In December 2020 a British Survey drone crashed into a house. The large commercial drone weighing 25 pounds fell from sufficient height to have caused serious injury or death. Fortunately the property was empty so no one was injured. A second drone was sent to find the crash site but this suffered a similar fate.
The UK Air Accident Board investigation noted that first airborne drone initially showed a GPS compass error. In this situation the drone should hover and revert to manual flight mode and a barometric pressure sensor takes over to maintain altitude. Unfortunately without knowing its movement relative to the ground a 15 mph wind took the drone out of sight of the operator over an industrial area. Rising ground level meant the drone struck a house at roof level and crashed into the garden.
According to the UK DROPS standard for industrial safety a 4 pound blunt object falling from a height of 6 metres is capable of injury or death to someone, even if wearing a hard hat.
The source of the GPS interference which affected the drone has not been identified but it has been speculated that it may have come from a GPS ‘jammer’. These devices are easily available online, from as little as US$30 and are sold as personal privacy devices. Whilst they are legal to own in the UK they are illegal to operate. They have been used in the US by truckers and others who don’t wish their vehicle’s location to be recorded. These devices interfere with all GPS receivers and systems such as those fitted on drones.