Report details 327 “close encounters” between drones and manned aircraft in U.S. airspace in the past two years

A new report released on Friday has found 327 “close encounters” between drones and manned aircraft in the United States during a period of less than two years.

The report by The Center for the Study of the Drone at Bard College, released on Friday, explored 921 incidents in the national airspace from December 2013 to September 2015. Co-authors Dan Gettinger and Arthur Holland Michel identified 327 “close encounters in which drones presented some level of hazard to manned aircraft, 90 of which involved commercial multiengine jets, and 594 sightings, in which drones were spotted near or within manned aircraft flight paths, but did not pose immediate danger of collision.”

Using data from the Federal Aviation Administration (FAA) and the U.S. Department of Interior, the report, titled Drone Sightings and Close Encounters: An Analysis, presents an analysis of altitude, distance from airports, drone-to-aircraft proximity, manned aircraft type, drone type and time of day. The study found that incidents were more likely to involve multirotor unmanned aircraft than fixed-wing drones, and predominantly occurred far above the FAA’s 400-foot ceiling for unmanned aircraft, often within five miles of an airport. In addition to the authors’ findings, the report presents extensive background on the issue and details the potential consequences of a collision between a manned aircraft and a drone.

Incidents are separated into two categories: sightings, incidents in which a pilot or air traffic controller spotted a drone flying within or near the flights paths of manned aircraft, though not posing an immediate threat of collision and close encounters, where a manned aircraft came close enough to a drone that it met the FAA definition of a “near midair collision” or close enough that there was a possible danger of collision. By these criteria, 35.5% of the incidents were close encounters and 64.5% were sightings. [click image below to enlarge]

In 158 cases, a drone came within 200 feet or less of a manned aircraft. There were also 51 incidents in which the proximity was 50 feet or less and 28 incidents in which a pilot maneuvered to avoid a collision with a drone. There were 38 close encounters involving helicopters; two-thirds of all incidents occurred between 10 a.m. and 6 p.m. local time.

With the holiday season approaching, the FAA estimates that up to one million new drones will be entering U.S. airspace, creating potentially dangerous situations for unmanned and manned aircraft.

“With more and more drones entering our airspace, ‘Drone Sightings and Close Encounters’ will serve as a reliable resource for policymakers and the industry as they work to develop strategies and solutions to address the growing number of potentially dangerous incidents between manned and unmanned aircraft,” said Gettinger in a statement. “Our hope is that this study can help engender a collaborative dialogue among stakeholders working on this issue.”

Founded in 2012, the New York-based Center for the Study of the Drone is a research and education initiative that looks to expand the public’s understanding of the opportunities and challenges associated with the development and proliferation of unmanned technologies. The center creates inquiry-driven content on unmanned technologies and their impact in both military and civilian spheres for stakeholders and the public at large.