Synthetic Vision. Photo by Rob Hardin/Ohio University
To cars speeding by on U.S. 50/32, Gordon K. Bush Airport looks like any other general aviation field. But some of the airplanes in its hangars are outfitted with unique high-tech equipment, and the collection of the sophisticated antenna arrays at the end of the runway can’t be found at any other airport.
This is the home of the Ohio University Avionics Engineering Center, the only organization of its kind in the United States. For the last 50 years, center researchers have been the Federal Aviation Administration’s (FAA) go-to experts for innovation in electronic systems that help aircraft communicate, navigate, and land safely.
“For the first 30-plus years, we didn’t have any peers—we were the only ones doing avionics work,” says Mike Braasch, the Thomas Professor of Electrical Engineering who headed the center from 2007 to 2011.
Although the field has grown, the center remains the nation’s premier avionics research institution.
“We’ve been doing this so long that we’ve built a critical mass of people, infrastructure, and equipment that allows us to do a broad range of research,” Braasch says.
The center was the brainchild of Richard McFarland, an Ohio University alumnus who had been in love with flying since his boyhood in Massillon, Ohio. In 1963, the center was just McFarland and a graduate student. Today, the center encompasses five faculty members with appointments in electrical engineering and computer science, 10 research engineers, and three technical associates, as well as 20 student interns.
McFarland envisioned an institution in which the brightest minds in engineering would solve real-world challenges in aviation. Not long after its launch, the center attracted national attention for its expertise. In 1971, the FAA and NASA created the Joint University Program for Air Transportation Research to advance aviation research. Its members are the Massachusetts Institute of Technology, Princeton University, and Ohio University. The program is still going strong, nearly 45 years later.
The center has been awarded more than $144 million in research grants and contracts since 1963. The university’s Stocker and Russ Endowments fund some offices, hangar space, and other special facilities and equipment needs. The external support comes from the FAA, NASA, aerospace companies, and aviation authorities all over the world that count on the center’s expertise.
And there is a lot of expertise here. If it has to do with national infrastructure supporting aviation navigation, chances are the center created, developed, prototyped, programmed, and/or tested it. Researchers have improved the Instrument Landing System that has been in use since the 1930s and are key players in the development of the Next Generation Air Transportation System (NextGen) system that will replace it. Some of the center’s projects—like real-time 3D virtual-reality cockpit displays—sound like science fiction, but they’re approaching reality.
Flight inspections are a big part of the center’s work, too. Engineers often help write the criteria the FAA uses to measure the safety and effectiveness of new technologies, and some participate in the agency’s test flights.
“The FAA performs a standardized final check to make sure everything is as it should be before a technology is authorized to be used by air crews and air traffic control,” says Mike DiBenedetto, who became the center’s director in 2011. “Very seldom does a civilian get to be on an FAA inspection flight, but we have several folks who have been asked along for their expertise.”
The center also has a seat at some important tables; researchers serve as advisors on national and international aviation issues.
“Technology comes and goes, but the ability to help the government solve problems, hard problems, is really our greatest hit,” says research engineer Trent Skidmore. “Whatever the technology problem of the day is, we solve it—we have the tools, the people, the math. We can apply all of those tools to solve whatever problem it is.”
Trent Skidmore is a senior research engineer at the Avionics Engineering Center. Photo Illustration: Ben Siegel/Ohio University.
1983: Where Are We? GPS Takes Off
Perhaps the center’s most significant contribution to avionics has been its work with the Global Positioning System, which dates to 1983. The center received its first grant for GPS work from the FAA in 1993, the same year that the system reached its initial operational capacity.
“When I first joined the center, somebody was talking about this GPS thing, satellites that were supposed to give your position accurate to 25 meters anywhere on Earth,” says Braasch, who began working at the center as an undergraduate intern in 1985. “It was said with a chuckle because it was like, ‘Yeah, right.’ Now it’s more like five meters or less.”
Making GPS signals more accurate was vital to making them useful for aircraft navigation and landing. Airports have used the Instrument Landing System (ILS) — basically radio beacons transmitting from the end of runways — to guide landing aircraft in poor visibility since the 1930s. Much of the center’s early work revolved around improving and maintaining ILS equipment; Richard McFarland, the center’s founder, was a leading ILS researcher whose work is still used at airports around the country.
