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Originally published in the Summer 2002 Virginia Tech Research Magazine.

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From the folks who brought us space travel —

Faster, safer, cheaper air travel

By Liz Crumbley,
College of Engineering

Detail of General Aviation Timeline painting by Bill Kluge.

flight simulator photo

Jason Saleem (standing) and Jeff Lancaster, Ph.D. students in industrial and systems engineering, check configurations on the cockpit simulator used for human factors tests of pilots as part of the SATS project. The simulator, manufactured by Elite Simulations Solutions, can be re-configured to simulate as many as six different general aviation cockpits, including the Cessna 172 (as shown in the photo) and the King Air B-200. The simulator matches the panels of actual aircraft and is FAA approved for pilot training. As the SATS project progresses, the Virginia Tech simulator will be connected with others at NASA/Langley and George Mason University. Photo by Rick Griffiths.

If the folks who put Neil Armstrong on the moon have their way, before too long you’ll be able to travel from your hometown to a meeting 200 miles away and be back before supper, without spending hours standing in long lines at airport terminals or dodging 18-wheelers on the interstate. And it will cost you little more than it would to drive.

NASA — the National Aeronautics and Space Administration — intends to reduce inter-city travel time in the United States by one-half within 10 years and by two-thirds within 25 years, while keeping costs low and improving safety. Teaming with the Federal Aviation Administration (FAA), industry, and several universities, NASA has launched the Small Aircraft Transportation System (SATS) research program.

More than 98 percent of people in the United States live within 30 minutes of the nation’s 5,000 or more small airports. Simply stated, the idea behind SATS is to develop a system for safer, faster, and less expensive small planes to take off and land at these airports, enabling passengers to fly directly from one town or city to another.

“Two things have happened that can make all of this possible — the information age and jet technology,” says Howard Swingle. A licensed airplane pilot and a senior research associate in Virginia Tech’s Via Department of Civil and Environmental Engineering (CEE), Swingle is director of the university’s SATS program, a group of faculty members and graduate students who will help lay the groundwork for NASA’s master plan.

The NASA/Langley Research Center in Hampton, Va., has established “SATSLab” teams in Virginia, Florida, North Carolina, and Maryland. Virginia SATSLab research is being conducted at George Mason University, Virginia Tech, and Ohio University. The group hopes to use the municipal airports in Blacksburg (Southwest Virginia) and Manassas (Northern Virginia) for research and testing.

The Blacksburg airport is a good example of the improvements in travel that could be brought about by the SATS program. Many Virginia Tech and local business people travel out of Blacksburg to other localities in the state. “People who have to go to Northern Virginia for meetings usually end up spending the night,” Swingle notes. “If they could fly, they could make the trip in 90 minutes. Or they could get to Danville in 30 minutes.”

CEE Professor Toni Trani, a lead researcher in the SATS program and director of the FAA Air Transportation Center of Excellence in Operations Research, cites four major challenges facing NASA and SATS researchers in developing a successful system:

Improvements must be made in general aviation safety. General aviation is defined as all aviation other than commercial or military aviation — everything from twin-engine planes to corporate jets. The fatality rate of general aviation planes per million hours traveled is seven times the fatality rate of passenger cars; based on millions of miles traveled, the fatality rate of general aviation travel is three times that of automobile travel.

Increased air traffic would require methods for preventing en route conflicts. “If the SATS system attracts 5 to 10 percent of commercial air traffic in the U.S., that would add about 100,000 flights per day to the current 60,000 flights per day,” Trani says. “Resolving en route air conflicts would be especially important over metropolitan areas.”

Technology is needed at airports and on board planes to enable pilots to land in such low visibility conditions as fog and rain. In addition, technology at small airports will have to be boosted to support a significant increase in the volume of air traffic.

Improvements at small airports will have to be made in ways that are affordable. “Most small airports can’t afford traditional radar and air traffic control systems,” Trani says. “The SATS goal is to achieve optimal landing and takeoff opportunities using minimal equipment and staff.

“Cost will be a major factor in the program’s success,” adds Trani, who is working with recent Ph.D. graduate Hojong Baik and M.S. candidates Chad Ackely and Senanu Ashiabor to determine the economic feasibility of SATS. “The cost to the consumer will have to be competitive with other modes of travel.”

A plane for all seasons

“The U.S. has more than 500 airports equipped with radar systems costing about $9 million each,” says Tim Pratt, a professor in the Bradley Department of Electrical and Computer Engineering (ECE) at Virginia Tech. “But there are about 5,000 small airports with no radar or air traffic control. A major goal of SATS is to equip these airports to handle increased traffic in all kinds of weather.”

Pratt and ECE graduate students Eric Shea and Charles Florin are working on the Traffic Collision Avoidance System (TCAS) — a device that tells a pilot when other aircraft are in the vicinity and how to avoid them. TCAS is already used on large commercial airplanes.

One of Pratt’s goals is to adapt TCAS so that it can be housed on the ground at small airports to detect aircraft in the vicinity and alert incoming planes. “TCAS would fill the role of an air traffic control system at small airports,” he explains. “The intention is to equip an airport like Blacksburg’s with its own automated air traffic control.”

