Joint Combat Aircraft

Following the Sea Harrier's retirement, the Harrier II was removed from service in 2011.

In January 2001, the UK signed a Memorandum of Understanding (MoU) with the US Department of Defense for full participation in the Joint Strike Fighter project, confirming the JSF as the JCA. This gave the UK significant input into aircraft design and the choice between the Lockheed Martin X-35 and Boeing X-32.[4] On 26 October 2001, the DoD announced that Lockheed Martin had won the JSF contract.

On 30 September 2002, the MoD announced that the Royal Navy and RAF will operate the STOVL F-35B variant. At the same time it was announced that the carriers would take the form of large, conventional carriers, which will be adapted for STOVL operations. The carriers, expected to remain in service for 50 years, will be convertible to CATOBAR operations for the generation of aircraft after the F-35.

In 2007, the Ministry of Defence confirmed its order for two Queen Elizabeth-class aircraft carriers.

The UK has invested GBP £1.08 billion in development funding for the JSF. Britain has also worked for five years for an ITAR waiver to allow greater technology transfer associated with the project. The effort, backed by the Bush administration, has been repeatedly blocked by US Congressman Henry Hyde because of his concern about potential technology transfer to third countries.[5] On Friday 27 May 2006 President Bush and Prime Minister Tony Blair issued a joint statement which announced "both governments agree that the UK will have the ability to successfully operate, upgrade, employ, and maintain the Joint Strike Fighter such that the UK retains operational sovereignty over the aircraft."[6]

In February 2006 the chairman of the Commons Defence Select Committee stated that unless the UK got "all the information and technology it requires to maintain and upgrade the aircraft independently.... [it] might have to consider whether to continue in the programme.[7] Lord Drayson, Minister for Defence Procurement, while on a government visit to Washington to speak to members of Congress stated "We do expect [the software] technology transfer to take place. But if it does not take place we will not be able to purchase these aircraft", and has mentioned that there is a 'plan B' if the deal falls through.[8] A suggested likely option was the development of a navalised Typhoon. Mike Turner has said it was not what he recommend, but "as Lord Drayson has made clear, there needs to be a fall-back in case something goes wrong."[9]

British F-35Bs aircraft operating from HMS Queen Elizabeth

As part of the 2010 Strategic Defence and Security Review, it was announced that the previous intention to order 138 STOVL F-35Bs had been changed to a smaller number of CATOBAR F-35Cs, with the anticipated entry to service delayed until around 2020. Only one Queen Elizabeth-class aircraft carrier would be equipped with a catapult, and was expected to normally include twelve F-35Cs in its air wing.[10] In early 2012 the UK joint chiefs of staff publicly petitioned the Prime Minister to change the order back to the F-35B, on the grounds of lower cost, quicker implementation of fixed-wing carrier capability and the ability to operate both carriers with fixed-wing aircraft. On 10 May 2012, Philip Hammond announced that the coalition government had reverted to the Labour government plan to operate the F-35B STOVL variant.[11]

In 2013 the Defence Select Committee said "We urge the MoD to learn the lessons of this closed, rushed and flawed decision of 2010."[12]

Both the F-35s and the carriers are the main elements of "Carrier Strike", the term for an initial capability for both elements along with the Merlin Crowsnest airborne radar system.[1] This was declared in January 2021:

all elements of the group from fighter jets to radar systems to anti-ship weapons have been successfully brought together and operated. Both the air and naval elements of the Carrier Strike Group have now met this milestone, which includes qualified pilots and ground crews being held at short notice for carrier-based operations and trained to handle weapons and maintain the equipment. Another marker of success at this stage includes the ability to deploy Anti-Submarine Warfare capabilities such as frigates and destroyers, as well as both fixed and rotary wing aircraft including Merlin helicopters to operate alongside the carrier.[13]

Full operational capability is expected in 2023.[13] The next step is the introduction of the second carrier and a second squadron of F-35Bs to allow the carriers to operate the full range of intended roles; this capability, "Carrier Enabled Power Projection", is expected in 2026.[1] However, in early 2022 one analysis suggested that the second F-35 squadron might not stand up before 2026 and that a third frontline F-35 squadron might not be active before 2030.[14] In September 2022, it was reported that the Fleet Air Arm Squadron (809 Naval Air Squadron) would formally re-commission in 2023 but that it would not be considered "deployable" for a further two years.[15]

As of the end of 2022, 29 F-35Bs had been delivered to the U.K. (three of these being based in the U.S. for test and evaluation purposes). Seven additional aircraft are expected to be delivered in 2023, four in 2024 and seven in 2025, completing the delivery of the planned 48 tranche 1 (one of which was lost in 2021).[15][16]

However, as of the end of 2022, U.K. Defence Secretary Ben Wallace reported that the RAF and Royal Navy faced a considerable challenge in providing even the existing modest F-35B fleet with qualified pilots. As of late 2022, there were only 30 qualified British pilots (plus three exchange pilots from the United States and Australia) for the F-35. The average wait time for RAF trainee Typhoon and F-35 pilots, after completing the Military Flying Training System, was approximately 11 and 12 months respectively. A further gap of 68 weeks existed between completing Basic Flying Training and beginning Advanced Fast Jet Training.[17]

In February 2023, the Chief of the Air Staff, Air Chief Marshal Sir Mike Wigston, reported that the number of F-35 pilots had grown to 34 UK pilots with a further 7 to complete training by August 2023.[18]