Its decision to opt for the F-35B variant's linked to several factors, including timeframe and cost - with the F-35C previously in the frame now not expected to be in-service for another 11 years.
It'll cost an estimated £50+m to amend the Royal Navy F-35 order from -C to -B but, according to the UK Defence Secretary, that's still cheaper than sticking with the other model. It'll also take away the need to heavily modify the pair of future Queen Elizabeth-class carriers, as would have been required to operate the F-35C.
Joint Strike Fighter Switch
"This government will not blindly pursue projects and ignore cost growth and delays, Defence Secretary Philip Hammond said in a statement on the Joint Strike Fighter switch. "When the facts change, the responsible thing to do is to examine the decision made and be willing to change, however inconvenient that may be."
As things now stand, initial Royal Navy F-35B Joint Strike Fighter trials should begin in 2018 and the Fleet Air Arm should have a squadron of JSFs operationally-ready in 2020. It's not yet been decided how many F-35Bs will be purchased but that information's set to form part of the 2015 Strategic Defence and Security Review.
The F-35B purchase will bring back to the Royal Navy a STOVL capability missing since the retirement of the Naval Strike Wing's Harrier GR9s, at the end of 2010.
Government F-35 Switch
According to a late-April comment made by Peter Luff - Minister for Defence Equipment and Support - prior to the Government's F-35 switch announcement, the UK had so far invested more than £1.8bn in the Joint Strike Fighter project. Of this figure, over £1.5bn's gone towards developing and demonstrating its systems, while £330m's been allocated towards its manufacture.
"The 2010 SDSR decision on carriers was right at the time, but the facts have changed and therefore so too must our approach", Hammond added. "I am not prepared to tolerate a three-year further delay to reintroducing our carrier strike capability.
"This announcement means we remain on course to deliver carrier strike in 2020 as a key part of our Future Force 2020."
Image copyright US Navy