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The ABCs of ADS-B – Your Complete Guide to Compliance

2018-06-22  |  White Papers
ADS-B Compliance

The ABCs of ADS-B

Your Complete Guide to Compliance

If you work in the Aviation industry, you have undoubtedly heard of ADS-B technology. The acronym stands for Automatic Dependent Surveillance-Broadcast, and it’s going to augment, and maybe even one day replace, conventional radar surveillance of in-flight and on-ground aircraft. For decades, air traffic control systems have been using radar to “see” aircraft in flight. Using modern GPS technology, aircraft are now able to broadcast information that will identify and provide location information to Air Traffic Control systems far more accurately than existing surveillance.

This new system requires installation of an ADS-B transponder, connected directly to an accurate GPS unit. This equipment must be connected to a panel-mounted unit in the cockpit.

The FAA has mandated that all aircraft operating in controlled airspace in the United States be compliant with the ADS-B standards as of January 1, 2020. Australia, Europe, China, and the rest of the world are implementing requirements for ADS-B equipment in aircraft at differing paces. Canadian aircraft are being upgraded to use the new system, even though there is no implementation date in the country, because many companies fly over the US border quite often. The superiority of the ADS-B technology guarantees that, no matter where an aircraft is operated, it will soon have to be equipped with equipment compatible with the system. This requirement will extend to vehicles operating on taxi and runways at controlled airports as well.

Countdown till ADS-B

Eastern Time

What is ADS-B?

ADS-B operates automatically in that it requires no input from the pilot or flight crew in order to work, and dependent because it requires input from the airplane’s navigation system. Aircraft position data provided by ADS-B is far more precise than conventional radar surveillance, and provides other information to ground controllers, and other aircraft equipped with ADS-B In equipment, including aircraft type, origin, and destination.

FAA Regulation


The FAA estimates that between 100,000 and 160,000 general aviation aircraft will need to equip with ADS-B Out by the time the rule is enforced Jan. 1, 2020.

Ins and Outs

ADS-B has two distinct information paths. ADS-B Out is the transmission of GPS location information from the aircraft to the air traffic control system. ADS-B In technology provides information for the pilot and flight crew to use, including information regarding surrounding aircraft. As an added bonus to those flying in the US, weather information is available for free via UAT equipment via ADS-B In. While many operators are installing it as a matter of course, the regulations for ADS-B compliance only refer to ADS-B Out. There is no reference to mandatory installation of ADS-B In capable equipment.

Equipment Needed for Compliance

You will need to install:

1. A WAAS (Wide Area Augmentation System) compliant GPS receiver, interfaced to your ADS-B Out Transmitter.

There are many manufacturers of WAAS GPS units, including Honeywell, GARMIN, Rockwell Collins, and a host of others. Models all have their pros and cons, but any WAAS compliant unit will satisfy the demands of regulatory bodies for ADS-B use.

2. A transmitter (or transceiver, for ADS-B In capability).

There is no such thing as a portable ADS-B Out unit - all installations must be permanent and panel-mounted. ADS-B In units, often tablet-based, have recently confused the market. They are ADS-B devices, but they are primarily made to take advantage of the free weather reports that the system provides. They do not contribute to compliance in any way. There are many manufacturers of ADS-B Out equipment, including Rockwell Collins and Trig Avionics.

UAT or ES?

There are two choices when it comes to ADS-B. There is a 978 MHz “Universal Access” Transceiver (UAT), and a 1090 MHz “Extended Squitter” (ES) standard. In 2020, the FAA will allow UAT units in aircraft operating below 18,000. For flights above this altitude, ES models must be used. ES allows for more information to be passed (or squittered) from aircraft to controllers, and is generally regarded to be the “way of the future” for ADS-B, so many or most owners who are installing units now are choosing to future-proof their systems by opting for the 1090 MHz models. The 1090 ES equipment is expensive, but more capable than the 978 UAT transmitters. If you are operating outside of the United States, 1090 ES is your only option.

When to Install?

Many owners are minimizing costs by combining ADS-B systems installations with other large maintenance jobs. This minimizes aircraft downtime, and doing multiple jobs at once can bring down the total cost. They are also cognizant of the fact that many owners will put off their installations until the last possible moment, which is likely to lead to increased cost and shortage of components and service personnel in the last few months leading up to the deadline. The regulatory bodies will be unwavering in their timeline, so it’s recommended that the job be scheduled the next time the aircraft requires any major maintenance. Installation costs and timelines vary greatly, dependent on variables like the type of aircraft, type of existing avionics, and other jobs undertaken by an installer. It’s best to presume that 2019 will be very busy for all, so installations should be scheduled sooner rather than later.

ADS-B Quote

We started preparing for ADS-B in late 2018. We expect to be ready just in time.

Compliance Engineer, SF Bay Area

Certification and Testing

Initial certification of ADS-B compliance is issued by the appropriate regulatory body (FAA in the US and Transport Canada in Canada), based on a report generated by the avionics installer who performs the work. In order to obtain the report, test equipment is used to produce a report that indicates the system is performing within specifications. For installers, this equipment is key. They can conveniently perform a proper test of the system – checking the transponder and receiver separately to ensure performance, and then together to verify compatibility. Most importantly, ADS-B equipment out of spec won’t perform as expected, and won’t protect people as designed.

This is where quality measurement tools, like the Viavi Avcomm IFR6000, can make a huge difference. When combined with the available ADS-B Integrity software, the system is able to measure all functions of the ADS-B out installation and ensure that it is performing correctly, before the aircraft ever leaves the ground. In the US, an STC (Supplemental Type Certificate) is required when making significant changes to an aircraft. Testing with the Viavi IFR6000 and ADS-B integrity software doesn’t require an STC, which can save considerable cost and inconvenience for owners. You can be sure that when the aircraft is put to the official certification test, it will pass. This saves time and money, as the aircraft will have to be flown only once, during the government test.

Ty, Testforce

Expert Tip

The VIAVI ADSB Integrity software makes running tests and generating reports quick and easy and automates the process.

Ty, Testforce

Given the impending deadline for compliance, a rush of aircraft installations of ADS-B equipment is forecast. Maintenance will also be required by virtually all aircraft in the future, so investment in a test set would be a prudent course of action for any company that deals with Avionics installation.

The Viavi Avcomm IFR 6000 can be used to test all types of transponders, including UAT and ES ADS-B equipment. It provides accurate measurement of transponder frequency, power, and receiver sensitivity. It simulates the airborne environment necessary to certify the system. Viavi’s easy-to-use equipment is able to simulate range and velocity conditions, verifies station identification, and squitter control. In short, for installation of ADS-B equipment, it provides all the measurements required to know that the equipment is functioning and that all of the components (GPS, Transmitter or transponder, and antennas) are working as intended.

Testforce is a leading seller for the IFR 6000 Multifunction Ramp Test Set by Viavi, providing not only sales, but expert advice regarding its installation and use. To set up a consultation with a Testforce Technical Account Manager, speak with a Customer Support Representative by clicking the orange "Chat now" button in the bottom right corner, or call directly 1-888-880-6804.

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