How to Get your Aircraft Compliant with ADS-B Requirements

What’s one of your least favorite things about being a pilot? If you said, “Keeping current with changing regulations,” you’re not alone. One industry-redefining rule, the FAA ADS-B Out mandate, has been in effect since January 1, 2020, and compliance is still required to fly in most controlled airspace.

The FAA bills ADS-B as, “an environmentally friendly technology that enhances safety and efficiency, and directly benefits pilots, controllers, airports, airlines, and the public.”

On the other side of the fence are those who see ADS-B as a complex, confusing, and expensive alternative to standard radar.

The important thing is this: whatever your personal opinion on the matter, if you are a pilot flying in ADS-B rule airspace, your aircraft must comply with regulations.

Now you probably have a few questions like, “What is ADS-B airspace?” or “What type of device do I need to install to meet ADS-B requirements?” You may be wondering, “How much will it cost to make my aircraft ADS-B compliant?”

Keep reading for these answers and more, plus we will share our recommendation for an easy, low cost product solution that will have you ADS-B compliant.

First, let’s start with the basics.

What is ADS-B?

Are you ready to memorize another acronym? ADS-B stands for Automatic Dependent Surveillance Broadcast.

That is the fancy way of saying that the positions, altitude and velocity of aircraft equipped with ADS-B Out transmitters (more on those later) and a WAAS GPS will be automatically reported and broadcast at regular intervals to other ADS-B enabled aircraft and ATC.

Put simply, ADS-B provides an updated way for pilots to view each other’s positions and for ATC to manage air traffic.

Upgrading to ADS-B is an integral part of the ATC’s continuing NextGen program rollout, and the ADS-B Out system will ultimately replace radar as the primary method for separating aircraft.

The FAA 2020 Mandate

As of January 1st, 2020, the FAA has mandated that all aircraft flying in the airspace designated by 14 CFR 91.225 must have ADS-B Out avionics that meet the performance standards outlined in 14 CFR 91.227. Not following these requirements might result in being denied access to the specific airspace.

What airspace is ADS-B required for?

What you really want to know is whether the ADS-B Out mandate affects you, right? The answer to that is, “Most likely.” ADS-B requirements apply to most controlled airspace including any airspace that had formerly required aircraft to have a Mode C transponder.

ADS-B Out devices are required on every aircraft with an electrical system that is operating:

• In Class A airspace, under 91.225(a)
• In Class B and Class C airspace areas, under 91.225(d)(1)
• Within 30 nautical miles of an airport listed in appendix D, section 1 to part 91, from the surface upward to 10,000 feet MSL, under 91.225(d)(2). This is the same ring as the Mode C veil in 91.215(b)(2), and the airports are named in the appendix rather than in the rule itself
• Above the ceiling and within the lateral boundaries of a Class B or Class C airspace area designated for an airport, upward to 10,000 feet MSL, under 91.225(d)(3)
• In Class E airspace within the 48 contiguous states and the District of Columbia at and above 10,000 feet MSL, excluding the airspace at and below 2,500 feet above the surface, under 91.225(d)(4)
• In Class E airspace at and above 3,000 feet MSL over the Gulf of Mexico from the coastline of the United States out to 12 nautical miles, under 91.225(d)(5)

Class E airspace below 10,000 feet MSL, other than the Gulf of Mexico case above, generally does not require ADS-B Out. Aircraft that were never originally certificated with an engine-driven electrical system and have not had one installed since, including balloons and gliders, are treated separately under 91.225(e).

Want to confirm whether you will need ADS-B for the specific airspace you intend to fly in? Check out the FAA’s ADS-B transmitter maps along with their "Getting to Know Your ADS-B System" to verify requirement details.

What are the benefits of ADS-B?

ADS-B In and Out work together to improve flight capabilities. Planes can receive messages from ground control and other aircraft, providing pilots with better situational awareness. This includes TIS-B and FIS-B data, as well as information from nearby planes.

ADS-B is also beneficial in non-radar environments like the Gulf of Mexico and Colorado mountains, where ground radios can be placed in difficult terrain for more accurate tracking.

