Late last year, a study found that there were 327 close encounters between airplanes and recreational drones over a period of 21 months, and warned that it was just a matter of time before there was a serious collision between the two. The study, conducted by the Center for the Study of the Drone at Bard College, warned that, "with sufficient speed, bird strikes have been known to penetrate the cockpit." The report went on to note that, "it's entirely possible, then, that a drone could also break through into a cockpit, potentially causing serious harm to the pilots or other occupants."
Now, a new study finds that when it comes to drones and planes, there’s just not that much to worry about. Published by the Mercator Institute of George Mason University, the new report argues that because drones are typically quite small, fly solo (as opposed to in a flock like birds), and their encounters with airplanes are so infrequent, they pose less risk to aircraft than birds. (The report did not mention human-carrying drones, though.)
There haven’t been any reports of drones hitting planes yet, and, as Popular Science pointed out, in a different paper, one of the study’s authors noted that airplanes have hit more turtles than drones. What planes do hit frequently is birds, though, which is why the authors of the new study looked at bird strikes, instead of near misses with drones.
For their study, the researchers consulted over 25 years of F.A.A. "wildlife strike" data and found that risk of damage to aircraft is incredibly small. "On average, only 3 percent of reported small-bird strikes ever result in damage, compared to 39 percent of large-bird strikes," the study reported, noting that drones typically weigh the same as a small bird. "Given the voluntary nature of strike reporting, the true percentage of strikes causing damage is probably much lower, as strikes that do not cause damage can be either missed or underreported."
According to Ars Technica, in 25 years of FAA data, “there have been only 37 incidents of wildlife strikes that caused injuries or death.” Considering there are approximately 27,000 commercial aircraft flights per day in the U.S., it seems clear that birds pose a very small risk to travelers, and drones an even smaller one.