The US Federal Aviation Administration will retain most ground-based navigation as back-up in case the global positioning system (GPS) is deliberately or accidentally jammed. As a result, savings from the move to satellite navigation will not accrue for at least 20 years.
Airspace users have been briefed on the plan due to be presented by July to the US Department of Transportation, which will make recommendations by December.
Although the FAA intends GPS, with wide-area and local-area-augmentation systems, to become the primary means of US airspace navigation, aircraft will have to carry ground-based back-up. General aviators must retain a VHF omni-range (VOR) receiver, while business aircraft and airliners will have to carry VOR, distance measuring equipment (DME) and instrument landing system (ILS) receivers.
The FAA is to retain all 930 DME stations, but reduce VORs to 450-550 sites by 2102. Category II and III ILSs will remain, but Cat I ILSs will be cut to a runway per airport.
Source: Flight International
