Graham Warwick/WASHINGTON DC
The first phase of the revised modernisation plan for the US National Airspace System (NAS) is to concentrate on ground infrastructure improvements. "There will be little impact on avionics equipment," says a senior Federal Aviation Administration official, indicating that features such as automatic dependent surveillance-broadcast and the global positioning system (GPS) "...will not be part of Phase 1", expected by 2002.
Government industry advisory body RTCA was scheduled to present its recommendations on the timing and sequencing of the first phase of NAS modernisation to FAA Administrator Jane Garvey on 2 March. Garvey asked the RTCA's Free Flight Select Committee in February to advise the agency's NAS Modernisation Task Force on what Phase 1 should consist of.
Only five elements of the Free Flight airspace management concept are being considered for the first phase, all but one ground based. These include the conflict probe, sequencing tools, collaborative decision-making - and an initial demonstration of controller-pilot datalink communications.
The FAA is trying to decide what elements to deploy, and where, to give airspace users early benefits. "Maybe we can get 70% of the benefits [of free flight] at 10% of the sites, then go national later," the official says. NAS Phase 1 could be deployed nationally by 2005, by which time the GPS wide area and local area augmentation systems would be fully available and the USA could begin decommissioning its ground-based navigation aid network, the official suggests.
Phased modernisation has become necessary after the FAA failed to secure the budget required to implement the nationwide upgrade envisaged in Version 3.0 of the NAS architecture plan. This was drafted in response to Gore Commission recommendations that the NAS be modernised by 2005, "-and was not constrained by budget", the official says.
When the Clinton Administration presented its fiscal year 1999 budget to Congress in January, it became obvious that the FAA was not going to get the money it needed. "We were over budget, feedback from users of the system was not universally positive, and some of the implementation components were risky," the official says.
The FAA is now trying to draw up a "less risky, more affordable" phased modernisation plan that stays within its budget.
Source: Flight International
