Class B airspace surrounds the busiest airports in the United States, generally from the surface to 10,000 feet MSL, in layers that resemble an upside-down wedding cake. To fly VFR inside it you need an explicit ATC clearance, at least a private pilot certificate or a specific instructor endorsement, a two-way radio, a transponder with altitude reporting, and ADS-B Out. The VFR weather minimums are 3 statute miles visibility and clear of clouds.
This guide is part of our Airspace and Weather guide. If the alphabet of airspace is still new, start with airspace classes and the VFR weather minimums.
What Class B airspace is
The Aeronautical Information Manual (AIM 3-2-3) describes Class B as airspace that generally extends from the surface to 10,000 feet MSL around the nation’s busiest airports in terms of IFR operations or passenger enplanements. Each area is individually tailored, with a surface area and two or more layers, and is designed to contain the published instrument procedures once an aircraft enters it. Every aircraft needs an ATC clearance to operate inside, and every cleared aircraft, VFR included, receives separation services. That service never relieves you of see and avoid, wake turbulence avoidance, terrain clearance or the weather minimums.
Dimensions: the upside-down wedding cake
FAA Order JO 7400.2, which governs airspace design, says there is no standard Class B design. Most follow the same pattern:
- Surface area: around the primary airport, Class B starts at the ground and runs up to the ceiling.
- Shelves: farther out, the floor steps up with distance, so you can fly under a shelf without entering Class B.
- Ceiling: normally no higher than 10,000 feet MSL, though high field elevation, terrain or operational needs can justify more.
- Outer edge: no more than 30 NM from the primary airport, inside the Mode C and ADS-B Out veil.
Reading Class B on a chart
Class B appears on sectional charts and the larger-scale Terminal Area Charts (TACs) as solid blue lines. Each sector shows its ceiling over its floor in hundreds of feet MSL, so 100 over 30 means 10,000 and 3,000. A floor with a plus sign, such as +40, begins above that altitude, so 4,000 feet there is outside the Class B. The 30 NM veil is a solid magenta line, and some TACs carry a VFR Flyway Planning Chart on the back.
What you need to enter Class B airspace
The AIM is direct: do not request a Class B clearance unless you already meet 14 CFR 91.131, 91.215 and 91.225.
| Requirement | Rule | What it means |
|---|---|---|
| ATC clearance | 91.131(a) | Required before entry, regardless of weather |
| Pilot certificate | 91.131(b) | Private or higher, or a recreational, sport or student pilot with the required training and endorsement |
| Two-way radio | 91.131(c) | Able to talk to ATC on that Class B’s frequencies |
| Transponder | 91.215 | A 4096-code or Mode S transponder with Mode C altitude reporting |
| ADS-B Out | 91.225 | Installed equipment, required in Class B, in the veil, and above the ceiling within its lateral limits up to 10,000 feet MSL |
IFR flights also need a VOR or TACAN receiver or a suitable RNAV system.
Pilot certificate rules
Under 91.131(b), the pilot in command must hold at least a private pilot certificate, or be a recreational pilot who meets 61.101(d), a sport pilot who meets 61.325, or a student pilot who meets 61.94 or 61.95. Recreational and sport pilots qualify through logged training on radios, towered airports and Class B rules, plus an instructor endorsement.
Section 4 of Appendix D to part 91 lists 12 airports where solo student, sport and recreational pilot operations are not permitted; you need at least a private pilot certificate to take off or land there:
- Atlanta Hartsfield-Jackson, Boston Logan, Chicago O’Hare and Dallas/Fort Worth
- Joint Base Andrews (Camp Springs, Maryland) and Ronald Reagan Washington National
- Los Angeles, Miami and San Francisco International
- Newark Liberty, New York JFK and New York LaGuardia
That limit covers takeoffs and landings. With the right endorsement, a student can still solo in the surrounding Class B airspace.
Student pilot solo endorsement (61.95)
A student may not solo in Class B unless (14 CFR 61.95):
- An authorized instructor gave you ground and flight training on that Class B area, with the flight training in that specific area.
- That instructor endorsed your logbook within the 90 days before the flight.
- The endorsement says you were found proficient to solo in that specific Class B area.
Solo flight to, from or at an airport inside Class B takes a separate endorsement under 61.95(b), with training at that airport and the same 90-day window. Students seeking a sport or recreational certificate use 61.94 instead, and the FAA’s sample wording is in AC 61-65K (A.12 and A.13). Student limits still apply: no flight as pilot in command with less than 3 statute miles of visibility by day or 5 at night, and nothing contrary to your instructor’s logbook limitations (61.89). Keep the endorsement in your pilot logbook; the student pilot certificate guide covers the other solo rules.
Transponder, ADS-B Out and the 30 NM veil
The equipment rules reach beyond the blue lines. Within 30 NM of each location in Appendix D, section 1 (37 locations, generally Class B primary airports), you need a transponder with altitude reporting and ADS-B Out from the surface to 10,000 feet MSL, even if you never enter Class B. Aircraft never certificated with an engine-driven electrical system, plus balloons and gliders, are exempt in the veil if they stay outside Class A, B and C airspace and below the Class B or C ceiling or 10,000 feet MSL, whichever is lower.
