A British Airways flight travelling from London to Seattle is returning to Heathrow airport due to a "technical problem".
Flight BABA49 left the airport at 2.15pm with 218 passengers for the eight hour flight. Reports say the Boeing 777 was forced to circle the Irish Sea to dump fuel before returning to the airport.
Air Live said Heathrow is expecting the flight to arrive in 15 minutes.
A spokeswoman told The Mirror: "The aircraft is returning to Heathrow Airport as a precaution due to a suspected technical problem. Our pilots are highly trained to deal with these scenarios.
"Our engineers will inspect the aircraft to determine what the issue was."
It cited reports suggesting there had been a problem with cabin oxygen, although this has not been confirmed.
A spokesperson for BA said it could not speculate on this report and said engineers will look at the aircraft to determine the issue as soon as it arrives back the at airport.
"The pilot made a decision to come back to the airport as they sometimes do. It is standard procedure for it to return to the airport it left from, which in this case is Heathrow," the spokesman added.