Heathrow runway was closed after illegally flown drone was 3ft from hitting 200mph Finnair plane

The main runway at Heathrow had to be closed after an illegally flown drone came as close as 3ft to smashing into an airliner flying at nearly 200mph, a report has revealed.

The alarm was first raised when the drone was spotted ‘in the vicinity’ at a height of 3,000ft by the pilots of two passenger jets on their final approach to the airport.

The crew of a Finnair flight from Rome were warned by air traffic controllers about the reported drone around three miles south of Maidenhead, Berkshire.

But a report by the UK Airprox Board said the pilots elected to continue as the drone was reportedly ‘staying to the right of the centreline’ of their flight path.

As they neared the drone it ‘flew under the left wing, only a few metres from the engine’ of their A320 aircraft which could have been carrying up to 174 passengers.

The crew of a Finnair flight from Rome were warned by air traffic controllers about the reported drone around three miles south of Maidenhead, Berkshire (file photo of drone near Heathrow Airport)

The Finnair pilots rated the risk of a collision as ‘high’, and estimated that the drone was between 3ft and 10ft directly below their aircraft ten miles west of Heathrow.

It is believed to be one of the closest ever near misses between a drone and an airliner to be recorded in UK airspace.

The device which was said to be ’round shaped’ and a ‘purple/turquoise colour’ was being flown at more than seven times the normal legal maximum height for drones of 400ft.

The report said that air traffic control was informed and the Finnair plane landed safely on the northern runway at Heathrow just before 12.40pm on April 8 this year.

But the report said that the runway known as RW09L was immediately closed to flights following behind the Finnair plane.

The other planes were directed to land instead on the southern runway known as RW09R so they did not come into conflict with the drone.

The Heathrow Approach controller considered the move necessary due to the ‘immediate risk’ posed to other aircraft.

UKAB which is the official body assessing near misses rated it as a Category A incident, the most serious ranking where there is said to be a serious risk of collision.

It is believed that the drone operator was never traced, but if they had been caught they could have potentially been jailed for up to five years for endangering an aircraft.

The report said: ‘In the Board’s opinion the reported altitude and/or description of the object were sufficient to indicate that it could have been a drone.

‘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 flightpath of the Finnair flight from Rome which came as close as 3ft to smashing into a drone while flying at 200mph coming into land at Heathrow Airport 

The report said that a safety investigation by NATS (formerly National Air Traffic Services) had found no trace of the drone on radar records at the time of the sightings.

The incident follows a series of other reported near misses between drones and passenger aircraft in skies above the UK.

Most cases are thought to involve rogue operators flying their devices to illegal heights after by-passing maximum altitude software to try and get dramatic videos of aircraft flying by.

Pilots have repeatedly warned of the danger of drones smashing cockpit windows or damaging jet engines, especially during critical times before landing or just after take off.

A spokesperson for Finnair confirmed that the incident involved a flight being operated by the Finnish airline on behalf of British Airways.

The spokesperson added: ‘Getting accurate estimates of distance is challenging at high speed, so 3 to 10ft is only an estimation of the distance from the drone.

‘Flying drones in areas where it is strictly forbidden shows that some drone enthusiasts have ignored safety regulations.

‘We want to express our concern about this irresponsible activity. These cases endanger air traffic safety and can cause flight operations disruptions.

‘Safety is the cornerstone of aviation, and we also expect a strong safety culture from drone enthusiasts.’

Flight data records reveal that the two flights which reported the drone before the near miss with the Finnair plane were potentially a British Airways flight from Stuttgart, Germany to Heathrow and an Aer Lingus flight from Cork in the Republic of Ireland.