CAA: GA News, "Airports to Get Guidance Systems Early"

["Stephen Irwin" <stepheni@xxxxxxxxx>]

Wednesday, March 13, 2002

Airports to Get Guidance Systems Early 
FAA to Introduce Procedures for Using Satellite Data at Smaller
Facilities 
By Don Phillips
The Washington (DC) Post


Regional airlines, business aircraft and small private planes will be
able to land more safely at more than 2,500 small airports using
satellites for guidance under new procedures to be introduced by the
Federal Aviation Administration starting late next year, two years
earlier than planned.

The FAA was able to move up the start date and implement the new landing
procedures at lower cost than expected because of a mathematical formula
developed by Mitre Corp., agency officials said. The FAA will begin the
process next year at five airports, which have not been selected, and
phase in the system at 350 airports each year thereafter.

The new landing procedures should be a huge help to pilots trying to
land when bad weather makes it difficult to see the airport.

Most large airports used by commercial jets have landing systems that
let pilots descend at least to an altitude as low as 200 feet or even to
land in zero visibility by using aircraft instruments.

But most smaller airports used by general-aviation aircraft and many
used by turboprops and regional jets do not have such instrument-landing
systems. In a pea-soup fog, a pilot headed to such an airport would not
be able to land.

The new procedures should enable a pilot to descend smoothly to an
altitude of at least 250 feet in zero-visibility conditions, at which
point the pilot might be low enough to see the airport and continue the
landing. If not, the pilot could abort the landing and fly elsewhere.
Without this system, pilots have to make that decision at higher
altitudes.

The new system will work by greatly refining the information provided to
pilots through satellite signals from the same Global Positioning System
(GPS) long used for navigation in planes, ships and pleasure boats, and
more recently in some passenger cars.

Technology known as a Wide Area Augmentation System (WAAS), which
refines GPS signals to determine positions more accurately, already
covers 90 percent of the country. When combined with the new
mathematical formula, planes equipped with a relatively inexpensive WAAS
box could be guided on a far more precise path than by GPS signals
alone.

With such information, pilots also would be able to descend gradually,
rather than use "step down" approaches in which planes descend for a
distance, then fly level for a while to clear obstacles, then descend
again. This process, which pilots sometimes call "dive and drive," is
less safe than smooth "stabilized approaches." The plane's approach path
also would be much narrower, reducing the danger of hitting obstacles on
the sides of the flight path.

Aviation groups welcomed the FAA decision. "A stabilized approach with
vertical guidance is a safer approach," said Warren Morningstar of the
Aircraft Owners and Pilots Association

Ron Swanda, vice president for operations at the General Aviation
Manufacturers Association, said that while the decision is "long
overdue" it will provide more efficient and safer approaches at small
and medium-size airports.

The WAAS is one of several satellite aids and procedures scheduled to be
introduced in the aviation system over the next decade. The WAAS
consists of 25 radio towers that receive GPS signals, send it to two
master ground stations on the East and West coasts for instant
processing via communications satellite, then broadcast the more
accurate signals. Other towers are planned for the 10 percent of the
country that is not now covered, particularly in vast areas of Alaska.

Monte Belger, FAA deputy administrator, said the system would be of use
in many developing countries, which could put the WAAS technology in
place at a fraction of the cost of instrument-landing systems.

To use the system, aircraft would need special equipment, which the FAA
estimated could cost $5,000 to $10,000 per plane.

Some people in the airline industry have expressed skepticism about the
new system, however, fearing it will divert attention and resources from
other programs that would be of much greater benefit to the major
carriers.

Such programs include a "required navigation performance" (RNP)
procedure that uses many resources, including satellites, on-board
guidance systems, radio beacons and other ground sensors to keep
airliners on a precision course to an airport. RNP has proved to be more
accurate than instrument-landing systems at greater distances from
airports. The FAA plans to implement an RNP procedure on the approach to
Reagan National Airport that follows the Potomac River past the White
House, also providing a potential security benefit because it would be
easy to instantly spot any straying aircraft on radar screens.

But Nicholas Sabatini, FAA associate administrator for regulation and
certification, promised there would be no letdown in efforts to
introduce RNP and other navigation tools. He pointed out that more
sophisticated systems such as RNP are needed for larger planes, which
have sophisticated flight-management systems.


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