British F-35Bs have departed RAF Marham for flight trials with Royal Navy aircraft carrier HMS Queen Elizabeth in the North Sea.
It follows trials with HMS Queen Elizabeth last year off the east coast of the US.
The first two fighter jets, from 617 Squadron, took off from their Norfolk base on Tuesday afternoon.
"The whole mandate, if we’re going to do this, is to train day and night how to get from the ship, to the ship, and actually war fight and deliver a capability," Group Captain James Beck, Station Commander RAF Marham, told Forces News.
"This is the complete circle.
"Our instructors learn how to fly it, test all the procedures and this is the event where the instructors are now teaching the students, who happen to be 617 Squadron, and that will be, effectively, our culmination ready to declare a warfighting capability at the end of this year."
A total of four F-35B have today deployed to the aircraft carrier today to join up with 617 Squadron personnel already on board, but more will soon follow.
Watch: The moment the first two F-35Bs left RAF Marham earlier today.
"We haven't done this for so long, since the retirement of the Harrier GR9," said Gp Capt Beck.
"With F-35, the jet is so different to anything that we’ve ever had before, so there's a new way of engineering, a new way of flying it, a new way of working to and from the ship.
"The autonomy is just incredible and as such we’ve got a blank piece of paper in many areas and we’re now just starting to scribe what that looks like," Group Captain Beck said.
The Lightning Force is formed by Navy and Air Force personnel.
The aircraft, which can operate from both land and sea, have short takeoff and vertical landing capabilities.
Britain plans to eventually have 138 F-35Bs.
The UK owns 18 of the aircraft, 15 of those based at RAF Marham, with an order placed for an additional 30 jets.
Gp Capt Beck says now the aim is for "initial operating capability maritime" to be declared for the F-35B by the end of 2020.
"This is the culmination where we start to put it through its testing from a warfighting capability [perspective]," he said.
Later this year, crews will work alongside personnel and aircraft from the US Marine Corps to further understand the capability of the F-35B aircraft.
Gp Capt Beck said the Lightning jet will be examined with the question "Are we good to go to war?" being asked.
"Once we've got that assurance at the end of this year, the intent is to be able to declare initial operating capability maritime, which is a major milestone," he added.
HMS Queen Elizabeth has been undergoing sea trials off the UK coast for the last few weeks, following a period of at-sea quarantine because of the coronavirus crisis.
Last month, the Navy said the £3 billion aircraft carrier was "one step closer" to its first operational deployment.
The ship is due to be operational in 2021, with F-35Bs from 617 Squadron operating from its flight deck.
The squadron, known as 'The Dambusters' after the famous World War Two raids on German Dams in the Ruhr Valley in 1943, recently appointed its first Royal Navy commanding officer.