Airbus A320 plane in near-miss with drone near Heathrow Airport
Aviation near-miss investigators have expressed their "considerable concern" that a device believed to be a drone came within 20ft of a passenger plane at Heathrow Airport.
The Airbus A320 was 700ft from landing when the pilot reported seeing a small black object to the left of the aircraft, the report by the UK Airprox (aircraft proximity) Board (UKAB) said.
The object "passed about 20ft over the wing" and appeared to be a small radio-controlled helicopter, the report said.
The object did not strike the plane and the pilot was able to make a normal landing in the incident on July 22 this year.
But it added that it had been a distraction during a critical phase of the flight. Air traffic controllers were told of the incident and following aircraft were notified.
The UKAB also gave the incident an A rating - meaning that there had been "a serious risk of collision".
The UKAB said: "Despite extensive tracing action and the proactive assistance of local model flying club members, it was not possible to trace the operator of the model aircraft in question."
Earlier this year, airline pilots' association Balpa demanded better protection for the public against the risks of drones.
It wants drones, which share airspace with passenger and freight airliners, to meet the same safety standards as piloted aircraft.
Balpa general secretary Jim McAuslan said: "The UK should become a 'safe drone zone' so we can make the most of the major business and leisure opportunities offered by remotely piloted aircraft, while protecting passengers, pilots and residents.
"The technology is developing quickly and we could see remote aircraft the same size as a Boeing 737 being operated commercially in our skies within 10 years.''