FAA navigation system running late again

A critical system in the Federal Aviation Administration's plans to use satellite navigation again is behind schedule because of problems found during testing, FAA Administrator Jane Garvey said Thursday.

The Wide-Area Augmentation System (WAAS), a ground- and space-based system of 24 reference stations that correct and verify a positioning signal received from the Defense Department's Global Positioning System satellites, was having problems identifying whether a satellite signal is accurate.

WAAS, which is being designed by Raytheon Co., Lexington, Mass., was scheduled to go operational this September after a 14-month delay because of software development problems. The goal of WAAS is to improve the ability of aircraft to make precision approaches and landings.

The most recent glitch was discovered during Raytheon's tests of the system in the past two months, Garvey said before a joint hearing of the Senate Budget Committee and the Senate Appropriations Committee's Transportation Subcommittee. Although the tests demonstrated the system's ability to provide accuracy within 3.5 meters — better than the 7-meter requirement — they also showed the WAAS integrity-monitoring system produced too many false alarms, Garvey said.

FAA and Raytheon officials will conduct a technical review of the system next week to decide how to solve the problem, Garvey said.

Raytheon could not be reached for comment.

WAAS safety requirements allow only one failure in 10 million events, said Katherine Creedy, an FAA spokeswoman. The tests will be stopped until an action plan is approved, she said. The problem is not purely a software problem but also involves other architectural issues, she said.

A new date for operational capability has not been set.

In addition to slips in the WAAS schedule that moved its deployment from 1998 to 2000, the program's budget has increased from early estimates of $893 million to $3 billion, said Kenneth Mead, inspector general at the Transportation Department.

More information on WAAS is available at gps.faa.gov.