Joint Combat Aircraft

The Joint Combat Aircraft (JCA) is the official designation of the United Kingdom Ministry of Defence used for the F-35 Lightning II. The F-35, formerly the Joint Strike Fighter, is the result of the Joint Strike Fighter program.
JCA has been closely aligned with the "Future Carrier" (CVF) programme due to the interdependencies between the two; the latter developed into the . 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. The next steps 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.
Programme history.
The JCA programme began as a result of the approval of a "Staff Target" in 1996 for a Future Carrier Borne Aircraft (FCBA), a multirole fighter/attack aircraft to replace the Royal Navy's Sea Harrier FA2.
In 1998 the British Government published its Strategic Defence Review (SDR) which confirmed the strategy for future British carrier aircraft:
Various carrier aircraft types and carrier configurations were studied. The SDR singled out the Joint Strike Fighter (JSF) as "a strong contender"; the UK had signed a Memorandum of Understanding signed in December 1995 making it a partner in the JSF Concept Demonstration phase. Other aircraft considered were the F/A-18E, Dassault Rafale-M, a 'navalised' Eurofighter Typhoon, and an "advanced Harrier". 
The requirement to replace both Navy and RAF Harriers led to the renaming of the programme as Future Joint Combat Aircraft (FJCA) in 2001. Later, in the third and final name change of the project, the word "future" was removed.
Aircraft selection.
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. 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.
Technology transfer.
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. 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."
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. 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. 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."
2010 Strategic Defence and Security Review.
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. 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.
In 2013 the Defence Select Committee would say "We urge the MoD to learn the lessons of this closed, rushed and flawed decision of 2010."
Initial capabiltiy.
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. This was declared in January 2021:
Full Operational Capability is expected in 2023. 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.
Basing.
In March 2013 it was announced that the F-35 main base will be RAF Marham, in Norfolk.