An Aviation Rulemaking Committee (ARC), tasked by the FAA to advise on ADS-B in introduction strategies, has recommended that the system not be mandated. In large part, this is because many of its potential applications have yet to be fully defined so the benefits payback period on an operator’s investment in the near future would be well outside the typical three-year standard for the major airlines, considered the system’s predominant user group. The ARC estimated that today, 18 to 20 years might be closer to the mark, and suggested that a three-year return is unlikely before 2028, which is therefore regarded as the likely starting point of airline fleet equipage. In turn, this would suggest an ADS-B in mandate would not occur until sometime after 2030.

A Costly Proposition

Yet it was a thoughtful recommendation. Many believe ADS-B in is the essential end state of the system, providing the safety benefits of situational awareness and optimal separation to all airspace users rather than a few with deep pockets. And today, deep pockets would certainly be required. The report described three airline scenarios: forward fit (new aircraft starting production), retrofit of current models in production and retrofit of types no longer in production, along with their estimated acquisition and installation costs in the near, mid and long term.

The estimates ran from a near-term forward fit at $130,000 to $290,000, to a long-term, out-of-production aircraft retrofit between $763,000 and $1.2 million, with the latter reflecting likely upgrades to its by then obsolete displays and other peripherals. The ARC anticipated that the retrofit costs for some out-of-production–though airworthy–aircraft could result in operators removing them from service.

Consequently, the report hinted at the advantage of a “Best equipped, best served” approach, where older aircraft would merely be barred from entering high-density airspace. On the other hand, the current ADS-B out rule appears to require retention of ATCRBS transponders in aircraft, plus the supporting secondary surveillance radar network, as far ahead as, say, 2035 to maintain surveillance of aircraft not yet equipped with ADS-B in.

This has raised an interesting issue among general aviation aircraft owners AIN contacted. The current ADS-B out mandate requires, with relatively few exceptions, that all aircraft must install ADS-B transmitters before Jan. 1, 2020. If we accept the widely held view (politicians and mainstream media reporters excepted), that ADS-B out serves no useful purpose to pilots, and is unacceptable for reducing ATC separation below five miles in domestic airspace, then sliding the ADS-B out mandatory compliance date to, say, Jan. 1, 2025, or even later, considering a likely 2032 ADS-B in compliance date, spells significant economic benefit for operators. First, the operator avoids the unnecessarily early purchase and installation of pre-2020 era ADS-B technology that, by 2030, will be obsolete. Second, if the well known GPS and personal computer cost and capability paradigms apply, the ensuing five or more years would bring even better, more efficient and less expensive ADS-B units, aided by heightened industry developments as the in compliance date draws closer. In turn, that could greatly increase the market adoption of ADS-B in, which should be the desired end state of ADS-B in the NAS.