GAO hits satellite navigation plan

It is not clear that the benefits of a satellite-based navigation system

being developed by the Federal Aviation Administration are worth the costs,

according to a General Accounting Office report released last week.

The FAA's Wide-Area Augmentation System, a network of ground-based reference

stations and communications satellites, is being designed to verify and

correct the signal received from the Defense Department's Global Positioning

System satellites before sending the information to pilots.

The FAA had planned to provide initial capabilities by September 2000

but has pushed that back to 2002 and scaled back some of its plans. The

program has suffered from software problems and increasing costs.

GAO estimates the FAA may need three or more years to demonstrate the

requirement that WAAS will virtually never fail to warn pilots of an erroneous

GPS signal — which is known as integrity. That could cost an additional

$200 million to $240 million.

"The difficulties in proving the integrity requirement have occurred

largely because FAA management and the integrated product team underestimated

the complexity of resolving the integrity issue and, as a result, failed

to recognize the seriousness of the problem," according to the GAO report,

"National Airspace System: Persistent Problems in FAA's New Navigation

System Highlight Need for Periodic Evaluation," requested by Sen. Richard

Shelby (R-Ala.), chairman of the Senate Appropriations Committee's Transportation

Subcommittee.

GAO is pleased with the FAA management's new approach, which allows

time for collecting and evaluating data on system performance, the extent

to which users have purchased equipment and the availability of emerging

new technologies for the new navigation system. However, GAO recommended

the FAA devise a specific plan for reevaluating WAAS at critical points

in development and having the progress of the system independently validated

at the checkpoints before Congress approves additional funding.

In response to the report, the FAA told GAO that users would receive

major benefits from any level of precision approach into airports, and airports

would not necessarily need to upgrade their facilities to take advantage

of the approaches. The FAA also stressed some cost growth resulted from

other factors, such as changes in the way the Transportation Department

calculates project costs.