Investigators have disclosed that an Airbus A320 crew took evasive action to avoid a drone during the final stages of an approach to London Gatwick earlier this year.
The UK Airprox Board states that the A320 had been descending through 1,700ft in the "final stages" of its ILS approach to Gatwick's runway 26 on 28 April.
One of its pilots saw a "dark coloured" drone ahead of the aircraft and took "avoiding action" involving 5-8° right bank.
The crew estimated to the board that the aircraft and drone were at the same height, but separated by 80-100ft horizontally.
Investigators classified the incident as bearing the highest category of collision risk.
The Airprox Board similarly classified as high-risk an incident which occurred about six weeks later, on 6 June, when a Boeing 747 was passing 3,500ft on approach to runway 27L at London Heathrow.
It states that the crew "clearly saw a yellow and orange quadcopter" pass down the left side of the aircraft, with a vertical separation of just 20ft and horizontal separation of 40ft.
Police took a statement after the aircraft landed. "The pilot’s overall account of the incident portrayed a situation where providence had played a major part in the incident," says the Airprox Board.
Neither the operator of the A320 nor that of the 747 has been identified by the investigators.