FAA opens up WAAS
Some aviation users and all nonaviation users were given access to the Federal Aviation Administration's satellitebased navigation signal as of Aug. 24, and key decisions about the future capabilities of the $3 billion system are expected to be made by early September, government and industry officials say.
Some aviation users and all nonaviation users were given access to the Federal
Aviation Administration's satellite-based navigation signal as of Aug. 24,
and key decisions about the future capabilities of the $3 billion system
are expected to be made by early September, government and industry officials
say.
The FAA decided to make the Wide Area Augmentation System signal available
to aviation users to increase situational awareness while on an airport
surface and while flying under visual flight rules — when instruments are
not required to overcome poor visibility. Nonaviation users include boaters
and hikers. The decision came after prime contractor Raytheon Co. performed
a 21-day test of WAAS' ability to offer a continuous, reliable signal.
WAAS is a network of ground reference stations that improve positioning
information from Global Positioning System satellites and send that data
to aircraft.
During the most recent tests, WAAS demonstrated its ability to provide
pilots with horizontal accuracy of 1 meter to 2 meters and vertical accuracy
of 2 meters to 3 meters throughout the continental United States, the FAA
said.
During similar tests last year, WAAS accuracy was found to exceed expectations,
but other software bugs were discovered in Raytheon's system. Tests of the
system's integrity — its ability to verify that the information it provides
is correct — found that WAAS may provide misleading and hazardous information
to pilots.
An independent panel was established early this year to research solutions
to the integrity problem. Unless WAAS meets the requirement of only one
failure in 10 million operations, it cannot be certified for use in safety-critical
applications. Initial operating capability is planned in 2002, a two-year
delay from the previous estimate.
FAA's WAAS program manager Dan Hanlon said he expects decisions to be
made based on the panel's findings within a few weeks. The panel is trying
to find technical solutions that will allow aircraft to use WAAS to get
within 200 feet above the runway and a half-mile away.
The panel has offered several ways to get that capability, but it will
be expensive and will require Raytheon to redesign some of its WAAS architecture,
said Doug Helton, vice president of air traffic services and technology
for the Aircraft Owners and Pilots Association. The decision will be "whether
the extra 50 feet is worth the extra cost," he said.Related links
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