With the number of small uncrewed aerial systems (sUAS, aka drones) increasing, researchers at Embry-Riddle Aeronautical University (ERAU) have developed a new method to quantify close calls between them and piloted aircraft. In a paper published in the SAE International Journal of Aerospace, researchers from the university noted there were at least 24 near-midair collisions (NMACs) around Dallas-Fort Worth Airport (KDFW) between August 2018 and July 2021. NMACs are defined as a drone coming within 500 feet of a piloted aircraft.
For the study, the researchers used drone and aircraft telemetry data collected from a UAS detection device attached to an antenna mounted on the roof of the airport’s Terminal C concourse. It captured flight data—including altitude and launch location—for each of the nearly 460,000 drone flights within a 30-mile radius of KDFW during that span. That data was combined with ADS-B and Mode S signals and fed into a proprietary data analytics software package.
Until now, any information on such near-midairs came solely from the reports of multitasking pilots who were able to spot the drones. Even so, in 2021 alone, the FAA received a staggering 2,596 reports of drone sightings by pilots nationwide.
The ERAU researchers noted that most of the close encounters in its study took place within 1.5 miles of a runway approach or departure zone, leading them to recommend expanding the runway exclusion zone for drones at high-risk runways from one mile to 3.5 miles.
“That modification would provide enhanced protection from piloted aircraft operating at less than 500 feet above ground level during approach or departure,” explained Ryan Wallace, an ERAU associate professor of aeronautical science. “Typically, small uncrewed aircraft don’t fly above 400 feet.”
According to the FAA, in 2020 there were approximately 1.5 million sUASs operating in U.S. airspace and the agency expects this to rise to nearly 2.4 million by 2025.
“The proliferation of drones, particularly ones available to the general public, poses obvious risks,” said Stephen Rice, a collaborator in the research and professor of human factors, adding that not all drone operators are responsible. “Many of them are not even aware of the rules they must follow.”
Starting on September 16, all drone pilots who are required to register their UAS must comply with requirements for a remote identification (RID) signal on their equipment, a requirement the ERAU researchers said will enhance safety by position reporting and enable further accounting and analysis of MNAC situations.