What is Class C airspace?
Class C airspace is controlled airspace around mid-size US airports that have an operating control tower, radar approach control, and enough IFR or airline traffic to qualify. It normally has a 5 nautical mile core from the surface to 4,000 feet above the airport, plus a 10 nautical mile shelf from 1,200 to 4,000 feet above the airport. A drone needs prior FAA authorization only for the parts it actually enters.
Class C airspace sits around roughly 120 US airports, from Burlington, Vermont to Tucson, Arizona. The rule itself is short. 14 CFR 107.41 says no one may fly a small unmanned aircraft in Class B, C or D airspace without prior authorization from Air Traffic Control. Applying it takes more care. Class C altitudes are charted in feet above sea level, so a lot of land inside the outer ring isn't Class C at 400 feet, some Class C areas only exist during published hours, and some have cutouts for smaller airports underneath. For how the six classes fit together, see types of airspace.
Table of contents
- What is Class C airspace
- Class C airspace dimensions
- Do you need authorization under the outer shelf?
- Part-time Class C airspace
- Cutouts and satellite airports
- How to identify Class C on a sectional chart
- How to fly a drone in Class C airspace
- Manned aircraft rules that do not apply to drones
- Managing Class C jobs across a team
- Frequently asked questions
What is Class C airspace
Class C airspace is controlled airspace around busy mid-size airports, one step below Class B. The Aeronautical Information Manual, section 3-2-4 defines it as airspace from the surface to 4,000 feet above airport elevation around airports that have an operating control tower and radar approach control, and that meet a minimum number of IFR operations or passenger enplanements.
Examples include Burlington (BTV), Madison (MSN), Tucson (TUS) and Santa Barbara (SBA). It sits between Class B around major hubs and Class D around smaller towered airports. For drone pilots all three work the same way: authorization first, usually through LAANC.
Class C airspace dimensions
A standard Class C area has a surface core out to 5 nautical miles and a shelf out to 10 nautical miles. Here is what each piece means for a drone flying at or below 400 feet.
| Piece | Lateral extent | Floor | Ceiling | Authorization needed at 400 ft AGL? |
|---|---|---|---|---|
| Surface area (core) | 5 NM radius | Surface | 4,000 ft above airport | Yes, everywhere inside it |
| Shelf area | 5 to 10 NM radius | 1,200 ft above airport (charted MSL) | 4,000 ft above airport | Usually no; depends on terrain height (see next section) |
| Outer area | Normally 20 NM, not charted as Class C | Radio/radar coverage | Approach control's airspace | No; it is not Class C airspace |
Three details trip people up.
First, every number is set relative to the airport's elevation and published in MSL (feet above sea level). The FAA's legal description of Burlington's Class C reads "from the surface to and including 4,400 feet MSL within a 5-mile radius." Burlington's field elevation is 335 feet, so that ceiling is about 4,065 feet above the runway, not above whatever ground you are standing on.
Second, real Class C areas are rarely perfect circles. Burlington's shelf floor is 1,500 feet MSL west of the airport, toward Lake Champlain, and 2,200 feet MSL to the east, where the ground rises. Shapes get cut and shifted around terrain, approach paths and neighboring airspace.
Third, the "outer area" is an ATC service area for manned aircraft. It is not part of Class C and has no effect on drone authorization.
Do you need authorization under the outer shelf?
Usually not. The shelf floor typically sits 1,200 feet above the airport, which is far above the 400-foot Part 107 ceiling, so a drone flying beneath it is not in Class C at all. The authorization question depends on what lies under the shelf.
The math takes a minute. Take The Eastern Iowa Airport in Cedar Rapids. Its field elevation is 869 feet and its shelf floor is 2,100 feet MSL.
Ground at 900 feet MSL plus a 400-foot flight puts the drone at 1,300 feet MSL, 800 feet below the shelf. Not Class C.
Now run the same check where terrain climbs. At Burlington, the east-side shelf floor is 2,200 feet MSL. A hypothetical job on a 1,850-foot hillside under that shelf puts a 400-foot flight at 2,250 feet MSL, which is 50 feet inside Class C. Drop the planned altitude to 300 feet and you stay out of it.
So the rule of thumb is: shelf floor (MSL) minus ground elevation (MSL) = the height you can climb before entering Class C. If that number is above your planned altitude, the shelf doesn't affect the flight.
