Aug. 26, 1997
Headquarters, Washington, D.C.
NASA Langley Research Center
NASA Ames Research Center
FAA Headquarters, Washington, D.C.
RELEASE NO. 97-105
NASA TESTS CONCEPTS FOR LOW-VISIBILITY AIRPORT OPERATIONS
NASA is demonstrating technology on the runways and taxiways of Hartsfield-Atlanta International Airport that promises to keep traffic moving safely and efficiently day or night regardless of visibility.
The technology is actually many technologies integrated into one super system. On the ground is a Federal Aviation Administration-developed system of ground surveillance sensors and other equipment. Onboard NASA's Boeing 757 research aircraft are the airborne systems and displays.
The research program calls for a total of 53 flight tests and demonstrations at Hartsfield-Atlanta to be completed by the end of August. Demonstrations will be to about 100 airline and industry executives and officials of the FAA and other government agencies.
"The idea is to demonstrate the feasibility of safely performing low-visibility operations at capacities that currently are performed in clear weather," said Steve Young, flight test co-principal investigator from NASA Langley Research Center, Hampton, VA. "We've all experienced what happens to the air traffic system when weather slows traffic at an airport. And the trend is toward more traffic delays. This work has the potential to slow that trend as well as improve safety."
The research is part of NASA's seven-year Terminal Area Productivity (TAP) program begunin 1994, led by NASA Ames Research Center, Moffett Field, CA. TAP is part of the agency's aviation system capacity program, expected to substantially increase aviation system throughput in all weather conditions.
For the Atlanta effort, dubbed the Low Visibility Landing and Surface Operations (LVLASO) program, the cockpit display system is an integration of two subsystems. The Roll-Out Turn-Off (ROTO) guidance subsystem was developed at Langley and aids the pilot during the roll-out and turn-off portion of the landing (after touchdown, rolling down the runway and exiting the runway onto the taxiway). The Taxiway Navigation & Situation Awareness (T-NASA) display subsystem was developed by Ames and is being used in the Atlanta deployment as a pilot aid during taxi.
As the research aircraft approaches the runway, computer-generated graphics outline the correct runway and its precise location on a glass visor mounted between the pilot and the cockpit windshield. Upon contact with the ground, the pilot's aircraft position and that of other aircraft is shown on an electronic moving map of the airport on the instrument panel. With GPS satellite positioning and an airport layout database the displays are updated in real time. During roll-out and turn-off from the runway, the head up display provides the pilot with guidance so that runway occupancy time is minimized.
The glass visor, or head-up display, shows the edges of the runway and taxiway with a series of computer-generated "cones" in a virtual reality manner. During taxi, a turn is indicated by virtual cones and signs showing the angle and direction of the turn. As the pilot taxis, the virtual cones and signs move and change as if they were actual objects on the taxiway. The pilot's cleared route looks like a virtual highway on the ground.
"Earlier studies with the Ames display system have shown that making it available to the pilot virtually eliminates the kind of navigation errors that crop up in low visibility conditions, when the pilot has trouble seeing surface signage and other salient landmarks," said Ames T-NASA co-principal investigator Robert McCann.
Ground-based components consist of a surveillance system that provides traffic positions to the 757 via a computer datalink and a controller interface that allows air traffic controllers to transmit instructions to the aircraft by computer in parallel with normal voice communications. The controller is also automatically informed via this computer link if the 757 deviates from its approved path.
A combined ground and airborne system can reduce the growing number of ground accidents and close calls by increasing the situational awareness of both pilots and controllers. Additionally, the digital datalink greatly eliminates the possibility of miscommunication between controller and pilot.
Other flight demonstration team members are Rockwell International, Cedar Rapids, IA; Cardion, Inc., Woodbury, NY; St. Cloud State University, St. Cloud, MN; Volpe National Transportation Systems Center, Cambridge, MA; Jeppesen Sanderson, Englewood, CO; Trios Associates, Inc., Greenbelt, MD; Project Management Enterprises, Inc., Bethesda, MD; Rannoch Corp., Alexandria, VA; and QuesTech, Inc., Falls Church, VA.
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