In an October report titled “FAA faces significant risks in implementing the automatic dependent surveillance-broadcast program and realizing benefits,” the Department of Transportation’s Inspector General (IG) criticizes the FAA’s uncertainty on avionics costs and specifications, ground station contracting arrangements and program oversight, among other things.

“The greatest risks to successfully implementing ADS-B,” the IG stated, “are airspace users’ reluctance to purchase and install new avionics for their aircraft, and the FAA’s ability to define requirements for the more advanced capabilities.” While noting that the FAA’s cost analysis for U.S. user equipage ranged from $2.5 billion to $6.2 billion, the IG added that the agency’s opening mandate for ADS-B out merely replicates existing radar coverage and provides users with few new benefits.

New benefits would come only with ADS-B in, but that system’s costs and capabilities might not mature for at least two years. Similarly, the extent of necessary modifications to controller displays and supporting automation to accommodate ADS-B-equipped aircraft, and their associated costs, are not yet defined–itself a “significant ­challenge.” Until these uncertainties are addressed, the IG stated, “progress with ADS-B will be limited, and the potential for cost increases, delays and performance shortfalls will continue.”     

                     
The ground station contract was also of concern. In 2007, the FAA awarded a phased contract to ITT for the nationwide ADS-B ground stations, with an estimated cost of around $4 billion through 2035. The contract departed from normal FAA practice by having ITT design, build, install, operate, maintain and then own the roughly 800 U.S. stations at its own cost, with the FAA billed for the ADS-B service at an initial $90 million per year, after all stations become operational in 2013, regardless of traffic volume or FAA technical readiness to use the aircraft transmissions.

In reviewing the FAA’s supporting data for this approach, the IG estimated that the agency’s normal contracting process could have saved approximately $600 million in the program’s first phase. The FAA responded that it expected to recover that amount by sharing the income from ITT’s sale of the ADS-B data to airports and other parties. (This might be a hard sell, in view of other, potentially cheaper ADS-B tracking technologies.)

The IG also noted that the minimal involvement of FAA technical personnel in the ITT activity could result in their “knowing very little about a ­system that is expected to be the foundation of NextGen.” Additionally, the IG revealed several instances of the FAA’s lack of strict oversight of contract expenditures.

After Jan. 1, 2020, all aircraft in U.S. airspace must carry at least ADS-B out avionics, and their signals will be transmitted to both the ground stations and those aircraft carrying ADS-B in avionics. The IG emphasized, “A key ADS-B priority is its air-to-air applications–a primary benefit expected by airspace users.” Here, the FAA has opted for the international 1090 MHz ADS-B standard for large aircraft and the lower-cost universal-access transponder (UAT) for general aviation.

Equipage Incentives Needed
Developed for the FAA’s Alaska Capstone ADS-B evaluation program, the UAT is unique to North America and uses an entirely different radio frequency. However, since under ADS-B everyone should see everyone else, the FAA devised the ADS-R–for ReBroadcast–concept, where the ground stations will “translate” incoming UAT signal data into 1090 MHz-compatible formats and then rebroadcast them up to large aircraft, and vice versa.

It’s an interesting concept, but the IG noted that the airlines believe it might not be technically feasible, or sufficiently accurate, for collision avoidance or self-separation. The FAA responded that all ground stations would have dual frequency capability by 2014. Oddly, however, the IG could not determine the cost of ADS-R stations from the ITT contract, and quoted an FAA official as stating that their  complexity “may be cost prohibitive to implement nationwide.” Left unsaid was the thought that without ADS-R or something similar, a key safety benefit of ADS-B in the NAS disappears.  

The IG reported user concerns about the cost of ADS-B avionics. The FAA had estimated 1090 MHz “Out” equipment as being between $32,000 and $174,640, with “In” packages running from $162,250 to $670,000. UAT avionics were significantly less expensive, at $7,644 to $10,920 for “Out” units and $10,444 to $29,770 for “In” systems. (Note that only 1090-MHz ADS-B systems are permitted in upper airspace.)

The IG proposed that complete ADS-B compliance by the user community would likely be achieved only through purchase incentives, such as various forms of tax relief, priority ATC handling and access and so on.

Government officials, including DOT Secretary LaHood, seem to understand this message in principle but there appears so far to have been no serious exploration of the incentive options.

Last, the IG dealt with security of ground stations, radio datalinks, aircraft avionics and the GPS signals that are included in the ADS-B data stream. This is no trivial issue, with some industry observers suggesting that the FAA has unwisely downplayed the security aspect, since the four key linkages in the ADS-B “chain” are each vulnerable to deliberate interference, and where losing any one of them essentially disables all of them. In his report, the IG recommends that the FAA should “work with the U.S. intelligence community to assess potential threats to the ADS-B system and ways to mitigate them.”