Virgin Flight VS43, bound for Las Vegas, was forced to turn around and make an emergency landing at Gatwick airport this afternoon.
One passenger told The Mirror that some passengers were "anxious".
Dan Crane, from Bromsgrove, told the paper: "The mood was quiet and (we were) just waiting for the captain's next announcement." However, other passengers have told Sky News that the landing was "smooth".
Here's video footage of the landing.
There has been praise for the way the pilots handled the situation.
Emergency vehicles rushed to the plane.
These passengers appeared unconcerned by events.
This one rather less so.
At Heathrow, passengers were watching the drama play out.
Incoming and outbound flights from Gatwick have now been suspended.
Virgin Atlantic is apparently checking the plane over before letting passengers off.
Original story below.
A spokesperson for Virgin Atlantic has confirmed to The Mirror that Flight VS43 will make a "non-standard landing procedure" at Gatwick airport shortly.
A Gatwick spokesman told BuzzFeed News:
We can confirm that Virgin Atlantic Flight VS043 which departed Gatwick Airport at around 11.45am is returning to Gatwick after the aircraft developed a technical fault. In line with standard procedure, emergency services are on standby at the airport purely as a precaution.
A South East Coast Ambulance Service spokeswoman told BuzzFeed News the service is in "liaison with the airport following pre-agreed process for incidents such as this". They have a "number of resources on the scene" and staff/managers in support roles, she added.
The drama began an hour ago when the flight, which was bound for Las Vegas from Gatwick, was seen to have turned around and began circling its airport of origin.
The Mirror quoted an airline spokesperson who said:
Our Las Vegas flight turnback is actually a precautionary measure because of a small technical problem.
We're expecting it back at Gatwick very shortly and after that time I can send you an updated statement including plans to rearrange the flight for passengers.
Eyewitnesses posted pictures of the plane on social media. Some claimed that its landing gear was locked.
After circling Gatwick, the plane did several loops off the coast of north Devon.
It then circled off the Sussex coast.
A Virgin Atlantic spokesperson told the Mirror:
Virgin Atlantic can confirm that flight VS43 on 29 December, travelling to McCarran International Airport Las Vegas, returned to London Gatwick due to a technical issue with one of the landing gears.
The aircraft is preparing to implement a non-standard landing procedure at Gatwick airport.
A further update will be issued as soon as possible.