Drones: What are the rules for flying unmanned aircraft?

As an investigation is launched after a British Airways flight is believed to have been struck by a drone at Heathrow Airport, here is a look at the rules governing use of the unmanned aircrafts.

According to the Civil Aviation Authority (CAA), the rules are as follows:

• An unmanned aircraft must never be flown beyond the normal unaided "line of sight" of the person operating it - this is generally measured as 500m (1,640ft) horizontally or 122m (400ft) vertically.

• An unmanned aircraft fitted with a camera must always be flown at least 50m (164ft) distance away from a person, vehicle, building or structure.

• An unmanned aircraft fitted with a camera must not be flown within 150m (492ft) of a congested area or large group of people, such as a sporting event or concert.

• Operators must have a CAA licence to fly a drone for commercial purposes.

There are no established operating guidelines for drone but the CAA stresses that "anyone flying a drone either recreationally or commercially has to take responsibility for doing so safely".

Drone pilots risk criminal prosecution for unsafe flights

• Drone pilots are liable to criminal prosecution if they fail to conduct a flight in a safe manner.

• They can be punished with up to five years in prison if they recklessly endanger an aircraft.

• Users can also be prosecuted under the Air Navigation Order 2009 if they fly their drone beyond their line of sight.

Last September, a man was prosecuted for flying drones over Premier League football stadiums, the Houses of Parliament and near Buckingham Palace.

Nigel Wilson, 42, from Nottingham, used the drones to shoot videos which he uploaded on to his YouTube channel.

It was the first time an individual was prosecuted for using drones following a police-led operation and Mr Wilson was fined £1,800.