It helps speed up search and rescue operations by providing precise information on an aircraft's last known location.

Difference Between ADS-B In and ADS-B Out

Are you wondering about the differences between ADS-B Out and ADS-B In? The answer is pretty much how it sounds: one pertains to outgoing data, while the other focuses on incoming data.

• ADS-B In is valuable for receiving information, including traffic updates and weather conditions, which are transmitted from pilots with ADS-B Out and ground stations to the cockpit.
• ADS-B Out transmits information from the aircraft to Air Traffic Controllers (ATC) and fellow pilots.

What type of device do I need to meet the ADS-B requirements?

Now that you’ve established your need to meet the ADS-B requirements, it’s tempting to fall into the trap of thinking that your existing ADS-B In device makes you compliant with the ADS-B Out regulations, but don’t go there.

The ADS-B system includes both ADS-B In and ADS-B Out devices. ADS-B In receivers are very useful and allow you to receive important FIS-B data among other things, but you will still need additional devices to fulfill the ADS-B Out requirements.

To be compliant, your aircraft will need to be outfitted with both a Version 2 ADS-B Out transmitter and a compatible GPS position source or a single device that fills both those roles.

ADS-B Systems

Your ADS-B Out system can be one of two types (depending on what airspace you operate in): either a 1090ES (Mode S transponder with extended squitter) that operates on the 1090 MHz frequency or a Universal Access Transceiver (UAT) on 978 MHz.

A 1090ES system is required if you will be flying at or above Flight Level 180. Below 18,000 feet MSL, either type of system checks the box.

Since most other countries operate on 1090 MHz, set your aircraft up with the 1090ES system if you plan to make international flights.

What the regulations actually require: 14 CFR 91.225 and 91.227

Two sections carry the ADS-B Out rule. Section 91.225 says where the equipment is required and which standards it has to meet, and section 91.227 sets the performance numbers the equipment has to hit. Both were read from the current text on eCFR in August 2026, and both are worth reading before you commit to an installation.

91.225: 1090ES and 978 UAT are not interchangeable everywhere

The airspace list above comes from 91.225(d). Class A is handled separately in 91.225(a), and that separation is exactly what decides your datalink.

• Class A airspace, 91.225(a): the aircraft must have equipment meeting TSO-C166b or TSO-C166c. Those are the 1090 MHz Extended Squitter standards. The UAT standards are not listed there, so a 978 MHz UAT installation does not satisfy Class A.
• Below 18,000 feet MSL in the 91.225(d) airspace, 91.225(b): the aircraft may meet TSO-C166b or TSO-C166c, or TSO-C154c or TSO-C154d. The C154 standards are the Universal Access Transceiver standards on 978 MHz. Either datalink is acceptable there.

Section 91.225(i) puts the frequencies right in the titles of the standards it incorporates: TSO-C166b and TSO-C166c cover equipment "Operating on the Radio Frequency of 1090 Megahertz (MHz)," and TSO-C154c and TSO-C154d cover "Universal Access Transceiver (UAT)" equipment on 978 MHz.

One paragraph is easy to miss once the install is signed off. Section 91.225(f) says that, with narrow exceptions, each person operating an aircraft equipped with ADS-B Out "must operate this equipment in the transmit mode at all times." Deviation timing sits in 91.225(g): for an inoperative unit the request to ATC may be made at any time, and for an aircraft that is not equipped the request must be made at least one hour before the proposed operation.

91.227: why a tablet GPS cannot make you compliant

For aircraft broadcasting ADS-B Out as required under 91.225(a) and (b), section 91.227(c)(1) sets five figures the system has to meet: Navigation Accuracy Category for Position (NACp) less than 0.05 nautical miles, Navigation Accuracy Category for Velocity (NACv) less than 10 meters per second, Navigation Integrity Category (NIC) less than 0.2 nautical miles, System Design Assurance (SDA) less than or equal to 1 in 100,000 per flight hour, and Source Integrity Level (SIL) less than or equal to 1 in 10,000,000 per flight hour or per sample. Section 91.227(e) caps latency: geometric position must be transmitted no later than 2.0 seconds after it is measured, and no more than 0.6 seconds of that may be uncompensated. A consumer GPS does not carry those integrity figures, which is why the position source has to be part of the certified installation.

