A video of a home-made drone firing what appears to be a pistol has been posted onto YouTube.
The video, which cannot be independently verified by the Guardian, appears to show a small calibre handgun strapped to quadcopter with an elongated frame. The author of the video has not replied to requests for comment.
In the video, the pistol appears to fire four times, propelled backwards with each shot by the recoil. The drone compensates for the force, adjusting its height and position after each shot.
Typically quadcopters have symmetrically distributed propellers for maximum stability and control during flight. But increasing the separation between the front and rear propellers helps to overcome and control increased forces, such as the recoil of a gun, in a front-to-back direction.
The home-made nature of the drone indicates that the technology could see wider use, but it is not the first of its kind. A video purporting to show a handgun mounted beneath an octocopter firing at a series of objects was created as an advert for a screen protector firm in 2013.
Civil drones have become a hot-button topic, with many available for less than £100 capable of carrying cameras and other payloads, which has provoked privacy fears and threats of drones being shot out of the sky.
Restrictive laws on the piloting of drones are currently under revision in the US, where companies such as Amazon have sought to use them for deliveries among other activities.
Their commonplace use in cinematography has led to operators requiring licences for operation within populated areas, with accidents involving drone crashes highlighting the dangers.
Current UK legislation by the Civil Aviation Authority dictates that drones cannot be flown within 50m of a building or a person and within 150m of a built-up area. In addition, the maximum flight height is 400 feet, and the drone has to remain in line of sight and within 500m of the pilot.
Pilots must complete a training course and apply for a permit from the CAA to fly the drone for commercial purposes.