Pratt and his students also will have to figure out how to fit airplanes with receivers for TCAS signals. “Under the SATS concept, pilots can become their own air traffic controllers,” Pratt says. Unlike commercial airline pilots, general aviation pilots typically don’t (or shouldn’t) fly in bad weather, partly because many aren’t qualified to do so, but also because most private planes and small airports aren’t equipped for bad weather landings.

“One goal of SATS is to make small planes more useful and to open up general aviation as a popular mode of transportation,” Pratt notes. “We’re working on ways to make planes automated to the point that pilots would have few decisions to make.”

Another advance that will make small planes more automated is the Global Positioning System (GPS), a worldwide radio-navigation system, developed by the U.S. Department of Defense, that uses a network of satellites to pinpoint locations on earth. “NASA has ‘photographed’ all of the U.S. with GPS from the Space Shuttle,” Swingle notes.

This technology can provide pilots with location, navigation, tracking, and mapping information. “The SATS plan is to have all planes equipped with GPS,” says Swingle. “A GPS device can transmit information about a plane’s location to the ground and then to other pilots in the area.”

Before NASA embarked on SATS, it sponsored the AGATE (Advanced General Aviation Transport Experiments) and GAP (General Aviation Propulsion) programs. Aerospace and mechanical engineers developed technologies for better engines, less expensive manufacturing techniques, more automated cockpit controls, and improved pilot training processes and safety. “Small aircraft design hadn’t progressed for almost 40 years,” Swingle says. “But now there are manufacturers producing planes with advanced automation.”

The human factor

In addition to equipping airports with new technology and developing SATS-type aircraft, NASA needs to be sure that pilots are ready for a brave new world of flying.

“By increasing automation and information in the cockpit, SATS will change the role and function allocation of pilots,” says Brian Kleiner, associate professor in Virginia Tech’s Grado Department of Industrial and Systems Engineering (ISE) and director of the Human Factors Engineering and Ergonomics Center.

“The end vision of SATS is the pilot as ‘supervisory controller’,” adds Jason Saleem, a Ph.D. candidate in ISE’s Macroergonomics and Group Decision Systems Laboratory.

Kleiner and Saleem, along with John Casali, ISE department head and director of the Auditory Systems Laboratory; Gary Robinson, research professor; and Ph.D. student Jeff Lancaster, are conducting studies using a cockpit simulator developed by the Elite Corp. and approved by the FAA for pilot training. The simulator can be reconfigured to represent the cockpits in different types of small planes, including the Cessna and King Air (e.g. the “Hokie Bird”). The ISE researchers also will modify the simulator to resemble the automated cockpits developed as part of NASA’s AGATE program.

“We’re especially interested in safety,” says Kleiner. “SATS-type planes will be faster than current single-pilot aircraft and will be as fast as two-pilot aircraft, but they are expected to be flown primarily by single pilots.”

Using a number of human factors research questions, the ISE team will study local pilots who fly different types of general aviation planes. For example, can a single pilot safely land a plane in bad weather and at a steep descent angle at an airport that has no radar or air traffic control? If SATS comes into full swing as an alternative to commercial airline and interstate highway travel, many pilots will have to learn to manage diverse factors, such as low visibility, steep descents, and bad weather.

“Pilots also will have to track other planes in the vicinity when they’re flying into airports with no air traffic control or radar,” Kleiner says. This is where expertise from the Auditory Systems Laboratory comes into play. Casali, Robinson, and Lancaster are studying a different aspect of pilot response.

“A major question in our experiments will be how many separate aircraft a pilot can comprehend while receiving traffic information transmissions through headsets,” Lancaster says. At major airports, air traffic controllers keep track of all incoming and outgoing planes. At small airports, pilots themselves have to retain information about the locations of other aircraft.

“For SATS to be successful, general aviation pilots will need to learn to be confident and competent to fly in all kinds of weather and heavy air traffic,” Swingle says.

The fear factor

NASA conceived the idea of SATS years ago. After September 11, 2001, will the public embrace the notion of more frequent flying?

“Corporations may be more interested in SATS since September 11,” says Kleiner. “Many companies might feel safer flying their executives in corporate jets. However, the government may still have reservations about the security of small planes and airports.”

“September 11 has greatly increased awareness of flight safety,” agrees Trani. “More large corporations want their own planes now — and SATS planes would be less expensive than corporate jets have been in the past.”

Trani says that SATS jets also might become more attractive to companies because of security precautions that commercial airlines are forced to take, such as passenger and baggage scanning and the move toward eliminating first class and business lounges in airports.

But security measures will become a critical issue at smaller airports if SATS significantly increases public use of general aviation travel, Trani notes. “Small airports need to be as secure as major airports, but the small ones can’t afford expensive X-ray machines and the staff to operate them,” he notes. “Better screening of the people who have access to aircraft will be the best security measure, and the FAA has proposed new guidelines for screening pilots and student pilots.”

“SATS is a complex program,” Swingle says. “This will be an evolution, not a revolution — but it will evolve.”