For US student pilots
Class B transition: asking to cross the Bravo
Class B is the one airspace where a reply with your call sign is not enough. You need a clearance, and the controller has a fixed form of words for it. Knowing that form is the whole skill: you will either hear “cleared” and “Bravo” in the same sentence, or you stay out.
What you need before you ask
A two-way radio, and unless ATC authorizes otherwise a transponder with altitude reporting and ADS-B Out (AIM 3-2-3 b 5). A private pilot certificate, or a student pilot certificate with the Class B endorsement required by 14 CFR 61.95 (b 3). Within 30 miles of the primary airport, the Mode C veil, the transponder requirement applies whether or not you enter the Bravo (b 6).
Who to call, and when
Aircraft not landing at the primary airport may get a clearance to transit when traffic permits (AIM 3-2-3 d 2 (c)). Call the approach control on the frequency for your sector, well before the boundary, and make contact in relation to the geographical fixes shown on the terminal area chart, because that is how the controller sequences you (d 2 (a)). Give position, altitude, squawk if you have one, and what you want.
NorCal Approach, Cessna Three One Six Zero Foxtrot, over the Dumbarton Bridge, two thousand five hundred, squawking one two zero zero, request Bravo transition to Half Moon Bay via the Bay.
The words that clear you in
The controller’s phraseology is fixed: “cleared through”, “cleared to enter” or “cleared out of Bravo airspace”, usually with a route and “maintain (altitude) while in Bravo airspace”, or “cleared as requested” (JO 7110.65 7-9-2 a). Read it back with the altitude and your call sign (AIM 4-4-7 b).
Cessna Six Zero Foxtrot, squawk four six one two, cleared through Bravo airspace via the Bay, maintain two thousand five hundred while in Bravo airspace.
Squawk four six one two, cleared through the Bravo via the Bay, maintain two thousand five hundred, Cessna Six Zero Foxtrot.
The words that do not
A squawk is not a clearance. “Radar contact” is not a clearance. “Remain outside Bravo airspace” means exactly that, and the controller may add a reason or a time to expect further clearance (7110.65 7-9-2 a, c). Until you hear “cleared” with “Bravo”, stay below the floor or outside the lateral limit.
While you are inside
You are sequenced and separated from other traffic (AIM 3-2-3 e), and you fly the route and altitude you were given. A VFR pilot is still expected to tell ATC if complying with a heading or altitude would break a VFR rule such as cloud clearance (7110.65 7-9-2 a note 1); say “unable” and why.
Leaving
ATC normally tells you when you leave: “leaving (name) Bravo airspace”, often followed by “resume own navigation” and either “remain this frequency for traffic advisories” or “radar service terminated, squawk one two zero zero” (7110.65 7-9-2 d; AIM 3-2-3 d 2 (b)). Radar service does not end with the advisory unless the controller says so. Acknowledge with your call sign and, if terminated, set 1200.
Or go around it
The AIM encourages VFR aircraft to fly above or below the Bravo or through the published VFR corridors where they exist, using 122.75 to exchange position reports with other aircraft in a corridor (AIM 3-2-3 d 2 (c)). On a busy day the corridor is often faster than waiting for a clearance.
Airspace classes & what you must do on the radio
US airspace is by class. The radio requirement rises with the class. [AIM chapter 3; 4-3-2; 4-4-6]
- Class B
- A clearance is required: you must hear “cleared into the Class Bravo” before entering. Expect a squawk first and “remain clear” until cleared. Mode C transponder within 30 miles of the primary airport.
- Class C
- Two-way radio communication with the approach control must be established before entry — a reply that uses your call sign. A transponder with altitude reporting is required.
- Class D
- Two-way communication with the tower before entering the surface area; initial call about 15 miles out. “Aircraft calling, stand by” does NOT establish communication — remain outside. [AIM 4-3-2 a]
- Class E surface area
- No radio requirement in VFR conditions; a Special VFR clearance below basic VFR.
- Special VFR
- A clearance to operate in a surface area below VFR minima: clear of clouds, at least 1 statute mile. Request it from the tower where there is one; state your intentions in enough detail to fit the traffic. [AIM 4-4-6]
NorCal Approach, Cessna One Seven Two Sierra Papa, one two miles south of Palo Alto, three thousand five hundred, request Class Bravo transition to San Carlos.
Traffic advisories & how to answer
The controller gives traffic as a clock position, a distance, a direction of travel or relative movement, and the type and altitude if known. [JO 7110.65 2-1-21]
Traffic, eleven o’clock, one zero miles, southbound, converging, Cessna, one seven thousand.
- Traffic in sight
- You have it. [P/CG]
- Negative contact
- You cannot see it — you may ask for a vector to avoid it. Also: unable to raise ATC on a frequency. [P/CG]
- Not “roger”, not “looking”
- “Looking” is not a P/CG term; “roger” tells the controller nothing about whether you see the traffic.
Ask for the Bravo and hear what comes back
TowerTalk's Exercise I works Class B, C and D entries with an AI approach control that answers what you say, at a real US airport, graded with the AIM paragraph.
Related
Study aid, written in our own words from the FAA Aeronautical Information Manual (Change 3, 7/9/26) and the Pilot/Controller Glossary, with paragraph references so you can check each point. Last reviewed 10 September 2026; awaiting review by a US flight instructor. It does not reproduce those documents and is not a substitute for them — always defer to the AIM, the current FAA publications, your instructor and your examiner. TowerTalk is not approved or endorsed by the FAA.