A report found there have been at least 241 close encounters between drones and manned aircraft, reports the Chicago Tribune.
Two aircraft must fly within 500 feet of each other to meet the Federal Aviation Administration's definition of a near midair collision.
The report is based on an analysis of government records detailing 921 incidents involving drones and manned aircraft between Dec. 17, 2013 and Sept. 12, 2015.
Ninety of the close encounters involved drones and commercial jets, the majority of which had the capacity to carry 50 people or more.
According to the Tribune, 64.5 percent of those incidents were sightings of drones in the vicinity of other aircraft with no immediate threat of collision.