ADS-B Out has become a firm 2020 requirement

FAA's final rule on this new identification instrumentation is here. What should you know now and how should you prepare to be compliant?

By Bill Gunn
Contributing Writer

Automatic dependent surveillance–broadcast (ADS-B) is a superior positioning system ATC will use to replace radar. Planned growth for ADS-B as part of NextGen will alter the pilot/controller relationship. The question is whether you and your company are ready for the change.

ADS-B ground transceiver sites are operating today in most of the US, providing aircraft positioning in some areas and safety of flight information to the cockpit of equipped aircraft. FAA is on track to have these ADS-B ground infrastructures complete throughout the US by the end of 2014.

The added value of ADS-B is sufficient that PHI chose to configure much of its fleet operating to and from rigs in the Gulf of Mexico even before the ADS-B Out final rule was published. (See "Offshore giant PHI improves performance in Gulf of Mexico," Pro Pilot, Sep 2011, pp 38–43.)

ADS-B has 2 modes or functions—out from the aircraft and in to the aircraft, referred to as ADS-B Out and ADS-B In, respectively. Within each function there are 2 protocols, or means of transmitting data—1090 extended squitter (1090ES) and universal access trans­ceiver (UAT). UAT is only used in the US below FL180—at FL180 and above 1090ES is required. It is also the worldwide standard.

ADS-B Out transmits precise location and other information about the aircraft to ground stations and other aircraft that are like-protocol ADS-B In equipped. It is important to note that current trans­ponder, Mode C or S and RVSM equipment requirements are not changed or affected by the ADS-B rule and will remain a requirement.

ADS-B Out is mandated after Jan 1, 2020 for aircraft operating in the controlled airspace that requires transponders today.

FAR 91.225 explains the airspace and protocols required, while FAR 91.227 gives the performance requirements. AC 20-165 provides guidance for the installation and airworthiness ap­proval of TSO C166b (1090ES protocol) or TSO C154c (UAT protocol) ADS-B Out functions for aircraft.

At present ADS-B In is optional, but the final rule on this has not been published. The aviation rulemaking committee (ARC) for ADS-B In published its report on Sep 30, 2011. Many recommendations were given to FAA but perhaps the most interesting is the one that ADS-B In should remain optional—ie, with no required mandate as with ADS-B Out.

Aircraft outfitted today with ADS-B In avionics can take advantage, around much of the country, of broadcast services of data—including graphical and textual weather, Notams and airspace and traffic advisories—to the flightdeck. The ARC's intention seemed to be that FAA would best serve the flying community if the marketplace drove development of the ADS-B In function.

It is important to understand that terrain, weather and traffic information provided by ADS-B In is advisory only—it does not alter the pilot's requirement to see and avoid traffic or the controller's obligation to separate and manage traffic. The stand-alone separation for TCAS II systems remains unchanged by ADS-B In.

FAA's plan for full Next­Gen deployment will require this "in" function. The ARC stated that this aspect of ADS-B is not yet fully developed and that mandated technical standards today would be obsolete tomorrow. The final rule from FAA on ADS-B In, when published, will determine if this function remains optional or mandatory in the near future.

Equipping your aircraft

ADS-B Out function requirements for the US airspace system after Jan 1, 2020. FAR 91.225 elaborates on the required airspace for each protocol (1090ES and 978 UAT).

There are many options to consider here, and the cost/benefit ratio will differ for each aircraft—even for similar aircraft in a company's fleet. For operators, the bottom line is this—What do I need, what will it cost in time and money, and what should I plan for change and growth in the future?

Valero Energy Aircraft Maintenance Supervisor Richard Murphy offers his company's take on up­grades. Valero is a worldwide Gulfstream G450/G550 operator.

"Sometimes there are long lead times for equipment and maintenance slot availability for upgrades," says Murphy. "Don't wait until the last few months before the mandate goes into effect.

Talk to reputable maintenance organizations and OEMs to determine what equipment will need to be added, modified or removed. Are there additional operational considerations, training requirements, tooling or maintenance actions required with the upgrade?

"Consider installing avionics upgrades in conjunction with inspections or paint and interior upgrades. Sometimes interior access is extensive and installing upgrades in conjunction with other maintenance can save down time and money. You may also be able to bundle a work package and receive additional discounts."


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