Volume 10, Number 2 • March/April 2002 • Aerospace Technology Development

Experiments Aid Airspace Safety

Scaled Composites’ Doug Shane examines the screen of his ground control station during tests in New Mexico. Shane used this configuration as the ground control station to remotely pilot the Proteus aircraft during a NASA-sponsored series of test flights. Photo courtesy of Dryden Flight Research Center.

An alliance of teams from NASA, the US Navy, New Mexico State University in Las Cruces and industry recently demonstrated how remotely piloted aircraft can operate safely in the National Airspace System (NAS). Critical to gaining access to the skies is the requirement for remotely flown airplanes to be able to detect and avoid collision courses with other aircraft.

Using three detection systems, the teams—working as part of NASA’s Environmental Research Aircraft and Sensor Technology (ERAST) program—flew up to three aircraft, including a high-speed NASA F-18 jet, on simulated collision courses. Meanwhile, onboard technology automatically detected the threat and proposed a flight path to keep the aircraft out of danger. While all the aircraft in the tests had pilots onboard, the instrumented test airplane used equipment intended to permit future uninhabited aircraft to avoid other airplanes in flight. This new sensor technology may also benefit commercial airliner safety.

Central to the tests was the Proteus aircraft built by Scaled Composites in Mojave, California. Proteus carried see-and-avoid electronic devices that detected incoming airplanes.

Aircraft manufacturers are devising a variety of unpiloted aircraft capable of performing long- duration missions. Low-cost uninhabited aerial vehicles (UAVs) can be used to monitor wildfires, study environmental phenomena, relay cellular phone service and keep an eye on petroleum pipelines and remote borders. But before these UAVs can fly routinely in the national airspace along with traditional airplanes with pilots onboard, technologies must be validated to enable UAVs to mingle safely in the skies.

“The ERAST alliance has the opportunity to significantly increase the utility of remotely piloted aircraft by developing systems that enable UAVs to detect and avoid other aircraft,” said NASA ERAST program manager Jeff Bauer of Dryden Flight Research Center, Edwards, California.

“The Federal Aviation Administration (FAA) must certify remotely piloted aircraft before they will be allowed to fly in the national airspace” Bauer explained. “Our allied efforts can help open the door to airspace use by UAVs. We can recommend certification and regulatory procedures to the FAA based on actual flight verification of remotely piloted aircraft safety systems.”

The goals of the flights over southwestern New Mexico were to demonstrate see-and-avoid equipment capabilities and to show how a remotely piloted aircraft can be in constant communication with its ground pilot, even at distances over the horizon, by relaying signals via satellites.

The flight tests mobilized the resources of Dryden and ERAST partners, including the New Mexico State University Technical Analysis and Applications Center (TAAC) in Las Cruces, Scaled Composites, the Navy and Modern Technology Solutions, Inc. (MTSI) of Alexandria, Virginia. FAA observers also witnessed the operations at Las Cruces.

For the tests, Proteus was fitted with a Skywatch HP traffic advisory system, a radio-based device for detecting other aircraft. Additionally, Proteus carried two “non-cooperative” sensors—devices that don’t require signals or transmissions from any other source—to detect the presence and course of other aircraft. These sensors are an Engineering 2000 infrared sensor and an Amphitech radar, both mounted in the nose of Proteus. Q

For more information, contact Fred Johnsen at Dryden Flight Research Center, 661/276-2998, fred.johnsen@dfrc.nasa.gov. Please mention you read about it in Innovation.

NASA Official: Jonathan Root • Web Design: Printing & Design Office, NASA Headquarters • Credits