Section 91.227(d) also lists what the aircraft has to broadcast, and it names four elements the pilot enters during the appropriate phase of flight: the Mode A transponder code specified by ATC, the aircraft identification filed on the flight plan or used with ATC, an indication that the flight crew has identified an emergency, radio communication failure or unlawful interference, and IDENT.

The transponder rule is separate, and it did not go away

ADS-B Out did not replace the transponder requirement. Section 91.215 still requires an operable transponder with Mode C altitude reporting in the airspace paragraph (b) lists, and 91.215(c) requires you to operate it, including Mode C if installed, in that airspace or in any controlled airspace. Read those two paragraphs together: paragraph (c) governs operating a transponder you already have, while the airspace in which one must be installed is the list in paragraph (b). A transponder is not required in every piece of controlled airspace. Separately, section 91.413 says no person may use an ATC transponder specified in 91.215(a) unless it has been tested and inspected within the preceding 24 calendar months and found to comply with appendix F of part 43.

It is also worth knowing where the rule is not. Section 91.205, the instrument and equipment list for day VFR, night VFR and IFR, does not use the word transponder and does not mention ADS-B. Those requirements are airspace-based, and they live in 91.215 and 91.225 instead.

Check the current rule before you act on this

Regulations change, and the summaries on this page are a reading aid, not the regulation. The controlling text is the current version of 14 CFR part 91 at eCFR, which is where every quotation here came from. Nothing on this page is legal advice or an airworthiness determination. Equipment choices, installations, approvals and logbook entries belong with your avionics shop and your mechanic, and questions about a specific operation belong with your local FSDO.

What drives the cost of making your aircraft ADS-B compliant?

Three things move the number: which datalink you choose, how much of the job the hardware does for you, and the shop labor to install it and sign it off. A unit that bundles the ADS-B Out transmitter with its own WAAS position source takes a separate GPS off the bill. A unit that replaces an existing position light avoids opening the panel. A path that also replaces the transponder asks more up front but leaves you with a Mode S box that is legal in Class A and outside the United States. Ask your avionics shop for a quote that separates hardware, labor and paperwork, and check current pricing on the individual product pages in our GPS and ADS-B receivers collection.

Which ADS-B device should I choose?

Here’s the good news you were waiting for: despite all the complexities of the ADS-B program rollout, there is a simple and cost-effective solution that will get you compliant without pricy equipment or a complex installation process.

The skyBeacon by uAvionix is an all-in-one device that integrates an ADS-B UAT Out transmitter, WAAS GPS and LED wingtip position light. The beauty of the skyBeacon is that a single unit provides everything you need to meet the ADS-B requirements and it does so while eliminating the need for a new transponder and new wiring.

The skyBeacon is compatible with your existing Mode C or Mode S transponder and it transmits data using your aircraft’s existing wiring system. You can mount your skyBeacon in just 10 minutes simply by replacing your aircraft position light with the skyBeacon.

The skyBeacon has earned our recommendation as the simplest route to meeting the ADS-B Out requirement for a U.S. aircraft operating below 18,000 feet MSL. See the skyBeacon product page for current pricing.

Frequently Asked Questions

Is ADS-B Out mandatory for all pilots?

It depends on where you fly. Section 91.225 requires ADS-B Out in Class A airspace, in Class B and Class C areas, within 30 nautical miles of an airport listed in appendix D, section 1 to part 91 up to 10,000 feet MSL, above a Class B or Class C ceiling up to 10,000 feet MSL, and in Class E at and above 10,000 feet MSL in the 48 contiguous states, excluding airspace at and below 2,500 feet above the surface. Aircraft never certificated with an engine-driven electrical system, including balloons and gliders, are treated separately under 91.225(e).

Can I use a portable ADS-B device to meet the mandate?