Two caveats before you skip the authorization:
- Check what lies underneath. The airspace below a Class C shelf is usually Class E starting at 700 or 1,200 feet, or Class G to the surface. Some airports also have a Class E extension running out from the core along an instrument approach path. It starts at the surface, but FAA guidance says an extension to a Class C surface area (type E3) does not need a 107.41 authorization; only a Class E surface area designated for an airport does. The extension still marks where arriving aircraft descend, so plan with that traffic in mind. The Class E airspace guide covers surface Class E in more detail.
- Trust the map over the circle. If the FAA UAS Facility Maps show a LAANC grid at your site, the FAA treats that spot as controlled airspace that needs authorization. No grid usually means no authorization is needed there, but confirm it on a current chart before you rely on that.
Part-time Class C airspace
Some Class C areas exist only during published hours. In the current edition of FAA Order JO 7400.11, which holds the legal description of every US airspace area, about 50 Class C areas are written as part-time. Roughly 20 are effective on dates and times "established in advance by a Notice to Airmen" (Burlington, Lincoln, Madison and Santa Barbara among them); the rest are tied to the operating hours of the tower and approach control.
Outside those hours the airspace reverts to another class, usually Class E, and sometimes Class G. The Chart Supplement entry for the airport gives the hours and the fallback class. Burlington's entry, for example, lists Class C service while approach control is open and "other times Class E."
For a drone pilot this changes less than you might hope:
- Reverts to a Class E surface area: you still need authorization. Section 107.41 covers Class E surface areas designated for an airport, so an evening flight after the approach facility closes is still controlled airspace.
- Reverts to Class G: no authorization is needed for that period, but the change needs to be confirmed against the Chart Supplement and current NOTAMs, not assumed.
Part-time status matters most for night and early-morning work. Check the hours for the exact date of the flight, because facility hours change and the change is published by NOTAM. The guide to filing and reading NOTAMs explains where to look.
Cutouts and satellite airports
Class C areas often exclude pockets of airspace around smaller airports underneath them. Madison's Class C description excludes a 1.5-mile radius around Waunakee Airport, which sits on the edge of the 5-mile core. The AIM also describes "procedurally excluded" areas around satellite airports with their own control towers.
For drone work these cutouts are a trap in both directions:
- A cutout around a small field may still be other controlled airspace, or it may be Class G next to an active runway with no tower watching it. Neither is a place to fly casually.
- A site just outside the cutout boundary is back inside Class C core, where UAS Facility Map grids are often low.
The safest habit is to plan from the UAS Facility Map and the current sectional together. Never go by the general shape of the rings. The airspace for drones guide covers the wider pre-flight check.
How to identify Class C on a sectional chart
Class C airspace is drawn on sectional charts with solid magenta lines. Class B uses solid blue and Class D uses dashed blue, so magenta identifies Class C immediately.
Inside each segment you will see a fraction showing ceiling over floor, in hundreds of feet MSL:
- 44/SFC in the core: Class C from the surface to 4,400 feet MSL.
- 44/22 in the shelf: Class C from 2,200 to 4,400 feet MSL.
- 44/15 in another shelf segment: same ceiling, lower floor of 1,500 feet MSL.
Apps such as B4UFLY and most LAANC providers shade Class C for you. For a shelf-edge site or hilly terrain, read the actual fraction and subtract the ground elevation as shown above.
How to fly a drone in Class C airspace
To fly a drone in Class C airspace you need prior FAA authorization. You request it through LAANC for flights at or below the UAS Facility Map altitude, or through FAA DroneZone for anything LAANC cannot approve. A typical Class C job follows four steps.
1. Look up the grid ceiling. The UAS Facility Map splits the core into grid squares, each with a maximum altitude LAANC can approve automatically. Typical values are 0, 100, 200 and 400 feet. Grids under the approach and departure paths are usually 0 or very low.
2. Request through LAANC. If your planned altitude is at or below the grid value, an FAA-approved LAANC provider can usually return an approval in seconds. You can submit up to 90 days ahead. The LAANC authorization guide walks through the request and the details that cause rejections. Recreational flyers operating under 49 U.S.C. 44809 can also use LAANC, but only at or below the grid altitude.
3. Use further coordination or DroneZone for anything above the grid. Part 107 pilots can request altitudes above the grid ceiling through LAANC further coordination. A human at the ATC facility reviews it, and requests must be submitted at least 72 hours before the flight. For airports without LAANC, or an operation that also needs a waiver, apply through FAA DroneZone. The FAA's Part 107 airspace authorizations page lists the current options.
4. Fly the authorization as written. The approval is tied to a specific area, maximum altitude and time window. If the job overruns the window or the client asks for a higher shot, you need a new authorization. Add the authorization check to your drone pre-flight checklist so the crew on site confirms the number, altitude and window before launch.
