Air Transport

The US Government has revised the schedules for phasing out most land-based radio navigation systems after acknowledging the vulnerability of the global positioning system (GPS) to intentional and unintentional interference. The delayed 2001 Federal Radio navigation Plan, jointly released by the Departments of Defense and Transportation (DoT) last week, provides more time to move to GPS as the primary - but not sole - means of navigation.

The revised plan continues the DoT's policy of operating Loran-C in the short term, while evaluating the long-term need for the ground-based radio navigation system, which proponents argue, is the ideal back-up to GPS. The department is completing studies of Loran-C's suitability as a back-up system, and will make a decision this year.

The US government remains "committed to switch to a satellite-based navigation service for transportation", says DoT director of radio navigation Michael Shaw - but a "fail-safe mode" of ground-based navigation will have to be maintained even after the transition to GPS. "Some individuals were overly optimistic in saying [GPS] would be the only system needed," he says.

A US aerospace panel is calling for increased civil-military co-operation to avert looming air transport gridlock. The Commission on the Future of the United States Aerospace Industry is not due to report until November but has issued urgent interim recommendations. It says that co-operation on air traffic control issues among the USAir Force, CIA, National Reconnaissance Office and Federal Aviation Administration is needed to create an integrated plan that includes space-based components.