All four of the most serious UK airprox incidents considered by investigators’ latest in-depth review involved drones or other unidentified objects in London airspace.

The incidents occurred in the second half of August, with two involving Airbus A320s and a third affecting a Boeing 777. A fourth airprox concerned a helicopter air ambulance.

One of the A320 encounters occurred at about 6,000ft, involving a quadcopter drone, while the second took place at 3,200ft on approach to London Heathrow.

The 777 had also been conducting an approach to Heathrow, and was proceeding to the Lambourne holding stack at 10,000ft when an unknown object passed at about 50ft distance.

Its crew stated that the object was blue and “certainly not a balloon”, according to the UK Airprox Board.

Investigators also analysed other drone-related air transport incidents during the same review, involving an A319 and A320 over London, a 777 near Newcastle and a Bombardier turboprop on approach to Birmingham.

Source: Cirium Dashboard