Drone missed passenger jet landing at Heathrow by 20ft
A drone came within 20ft (6m) of hitting a passenger jet on its final approach to London's Heathrow Airport, an aviation safety hearing was told.
The Airbus A319, which can carry up to 156 passengers, was flying at 500ft (152m) on 30 September when the drone passed just 20ft above it.
The pilot involved told the UK Air Proximity Board (UKAB) it was not possible to take avoiding action.
Police were informed but the drone operator has never been traced.
'Bare minimum' distance
The incident was in the most serious risk category because of its proximity to the jet.
The drone was violating the Civil Aviation Authority regulations as it did not have permission to be above 400ft (122m) within the control zone around Heathrow Airport, officials said.
The UKAB concluded the aircraft and the drone were separated by about a wingspan, which is considered to be "the bare minimum", and the drone had not shown up on radars.
The UKAB's latest monthly meeting considered six possible near-miss incidents between aircrafts and drones.
Days after the Heathrow incident, the pilot of a Dornier Do328 short-haul plane, which carried about 30 passengers, reported a drone passing his left wing by less than 50ft shortly after taking off from Manchester Airport.
The incident on 2 October occurred at an altitude of 3,000ft and the pilot believed the drone must have passed over the propeller and assessed there was a high risk of collision.
Since December the UKAB has published details of seven near-misses involving drones, including a drone coming within metres of colliding with a jet above the Houses of Parliament on 13 September.