An aviation rulemaking committee says immaturity of automatic dependent surveillance-broadcast (ADS-B) "In" applications combined with "uncertainties" in the achievable benefits of the technology means that there is no near- or mid-term business case for operators to equip.

"Therefore at this time, the [ADS-B In Aviation Rulemaking Committee] does not support an equipage mandate," the group concluded in its 30 September report to the US FAA, which chartered the government/industry group in June 2010. FAA published the final report on 17 November.

Instead, the group suggested the FAA promote voluntary equipage "as its ADS-B In strategy for the foreseeable future".

FAA had tasked the ARC with making recommendations for how the aviation community should proceed with ADS-B In, which brings GPS-based ADS-B surveillance information from other aircraft into the flight deck for a growing number of situational awareness, navigation, air traffic and safety functions.

ADS-B In is widely considered a value-added natural extension of ADS-B "Out", which broadcasts an aircraft's GPS-based position, identification and other information for air traffic surveillance functions. By rule, operators must equip with ADS-B Out technology for FAA surveillance functions by 2020.

A variety of ADS-B In demonstrations have been completed or are on-going between the FAA, avionics manufacturers and airlines. Included are air traffic situation awareness with indications and alerts (SURF-IA) tests with US Airways, in-trail procedures (ITP) with United Airlines, and flight deck-based interval management spacing (FIM-S) with UPS, US Airways and JetBlue.

Avionics makers, including L-3 subsidiary ACSS and Honeywell, are key providers of first generation ADS-B In equipment, which usually includes a cockpit display of traffic information (CDTI) on an electronic flight bag or multi-function display.

While the ARC recommends accelerating demonstration projects, in part to help better define equipment standards and certification/operational approval guidance, it prioritised which applications should be matured first.

Most important are CDTI-assisted visual separation (CAVS), FIM-S, traffic situation awareness with alerts (TSAA) and oceanic ITP.

The group asked that the FAA delay funding on self-separation, or delegated separation, applications in favour of a concept called "defined interval". Under defined interval, air traffic controllers maintain separation responsibility while assigning pilots a "spacing task that must be performed within defined boundaries", the report stated.

Source: Air Transport Intelligence news