Investigators surveyed the site of the UPS cargo plane crash in Kentucky.

Footage shows National Transportation Safety Board personnel deploying drones over the charred site in Louisville on November 6.

The McDonnell Douglas MD-11 aircraft had ploughed through the community at the edge of an airport on November 4, killing 14 people in the crash and subsequent fire.

The Federal Aviation Administration (FAA) said the accident happened when 'the left-hand engine and pylon detached from the aeroplane during takeoff', adding the cause was under investigation.

All MD-11 aircraft were grounded for inspections because 'the unsafe condition is likely to exist or develop in other products of the same type design', the FAA warned.

The UPS said emergency plans were in place to ensure delivery services were not disrupted. It said: 'Nothing is more important to us than the safety of our employees and the communities we serve.'

Aircraft manufacturer Boeing said there were around 70 MD-11s operated by the UPS, FedEx, and Western Global.