descend below the base of the shelf during an approach may meet aircraft that have no transponder or ADS-B, which is one reason to keep a careful watch for manned traffic under a shelf even when no authorization is required there.

Sources (checked 2026-11-14): AIM 3-2: Controlled Airspace.

What is a sensible order of checks before a Class C flight?

  1. Place your site relative to the two magenta rings. Inside the inner ring, authorization applies from the surface up.
  2. If you are between the rings, read the shelf label and note the floor in MSL.
  3. Estimate ground elevation, add your planned altitude AGL, and compare to the floor.
  4. If you are under the floor, no Class C authorization applies at that altitude. Check Class E or Class G below, and watch for manned traffic that descends under the shelf on approach.
  5. If you are inside, apply through LAANC or FAADroneZone for the exact location, time and altitude.

How does Class C relate to Class B, Class D and Class E?

Class C sits between B and D in size. It is smaller than Class B and larger than Class D, and the AIM describes Class C airports as served by a radar approach control, which it does not say of Class D. Around the edge of the shelf, the airspace below the shelf and outside the core is usually Class E (700 or 1,200 ft AGL, or higher) with Class G beneath. On a chart where a Class C shelf runs up to a Class B floor, the ceiling label is T instead of a number. When the tower closes, Chart Supplement entries may say the airspace reverts to Class E or Class G at other times.

Sources (checked 2026-11-14): FAA Aeronautical Chart Users' Guide (effective 9 July 2026); AIM 3-2: Controlled Airspace.

What are the common test traps for Class C?

For more practice with these labels, see the free chart lessons and the overview how to read airspace classes.

Free practice questions on this topic

4 original questions from the Sectional Cue bank. Try each one, then open the answer.

Class C surface area
1. In Figure 20, a contractor wants to fly a roof survey at 150 ft AGL inside the Norfolk Class C area labeled 40 over SFC, beside Norfolk Intl. What applies? (uses Figure 20, open the free chart lesson)

  1. Class C from the surface to 4,000 ft MSL, so prior ATC authorization is required
  2. Class D from the surface to 4,000 ft MSL, so authorization is needed only above 400 ft AGL
  3. Class E from the surface, so no authorization is needed below 400 ft AGL
Show answer and explanation

A. Class C from the surface to 4,000 ft MSL, so prior ATC authorization is required

The solid magenta lines and the 40 over SFC label mark Class C from the surface up to 4,000 ft MSL. Part 107 requires prior ATC authorization for any operation in Class C. The area is not Class D, and authorization is not tied to flying above 400 ft AGL. It is not Class E either, because the solid magenta boundary marks Class C.

Source: FAA-CT-8080-2H, Figure 20; 14 CFR 107.41

Class C shelf floor
2. In Figure 20, the Norfolk Class C label just north of the Norfolk Intl data block reads 40 over 12. Assume the ground under that shelf is 20 ft MSL. Does a drone at 300 ft AGL there need a Class C authorization? (uses Figure 20, open the free chart lesson)

  1. Yes, because Class C starts at the surface anywhere inside the outer magenta circle
  2. No, because the shelf floor is 1,200 ft MSL and the drone is at about 320 ft MSL
  3. Yes, because the 12 means the shelf begins 120 ft above the ground
Show answer and explanation

B. No, because the shelf floor is 1,200 ft MSL and the drone is at about 320 ft MSL

Class C altitudes are in hundreds of feet MSL, so 40 over 12 is a shelf from 1,200 ft MSL to 4,000 ft MSL. A drone at 300 ft AGL over 20 ft ground is at about 320 ft MSL, below the shelf, so 14 CFR 107.41 does not require a Class C authorization for that altitude. Only the inner area marked SFC starts at the surface, and the 12 is 1,200 ft MSL, not 120 ft AGL.

Source: FAA-CT-8080-2H, Figure 20; Chart Users' Guide; 14 CFR 107.41

Class C shelf
3. In Figure 69, the magenta figures 40 over 12 are printed just north of the Corpus Christi International data block. What do they mean? (uses Figure 69, open the free chart lesson)

  1. Class C from the surface to 4,000 ft MSL within 12 NM
  2. Class C from 1,200 ft MSL up to 4,000 ft MSL in that shelf
  3. Class B from 1,200 ft MSL up to 4,000 ft MSL
Show answer and explanation

B. Class C from 1,200 ft MSL up to 4,000 ft MSL in that shelf

In a Class C label, the top number is the ceiling and the bottom number is the floor, both in hundreds of feet MSL, so 40 over 12 means 1,200 to 4,000 ft MSL. The 12 is a floor altitude, not a distance in NM. The airspace is drawn with solid magenta lines and named CORPUS CHRISTI CLASS C, so it is not Class B.

Source: FAA-CT-8080-2H, Figure 69; Chart Users' Guide; 14 CFR 107.41

Shelf floor calculation
4. In Figure 69, the obstruction 1037 (977) lies near the Class C sector labeled 40 over 15. Using it to estimate ground level, would a drone at 400 ft AGL there be inside that Class C sector? (uses Figure 69, open the free chart lesson)

  1. Yes; 400 ft AGL is above the 150 ft floor
  2. No; that sector begins at 4,000 ft MSL
  3. No; it would be at about 460 ft MSL, below the 1,500 ft MSL floor
Show answer and explanation

C. No; it would be at about 460 ft MSL, below the 1,500 ft MSL floor

The ground is about 1,037 minus 977, or 60 ft MSL, so 400 ft AGL is about 460 ft MSL. The bottom number, 15, is the floor in hundreds of feet MSL, so the sector starts at 1,500 ft MSL and the drone is below it. There is no 150 ft floor, and 4,000 ft MSL is the ceiling, not the floor.

Source: FAA-CT-8080-2H, Figure 69; Chart Users' Guide; 14 CFR 107.41

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Sources

How this page was made: written by Certloom Learning from the sources above, with the rules checked against the current regulation text. Practice items are original questions from the app's reviewed bank. Spot an error? certloomlearning@gmail.com.