NASA and its partners in the unmanned aerial systems industry are taking drones closer to operating in harmony with other aircraft in the national airspace system.
The technology and procedures developed during a nearly decade-long program have been assisting the FAA develop the rules for unmanned aircraft to safely coexist with other air traffic in the National Airspace System, according to NASA officials.
The goal is to enable new commercial and public service opportunities, such as real-time surveillance of fires, infrastructure inspections for pipelines, and medical transportation.
Flight Test Series One (FT1) kicked off the series in 2011 with the unmanned Ikhana aircraft at NASA’s Armstrong Flight Research Center (AFRC) in California. The early flights were completed to help the UAS-NAS project team develop foundational technologies for future flight series. FT1 involved the installation of the automatic dependent surveillance broadcast system (ADS-B) on the Ikhana, and launched the development of the Live Virtual Constructive Distributed Environment (LVC-DE).
The LVC-DE can sync NASA’s research centers to create a real-life simulated airspace that integrates manned and unmanned aircraft to test concepts, technologies, and procedures in the same airspace, NASA officials explained.
LVC-DE interfaces live flights at AFRC with simulated airspace and traffic at NASA’s Ames Research Center in California.
The IT&E team worked from FT1 through Flight Test Series Four (FT4) on evolving the LVC-DE capability. The data collected during these flight tests and associated simulations helped the FAA develop the Phase One DAA Systems and Airborne Radar MOPS.
As the team entered Phase Two of its operations, a milestone occurred when the Ikhana became the first remotely piloted aircraft to fly through Class E airspace without a safety chase aircraft.
The team was able to receive the first No Chase Certificate of Waiver or Authorization (COA) from the FAA to accomplish the demonstration flight. The Ikhana was able to demonstrate that a UAS with an onboard DAA system could safely detect and avoid other aircraft, NASA officials report.
Phase Two of the UAS-NAS Project shifted focus to a smaller sized unmanned aircraft, a Group 3 UAS that flies under 18,000′ and weighs more than 55 pounds.
The project selected the TigerShark XP, a Navmar Applied Sciences Corporation (NASC) UAS with a wingspan of 21.3′ for Flight Test Series Six (FT6). The aircraft was modified with a nose structure to integrate Honeywell’s Digital Active Phased Array, or DAPA-Lite, an early, developmental, low size, weight and power (SWaP), air-to-air radar system. The radar system underwent initial limited flight testing on a Honeywell helicopter test bed during Flight Test Series Five.
The TigerShark performed scripted encounters and full mission flights at Armstrong. The scripted encounters involved an “intruder,” a manned aircraft flying pre-planned paths in the vicinity of the TigerShark to trigger the DAA alerting and guidance. All encounters maintained a safety buffer, a vertical clearance, to ensure test effectiveness of the DAA alerting and guidance system, while maintaining a safe operation, NASA officials said.
The full mission flights involved interfacing via the Armstrong and Ames LVC-DE to integrate the live aircraft flying at Armstrong into the simulated Oakland airspace. The team was able to gather pilot performance data using specific DAA system constraints.
“Subject pilots,” expert drone pilots who were not aware of the details of the simulation, flew the full mission encounters against real and simulated traffic. The project selected seven pilots from active duty Air Force UAS squadrons. Two project researchers sat with the pilots to oversee the data collection during the flight.
The LVC-DE created virtual traffic as the TigerShark flew with a manned intruder entering its flight path. The system was also used as a central hub collecting data and translating messages from the DAA and Command and Control systems during flight.
The drone pilots relied on the DAA logic running on the UAS to avoid live and virtual traffic. Among other things, the full mission flights provided the team with data on pilot reaction time and workload, and system acceptability, NASA officials noted.
FT6 had its final flight in November, but the team will continue to work this year on data analysis, results documentation and providing inputs for DAA related MOPS updates.