Story ID: 
User consensus on ADS-B remains elusive
By: Andrew Wood
Caption: When the FAA called in March for public comment on its notice of proposed rulemaking (NPRM) on ADS-B equipage, it was with the understanding that there was
Word Count: 536
When the FAA called in March for public comment on its notice of proposed rulemaking (NPRM) on ADS-B equipage, it was with the understanding that there was wide user community acceptance of the system as the vital stepping stone to modernizing the National Airspace System. Everyone appeared to agree that ADS-B would be an essential element in the agency’s NextGen project.Ninety days later, at the close of the comment period, the agency had received several hundred comments from across the user spectrum. The common theme was “No, thanks.” And the responses didn’t coalesce around one or two critical issues that the agency could negotiate with the users. Rather, the objections were as diverse as the particular interests of the group making them, from private pilots to airframe manufacturers to major airlines.‘Irreconcilable’ Differences Among ARC MembersSo where was the common ground upon which consensus could be reached? To answer this question, the FAA in April called for an independent Aviation Rulemaking Committee (ARC), composed of representatives from across the civil community, and charged it with recommending equable solutions by September 26. The FAA often uses the ARC process to obtain user inputs and consensus, and the procedure played an essential role in developing the standards for RNP operations. But there were critical differences between the RNP and ADS-B cases. The RNP ARC held user meetings over an extended period, and the purpose of these meetings was to establish acceptable rules before their implementation and, importantly, for a non-mandatory application. The FAA took a different tack with ADS-B, establishing a smaller ARC just three months before the mandatory NPRM was released and reportedly presenting the committee with a virtually finished document.  The current, expanded ADS-B ARC was assembled only after the user community’s concerns became evident. And even then, the ARC was directed to review only specific sections of the NPRM. Notably, the issue of overall system security, including the vulnerability of GPS as its sole positioning service, was excluded, although this is now appearing to be a challenging ADS-B issue.  Consequently, people close to the committee have suggested to AIN that there is the possibility that it will not complete its task by September 26. One person told AIN, “We have these teeter-totter exchanges, where satisfying one group’s objections only increases the objections of the other groups.” No one is prepared to predict what will happen come September 26. The FAA is not bound to accept the ARC’s recommendations and can proceed with the original NPRM. But that seems extremely unlikely, in view of the almost unanimous rejection from the user community. A more probable outcome is to extend the ARC’s term, although one observer has described some of the differences between certain groups and the FAA, and among the groups themselves, as “irreconcilable.”If there is a lesson to be learned, it is that whereas new systems could be imposed on the aviation community in the past, today’s users must be consulted at the beginning of a concept’s development, particularly for a mandatory plan as all-embracing as ADS-B, to be accepted. As the saying goes, “you can lead a horse to water, but you can’t make him drink.”