The U.K. Airprox Board (UKAB) published their assessment of an incident on July 22, 2014 when an Airbus A320 came within 20 feet of a helicopter drone.
At the time of the incident the airplane was flying at an altitude of 700 feet while on final approach to runway 09L at London-Heathrow Airport. The altitude of 700 feet would put the plane at a distance of about 2 nautical miles from the runway (3,7 km).
The pilot of the airplane stated that a small black object was seen to the left of the aircraft as they passed 700 feet in the descent, which passed about 20 feet (6 meters) over the wing. It appeared to be a small radio controlled helicopter. The object did not strike his aircraft and he made a normal landing but it was a distraction during a critical phase of flight. ATC was informed of the object’s presence and following aircraft were notified.
The model helicopter did not appear on radar and, from the A320 pilot’s description, was probably of a size that could not be considered likely to do so.
The Board concluded that the cause of the Airprox was that the suspected model helicopter drone had been flown into conflict with the A320, and that the risk amounted to a situation that had stopped just short of an actual collision where separation had been reduced to the minimum.
The identity of the airplane was not revealed in the report, other than the description that it was a ‘blue and white’ A320.
The incident occurred at 14:16 UTC. About the incident time flight BA905 from Milan-Linate was on approach to ruway 09L. The flight was performed by an Airbus A320, G-EUYM. It is not confirmed that this was indeed the incident flight.