A British Airways plane came within a split second of smashing into an illegally-flown drone close to Windsor Castle, a report has revealed.

The A320 jet carrying up to 180 passengers and flying at 170mph was on its final approach to Heathrow when the co-pilot saw the ‘small blue drone’ from the cockpit.

The co-pilot who was in the right hand seat reported that the drone was ‘very close’ and certainly within 50ft – the equivalent of a ‘wing length’ of the aircraft.

The UK Airprox Board which investigates near misses reported that the close call happened at a height of 1,300 ft at 8.38am on May 9 this year.

Its official report gave the location as being Windsor Castle. It is not known if the King was in residence at the time.

It is believed that the near miss happened just as the plane had passed over the famous tree-lined Long Walk which leads to the castle and has hosted Royal wedding processions, state funerals and state visits.

The pilots immediately informed air traffic controllers at Heathrow who alerted the pilots of other inbound flights to watch out for drones in the area.

A visual check of the exterior of the plane which was identified on flight tracker records as a BA flight from Florence in Italy was carried out after the aircraft landed safely, but no damage was found.

Aviation experts have long warned of the risk of drones damaging cockpit windows or jet engines with potential catastrophic results.

The report rated the near miss as a Category A incident where there was a serious risk of collision and stated that the information available was ‘sufficient to indicate’ that the object 'could have been a drone'.

It added: ‘The Board considered that providence had played a major part in the incident and/or a definite risk of collision had existed’.

The suspected drone was being flown illegally as the whole of the Windsor area is in a no-fly zone for the devices.

But in any case, the height at which it was being flown was more than three times the usual maximum legal height of 400ft.

Most of the devices are fitted with software limiting their maximum height, but it can be over-ridden by patches bought on the internet.

It is believed that the drone may have been flown by someone trying to get dramatic video footage of an airliner in flight.

The operator could have been jailed for up to five years for endangering an aircraft if caught, but it is believed they were never traced.

Another UK Airprox Board report in December 2023 revealed that a drone missed a British Airways plane flying over Windsor at 270mph by just 60ft.

The near miss happened soon after the B787 Dreamliner carrying up to 216 passengers had taken off from Heathrow on a flight to Montreal, Canada, on July 25 that year. It was also rated as a Category A incident.

BA was approached for comment.