If equipment fails, ask ATC for a deviation: requests to continue with failed altitude reporting, transponder or ADS-B Out may be made at any time, but flying an aircraft not equipped with a transponder or ADS-B Out requires a request at least 1 hour ahead (91.215(d), 91.225(g)). A portable receiver provides ADS-B In only; see portable ADS-B receivers.
VFR weather minimums in Class B airspace
Under 14 CFR 91.155, VFR flight in Class B needs 3 statute miles of flight visibility and clear of clouds, with no 500 below, 1,000 above, 2,000 horizontal requirement. In the surface area, basic VFR also requires a ceiling of at least 1,000 feet to fly beneath it and 3 statute miles of ground visibility to take off, land or enter the pattern. Below that, you would need a special VFR clearance, which is prohibited for fixed-wing aircraft at many Class B primary airports.
Speed limits in and around Class B
- Inside Class B: 250 knots indicated below 10,000 feet MSL (91.117(a)).
- Under a shelf or in a VFR corridor: 200 knots indicated (91.117(c)).
- Exception: if your minimum safe airspeed is higher, you may fly at that speed (91.117(d)).
A trainer cruises well below 200 knots, so the useful lesson is why the rule exists: the airspace under the shelves is busy. Large turbine-powered airplanes using the primary airport must stay at or above the floors (91.131(a)(2)), so a jet can be just above a shelf while you are just below it. The AIM cautions VFR pilots against flying close to the boundaries, especially where a floor is 3,000 feet or less above the surface.
VFR corridors, flyways and transition routes
AIM 3-5-5 defines three kinds of published VFR routes that pilots often confuse:
| Route | What it is | Clearance or contact |
|---|---|---|
| VFR flyway | A general flight path on a VFR Flyway Planning Chart for flying around, under or near Class B | No clearance; talk to any tower whose Class C or D surface area you cross |
| VFR corridor | A hole through Class B with defined limits, surrounded by Class B | No clearance or ATC contact; 122.750 MHz urged for position reports |
| VFR transition route | A specific charted course through the terminal area | ATC contact required, plus a clearance for the Class B portion |
Corridors are rare in newer designs. Transition routes are often the practical way through: give ATC your position, altitude, the route name and your direction of flight, and stay clear until cleared.
How to request a Class B clearance
- Plan. Study the TAC or sectional for floors, checkpoints and transition routes. The chart’s approach control communications panel lists the Class B frequencies, often split by direction, and the Chart Supplement lists them for the primary airport. Have a plan that stays outside.
- Call early, from outside. The AIM says arriving pilots should make contact in relation to the charted reporting points, even when below the floor.
- Make a complete request. For example: “Springfield Approach, Cessna One Two Three Four Five, Skyhawk, ten miles north of the water tower at three thousand five hundred, request Bravo transition southbound to Lakeside.”
- Wait for the words. A clearance sounds like “Cessna Three Four Five, cleared through Bravo airspace” (or “cleared to enter” or “cleared out of”), usually with a route and altitude. A squawk code, “radar contact” or a heading is not a clearance, and “remain outside Bravo airspace” means stay out.
- Fly the clearance. Assigned altitudes may not match the usual VFR cruising altitudes until ATC says “resume appropriate VFR altitudes.” If an instruction would take you into a cloud, toward terrain or into wake turbulence, tell ATC and get a revised clearance.
- Departing the primary airport? You need a clearance to depart, too; tell clearance delivery your altitude and route.
It is the same radio work you practice at any towered field, only busier. Review towered airport communications and phraseology and the phonetic alphabet first.
Not sure you heard a clearance? Ask before you cross the line: “Confirm Cessna Three Four Five is cleared into Bravo airspace.” And when you plan to stay under a shelf, keep a few hundred feet below the floor, because altimeter error and turbulence can carry you into it.
Gear for flying near Class B
What you'll need
The references and kneeboard tools that make a Class B transition easier to plan and fly.
Frequently asked questions
Do you need a clearance to enter Class B airspace?
Yes. 14 CFR 91.131 requires an ATC clearance before you operate in Class B, regardless of weather. Listen for “cleared through” or “cleared to enter” Bravo airspace; a squawk code or “radar contact” is not a clearance.
Can a student pilot fly in Class B airspace?
Yes, with a specific endorsement. Under 14 CFR 61.95, a student needs training in that Class B area and an instructor endorsement dated within the previous 90 days. Solo student takeoffs and landings are not permitted at the 12 airports in Appendix D, section 4.
What are the VFR weather minimums in Class B airspace?
3 statute miles of flight visibility and clear of clouds (14 CFR 91.155).
Do I need ADS-B Out to fly under a Class B shelf?
Usually, yes. Within 30 NM of the airports in Appendix D, section 1, a transponder with altitude reporting and ADS-B Out are required from the surface to 10,000 feet MSL, even below the shelves, with a limited exception for aircraft certificated without an engine-driven electrical system.
What is the speed limit under Class B airspace?
200 knots indicated beneath a Class B area and in VFR corridors (14 CFR 91.117(c)). Inside Class B below 10,000 feet MSL, it is 250 knots.