The UK’s Airprox Board https://www.airproxboard.org.uk/Monthly-Meeting-February-2018.aspx has given an ICAO Risk A (“The risk classification of an aircraft proximity in which serious risk of collision has existed”) classification to the near collision on 7 January 2018 of an Airbus A319 with a drone, near London Heathrow airport.
According to the board:
“The A319 pilot reports that on climb-out from Heathrow, passing 4800ft a medium-sized, white drone passed directly overhead, with an estimated separation of 20ft. There was no time for the flight path to be altered. It was reported to ATC and to the police and written up in the tech log for a precautionary inspection.
Reported Separation: 20ft V/0m H
Reported Risk of Collision: High
Cause: The drone was being flown above the practical VLOS limit such that it was endangering other aircraft at that altitude and position. The Board agreed that the incident was therefore best described as the drone was flown into conflict with the A319.
Risk: The Board considered that the pilot’s estimate of separation, allied to his overall account of the incident and his inability to avoid the drone portrayed a situation where providence had played a major part in the incident and/or a definite risk of collision had existed.”