ROANOKE TIMES
Copyright (c) 1997, Roanoke Times
DATE: Friday, February 7, 1997 TAG: 9702070040
SECTION: NATIONAL/INTERNATIONAL PAGE: A-1 EDITION: METRO
DATELINE: WASHINGTON
SOURCE: Associated Press
THE FREE-FLIGHT SYSTEM, to be tested in Alaska and Hawaii starting in 1999, may ease traffic and allow quicker, safer flights.
Every high school geometry student learns that the shortest distance between two points is a straight line. The government is ready to let airplane pilots use that information.
If a two-year test is successful, the Federal Aviation Administration plans to allow carriers to ignore indirect but long-established routes and fly where they want.
It may sound like a dangerous free-for-all, but the agency expects the free-flight system to ease congestion and therefore be safer. Some flights will be quicker, not only because of the principles of geometry but because the lack of traffic will allow planes on some routes to fly faster.
The 24-month test for planes in Alaska and Hawaii is to begin in 1999. If successful, it will expand to the rest of the country, which could take more than a decade.
``The test gives us an airspace where all, or almost all, aircraft are properly equipped to use the system,'' said George Donohue of the FAA.
Most airliners now follow directions from ground-based controllers, crossing the country from checkpoint to checkpoint, often in zigzag paths that waste time and fuel.
For example, a flight from Los Angeles to Chicago follows a straight path across California, then veers sharply northeast through Nevada and Utah. In Wyoming, the plane takes a hard right and flies across the Plains into Chicago. A direct path would stay farther south, taking the plane across the northwest tip of Arizona and a corner of Utah before bisecting Colorado.
Established air routes allow controllers to follow where planes are and keep them at least three miles apart horizontally and 1,000 feet apart vertically.
As the number of commercial planes in service grows, so-called ``jet routes'' across the country are becoming more crowded.
With free flight, planes will no longer be confined to the narrow paths. Instead, pilots can choose their routes, taking advantage of favorable winds, avoiding storms and saving time and money.
As now, they will file flight plans.
Officials anticipate the system will spread planes out and make close calls less likely.
``Free flight is synonymous with benefits for everyone,'' said David Watrous, chairman of the government-industry panel that developed the plan. He said benefits will include safety, faster travel and reduced operating costs.
In the test, about 600 commercial and private aircraft in Hawaii and 1,400 commercial planes in Alaska will be equipped with special electronic gear, allowing them to plot routes using satellite navigation and to detect and avoid other planes. Air traffic controllers will keep watch to make sure planes don't come too close.
Many long-range aircraft pass through Alaska and Hawaii en route to Asia. Donohue said many of those planes already have much of the equipment that would be needed for free flight.
Alaska and Hawaii were selected for the test because they provide a relatively controlled environment with a manageable number of planes. In addition, Alaska offers a wide range of weather conditions and rugged terrain to help in evaluating the system's safety.
Equipping the nation's 200,000 aircraft with the necessary equipment could cost more than $7 billion, Donohue said. ``A major goal is to get the cost down so as to remove that barrier,'' he said.
Required equipment includes a global positioning system, digital radio, automatic surveillance broadcast system, weather links into the cockpit, radar and other items.
The complex gear will create electronic zones around each plane and allow air traffic controllers to order route changes if planes get too close. The size of the zones would vary depending on the size and speed of each plane.
LENGTH: Medium: 76 linesby CNB