An FAA-funded nationwide study led by Embry-Riddle Aeronautical University (ERAU) has found that small uncrewed aircraft systems (UAS) are frequently flying above the 400-foot ceiling established for drones, raising concerns about potential mid-air conflicts with crewed aircraft. The report used Remote ID signals collected from sensors across the U.S. to analyze flight activity at 43 aerodromes, including airports and heliports.
Because the study did not distinguish between authorized flights and violations, some high-altitude flights may have occurred under FAA waivers or certificates. However, researchers noted that flights above 500 feet were likely recreational, based on the types of drones identified.
Researchers documented 6,037 drone flights with altitude data, of which at least 573 reached between 400 and 500 feet, and 781 exceeded 500 feet. Factoring in duration, drones were found to be flying in airspace used by crewed aircraft for roughly 10% of the cumulative flight time observed.
“Study data suggests that a sizable number of small UAS flights take place above that altitude, which could impact the operation of manned aircraft,” said Ryan Wallace, associate professor of aeronautical science at ERAU and principal investigator on the project.
The study also noted heightened risk near airports, particularly heliports. Small UAS were detected within 0.5 nm—about 3,000 feet—of heliports, which are often omitted from aeronautical charts and obscured, and “are often hidden within urban sprawl,” Wallace noted. The report recommends updating aeronautical charts to include heliport locations and reduce unintentional proximity by drone operators.
Embry-Riddle faculty involved in the project emphasized that the findings will help inform future FAA rulemaking, especially as beyond-visual-line-of-sight operations and commercial drone applications continue to expand.
“This research helps inform both current policy gaps and future regulatory priorities,” aviation doctoral student Sang-A Lee said.
Research was conducted with support from Kansas State University and Wichita State University’s National Institute for Aviation Research. Remote ID signals—required by the FAA since 2023 for most registered drones—provided flight data that enabled the team to map hot spots and risk zones across the National Airspace System.