UK investigators have disclosed details of three more encounters, within three days, between commercial aircraft and unmanned aerial vehicles in London terminal airspace, including two in the highest collision risk category.
The UK Airprox Board states that an Airbus A320-family aircraft had been descending on its base leg over central London ahead of an approach to Heathrow’s runway 27L when its pilots sighted a “black drone” through the right-hand cockpit windows.
Its crew estimated that the vehicle probably passed over the right wing and horizontal stabiliser.
The Airprox Board has not indicated the operator of the jet involved in the 18 July incident, which occurred at around 4,900ft in daylight and visual conditions, in the vicinity of the Shard tower – the tallest office building in the UK.
Investigators state that the incident appeared to be a “very near miss”, adding that the vehicle’s operator could not be traced.
The event occurred two days after another encounter involving an A320-family jet on descent for runway 27L. Its crew had been advised of a possible drone sighting by a preceding aircraft, and had increased their vigilance, when they saw a quadrotor vehicle pass overhead to the left.
In its review the Airprox Board says the pilot noted the encounter took place during a period of high workload as the aircraft executed a continuous-descent approach. The operator of the vehicle could not be located.
Both events were assessed by the organisation as bearing a high risk of collision. The Airprox Board has also noted a third incident, which occurred on 17 July, during which an A319 passed a drone at a height of 1,000ft on approach to Heathrow’s runway 27R.
It states that the crew estimated the drone to be 100m away, adding that it was stationary and “possibly filming aircraft on approach”.