A London-bound passenger plane had to divert to Canada while halfway across the Atlantic after dropping more than 20,000 feet.

Passengers said the aircraft suddenly ‘dipped like a ferry’ and cabin crew ‘ran down the aisles’ while the plane spent two hours flying back in the direction it came from.

Lizzie Laming, 22, of Sittingbourne, Kent, said she watched in horror as United Airlines staff leapt into action after United Airlines’ Boeing 757 began losing height.

The aircraft, which set off from Washington DC last night, also turned around and flew two hours back before landing safely this morning at St John’s in Newfoundland, Canada.

Passengers are being taken on to London on other flights.

Ms Laming, who was joined by her friend Ellie Cauldwell, 22, from Bristol, said she had gone to sleep when she was jolted awake by the sudden movement of the plane.

‘The plane dropped and it felt like being on a ferry when it goes up and down,’ she said.

‘Most of the cabin crew were running up the aisles and we were not told anything for a while.

‘We could tell from the on-screen maps that we had lost height – from around 40,000ft to 20,000ft – and that we had turned round.

“We gathered there was something wrong with one of the engines.’

Ms Laming and Ms Cauldwell, who both attended Exeter University, were on a travel tour which included the U.S, having just completed their degree courses.

Both were put on a flight from St John’s to Newark, New Jersey and were being flown back to London from there.

A United Airlines spokesman in London said today: United flight 130 from Washington Dulles to London Heathrow diverted to St. John’s, Newfoundland, Canada.

‘There was a mechanical problem with an engine, and out of an abundance of caution, the pilot elected to divert the plane.

‘The Boeing 757-200 carrying 50 passengers and 9 crew members landed safely and without incident.

‘We re-accommodated customers on other flights to London.’

(Source: Daily Mail UK)