Data

Can Bird Collision Data Help Determine Drone Risk to Airliners?

Researchers have proposed drawing a parallel between the expected influx of UAS and birds flying in airspace in order to estimate how often collisions could happen.

by Brandi Jewett, Grand Forks Herald / March 21, 2016

(TNS) — Birds running afoul of airplanes is nothing new to aviators, but these animals may hold the key to predicting the risk small unmanned aircraft pose to the commercial airspace.

Researchers proposed drawing a parallel between the expected influx of unmanned aircraft systems, also known as drones, and birds flying in airspace in order to estimate how often collisions could happen.

An analysis by the Mercatus Center at George Mason University found the risk posed by small unmanned aircraft — defined as more than 2.5 pounds but less than 55 pounds — was acceptable in terms of the aviation industry.

When calculated, the probability of a drone hitting an airplane was 0.0000306 per 100,000 flight hours. The probability is even less for unmanned aircraft under 5 pounds.

“Given that there are likely now more than 1 million UAS in U.S. airspace, if they had equivalent flight hours to birds, we might expect at least one UAS collision with an aircraft per year,” the analysis stated. “However, taking into consideration human agency and the far more limited time most UAS spend in the air, the true UAS collision rate is likely orders of magnitude lower.”

There has not been a report of an unmanned aircraft striking an airplane as of the study’s publication earlier this week.

The conclusion is good news to those in the unmanned industry, who have been dogged by unfavorable perceptions that many of them are flying their aircraft irresponsibly.

“Any kind of validation in research that really points to the safety that’s inherent with unmanned systems, with appropriate training, with all the safeguards that are in place, I think that’s always positive news,” said Doug McDonald, director of special operations for Unmanned Applications Institute International in Grand Forks.

He credited safety standards and educational campaigns put forth by the Federal Aviation Administration, the Academic of Model Aeronautics and other organizations.

The FAA in particular has been pushing “Know Before You Fly,” an online resource that provides safety guidelines for recreational, commercial and public agency users of the technology.

Airport safety

Among the safety guidelines is one telling unmanned aircraft operators to call an airport to get permission to fly within 5 miles of its property.

Grand Forks International Airport is located in what some would consider the hub for unmanned aircraft technology in the state, but in the two months he has served as its executive director, Ryan Riesinger said there hasn't been a problem with aircraft interfering with flights.

The FAA does track reported sightings of drones by pilots and air traffic controllers.

One report from its database shows a pilot training at Grand Forks International Airport noticed an unmanned aircraft flying at 1,400 feet in April 2015, but the pilot noted no evasive action was taken.

It's one of two such reports recorded in North Dakota between November 2014 and August.

Getting a handle on operators flying drones where they shouldn't be has been a work in progress for the FAA.

"The FAA has been working on this, and because it's such a new industry and a fast-growing industry, I think they've been having to learn themselves the best way to handle this," Riesinger said.

At airports Riesinger worked previously, he did recall pilots of unmanned aircraft calling to seek permission to fly near the property but that those flights did not cause problems.

Like McDonald, he credits educational resources that encourage safer drone flights.

Wildlife collisions at Grand Forks International Airport are much more common than unmanned aircraft sightings.

More than 100 wildlife strikes were reported from 2009 to 2016 at the airport, though none resulted in injuries or fatalities. That data includes reports of collisions between planes of all ownership types and all types of animals reported as striking a plane.

Of the 375 strikes submitted across North Dakota in the same time frame, no injuries or fatalities were reported. In total, wildlife strike from 2009 to 2016 have caused more than $800,000 in damage.

Study data

Though sightings of unmanned aircraft by airline pilots has proven to be rare so far in North Dakota, other encounters—some resulting in near-collisions—have been reported around the country.

These events have generated media stories that warn of skies will be overrun by these devices.

When it comes to these fears, the numbers just don't hold up, according to the Mercatus Center analysis, which estimates there are 10 billion birds flying in the U.S. airspace compared to 1 million drones.

"Contrary to sensational media headlines, the skies are crowded not by drones, but by fowl," the study stated.

The Mercatus Center researchers analyzed 25 years of wildlife strike data that is compiled by the FAA from volunteer submissions. The data reviewed for the study only included collisions between birds and commercial aircraft.

Researchers found that of the roughly 14,300 incidents where a bird struck an airplane, only 37 resulted in injuries or fatalities.

Mercatus researchers found nationally a majority of damaging strikes were caused by birds considered medium to large in size, which can be of similar in stock to an unmanned aircraft. For example, a large bird, such as an adult Canada goose, can weigh between 12 and 14 pounds. That dwarfs the 7-pound DJI Inspire 1, one of the most popular drone models available.

The study did acknowledge that birds and drones do not have similar compositions, and it's possible the rigid body of a small aircraft could cause more damage.

By the numbers

  • 10 billion birds flying in the U.S.
  • 1 million unmanned aircraft flying in the U.S.
  • 160,000 wildlife strikes since 1990.
  • 14,314 bird strikes since 1990.
  • 0 unmanned aircraft strikes reported.
  • 238 wildlife strikes resulting in injuries or fatalities.
  • 37 bird strikes resulting in injuries or fatalities.

Soure: Mercatus Center

©2016 the Grand Forks Herald (Grand Forks, N.D.) Distributed by Tribune Content Agency, LLC.