FAA charts course for WAAS

The Federal Aviation Administration remains committed to incrementally developing its satellite navigation system but also acknowledged that the business case for a key system in that effort may have changed.

The Federal Aviation Administration remains committed to incrementally developing its satellite navigation system but also acknowledged that the business case for a key system in that effort may have changed.

The FAA announced plans April 10 to offer a safety-certified Wide Area Augmentation System in September 2003 that offers lateral and vertical guidance for landings up to the point when an aircraft is 400 feet above a runway and three-quarters of a mile away.

After the initial capability is in place, the FAA will increase coverage for the continental United States. A decision about if — and when — WAAS will offer a Category 1 precision approach, which provides guidance up to 250 feet above the runway and about a half mile away at some airports, is expected in September. The plans are based on the technical specifications of a WAAS Integrity Performance Panel and recommendations by an independent review board moderated by the Institute for Defense Analyses, Alexandria, Va. The review board's January report to the FAA said the plan was an "affordable pathway" to satellite navigation.

"I have a lot of my soul in this program," said Steven Zaidman, FAA associate administrator for research and acquisitions. "I'm encouraged that we have a date, a commitment."

Still, Zaidman called for the agency to re-evaluate the business case for WAAS because of continued cost overruns and the slow rate of decommission of traditional ground-based navigation aids.

"If there's not value for the money, we have to be upfront about that," he said. "I want to know my investment strategy is sound."

Since it began in December 1994, total program costs for WAAS have increased because of a change of contractor and delays developing software that measures the Global Positioning System signal's reliability. Zaidman said Ray-theon Co.'s contract now will remain steady at $494 million. Total program costs through 2020, including facilities, equipment, operations and maintenance, are estimated at more than $3 billion.

Zaidman said Raytheon is confident that it can deliver the initial system by June 2003. The FAA is offering the company incentives to do so, although Zaidman declined to give amounts, citing ongoing contract negotiations.

Raytheon spokeswoman Blanche Necessary said the company would meet with the FAA today to discuss details. Raytheon is fully committed to "expeditious completion" of the new safety algorithms for WAAS, she said.

Potential WAAS users remain skeptical.

"It's so far over budget and behind schedule that while, yes, our members — who fly into many small airports — would welcome WAAS, we're not holding our breath," said Clif Stroud, spokesman for the National Air Transportation Association, which represents charter aircraft operators, flight trainers and ground service providers.

Warren Morningstar, a spokesman for the Aircraft Owners and Pilots Association, agreed. "While we are strong supporters of WAAS, we are not going to be supporters at whatever cost. It does have to make economic sense."

MORE INFO

WAAS defined

The FAA's Wide Area Augmentation System uses a network of ground reference

stations to verify and correct location information received from Global

Positioning System satellites. WAAS also offers an integrity monitor that

warns pilots if it predicts GPS data will be unreliable.

WAAS was designed to provide 7-meter accuracy but provides 3-meter

accuracy or better.