The UK has taken delivery of an additional two Lockheed Martin F-35B Lightning IIs growing the number of examples of the fifth-generation multi-role stealth fighter delivered to date to 32 aircraft.

The new short take-off and vertical landing (STOVL)-configured F-35Bs – serials ZM166 ‘032’ (callsign ‘ASCOT 9672’) and ZM167 ‘033’ (callsign 'ASCOT 9671’) – arrived at RAF Marham, Norfolk, after completing a transatlantic delivery flight from Lockheed Martin’s F-35 production facility in Fort Worth, Texas, on June 22. Delivery of these two new Lightning IIs was supported by an RAF-operated Airbus A330-243MRTT Voyager KC2/KC3 from RAF Brize Norton in Oxfordshire, which provided air-to-air refuelling services during the flight.

These F-35Bs are the first two of an expected seven aircraft that are due to be delivered to the UK by the end of 2023. While the UK initially committed to acquiring 138 F-35Bs as a replacement for its now-retired Harrier and Tornado fleets, London has only committed to an order of 48 aircraft so far – all of which are expected to be delivered by the end of 2025. Despite the UK having received 32 F-35Bs in total to date, three of these are used for testing purposes in the US and one was lost to attrition following a failed take-off from HMS Queen Elizabeth (R08) while the aircraft carrier sailed through the Mediterranean Sea on November 17, 2021. This leaves just 28 examples of the type in operational frontline service at RAF Marham.

The delivery of these new F-35Bs comes just months after the F-35 Joint Program Office (JPO) signed a £161m ($204m) deal with Lockheed Martin and BAE Systems (serving as a subcontractor) to provide maintenance and training support to the UK’s existing Lightning II fleet. The new contract, which was inked in April 2023, aims to support the British F-35B fleet until 2027, enabling the UK to operate the type with more freedom, increase the number of available flying hours and deliver mission planning, training and maintenance services with greater ease.

Speaking in a Parliamentary Defence Select Committee session on April 26, 2022, Air Marshal Richard Knight – who was then serving as the Deputy Chief of the Defence Staff and is now the RAF’s Chief of the Air Staff – revealed that the UK Ministry of Defence (MOD) was negotiating the purchase of another tranche of F-35Bs with the F-35 JPO. This tranche would consist of 26 new-build aircraft, in addition to the 48 examples already on order – growing the number of Lightning IIs on order to 74 (including the aircraft lost on November 17, 2021).

Addressing the possibility of future purchases and whether or not the UK will eventually field a 138-strong F-35B fleet, Knighton said: “We have said that the decision about further purchase, beyond that 74, will be taken in the middle of the decade, in the context of what we decide to do on our Future Combat Air System [FCAS] programme. It is perfectly plausible to imagine a situation in which we could have the fleet of 138 F-35s that we originally described back in the early 2000s.”