Is that a drone or a plane? Experts help explain the differences
High in the sky, is that a drone, a plane or a helicopter?
Experts studying unmanned aircraft systems — better known as drones – say it can be difficult to see from miles away. But there are clues.
According to John Slaughter, director of the University of Maryland’s Unmanned Aircraft Systems Research and Operations Center, a light in the sky at night can easily be misinterpreted.
“You can’t just walk out and say, ‘Oh, that’s not a drone,’ or ‘That’s one.’ All you can actually say is, ‘I saw a light in the sky,’” Slaughter said.
Dozens of mysterious night flights first spotted in New Jersey last month and now seen across the U.S. have raised concerns among residents and officials. Some of the concerns stem from the flying objects initially noticed near the Picatinny Arsenal, a US military research and production facility, and above President-elect Donald Trump’s golf course in Bedminster.
Airplanes and helicopters all have flashing lights and usually at least one red anti-collision light, often two. They are also equipped with navigation lights, which are stable, red and green colored lights like those on boats. Many will also have flashing white strobe lights on their wingtips. And they have bright landing lights.
Drones flying at night are only required to have one bright anti-collision light visible from 5 kilometers away. But drone owners can add other lights, so some have more than one. Drones are smaller, so if they have multiple lights they are close together, but at night it is often not possible to find out exactly how far away they are.
“A light is just a bright point,” Slaughter said. “And it could be 300 feet away, it could literally be 40 miles away and it looks the same.”
Drones are typically quieter and make a higher-pitched buzzing noise than the noise generated by the jet engines or propellers that power airplanes and helicopters. But larger drones can be louder and the sound can be difficult to distinguish from a distance.
Drones heavier than about half a pound (0.2 kilograms) may have an identification number displayed on the outside.
“You certainly wouldn’t see it at night, and you’d have to be up close to see it during the day, you know,” said Paul R. Snyder, director of the Unmanned Aircraft System program at the University of North. Dakota’s Aerospace Sciences School.
Airplanes and even helicopters tend to move smoothly through the air, but multi-helicopter drones can stop, turn 90 degrees and change course in an instant, Slaughter said.
“That kind of movement can give you an idea that you are looking at a drone, and not an airplane,” he said.
And the vast majority of drones will operate below 400 feet (122 meters), according to federal regulations.