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Class B, C, and D airspace: communication requirements explained

Lisa Chen, ATP
April 28, 2024
11 min read

In this article

A complete guide covering everything you need to know. Estimated reading time: 11 min read.

Flying into different classes of airspace can be intimidating for student pilots. Each class has specific communication requirements, and violating them isn't just embarrassing - it can have serious consequences.

This guide breaks down exactly what you need to do for Class B, C, and D airspace.

Understanding airspace classes

Class B: The busiest - **Found at:** Major airports (LAX, JFK, ORD, etc.) - **Requirements:** Clearance required to enter - **Equipment:** Mode C transponder required - **Two-way radio:** Required - **Key phrase:** "Cleared into Class Bravo"

Class C: Busy regional - **Found at:** Medium-busy airports - **Requirements:** Two-way communication required - **Equipment:** Mode C transponder required - **Two-way radio:** Required - **Key phrase:** Your callsign acknowledged

Class D: Controlled airport - **Found at:** Towered airports - **Requirements:** Two-way communication required - **Equipment:** No transponder required (generally) - **Two-way radio:** Required - **Key phrase:** Your callsign acknowledged

Class B airspace communications

Before entering

You MUST receive explicit clearance with the words "cleared into Class Bravo."

How to request Class B clearance

Initial call (10-15 miles out): "Los Angeles Approach, Cessna 1234 Bravo, request."

ATC: "Cessna 1234 Bravo, Los Angeles Approach, go ahead."

You: "Cessna 1234 Bravo is 12 miles southeast of Fullerton at 2,500, VFR to Van Nuys, request Class Bravo clearance."

ATC will either: 1. Clear you: "Cessna 34 Bravo, cleared into the Class Bravo, maintain VFR at or below 2,500, squawk 4521." 2. Deny: "Cessna 34 Bravo, remain clear of Class Bravo, standby." 3. Give alternative: "Cessna 34 Bravo, remain VFR at or below 1,500, cleared through the southeast Class Bravo corridor."

Critical: If you don't hear "cleared into Class Bravo," you CANNOT enter.

While in Class B

  • Follow all ATC instructions
  • Maintain assigned altitude/heading
  • Report as requested
  • Don't deviate without permission

Exiting Class B

ATC will usually say: "Cessna 34 Bravo, radar service terminated, squawk VFR, frequency change approved."

You: "Squawk VFR, Cessna 34 Bravo, good day."

Class C airspace communications

Before entering

Two-way radio communication must be established before entering.

How it works

Your call (before entering): "Sacramento Approach, Cessna 1234 Bravo, 10 miles south, 3,500, inbound with Information Alpha."

If ATC responds with your full callsign: "Cessna 1234 Bravo, Sacramento Approach, radar contact."

You're good to enter! Simply hearing your callsign = communication established.

What establishes communication?

  • ATC says your callsign: "Cessna 1234 Bravo..."
  • ATC says "aircraft calling, standby"
  • You can't hear their response
  • They don't acknowledge you

While in Class C

  • Comply with traffic advisories
  • Report altitude changes
  • Maintain VFR cloud clearances
  • Listen for other traffic

Exiting Class C

ATC will terminate service or you'll simply leave the airspace.

Class D airspace communications

Before entering

Establish two-way communication with the tower.

How to call

Standard inbound call: "Stockton Tower, Cessna 1234 Bravo, 8 miles south, 2,000, inbound for landing with Information Bravo."

Tower response: "Cessna 1234 Bravo, Stockton Tower, enter left downwind runway 29, report midfield."

You: "Left downwind 29, report midfield, Cessna 34 Bravo."

Transition through Class D

If you're not landing, you can request to transition:

You: "Stockton Tower, Cessna 1234 Bravo, 5 miles west, 2,500, request transition north to south."

Tower: "Cessna 34 Bravo, remain clear of Class Delta" or "Cessna 34 Bravo, cleared to transition, remain VFR at or above 1,500."

While in Class D

  • Follow tower instructions
  • Make position reports as requested
  • Stay alert for other traffic

Comparison table

FeatureClass BClass CClass D
Clearance neededYes, explicitNo, just contactNo, just contact
Magic words"Cleared into Bravo"Your callsignYour callsign
TransponderMode C requiredMode C requiredNot required
Speed limit250 kts below 10k200 kts below 10k200 kts
Can ATC deny entryYesRarelyRarely

Common mistakes by class

Class B mistakes: ❌ Entering without clearance ❌ Assuming "radar contact" = cleared in ❌ Not maintaining assigned altitude

Class C mistakes: ❌ Entering before hearing your callsign ❌ Entering when ATC says "standby" ❌ Not having transponder on

Class D mistakes: ❌ Entering without establishing contact ❌ Not making position reports ❌ Operating without radio

What if you accidentally enter?

If you bust Class B without clearance:

Immediately: "Los Angeles Approach, Cessna 34 Bravo, inadvertently entered Class Bravo, request clearance."

ATC will likely clear you and give you a phone number to call later. Be professional, acknowledge the mistake, learn from it.

If communication fails before entering:

Don't enter. Circle outside, try different frequency, or go around the airspace.

Tips for success

1. Study the airspace before flying

Know: - Lateral boundaries - Altitude limits - Frequencies - Entry requirements

2. Call early

Contact ATC 10-15 miles out, not 1 mile from the boundary.

3. Have your information ready

Position, altitude, destination, ATIS letter.

4. Write down all clearances

Especially altitude and heading restrictions.

5. Practice on the ground

Apps like ATC One offer specific Class B, C, and D scenarios where you can practice the exact communications needed without the stress of actual flight.

Conclusion

Class B, C, and D airspace aren't scary when you understand the requirements.

Remember: - Class B = Need explicit clearance - Class C = Need callsign acknowledgment - Class D = Need callsign acknowledgment

Plan ahead, call early, and follow instructions. You'll transition through controlled airspace like a pro.

Action item: Study the Class B, C, or D airspace near you. Plan a flight that requires communication with each class. Practice the calls until automatic.

Ready to practice what you just learned?

Reading is great, but real improvement comes from practice. ATC One lets you practice these exact scenarios with AI-powered voice recognition. Get instant feedback, build confidence, and master communications before your next flight.

About the author

LC

Lisa Chen, ATP

Airline Transport Pilot with extensive experience in ATC communications. Passionate about helping student pilots overcome their fear of radio communications and build confidence in the cockpit.

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