Class B Airspace for Drones: Part 107 Rules
Class B surrounds the busiest airports from the surface to 10,000 feet MSL. Where a Part 107 drone needs ATC authorization in it, and where shelves leave room.
Class B is the airspace around the nation's busiest airports. The AIM describes it as generally running from the surface to 10,000 feet MSL, with a surface area and two or more layers, some shaped like an upside-down wedding cake. For a Part 107 drone, the rule is short: any flight inside Class B needs prior ATC authorization under 14 CFR §107.41.
How does Class B look on a sectional chart?
The FAA Chart User's Guide says Class B is shown on sectional and terminal area charts, with the MSL ceiling and floor of each sector printed in solid blue figures with the last two zeros omitted. Each sector is outlined with a solid blue line.
| Chart label | Meaning |
|---|---|
| 100 over SFC | Surface to 10,000 ft MSL: the inner surface area |
| 100 over 30 | 3,000 ft MSL up to 10,000 ft MSL: a shelf |
| 100 over 70 | 7,000 ft MSL up to 10,000 ft MSL: an outer shelf |
All Class B altitudes are MSL. A floor of 3,000 feet MSL over terrain at 1,000 feet MSL is 2,000 feet above the ground, far above any drone. The Chart User's Guide also notes that a floor printed with a plus sign means the Class B starts above that altitude, so operations at and below it are outside Class B.
Where can you fly near Class B without its authorization?
Only in the surface area does Class B reach the ground. Under a shelf, the airspace beneath the floor belongs to another class, usually Class E or G. A drone at 400 feet AGL under a 3,000-foot shelf is not in Class B.
That is not the same as "no authorization needed". Satellite airports under a Class B shelf often have their own Class D or Class E surface areas, which need authorization from the surface up. Check what is under the shelf before you launch.
The solid magenta 30 NM circle around a Class B airport is the Mode C and ADS-B Out area for manned aircraft. It is not a drone authorization boundary. A Part 107 drone may not fly with a transponder on or with ADS-B Out transmitting unless the FAA authorizes it, under §107.52 and §107.53.
How do you get authorization in Class B?
The same way as in other controlled airspace: LAANC for routine requests up to the UAS Facility Map altitude for your grid, and FAA DroneZone where LAANC does not cover what you need. Grids close to the runways can show a facility map ceiling of 0 feet, which means LAANC will not approve an automatic authorization there. The LAANC post covers further coordination requests.
10,000 ft MSL
the usual top of Class B airspace, per the AIM
What the exam asks about Class B
The handbook element is UA.II.A.K1, sub-element a. Expect to read a sector's floor and ceiling from a chart excerpt, convert MSL to height above the ground using the terrain or airport elevation, and decide whether a point sits inside Class B or below a shelf. The airspace classes overview compares Class B with the other classes, and Class C follows the same shelf logic on a smaller scale.
Class B looks huge on the chart, but at 400 feet most of it is overhead.
Practice floors, ceilings and boundaries on the FAA figures used on the test.
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