FAA to use ADS-C to meet separation standards for US oceanic airspace


US Federal Aviation Administration officials have committed to using Automatic Dependent Surveillance – Contract (ADS-C) technology to reduce separation of aircraft in US oceanic airspace in the near-term “since the automation platform used for that airspace was designed for ADS-C”, the FAA has confirmed in a statement.

“The FAA will also be conducting a one-year operational evaluation of space-based ADS-B in the Caribbean beginning in March 2020 to evaluate further that technology and its potential benefits. Results from the operational evaluation will inform decision making around future investments,” added the agency

The FAA felt compelled to clarify its position after a war of words erupted between Inmarsat and Aireon over whether the FAA intends to implement Aireon’s space-based ADS-B in US oceanic airspace to support forthcoming new minimum separation standards for aircraft.

At the heart of the debate was a General Accountability Office (GAO) report which states flatly that the FAA has committed to using “enhanced ADS-C” to reduce separation of aircraft in US oceanic airspace, as part of its commitment to implement new international standards by 2022, while the agency will continue “to study space-based ADS-B for future use”.

Notably, according to the GAO report, FAA officials believe operational challenges to using space-based ADS-B for the region “have not yet been resolved”. The challenges cited relate to both the safety and cost of implementing space-based ADS-B.

Inmarsat’s Classic Aero and new SwiftBroadband-Safety (SB-S) services already power ADS-C over oceans and will ably support “enhanced ADS-C”. This is described by the GAO as using “the same ADS-C technology already installed on FANS-equipped aircraft”  but that the ATOP computer “would request that automatic position reports be sent more frequently to air traffic control. Aircraft equipped with ADS-C and transmitting position reports every 3.2 minutes would be eligible for ICAO’s proposed minimum separation standard of 20 nautical miles longitudinal.”

In an interview with Runway Girl Network after the GAO report dropped, Inmarsat vice president aviation safety and cybersecurity, Joseph Teixeira said: “We were surprised by the thoroughness and the fairness of the report because we have been saying this all along.

“We’re not against another layer of safety but we really did need a third party that would lay out the actual facts and we’re very happy the FAA and GAO laid out a very comprehensive report, and they checked with everyone – manufacturers and airlines, and the report really stands on its own.”

The FAA does not need additional money to move forward with new minimum separation standards via enhanced ADS-C, he said, because that is already in the budget.

Aireon, on the other hand, suggested that the GAO report is based on information that is up to two years old. “In the past year, substantial developments to both the regulatory standards, implementation and recognition of multiple operational, safety and cost avoidance benefit metrics have been made through extensive collaborative input from the US airlines, A4A, NATCA, ALPA and the FAA. In light of these advancements, the FAA’s position toward space-based ADS-B technology has changed considerably and FAA is exploring an accelerated path to implementation of space-based ADS-B in its oceanic airspace and the NAS,” said Aireon in a statement. “Aireon and the FAA are closely committed to using space-based ADS-B technology to create a safer airspace for the flying public.”

Matt Desch, the CEO of Iridium, which owns a 24.5% slice of the Aireon joint venture, added in a statement to RGN: “That report is out of date. I think you’ll find the FAA is moving forward more quickly these days than that report would imply, and are seeing the benefits are greater than they had previously calculated. The airlines, controllers, pilots and other constituencies are pushing them hard for space-based ADS-B benefits, and the FAA won’t want to give up their leadership position to the rest of the world in this area.’”

Responding to already-published media reports that Aireon sees the GAO report as old, Inmarsat’s Teixeira told RGN that it is “clearly not so. The decision was made by the FAA in April and the report is very clear.”

Given the clear divide – and wanting to hear it from the horse’s mouth – RGN yesterday evening reached out to the FAA for clarity, asking if it stands by the findings in the GAO report, and if the agency is – as Aireon suggests – accelerating its efforts to adopt space-based ADS-B to meet minimum separation standards.

The FAA has just released a statement, clarifying that it does not prefer one technology over another, but effectively confirming that it will press forward with ADS-C for reduced separation in the near-term.

The FAA’s full statement reads:

The FAA and its partners in the aviation industry are working to enhance safety and increase capacity in oceanic airspace through a phased approach that leverages near-term opportunities while the agency continues to gather data and study options for a long-term solution.

The agency does not prefer one technology over another. The agency also notes that separation standards are dependent on the communications, navigation and surveillance capabilities in an airspace. Therefore, the FAA is considering the long-term evolution of all of these capabilities to improve safety and increase capacity in oceanic airspace.

In the near-term, a technology called Automatic Dependent Surveillance – Contract (ADS-C) will be used to reduce separation in oceanic airspace since the automation platform used for that airspace was designed for ADS-C. ADS-C is an automated reporting system that provides an aircraft’s position and flight path intent, among other information, to air traffic controllers to apply separation in airspace without traditional surveillance coverage.

The FAA will also be conducting a one-year operational evaluation of space-based ADS-B in the Caribbean beginning in March 2020 to evaluate further that technology and its potential benefits.

Results from the operational evaluation will inform decision making around future investments.

RGN thanks the FAA for its timely response to this query.

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1 Comment

  1. Kieran O'CARROLL

    Perhaps now is a good time to do a Runway Girl article on Space Based VHF Communications?
    Empirical evidence proves time and time again that the C in CNS is key to maximizing the S benefits. As for N … an article on the none too transparent reasons for the recent extended GALILEO outage would be welcome and no doubt enlightening.

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