A Virgin Atlantic plane was just 10ft away from hitting a drone in the closest ever near-miss involving a passenger jet and one of the gadgets in UK airspace, a report has revealed.
It happened as the Virgin Atlantic jet was flying at around 250mph at 3,200ft on its approach to land at Heathrow.
The B787-9 Dreamliner carrying up to 264 passengers was passing over residential streets just north of Clapham Common when it was nearly hit by the drone.
A report by the UK Airprox Board (UKAB), which investigates near misses, said the "drone-like object was seen to pass just below the right wing, avoiding impact with the engine by an estimated 10ft".
The aircraft which was nearing the end of its eight and a half hour flight from Delhi landed safely after the narrow escape at 4.56pm on June 25 this year.
Air traffic controllers were immediately informed, but it is believed that police never found any trace of the drone operator who was flying his device at eight times the legal height.
The number of near misses between aircraft and drones has soared in recent years as the devices have become more popular, leading to fears of a catastrophic collision.
Experts fear that an impact with a heavy drone could disable a jet engine or cause serious injury to pilots by smashing the glass in a jet's windscreen, potentially posing more risk than a bird strike.
The Civil Aviation Authority confirmed that the near miss was believed to be the closest call ever between a drone and a commercial airliner over the UK.
It was feared a British Airways flight from Geneva was hit by a drone at 1,700ft over Richmond Park as it came in to Heathrow in April, 2016, but transport minister Robert Goodwill later revealed the object may have been a plastic bag.
Drone operators are normally only permitted to fly below 400ft and within sight of their devices, and are expected to stay well clear of airports and aircraft flight paths.
Operators who endanger the safety of an aircraft can be jailed for five years.
The UKAB report rated it as the highest possible Category A incident, meaning there was "a serious risk of collision".
It said: 'The drone was being flown beyond VLOS (visual line of sight) limits and on an airfield approach path, such that it was endangering other aircraft at that altitude and position.
"The Board agreed that the incident was therefore best described as the drone was flown into conflict with the B787.
"The Board considered that the pilot's overall account of the incident portrayed a situation where providence had played a major part in the incident and/or a definite risk of collision had existed."
The near miss led to Virgin Atlantic calling for tighter rules to prevent drones being flown near airports and flight paths.
An airline spokesman said: "Virgin Atlantic can confirm that pilots operating flight VS301 from Delhi to London on June 25 reported seeing a drone on their approach into Heathrow.
"The safety and security of our customers and crew is always our priority, and the pilots immediately reported the incident to Air Traffic Control in line with our procedures.
"It's vital that action is taken to regulate the use of drones near airports, and we urge the government to consider further proposals."