A significant number of all recreational drone flights sampled were conducted in ways that posed a hazard to navigation, according to a new study released this week by Embry-Riddle Aeronautical University researchers and published in the International Journal of Aviation, Aeronautics, and Aerospace. The study used data collected between May 17 and May 29, 2018, that used an AeroScope deployed on an educational building adjacent to the Daytona Beach (Florida) International Airport (DAB).
The AeroScope detects, identifies, and tracks DJI drones, a company with an estimated 72 percent of the recreational sUAS market. The device tracked 192 separate flights by 73 separate platforms and recorded location, altitude, and time of day. Following the sampling period the data was downloaded into electronic maps and UAS detection times were correlated with ADS-B data.
Researchers also evaluated sUAS detections against the FAA’s UAS Facility Map (UASFM) established for the Daytona Beach. The UASFM shows the maximum altitudes for authorized Part 107 UAS operations around airports that do not require additional safety analysis. “At least 21.5 percent were determined to exceed the maximum defined altitude limits of their UAS Facility Map area,” the study noted. In one case, a sUAS was detected at 90 feet msl within 0.25 nm from the approach path of DAB's Runway 7L just seconds after an aircraft had approached. The researchers concluded, “Assuming the pilot was performing the published ILS approach, the aircraft would have crossed the Runway 7L threshold crossing at a height of 58 feet agl (88 feet msl). It is highly probable that the aircraft descended through the UAS altitude while on approach.” Eight drones were detected within one nautical mile of the DAB center point, including one at nearly 200 feet msl and 0.68 nm from the Runway 7L centerline.
UAS detections ranged from as close as 0.83 statute miles (sm) to as far as 10.58 sm from DAB and even closer to other area airports and heliports. According to the study, “Unmanned aircraft operated as close as 0.50 nm to public airports and 0.35 nm to heliports. Of the 190 data points, 96.8 percent were detected within 5 sm of an aerodrome, with 84.2 percent detected within 5 sm of two or more aerodromes."
UAS flights were detected significantly after local sunset, as early as 1:24 a.m. and as late as 11:49 p.m. local time. The most common times for flights were between the hours of 7 p.m. and 10 p.m. Altitudes ranged from ground level to 1,286 agl, with the mean altitude of 238 agl; at least 6.8 percent of platforms were detected above 400 agl, eight between 400 and 500 agl, two between 500 and 1,000 agl, and three above 1,000 agl.
The majority of detections occurred within urban areas. Nearly 48.7 percent of detections occurred in residential neighborhoods; 28.3 percent near single-family homes, 20.4 percent near multi-family buildings, and 21.5 percent proximate to commercial, industrial, or public properties. Just 12.0 percent occurred near unimproved land and parks where drones could be operated relatively safely. One sUAS operated within 0.3 nm from the Tomoka Correctional Institution.
The researchers recommended providing pilots of manned aircraft with drone activity information as a way to mitigate airspace confliction including making drone Low Altitude Authorization and Notification Capability (LAANC) request information available to manned pilots.
