Study Finds 327 Close Encounters Between Drones & Aircraft in US


A new study out from The Center for the Study of the Drone at Bard College looks how often small drones have interfered with commercial aircraft and found 327 “close encounters” between 2013 and 2015. A close encounter is defined as an incident where a drone provided some level of hazard to the manned aircraft. The report shows some 921 incidents where drones were spotted in airspace shared by manned aircraft over the same period.

The study found that incidents were more likely to involve multirotor unmanned aircraft than fixed-wing drones, and predominantly occurred far above the Federal Aviation Administration’s 400-foot ceiling for unmanned aircraft, often within five miles of an airport.

The study comes at a time when the Federal Aviation Administration (FAA) estimates that up to one million new drones will be entering U.S. airspace as a result of holiday purchases. Smaller quadcopter like drones are becoming more and more popular with hobbyist users. However, there are significant policy questions involved in terms of how airspace is managed safely and whether drones violate private property if they fly over areas of land that aren’t owned by the drone operator. As CivSource reported earlier this year, a group of stakeholders worked with the FAA to create recommendations and drone registration rules that were released in November, in advance of the holiday shopping season. However, observers of the rules suggest that both current and new owners may not be aware of registration requirements or may ignore them.

The FAA is also engaged in a multi-state research effort to codify operational standards, pilot training, and general rules of the road for drones, but that is a longer term project.

The types of incidents included in the report do raise some questions about the safety of allowing small drones in the same flight paths as commercial manned aircraft. Report authors note that of the 327 close encounters, rules were already in place prohibiting drone use. To wit:

“Our findings indicate that incidents largely occur in areas where manned air traffic density is high and where drone use is prohibited. We counted 158 incidents in which a drone came within 200 feet or less of a manned aircraft (two-thirds of all Close Encounters in which a concrete drone-to-aircraft proximity is given), 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. One hundred and sixteen of the Close Encounters involved multiengine jet aircraft, 90 of which were commercial aircraft (the majority of which have the capacity to carry 50 or more passengers). We also counted 38 Close Encounter incidents involving helicopters.”

The report data was built from records at the FAA and Department of Interior. Those records do not always indicate the type of drone involved in an incident, but according to the authors – “of the 340 drones that were identified in the reports, 246 were multirotors (i.e. quadcopters, hexacopters, etc.) and 76 were fixed-wing.” Metropolitan areas saw the highest rate of incidents, usually between 10 a.m. and 6 p.m.

Full text of the report is available here.