UPDATE
An Olympic Legacy in the Sky
Heli-STAR demonstrates vertical flight transport potential in urban areas.
By John Toon
A research and development project conducted in Atlanta during the 1996 Centennial Olympic Games could help open the door for expanding helicopter transportation in crowded urban areas — and improving air traffic control in the nation's congested skies.
photo by Bob Cassanova
A helicopter participating in
Operation Heli-STAR lands at Georgia Tech's Cobb County Research Facility.
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Air traffic control radar now is the primary means for monitoring aircraft in flight, but ground clutter caused by obstructions such as tall buildings prevents tracking low-altitude flights in urban areas. That has restricted development of helicopter transportation in cities where clogged highways would make vertical flight an attractive alternative to ground transportation for passengers and cargo.
But the success of Operation Heli-STAR (Helicopter Short-Haul Transportation and Aviation Research) during the summer of 1996 may help change that. Supported by the Federal Aviation Administration (FAA), the project for the first time showed that communications, navigation and surveillance (CNS) equipment based on the Global Positioning System (GPS) could reliably track helicopters operating in large metropolitan areas.
"Operation Heli-STAR showed that the technology is here now to do low- altitude traffic control in urban areas," says Charles M. "Chuck" Stancil, manager of the Aerospace Sciences Branch of the Georgia Tech Research Institute (GTRI). "Everything that we planned and designed for the system worked. We could track the aircraft, communicate with them, send weather information, and even change the mission just by using digitized messages."
Some 88 aircraft equipped with this technology participated in Heli-STAR during the Games period in Atlanta. The aircraft used on-board GPS systems to determine their own positions, then reported that information every few seconds to a central ground station through a very high frequency (VHF) data link. Based on a system of Earth-orbiting satellites, GPS provides extremely accurate position information — and is not affected by the ground clutter that prevents use of radar.
In addition to providing information for ground controllers, Heli-STAR also sent data about all project aircraft operating in the area to multi- function displays installed aboard many of the helicopters. This information helped pilots watch out for nearby air traffic. The displays also included information on flight routes and ground obstacles such as transmission towers.
"This was the first time this technology had ever been used on such a large scale in this way, and it was very successful," reported Stancil. "Heli- STAR was operating in a real-world situation, carrying real cargo, serving real customers and working in an operational environment guided by air traffic controllers."
On its busiest day, the project processed 83,000 aircraft position reports between 6 a.m. and 10 p.m., tracking some 60 aircraft engaged in a wide range of cargo delivery and public safety missions, including critical security requirements.
Heli-STAR development began in 1994 with the FAA seeking to identify potential safety and operational issues and solutions for low-flying aircraft operating at events such as the Olympics. This requirement expanded later to address requirements for routes and airspace needed to support time-sensitive parcel package cargo.
Heli-STAR used 12 heliports strategically located around the Atlanta area to accommodate a flight schedule dictated by the needs of cargo shippers. Routes were established to minimize noise and avoid the restricted airspace set up around Olympic venues. On the ground, sophisticated equipment used bar-coding and an extensive computer network to track cargo as it moved through the transportation system to its final destination.
Heli-STAR was intended both to demonstrate the feasibility of the GPS- based equipment and to gather research information for development of future large-scale helicopter and low-altitude operations. Information obtained on cargo volume and costs should aid economic decisions that will have to be made for such systems.
"The lessons learned are really a collection of planning tips that would enable anybody else to do this anywhere in the continental United States, Alaska or Hawaii," Stancil explains. "You can literally set up a checklist based on what came out of Heli-STAR. If you do all these things, you will have touched all the bases necessary."
Among those key "bases" are state and local governments, which regulate heliports, zoning and related issues. Other key groups include the local aviation community, law enforcement agencies and the public at large.
The Heli-STAR program was itself the result of cooperation among numerous government and industry groups who shared the $10 million cost of planning, developing and implementing the project.
The FAA's General Aviation and Vertical Flight Program office served as the lead government office, and worked closely with the Agency's Southern Region and its Flight Standards and Airports Offices. The National Aeronautics and Space Administration's (NASA) Advanced General Aviation Transport Experiment (AGATE) program provided the CNS equipment through a program called the Atlanta Communications Experiment.
