Class D airspace requirements, a radio and contact before entry.

What Class D is

The AIM (3-2-5) says Class D "extends upward from the surface to 2,500 feet above the airport elevation (charted in MSL) surrounding those airports that have an operational control tower." It is charted on Sectional and Terminal charts with blue segmented lines.

Requirements

Pilot certification: "No specific certification required." Equipment: "Unless otherwise authorized by ATC, an operable two-way radio is required." The AIM lists no transponder or ADS-B Out requirement for Class D itself; transponder and ADS-B rules that apply by location, such as the Mode C veil, are separate.

Entry and departure

Two-way radio communication "must be established with the ATC facility providing ATC services prior to entry." Radio contact should start early enough to avoid entering before contact is established, and a reply without the aircraft callsign does not count. Departing a primary or satellite airport with a tower, communication must be established and maintained with the tower; from a satellite airport without a tower, as soon as practicable after departure.

Speed

At or below 2,500 feet above the surface within 4 nautical miles of the primary airport, no person may operate an aircraft at more than 200 knots (230 mph) indicated, unless ATC authorizes or requires it.

Part-time towers

Where the tower does not operate 24 hours, the airspace may revert to Class E or Class G. The hours are listed on charts and in the Chart Supplement, and the AIM says to check the Chart Supplement for specifics. Surface area arrival extensions of 2 miles or less stay part of the Class D surface area; if any extension is more than 2 miles, all extensions are Class E.

Separation

"No separation services are provided to VFR aircraft."

Worked example

A pilot with an operable radio approaches a towered field at 2,000 feet and calls the tower 10 miles out. The tower answers with the callsign and "standby." Contact is established and the pilot may enter. At 11 p.m. the tower is closed and the Chart Supplement says "other times CLASS E," so Class E surface-area rules apply instead.

Weather minimums are on the Class D VFR weather minimums page.

FAQ

What do I need to enter Class D airspace?

An operable two-way radio unless ATC authorizes otherwise, and two-way communication established with ATC before entry.

Does Class D require a transponder?

The AIM Class D list does not include one. Transponder rules that apply by location are separate.

Do I need a special pilot certificate in Class D?

No. The AIM says no specific certification is required.

What happens when the tower closes?

The airspace may revert to Class E or Class G, as listed in the Chart Supplement.

Does ATC provide separation to VFR aircraft in Class D?

No. The AIM says no separation services are provided to VFR aircraft.

Sources

Retrieved 2026-11-02. Regulation text read through the eCFR API (current as of 2026-10-29); AIM text read from the FAA publication URL below. Rules change; check the current text.

• AIM chapter 3, section 2, Controlled airspace (3-2-5): Class D definition, equipment, entry, departure, speed and part-time operation.
• 14 CFR 91.155, Basic VFR weather minimums: weather minimums referred to alongside the entry rules.