The UK now owns 21 F-35B Lightning jets, 18 of them based in Britain, after three new aircraft flew across the Atlantic from the United States.
British and American F-35Bs recently joined up with HMS Queen Elizabeth ahead of a multinational exercise.
Two squadrons of Lightning aircraft embarked on the ship in September - the largest group of aircraft on a Royal Navy carrier since HMS Hermes was in service.
In February, four F-35 Lightning fighter jets completed the first night landings on aircraft carrier HMS Queen Elizabeth in UK waters.
It followed the aircraft operating from the carrier during the month before - the first time British fighter jets had operated from a Royal Navy aircraft carrier in home waters in a decade - and the first launch of a British F-35B from UK waters in December 2019.
The UK's F-35Bs programme made history in 2019, 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 2019, 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 in 2018 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 landed on deck upon HMS Queen Elizabeth's return to Britain.
This week, three new F-35Bs flew from America to RAF Marham, bringing the UK's complement of Lightnings to 21 - 18 based in Norfolk and three in the US.
The UK has plans to eventually have 138 F-35Bs, with 48 of those by 2025.
The 138 figure was recently clarified by Sir Stephen Lovegrove as the "upper limit" of how many would be bought.
The UK owns 21 of the aircraft, 18 of those based at RAF Marham, with an order placed for an additional 30 jets.
Sir Stephen Lovegrove added he expects "more than 48" will eventually be purchased.
It is likely only one Queen Elizabeth-class vessel will be deployed at once, with up to 24 F-35Bs on an aircraft carrier at one time.
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 Lightning jets come in at a grand total of £190 million.
Who uses the jets?
The Royal Air Force started utilising the jets in missions in 2019, after training concluded in the United States.
The Lightning Force, made up of RAF and Royal Navy personnel, is based at RAF Marham in Norfolk and oversees operations involving the UK's F-35B aircraft.
The following squadrons fly the Lightning fighter jet:
- 17 Squadron, which is stationed at California's Edwards Air Force Base and has been responsible for operational testing of the UK's F-35Bs since 2014
- 617 Squadron, the first frontline F-35 unit, also known as the Dambusters, based at Marham
- 207 Squadron, which is the UK’s F-35 Lightning training squadron, also based at Marham
- 809 Naval Air Squadron, which is due to be stood up in 2023, will be the first Royal Navy formation to fly the F-35.
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 in 2018.
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).
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.
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 takes 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.
Her 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 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 F-35B 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 battlespace - 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."