Researchers from Oklahoma State University and Embry-Riddle Aeronautical University have issued a new study that shows that skilled pilots approaching a runway cannot reliably see unmanned aircraft systems (UAS) entering their airspace.
The study showed certified pilots failed to see a common type of quadcopter during 28 of 40 close encounters and drones that were motionless were virtually never detected by pilots with only 3 out of 22 motionless drones spotted by pilots. Drones in the study were detected at distances between 213 and 2,324 feet.
“Dangerous close encounters between aircraft and drones are becoming an increasingly common problem,” said Dr. Ryan J. Wallace, assistant professor of Aeronautical Science at Embry-Riddle. “Statistics on pilot sightings of drones continue to increase year over year, and what is being reported by pilots is probably just the tip of the iceberg. The vast majority of the time, unmanned aircraft are not being seen by pilots.”
In the past year and a half, incidents involving drones encroaching on restricted airspace have risen to the point where airports are examining installing their own defensive measures with the FAA requiring their approval before any countermeasures are put in place.
Late last year, a significant drone incident grounded flights at Gatwick Airport in the U.K., affecting the travel plans of about 110,000 passengers. In January, drone sightings near New Jersey’s Newark Liberty International Airport disrupted flights both in and out of the airport. Recently, it was reported that over the past five years there have been 117 alleged drone airport trespassing incidents in Ohio alone.
In the study’s best-case scenario, a drone was spotted at a maximum detection range of 2,324 ft, which would give a pilot only about 21 seconds to avoid a collision.
“That might be enough time if the drone was hovering in one spot, but not nearly enough if it’s in flight, headed for the aircraft,” said Dr. Matt Vance, assistant professor of aviation and space at Oklahoma State. “The situation is far more dangerous when both aircraft are moving. Our eyes are attuned to movement. When a drone is not moving, it becomes part of the background.”
An aircraft’s final approach is one of the most dangerous times to have a drone encounter because it can catch pilots unaware with little time to react. If a drone hits an engine, it could bring down the entire aircraft, researchers said.