No. Portable units are ADS-B In only. They pull traffic and weather into a tablet and are genuinely useful in the cockpit, but they broadcast nothing, so they cannot satisfy the ADS-B Out mandate. Compliance takes a Version 2 ADS-B Out transmitter together with a position source that meets the accuracy and integrity figures set in 14 CFR 91.227, installed and approved for your aircraft. A consumer GPS does not carry those figures, which is why the position source belongs to the certified installation.

Do I still need a transponder if I have ADS-B?

Yes, and the two rules are separate. ADS-B Out did not replace 14 CFR 91.215. Paragraph (b) of that section requires an operable Mode A 4096 code or Mode S transponder with Mode C altitude reporting in the airspace it lists, which includes Class A, Class B and Class C areas and the 30 nautical mile ring around an airport in appendix D, section 1 to part 91. That list is not the same as all controlled airspace, so a transponder is not required everywhere in controlled airspace. Paragraph (c) then requires you to operate an installed, operable transponder, including Mode C, in that airspace or in any controlled airspace.

Does ADS-B replace radar?

ADS-B is replacing radar as the primary surveillance method for air traffic control because it is more accurate and updates faster. The aircraft broadcasts a position from its own certified GPS source at regular intervals, rather than the position being measured by a ground sweep. Radar has not gone away, though. It stays in service as a backup, and it still sees aircraft that are not broadcasting, so controllers keep working with both sources.

Where exactly does 14 CFR 91.225 require ADS-B Out?

Paragraph (d) of 91.225 lists the airspace: Class B and Class C areas; within 30 nautical miles of an airport listed in appendix D, section 1 to part 91 from the surface upward to 10,000 feet MSL; above the ceiling and within the lateral boundaries of a Class B or Class C area up to 10,000 feet MSL; Class E in the 48 contiguous states at and above 10,000 feet MSL, excluding airspace at and below 2,500 feet above the surface; and Class E at and above 3,000 feet MSL over the Gulf of Mexico out to 12 nautical miles. Class A is covered separately in 91.225(a).

Can I meet the mandate with 978 UAT instead of 1090ES?

Below 18,000 feet MSL, yes. Section 91.225(b) accepts equipment meeting the 1090 MHz Extended Squitter standards TSO-C166b or TSO-C166c, or the 978 MHz Universal Access Transceiver standards TSO-C154c or TSO-C154d. For Class A airspace, 91.225(a) lists only the 1090ES standards, so a 978 UAT installation does not satisfy it. Most countries that mandate ADS-B use 1090 MHz, so if you fly above 18,000 feet or across a border, 1090ES is the choice that travels with you.

Does an ADS-B Out upgrade replace the 24 month transponder check?

No. Section 91.413 is unchanged by the ADS-B rule: no person may use an ATC transponder specified in 91.215(a) unless it has been tested and inspected within the preceding 24 calendar months and found to comply with appendix F of part 43. A further test is required after any installation or maintenance where a data correspondence error could be introduced, which covers many ADS-B upgrades, and the section limits who may perform it. Check for the entry before flying a newly purchased aircraft into Class B or C.

Recap

• The FAA’s ADS-B Out is required in airspace A, B, and C.
• Most pilots will be impacted by the requirements and will need to install the appropriate systems on their aircraft.
• To meet the standards, aircraft will be required to have a Version 2 ADS-B Out transmitter and a compatible GPS position source or a multi-functional device that fills both those roles.
• The skyBeacon by uAvionix is the easiest, fastest, lowest cost solution to get your aircraft compliant with the ADS-B requirement.
• The FAA released an FAQ on ADS-B for more information.

Have airspace-related questions?

Our guides are designed to help student pilots become professional pilots and for private pilots to brush up on their knowledge and skills.

• Temporary Flight Restrictions: Can You Fly Through a TFR?
• Restricted Airspace: What You Should Know
• 9 Types of NOTAMS Used in Aviation (Guide)
• Special VFR Clearance: Everything You Need to Know
• Class A Airspace and How it Differs from All Other Categories of Airspace

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