Authorization covers the airspace only. TFRs, weather minimums and every other Part 107 rule still apply.
Manned aircraft rules that do not apply to drones
Most Class C requirements are written for manned aircraft and do not apply to a Part 107 drone. The table separates the two.
| Class C requirement | Manned VFR aircraft | Part 107 drone |
|---|---|---|
| Entry permission | Two-way radio contact with ATC before entering | Prior authorization via LAANC or DroneZone; no radio call |
| Transponder with altitude reporting | Required in and above Class C up to 10,000 ft MSL | Not required |
| ADS-B Out | Required | Prohibited in transmit mode under 14 CFR 107.53 |
| Weather minimums | 3 SM visibility; 500 below, 1,000 above, 2,000 ft horizontal from clouds | 3 SM visibility; 500 below, 2,000 ft horizontal from clouds (107.51), same in every class |
| Speed limit | 200 knots below 2,500 ft AGL within 4 NM | 87 knots (100 mph) everywhere |
Low ceilings bring instrument traffic lower and closer, which is when a drone near an approach path is most dangerous. The weather guide for professional drone operations covers how to make that call.
Your aircraft will not catch the mistake for you either. From January 13, 2025, DJI's GEO update replaced its US no-fly zones with warning zones based on FAA data for most of its consumer and enterprise drones, so the aircraft warns rather than blocks takeoff inside a Class C core. The DJI Fly Safe guide explains what the warnings show.
Managing Class C jobs across a team
With several pilots near the same airport, things slip between planning and launch: a 400-foot plan on a 200-foot grid, an authorization for the wrong day, an approval number on one pilot's phone. A workable routine:
- Decide the airspace before you price the job. Check whether the site is in the core, under the shelf, or under a Class E extension, and what the grid ceiling is. A 100-foot grid changes the mission plan, and possibly the price.
- Record the authorization with the job. Keep the LAANC or DroneZone reference number, approved altitude and time window on the project record, not in a personal app account.
- Review flights after landing. Compare the flight log's maximum altitude against the approved ceiling, so a grid exceedance is caught internally rather than by a client or the FAA.
DroneBundle's airspace and flight planning tools show FAA controlled airspace with the LAANC grid heights on the same map as your project sites. Each project's site gets a plain airspace read, from no restrictions to authorization required or no-fly, including the LAANC ceiling where one applies. The LAANC authorization number stays on file with the project. After landing, synced flight logs can be replayed to check the altitude flown against the approval, and the flight approval workflow gives someone the job of reviewing each flight before it enters the record. Requests still go through your LAANC provider; DroneBundle keeps the airspace check and the paperwork in one place.
Class C sites come up often in construction and infrastructure work and utility corridor inspections. For repeat-visit work like drone construction monitoring, confirm every visit falls inside a valid authorization window as part of your drone flight planning routine.
Frequently asked questions
Can I fly a drone in Class C airspace?
Yes, with prior authorization from the FAA. Part 107 pilots and recreational flyers can request access through an FAA-approved LAANC app, which approves flights at or below the UAS Facility Map altitude in near real time. Part 107 pilots can also request higher altitudes through further coordination or FAA DroneZone.
What are the dimensions of Class C airspace?
Standard Class C airspace has a 5 nautical mile core from the surface to 4,000 feet above airport elevation, and a shelf from 5 to 10 nautical miles that runs from 1,200 to 4,000 feet above the airport. All altitudes are charted in MSL, and many areas are custom-shaped around terrain and nearby airports.
Do I need LAANC authorization under the Class C outer shelf?
Usually not, because the shelf floor is normally about 1,200 feet above the airport and your drone stays at or below 400 feet. Subtract the ground elevation from the shelf floor to confirm, and check the UAS Facility Map: a grid at your site means you need authorization.
What is the difference between Class C and Class D airspace?
Class C surrounds busier airports that have radar approach control and has a two-tier shape reaching 4,000 feet above the airport. Class D surrounds towered airports without that level of radar service and is usually a single cylinder up to about 2,500 feet. For drones the requirement is the same: prior ATC authorization. Learn more in our Class D airspace guide.
Plan Class C jobs without the last-minute scramble
The hard part of Class C work is getting the right airspace answer for the exact site, altitude and time, then flying what was approved. DroneBundle puts FAA airspace, LAANC grid heights, weather and the authorization record on the same project, so the office and the field work from the same information.
Start your 14-day free trial, no credit card required, or book a live demo to see how airspace checks, flight logs and approvals work for a multi-pilot team. Compare plans on the pricing page.
