No one is happy with long lines and delays at our nation’s airports. In
response to the growing need to improve the National Airspace System, NASA is
developing tools to ensure future air travel will be safe and efficient.

NASA, the Federal Aviation Administration (FAA), and the MITRE Corp., McLean,
Va., successfully conducted tests of the Multi-center Traffic Management Advisor
(McTMA) at air traffic facilities responsible for the northeastern United States.
Initial results indicate the software’s scheduling capabilities helped air
traffic managers prevent bottlenecks.

At the heart of McTMA is a powerful “trajectory synthesis” engine capable of
converting radar data, flight plans and weather information into accurate
forecasts of air traffic congestion. McTMA uses these forecasts and input from
air traffic personnel to generate a specific advisory, typically a small delay,
for each aircraft predicted to encounter congestion.

“McTMA is an advanced air traffic management system that makes possible a
fundamental shift in air traffic control form from distance-based to time-based
metering of aircraft,” said Tom Edwards, deputy director of the Aeronautics
Directorate at NASA’s Ames Research Center, Moffett Field, Calif. “Time-based
metering can reduce airborne delays and improve coordination and planning between
adjacent air traffic control facilities,” he added.

Tests were conducted with managers at the Air Route Traffic Control Centers in
New York, Washington, Boston and Cleveland; the Philadelphia Terminal Radar
Approach Control and the National Air Traffic Control System Command Center in
Herndon, Va.,

The successful tests validated the McTMA “distributed scheduling architecture,”
and helped air traffic managers prevent bottlenecks at the Philadelphia
International Airport.

“The evaluation successfully demonstrated the advantages of the McTMA departure
metering capability over current techniques,” said Tom Davis, principal
investigator for McTMA, and chief of the Terminal Area Air Traffic Management
Research Branch at Ames. “During several periods at Philadelphia, when airborne
holding is routinely encountered, no such holding was observed when McTMA was in
use,” Davis added.

Frequently, adjustments of just a few minutes at the point of origin can
alleviate airborne traffic jams at the destination. The result is safer and more
efficient operations for airlines and the flying public as the system produces a
steady but manageable flow of air traffic.

“Future tests will seek to gradually expand the McTMA operational envelope to
demonstrate multi-center, time-based metering of departures, arrivals and en
route flows to multiple destinations,” Davis said.

Earlier versions of the system are used to schedule arriving aircraft at Dallas-
Ft. Worth, Minneapolis, Los Angeles, Denver, Houston, Miami and Atlanta airports.
As testing progresses, McTMA’s time-based metering may be applied to departures,
arrivals and en route aircraft across broader airspace regions and air traffic

Testing of the newer McTMA system is scheduled to resume in February 2005 at the
same facilities. If fully successful, NASA and the FAA will work together to
bring the technology into future operations to benefit air travelers.

The program is managed by the Airspace Systems Division of NASA’s Aeronautics
Research Mission Directorate. The software was developed at Ames.

For information about the McTMA system and other air traffic management decision
support tools, visit:

For information about NASA aeronautics research, visit: