When Is ADS-B Required? Airspace, Exemptions, and Penalties

ADS-B Out is required whenever you fly in Class A, Class B, or Class C airspace; in the airspace above a Class B or Class C area up to 10,000 feet MSL; within 30 nautical miles of the major airports listed in Appendix D, Section 1 of Part 91 (the Mode C Veil); in Class E airspace at or above 10,000 feet MSL over the 48 contiguous states and D.C., except when you’re at or below 2,500 feet AGL; and in Class E at or above 3,000 feet MSL over the Gulf of Mexico out to 12 nautical miles from the U.S. coast. The rule has been in effect since January 1, 2020, and lives in 14 CFR 91.225.¹

Class D airspace and most Class E below 10,000 feet MSL are not rule airspace. You can operate there without ADS-B Out.

The Airspace Where You Need ADS-B Out

The regulation attaches the requirement to specific airspace types rather than to controlled airspace generally. The full list from 14 CFR 91.225(a) and (d):

Class A airspace, from 18,000 feet MSL up to FL600. Equipment in Class A must broadcast on 1090 MHz Extended Squitter.
Class B and Class C airspace, at any altitude within the lateral and vertical boundaries.
The airspace above Class B or Class C, within the lateral limits of that area, up to 10,000 feet MSL. This is easy to miss because the airspace over a charted Class B shelf ceiling is often technically Class E, but ADS-B Out still applies.
The Mode C Veil: the surface up to 10,000 feet MSL within 30 nautical miles of each airport listed in Appendix D, Section 1 of Part 91.
Class E airspace at or above 10,000 feet MSL over the 48 contiguous states and D.C., except at or below 2,500 feet above the surface. That carve-out matters where terrain rises close to 10,000 feet.
Class E airspace at or above 3,000 feet MSL over the Gulf of Mexico, from the U.S. coastline out to 12 nautical miles.

The Mode C Veil Catches People

The 30-nautical-mile ring is the requirement that surprises pilots who assume they’re clear because they’re outside charted Class B or Class C. Inside the veil, from the surface to 10,000 feet MSL, you need ADS-B Out and an operating altitude-reporting transponder even if the airspace you’re flying through is otherwise Class E or Class G.² The listed airports are generally the primary airports inside Class B areas.

Alaska, Hawaii, and the Territories

The Class A, B, and C requirements apply everywhere in U.S. domestic airspace, including Alaska, Hawaii, Guam, Puerto Rico, and the U.S. Virgin Islands.³ The 10,000-foot Class E rule, though, is limited to the 48 contiguous states and D.C. A flight at 12,000 feet in Class E over Alaska does not trigger the ADS-B Out requirement based on altitude alone. Class A, B, or C flight in those states and territories still does.

Aircraft That Don’t Need ADS-B Out

The rule exempts aircraft that were not originally certificated with an engine-driven electrical system and have not been retrofitted with one. This covers most gliders and hot-air balloons. Adding batteries or an electric starter later, without recertification of an engine-driven electrical system, does not disqualify the aircraft from the exemption.

Those aircraft can operate:

In Class E airspace at or above 10,000 feet MSL (the area in paragraph (d)(4) of the rule) without ADS-B Out.
Within the 30-nautical-mile Mode C Veil, as long as they remain outside any Class B or Class C airspace and stay below the ceiling of that Class B or C area, or below 10,000 feet MSL, whichever is lower.

A separate provision, added by a 2019 interim final rule, allows government aircraft on sensitive national defense, homeland security, intelligence, or law enforcement missions to disable ADS-B transmissions.⁴

Drones fit into the rule differently. An unmanned aircraft operating on a flight plan with two-way ATC communication must have ADS-B Out that meets the same performance standards as manned aircraft. Drone operators may not transmit ADS-B Out otherwise, unless the FAA specifically authorizes it.¹

If Your ADS-B Is Broken or Your Aircraft Isn’t Equipped

The regulation does not automatically ground you. It allows an ATC-authorized deviation, and the FAA processes those requests through the ADS-B Deviation Authorization Preflight Tool, known as ADAPT.⁵

The timing depends on the situation:

If your installed ADS-B Out has failed, you can request authorization at any time to fly to your destination, to a repair facility, or both.
If the aircraft is not equipped at all, submit the ADAPT request at least 1 hour before the flight and no more than 24 hours in advance.

Authorizations are issued flight by flight. The FAA has said it is unlikely to grant routine or repeated authorizations to operators trying to fly non-equipped aircraft through rule airspace on a regular basis.¹

Older Version 0 ADS-B equipment installed before 2011 does not meet current performance standards. An aircraft with pre-2011 hardware is treated, for rule airspace purposes, as needing an upgrade or an ADAPT authorization before entering.

What Happens If You Fly Rule Airspace Without It

The FAA treats unauthorized entry into ADS-B rule airspace as an equipment violation. Responses range from a counseling letter under the Compliance Program for a first, inadvertent mistake up to formal certificate action for repeat or deliberate violations. Fixed-term certificate suspensions, indefinite suspensions pending demonstration of qualification, and revocations are all available. Civil penalties for individual pilots can reach up to $100,000.⁶

The FAA conducts post-flight analyses of equipment compliance, so a quiet frequency during the flight is not evidence that no one noticed. Incorrect broadcasts, and missing broadcasts, are logged by the ground system. Filing a NASA ASRS report within 10 days of an inadvertent deviation remains a sensible precaution.

1
eCFR. 14 CFR 91.225 – Automatic Dependent Surveillance-Broadcast (ADS-B) Out Equipment and Use
2
Federal Aviation Administration (FAA). Aeronautical Information Manual – Section 2. Controlled Airspace
3
Federal Aviation Administration. ADS-B FAQ
4
Federal Register. Revision to Automatic Dependent Surveillance-Broadcast (ADS-B) Out Equipment and Use Requirements
5
Federal Aviation Administration. ADS-B Deviation Authorization Preflight Tool
6
Federal Aviation Administration. Legal Enforcement Actions