NASA completes first phase of tests, readies for next phase

The NASA Armstrong Flight Research Center in California last week completed the first phase of flight tests on detect-and-avoid technology that will enable large unnamed aircraft systems (UAS) to operate in the national airspace (NAS) above 500 feet.

From late April until the end of June, NASA’s Ikhana—a civilian research variant of the General Atomics Predator B UAS—flew 270 encounters against as many as four manned intruder aircraft simultaneously. As a result of the successful Phase I tests, NASA will fund Phase II flight tests set to begin in 2018, according to Debra Randall, chief systems engineer for the agency’s UAS in the NAS project.

“There’s been a tremendous amount of work in this area just in the last couple of years, and it’s not just NASA,” she said. “The progress made is phenomenal. I think it’s stellar and beyond what is typical.”

In the fourth and final round of the Phase I flight tests, the intruder aircraft were flown at different speeds, altitudes and geometries in relation to the Ikhana to test its detect-and-avoid algorithms and its maneuvering guidance. Six different intruder aircraft equipped with a variety of avionics were used to perform high-, medium- and low-speed encounters with the Ikhana.

“You may get an alert from one aircraft and then the guidance that tells the pilot to maneuver in such a way that now he’s getting alerted by one of the other three aircraft flying toward him,” explained Heather Maliska, UAS-NAS deputy project manager at Armstrong. “It’s all very interactive and very busy up there.”

Other than occasional adverse weather, reduced visibility caused by California wildfires and the coordination of fights with up to five aircraft at once, Maliska said the detect-and-avoid technology performed as expected. However, she noted that it will be up to researchers to analyze the data and determine exactly how well the technology performed.

Maliska said that the Radio Technical Commission for Aeronautics (RTCA) Special Committee 228 (SC-228) played a valuable and active role in developing the tests and monitoring their results. The committee will analyze data from the flight tests and use it to develop minimum operations standards (MOPS) for UAS command and control functions, detect-and-avoid systems and airborne radar that will assist the Federal Aviation Administration (FAA) in integrating UAS in the NAS.

The FAA, General Atomics and Honeywell International also participated in the flight tests and will be conducting their own data analysis. If all goes as planned, Randall said SC-228 will issue MOPS before the end of the year that the FAA can then use to develop technical and safety standards.

Maliska said the Ikhana—with support from General Atomics—proved to be an outstanding UAS research platform during flight testing that began last year.

“Ikhana’s done a great job,” she noted. “It’s been our workhorse and it’s done a really good job of supporting the flight test activity. We’ve got a great group of individuals flying that aircraft.”

Randall said receiving another four years of funding from NASA headquarters is testimony to how well the team has worked with SC-228 and the FAA—understanding the needs and objectives of both organizations and then executing the flight test mission to provide important research data.

“We’re on the right track and we’re doing good work,” she said.