British F-35B jets have left the UK to undergo landmark tests with the aircraft carrier, HMS Queen Elizabeth.
The £3.1 billion warship is currently off the east coast of the United States, where it is preparing to welcome British Lightnings on its flight deck for the first time.
The carrier left the UK in August to begin its part in Westlant 19.
Aircraft and pilots from 617 Squadron left RAF Marham in Norfolk for the US.
The pilots will be in the air for between nine and 10 hours and will first fly into Marine Corps Air Station Beaufort, South Carolina.
The aircraft will then fly and land on board HMS Queen Elizabeth.
Wing Commander John Butcher, Officer Commanding 617 Squadron, told Forces News it is a "huge moment".
"It marks a new chapter for 617 Squadron as we start our journey towards carrier operations," he said.
"I wouldn't say there's a specific wait of expectation but there is an air of excitement.
"We've got personnel here on 617 Squadron from the Royal Air Force and from the Royal Navy and on both sides of the service, we are looking forward to working alongside the carrier.
"That is the future of the Lightening force - we are, longer-term, to provide combat capability from the land or from the sea and this is the start of that journey."
The pilots will remain at Marine Corps Air Station Beaufort for a couple of days before meeting up with the aircraft carrier.
The deployment marks a key milestone in the progress of HMS Queen Elizabeth becoming fully operational.
Last year, she spent four months off America's east coast, conducting takeoffs and landings with US F-35s.
The F-35B is the UK's most advanced warplane ever, with British Lightnings flying their first operational missions in June.
Britain uses the 'B' variant of the F-35 and currently has 17 in service, but is expected to purchase a total of 138.
The jets, which have short takeoff and vertical landing (STOVL) capabilities, can operate from both land and sea.
HMS Queen Elizabeth is expected to be fully operational in her carrier strike role in 2021.