The Federal Aviation Administration investigated an incident last month involving a drone that nearly collided with a commercial airliner in U.S. airspace, but wasn't able to identify who was flying the unmanned aircraft or what type of plane it was.
The near-miss took place on March 22 outside Tallahassee, Florida. A U.S. Airways commuter flight operated by PSA Airlines traveling from Charlotte, North Carolina, was on an approach about five miles northwest of a runway at Tallahassee airport 2,300 feet above ground when it "passed an unreported and apparently remotely controlled aircraft," according to a statement from an FAA spokesman.
The commercial pilot reported the "near mid-air collision" to air traffic control and the agency investigated the incident, but "neither the UAS nor the pilot could be identified," it stated, referring to the acronym for unmanned aerial system.
Indeed, the commercial pilot -- whose identity hasn't been disclosed -- initially thought the two aircraft had collided, but an inspection of the airliner afterward found no damage, according to an article by Jack Nicas of The Wall Street Journal.
Jim Williams, who manages the unmanned-aircraft office at the FAA, disclosed the incident on May 8 during a drone conference in San Francisco and it's believed to be the first case of a large commercial passenger jet almost striking a drone, according to the article.
The news report said the pilot described the craft as "as a camouflaged F-4 fixed-wing aircraft that was quite small." The FAA spokesman said some media reports have speculated whether the aircraft was actually a QF-4 unmanned aerial target flown by the Air Force from Tyndall Air Force Base outside Panama City.
But a Defense Department spokesman told the Journal that "most military drones aren't painted with camouflage" and the FAA spokesman said it would be highly unlikely for a military aircraft from Tyndall to find itself in the landing approach of a passenger jet at Tallahassee.
Manned aircraft are required to fly at least 1,000 feet apart vertically and several miles apart laterally; and remote-controlled aircraft are supposed to be operated below 400 feet, according to the article.
The incident comes as the FAA is crafting guidelines for integrating unmanned systems into the national airspace by 2015. The spokesman said he wasn't aware of any impacts the incident may have caused to the agency's rule-writing efforts.