1993: Safe Landings: Developing Technology Systems
In the early 1990s, the FAA began looking at what it calls the Local Area Augmentation System, which would use GPS to guide navigation and landing at a closer range. In theory, a single LAAS installation could provide Category III capabilities (landings with 50 feet of visibility) for every runway at a given airport, making flying safer and more convenient.
Over a five-year period beginning in 1993, center researchers turned that theory into reality. Led by Russ Professor of Electrical Engineering and Computer Science Frank van Graas, the team resolved the problem of multipath, a phenomenon in which an aircraft receives not only the transmitted GPS signal, but also signals that bounce off the ground and nearby structures.
That allowed them to create a system that was precise enough for Category III landings; its effectiveness was proven in a series of test flights conducted between 1994 and 1998. Field testing of the system began in 1999, when a center-designed LAAS was installed at Dallas/Fort Worth International Airport for FAA and NASA evaluation. It took another 13 years before the FAA approved use of the first LAAS installations, at Newark Liberty International Airport and Houston Intercontinental Airport.
For more than 20 years, Frank Van Graas (right) has worked on technologies aimed at using the Global Positioning System (GPS) for navigation and landing. Wouter Pelgrum (left), who joined the center in 2009, is exploring backup GPS systems for the FAA’s Next Generation Air Transportation System (NextGen), including an enhancement to worldwide Distance Measuring Equipment (DME) system. Photo credit: Ben Siegel/Ohio University.
“Things in aviation move kind of slow,” says Skidmore, senior research engineer at the center. “The technology is always five or 10 years behind what’s in the labs. This process is in place because of safety.”
Creating the system isn’t enough. The FAA must know that the technology will work in all kinds of environments, under all types of conditions, and for all manner of aircraft. And it must work all the time. Based on its experience with LAAS, the center helped write the criteria that the FAA used to certify the installations at Houston and Newark.
Meanwhile, GPS has become ubiquitous. It’s now in our cars, our phones, and on our laptops.
“The same system that’s landing the most advanced fighter jet in the world is the same technology that’s helping you find the local Starbucks,” Skidmore says.
Skidmore is lending his GPS expertise to the National Coordination Office for Space-Based Positioning, Navigation, and Timing, which collects and analyzes information about military, civil, and commercial GPS usage. The office advises the National Executive Committee for Space-Based PNT—which advises the president.
“A lot of the work at the coordination office occurs because of the need to free up communication bands,” says Skidmore, who represents NASA for the office. “Would you rather have some kid download movies on his phone or be safe on a flight?”
1998: New airplane hangar or terminal? Avoiding signal interference
Even the best navigation and landing systems can be stymied by interference from structures — new hangars or terminals at the airport, a warehouse or office building — that distort radio signals. The Ohio University Navigation and Landing Performance Prediction Model (OUNLPPM) is a software program that helps aviation authorities troubleshoot problems with navigation and landing systems, analyze the impact of new real estate developments on those systems, and find the best location for new installations. The center licenses the software to users only if the buyer agrees to be trained by Ohio University personnel.
“If they don’t know how to use it, they call me every day,” says Simbo Odunaiya, a senior research engineer who participated in developing the model for the center.
OUNLPPM is in use by aviation authorities and aeronautics companies in 16 countries in North America, Europe, and Asia. It’s also used by the U.S. Air Force and the Army.
Simbo Odunaiya works with aviation authorities worldwide to avoid signal interference. Photo Illustration: Ben Siegel/Ohio University.
1999: Next Generation Air Transportation System
Radar-based air traffic control has been the norm since its introduction in the 1920s. The FAA wants to bring the United States into the 21 st century with an airspace system it calls the Next Generation Air Transportation System (NextGen).
Automatic Dependent Surveillance-Broadcast is a primary element of that plan. Through ADS-B, aircraft track their own positions via GPS and transmit that data to air traffic control. They also can receive data from nearby aircraft. ADS-B gives pilots of equipped aircraft more information at their fingertips about weather, air traffic, and terrain, all in real time.
Mike DiBenedetto became the center’s director in 2011. Photo Illustration: Ben Siegel/Ohio University.
Center researchers have been working with ADS-B since 1999, when the FAA asked the center for its help in testing and demonstrating early prototypes. Since then, the center has tested ADS-B for NASA and aerospace contractors as well.
