British F-35B aircraft have left the UK to fly to the United States ahead of starting tests on board HMS Queen Elizabeth.
The aircraft carrier is currently based off the east coast of the United States, but the Lightning jets will first fly to South Carolina before landing on the ship's deck.
History was been made in Britain's F-35Bs programme earlier this year when the jets completed their first operational missions.
The Lightning jets flew alongside Typhoon aircraft over Iraq and Syria in support of Operation Shader - the UK's contribution to the fight against so-called Islamic State.
The aircraft began their first overseas deployment in May. when six of the jets flew to RAF Akrotiri from RAF Marham.
It followed F-35B aircraft landing on the deck of the UK's new aircraft carrier HMS Queen Elizabeth for the first time last year as part of flight trials off the coast of the United States.
The landing was completed by US aircraft, flown by British pilots, while UK jets will land on deck when HMS Queen Elizabeth returns to Britain.
Britain plans to eventually have 138 F-35Bs.
A lift fan mounted behind the jet's cockpit allows the jet short takeoff and vertical landing (STOVL) capabilities.
Single-seat, single-engine fighters with integrated sensors, the warplanes will conduct missions and operations from the Royal Navy's Queen Elizabeth-class aircraft carriers.
By 2020, it is hoped they will reach their full operational capability.
How much will it cost?
The overall programme is the most expensive weapons system in military history. An estimated cost from 2015 put the price at £78 million per jet, without engine or electronics.
For everything included, the Lightnings come in at a grand total of £190 million.
Who will use the jets?
The Royal Air Force started utilising the jets in missions earlier this year after the current training concluded in the US.
The RAF and Royal Navy pilots from 207 Squadron will return from the training and reform as 617 Squadron, the Dambusters.
The squadron will be based at RAF Marham in Norfolk.
The F-35 programme is being rolled out internationally across the US, UK, Italy, Netherlands, Turkey, Canada, Australia, Denmark, Norway among others.
Israel claimed to be the first nation to use the aircraft in a combat situation, while the US conducted its first air strike using the F-35B last September.
The jet measures 15.6 metres (51.2ft) in overall length, has a wingspan of 10.7 metres (35ft) and a height of 4.36 metres (14.3ft).
Its top speed comes in at 1.6 Mach or 1,200 mph, that is 1.6 times the speed of sound.
The jets will have a maximum thrust tops 40,000lbs, an amazing range of 900 nautical miles and a combat radius of 833km.
The Lightning has a max G rating of 7G which can be compared to the g-force felt in Apollo 16 on re-entry to Earth (7.19g).
Unlike earlier generation fighter jets, the Lightning is designed to carry its weaponry internally, decreasing the drag and its radar signature.
Depending on missions, the typical armament on the F-35B includes a 25mm cannon, two bays for air missiles, a further two for bombs up to 450kg.
There are also two wingtip mounds for air-to-air missiles and four for air to surface or ground missiles.
The jet itself is made by many different companies. The main contractor is Lockheed Martin, with BAE systems making around 15 pieces of each airframe and Rolls-Royce making the lift fan.
Life on board HMS Queen Elizabeth
Rather than the traditional catapult launch, the F-35B will take off from HMS Queen Elizabeth via the ski jump ramp.
The jet is capable of two types of landing - vertically onto the deck, and also through the shipborne rolling vertical landing, which using forward airspeed, allows the aircraft to bring back several thousand pounds of extra weight to the ship.
HMS Queen Elizabeth itself weighs 65,000 tonnes and has a top speed of 25 knots.
Its flight deck is 280 metres long and 70 metres wide, enough space for three football pitches.
Lockheed Martin, the main American company building the jets, describes its stealth capabilities as "unprecedented".
By design, its advanced materials and other features make it "virtually undetectable to enemy radar".
However, the manufacturer has confirmed that its state-of-the-art communications system cannot link up with older planes.
This means the RAF's F-35 pilots will have to switch to older systems to make contact with the UK's Typhoon fighters, losing their stealth capability and becoming detectable by enemy forces.
These technology problems could turn out to be extremely costly, with some estimates saying that we could expect delays of up to five years and additional costs.
While some pilots have raved about the Lightning and defence experts hinted that there are classified capabilities that warrant the spend, others have condemned the warplanes.
In 2015, a test pilot revealed that during a dogfight, the advanced jet was unable to manoeuvre and shoot down a 40-year-old F-16 jet. Coincidentally one of the jets the F35B II is destined to replace.
Royal Air Force Squadron Leader Andy Edgell defended the aircraft saying: "It is an incredibly, incredibly powerful aircraft and I am not talking about thrust, the capabilities it brings to the battle space - it is incredibly powerful.
"The disappointing thing is I can't share all the details... I do think a lot of the critics would be quietened very quickly."