A drone flew within 20 metres of a plane on the approach to Heathrow, while another shocked pilots by appearing at 3,000 metres (10,000ft), a monthly update on near-misses has revealed.
Commercial jet pilots reported two “category A” incidents, the most serious class of near-miss, involving unmanned aerial vehicles (UAVs), known as drones.
In one case, an Airbus A320 pilot on the approach to Heathrow in October last year spotted a drone within just 20 metres, or “possibly within the wingspan” of the aircraft.
Investigators concluded that the drone had flown so close to the passenger jet that “providence had played a major part in the aircraft not colliding”. They also noted that the “blue and disc-like” craft appeared to be custom-made, rather than a commercially available model.
In the second of two serious UAV incidents, an A320 pilot taking off from Heathrow saw a red drone overhead, about 50 metres away from his right wing at about 1,000 metres.
The pilot noted that there would have been a “distinct possibility of damage” had a collision occurred, while investigators found that “a collision had only been narrowly avoided and chance had played a major part”.
A third drone sighting, deemed a less serious category B incident, involved an unmanned aircraft at an altitude that surprised pilots, who had “no time to react”.
The UK Airprox Board, which issues monthly reports on the threat of mid-air collisions, reported a pilot saying: “Was that a drone? At 10,000 ft!”
Large drones are not permitted to fly above 120 metres, or close to airports.
The “large drone”, which appeared to be stationary, came within 60 metres (200ft) of the aircraft, a distance deemed less risky than the category A incidents, but nonetheless “a situation where safety was not assured”.
A fourth drone sighting, involving a pilot on a sightseeing trip near the Binevenagh mountain in Northern Ireland, was deemed to be at the lowest level of risk, category E.
In all four cases, police were alerted but the operator of the drone could not be traced.
Pilots believe a collision with an airliner could be catastrophic and that the impact of a drone strike on a light plane or helicopter would almost certainly bring it down.
The British Airline Pilots Association has warned that the number of incidents could soar as people fly drones received as Christmas presents, often with little or no handling experience or understanding of the rules.
There have been 59 drone near-misses reported in the past 12 months. Drone sightings were among 21 incidents reported to the UK Airprox Board, six of which were deemed to be in the most serious category.
Among the other category A incidents was a near-miss in which a model aircraft was flown close to a Chinook military helicopter coming in to land at RAF Benson.
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