Technical assistance came from Science Applications International (SAIC), the FAA's technical support contractor. SAIC contracted with GTRI to provide local project management, cargo operations, data collection and analysis. The Project Operations Center was also established at GTRI's Cobb County Research Facility, near Dobbins Air Force Base.
The helicopter and private industry's contributions came through the Helicopter Association International (HAI), and the Atlanta Vertical Flight Association (AVFA). The Georgia Emergency Management Agency (GEMA) coordinated the public safety elements of the project.
ARNAV Systems provided the CNS equipment, while the Harris Corporation provided the air traffic control work stations. Other participants included Pan American Weather Services, Petroleum Helicopters, Inc., Genisys Operation, Albert and Associates, Inc., CommuniQuest and GNSS Corporation. U.S. Department of Defense agencies offered further assistance with equipment and certification.
Though the system worked very well, Heli-STAR aircraft carried less cargo than anticipated. Two factors combined to reduce cargo transportation.
The first was the absence of the gridlock that had been forecast for Atlanta's highways.
"The shippers found that traffic was much lighter than everyone had expected, and therefore they could move things faster using their trucks and courier vehicles than they would have under normal conditions," Stancil notes.
The second factor involved security arrangements surrounding Olympic visits by the president and vice president. The "security bubble" over these dignitaries shut down portions of Heli-STAR four times during the Games period for hours at a time, disrupting cargo deliveries and causing some shippers to rely on their ground vehicles for cargo designated for Heli-STAR.
photo by Gary Meek
Researchers tracked low-altitude
aircraft in Atlanta using this Operation Heli-STAR workstation.
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Stancil believes the success of Heli-STAR leaves developers of urban vertical flight programs with mostly non-technical issues to resolve.
"It's really a public perception issue now," he says. "The technical and engineering issues related to CNS are being resolved. Heli-STAR demonstrated that you can manage aircraft in a safe manner in an urban environment with this technology. The problem is how the public perceives helicopter activity in close proximity to where they live and work."
The two most important issues there involve noise and safety.
Heli-STAR contributed to the resolution of noise concerns by showing that helicopter operations can be "good neighbors." A central office established to field aircraft complaints got just 43 calls during the Games, none of them involving Heli-STAR aircraft.
"There was no distinguishing public response to the presence of helicopters, which is important in light of previous suggestions that people would have an aversion to helicopters," Stancil says. "We were very careful in how we designed routes, chose the altitudes and specified the flight patterns."
GTRI researchers also gathered extensive information about the acoustic contours surrounding two of the heliports before and during Heli-STAR operations. That information will be helpful in predicting the noise impacts of future terminal operations.
Stancil believes the perfect safety record established by Heli-STAR during the Games period should also go a long way toward resolving safety concerns.
For the future, researchers must continue to refine procedures and the user interface for the navigation equipment. They will also have to determine the limits of the system's ability to safely monitor aircraft.
"The next step will be to integrate this system into a precision flying operation in which we can understand the limits of safety and utility with regard to the GPS technology and the benefit it may provide for vertical flight transportation in urban areas," Stancil says.
Beyond expanding vertical flight in urban areas, Heli-STAR helped lay the foundation for an improved national air traffic control system that would use GPS technology for monitoring the thousands of commercial and general aviation aircraft criss-crossing the nation's skies.
Aircraft must now follow a rigid system of flight routes established decades ago that do not always offer the most optimal paths. GPS technologies could one day liberate aircraft from those pre-set routes, allowing "free- flight" that would reduce both fuel consumption and flying time.
"What we could do is take radar out of the primary surveillance mode of air traffic control and substitute CNS technology on the ground and in the air that would enable the aircraft to take off, point its nose in the direction it wants to go, and go," Stancil explains. "This would make air travel safer and faster. The net benefit to the traveling public would be to make air service a better product."
Further information is available from Mr. Charles Stancil, Aerospace and
Transportation Laboratory, Georgia Tech Research Institute, Georgia Institute of
Technology, Atlanta, GA 30332-0844.
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Last updated: Dec. 3, 1997