More recently, the center has helped the FAA as it introduces ADS-B across the United States. Two center researchers have flown nearly 1,400 hours all over the country to test the availability and accuracy of ADS-B signals.
“The flight evaluations we performed augmented FAA flight inspection efforts, reducing the time to implementation,” DiBendetto says. “Having such a role speaks favorably to the level of trust the FAA has for Ohio University—organizations outside the FAA are seldom given such critical evaluation roles.”
2000: Advanced Flight Displays
Your pilot has a six-pack in the cockpit. Not alcohol; not a washboard stomach — the set of six dials that indicate the aircraft’s position and speed. That same setup has remained the same since the late 1920s, even though most modern airliners have LCD screens instead of individual gauges.
Center researchers are working to ditch the six-pack in favor of a new advanced display for Synthetic Vision, an existing technology created by NASA and industry that combines satellite topography databases with GPS to show pilots a real-time, 3D image. The display, created through a collaboration between Maarten Uijt de Haag, the Edmund K. Cheng Professor of Electrical Engineering and Computer Science, and Erik Theunissen of Delft University in The Netherlands, is designed to greatly improve safety, particularly for small aircraft flying in bad weather.
While fatal crashes of commercial airliners have been virtually eliminated in the United States (the last fatal crash involving a major domestic airline was in 2001), 432 people were killed in general aviation crashes in 2012 alone, according to the National Transportation Safety Board.
Synthetic Vision could display all types of information for the pilot: the terrain, nearby air traffic, the weather farther ahead in the flight path. The trick is determining what information will be most useful and when — without confusing or distracting the pilot.
Center engineer Tony Adami and Uijt de Haag have created a system to test Synthetic Vision displays. They wrote computer code that combines commercial flight simulation software with their Synthetic Vision and other display algorithms.
“We can put a pilot in the simulator seat and say, ‘Try this maneuver using this information versus that information,’” Adami says. “We might simulate bad weather; we might turn off the simulation display so they can see only the Synthetic Vision screens.”
Jim Zhu (left) and Tony Adami (right) use the Galah, an unmanned aerial vehicle, to study new navigation technologies; Maarten Uijt de Haag (center) and Adami are involved in the development of Synthetic Vision. Photo credit: Ben Siegel/Ohio University.
2003: Unmanned Aerial Vehicles
Unmanned aerial vehicles (UAVs) have great potential in the domestic market. Farmers and ranchers could use them to check on crops and livestock at the farthest reaches of their land. Realtors could show potential buyers aerial photographs of properties. Instead of engaging in dangerous high-speed chases, law enforcement could track a fleeing suspect from the air. Fire officials could get live views of a forest fire, allowing them to warn their crews when the flames endanger them. And of course, Amazon.com wants to deliver your books via UAV.
UAVs are essentially more sophisticated versions of the radio-controlled model airplanes you might have flown as a child. But those models are always in your sight. To make UAVs safe for civilian use, engineers have to find ways to overcome multiple challenges.
“A UAV’s primary purpose isn’t to transport people or things; it’s usually to collect information, take pictures, and so on,” says Braasch. “At certain points it may hover or fly in circles. That changes the analysis because you’re not spending the bulk of the time in straight, level flight like a manned aircraft typically does.”
Some center researchers use the center’s Brumby UAV, which can fly more than 100 miles per hour for up to 60 minutes. It already has been equipped with a GPS receiver and a special data link to send navigation information back to the pilot.
Mike Braasch, the Thomas Professor of Electrical Engineering, headed the center from 2007 to 2011. Photo Illustration: Ben Siegel/Ohio University.
Others, such as Adami and Professor Jim Zhu, are working with the Galah and Telemaster vehicles to develop an advanced flight controller that would make UAVs completely autonomous in flight. The user would need only to tell the aircraft where to go and monitor its flight, without operating a remote control.
Zhu and Adami’s work has applications to manned aircraft as well. “Traditional autopilot is designed to relieve the burden from a pilot or to maximize fuel efficiency, but they’re not valid for anything other than normal flight,” Adami says.
If flight conditions change and the plane flies at an excessive pitch-angle, for example, the human pilot has to resume control from a traditional autopilot system. But Zhu and Adami’s algorithm can accommodate nonlinear flight. The same technology could go into rockets and other space vehicles, Adami says.
This story originally appeared in the Autumn/Winter 2014 issue of Perspective magazine.