What is Class B Airspace?
Class B airspace is the controlled airspace surrounding the busiest US airports — typically reaching from the surface to 10,000 ft MSL in an inverted-wedding-cake structure. Drones require LAANC authorization to operate in Class B.
Class B airspace exists around the FAA's 37 busiest commercial airports — JFK, LAX, ORD, ATL, DFW, SFO, etc. The shape is roughly a multi-tier inverted wedding cake: a surface-area cylinder at the airport itself, with progressively wider rings at higher altitudes (typically up to 10,000 ft MSL).
Drone operations in Class B airspace require LAANC authorization. The FAA's UAS Facility Map publishes per-grid-cell ceilings — the maximum altitude at which automatic LAANC approval is available. Cells directly under approach paths often have a 0 ft AGL ceiling, meaning automatic approval isn't available and a waiver is required.
Class B is depicted on aviation sectional charts as a solid blue line.
What this means for pilots
If you're flying near a major airport (anywhere within roughly 5–25 miles depending on the airport), you're probably in Class B. Check the LAANC ceiling for your specific cell before flight. Cells in the inner ring or under approach paths often require a waiver, which has a 90-day lead time.
FAQ
What's the difference between Class B and Class C?
Class B surrounds the busiest airports (37 nationally) and has the tightest restrictions. Class C surrounds smaller commercial airports and has slightly less complex geometry. Both require LAANC.
Can I fly under Class B at low altitude?
Often yes — the inverted-wedding-cake structure means the lower altitudes are restricted only near the airport itself. Beyond the surface area, you may be under Class B but in Class E or G airspace, where LAANC isn't required (though TFRs still apply).
How do I know if I'm in Class B?
Check a sectional chart or use Altoa's airspace check at altoa.io/can-i-fly-here.
Related terms
FAA regulations change. Verify current rules at faa.gov/uas before relying on this article for flight planning. Altoa is not the FAA.