November 28, 2011
“It’s just not ready for prime-time.”
That’s how NBAA Steve Brown – NBAA’s senior vice president for operations & administration, and the co-chair of an Aviation Rulemaking Committee (ARC) responsible for recommendations on Automatic Dependent Surveillance-Broadcast (ADS-B) “In” – characterized the procedural and technical development of this vital component to the FAA’s NextGen effort. After 17 months of research, Brown and other members of the committee reported to the FAA earlier this month that requirements and regulations for ADS-B “In” are not yet justified, given the current state of technology.
ADS-B is a collection of technology enhancements and accompanying procedures that rely on Global Positioning System (GPS) satellites to replace ground-based radar surveillance of the National Airspace System. There are two types of ADS-B, explained Brown, who has co-chaired two ARCs on the issue. ADS-B “Out” integrates an onboard GPS receiver with a new type of transponder that reports an aircraft’s position based on information derived from GPS. The FAA published its final rule on ADS-B Out requirements in May 2010.
ADS-B “In” is a set of cockpit applications based on GPS information that give flightcrews a real-time situational awareness, allowing for reduced separation of aircraft, more precise navigation and more efficient air traffic control.
“Based on what we know today, the set of applications that comprise ADS-B In is not fully mature yet,” Brown explained. “There’s additional research and development needed. There’s additional specification of standards for both design and implementation that need to be improved before there is a sufficiently mature system that can be deployed and used on a global basis.”
The cost, said Brown, would be significant. For new aircraft not yet built, the cost would be as much as $290,000 to build ADS-B In into the avionics panel. Retrofitting aircraft still in production could cost $425,000. Refitting aircraft no longer in production would, in the ARC’s opinion, could cost as much as $700,000.
“We’re very clear in the ARC report to the FAA that, overall, we believe ADS-B is very beneficial and that it should be implemented at some point in the future. We don’t specify a year,” Brown said. “Rather, what we did was lay out a great number of recommendations that suggest the kind of R&D and trials we believe necessary to mature the system.”
ADS-B Out will, according to FAA rules, be mandated beginning in 2020. While Brown said he hopes ADS-B In will follow a similar timeline, he reiterated that decision would be made on the basis of technological improvements.