Of the 516 stations completed so far, 511 are reporting on the ADS-B network. In addition to the ground ­stations, 223 interfaces between the ADS-B network and various FAA ­facilities will be needed. By mid-November, 143—or 64%—of these had been installed and tested, with another 45 in final design and site preparation stages.

So it appears that the crucial ADS-B “Out” program is very much on track. However, to make the program a success, operators will have to ensure their aircraft have the necessary avionics ­equipment. The agency has set a deadline of 2020 for aircraft to have ADS-B capability in many types of airspace.

While ADS-B “Out” will undoubtedly yield significant ATM advantages, many experts say that the real benefit for system users will come from ADS-B “In”. The “In” aspect would enable the display of other aircraft positions and weather data in the cockpit, improving situational awareness and potentially enabling more direct routings.

Although the FAA has set a deadline for ADS-B Out equipage, it has yet to do so for ADS-B In. An industry rulemaking advisory committee told the agency in September 2011 that it “does not support an equipage mandate” for ADS-B In.

In a report to the FAA, the advisory committee stressed that ADS-B In shows great promise. But “based on the current maturity of ADS–B In ­applications and uncertainties regarding the achievable benefits, there is not a . . . business case for near-term ADS–B In equipage.”

Instead of setting a mandate, the committee recommended that the FAA should provide incentives for voluntary equipage and use demonstration projects to define benefits and standards for ADS-B In.

At this point, the FAA and industry appeared to be on the same page regarding ADS-B In; however, their hands could be forced by Congress. The FAA reauthorization bill passed in February 2012 orders the agency to develop an ADS-B In rule, that would, among other things, require equipage by aircraft in capacity-constrained airspace by 2020.

It is not yet clear how the FAA will satisfy this congressional requirement. To help it decide, the agency called for the ADS-B In advisory committee to “give us recommendations on how to proceed with ADS-B In, in light of the reauthorization bill,” an FAA spokesman tells Aviation Week. The FAA “recently received the [committee] report and [is] reviewing it.” The report will be published in the Federal Register after the FAA review, although there is no set timing on when that will occur, says the spokesman.

Meanwhile, important signs of progress are finally emerging on another key FAA effort, the ERAM program. This has been among the agency’s most troubled—and most expensive—projects in recent years, and the agency has been frequently lashed by congressional lawmakers and government watchdog agencies for the problems in ERAM.

ERAM is aimed at replacing the backbone operating system used in the FAA’s 20 en route centers. It predates the NextGen program, as the contract to build the new system was awarded to Lockheed Martin in 2002; however, it is considered an essential building block for NextGen, since it will be needed for many of the new technologies and procedures being planned.