UK commits to F-35 retrofits

The UK will bring its F-35B fleet up to the latest TR-3 Block 4 standard, the government has confirmed. (Janes/Patrick Allen)

The United Kingdom has committed to retrofit its fleet of Lockheed Martin F-35B Lightning combat aircraft to the latest Technology Refresh-3 (TR-3) Block 4 standard.

Answering questions in the House of Commons on 18 September Minister of State at the Ministry of Defence (MoD), James Cartlidge, said a decision to bring the country's fleet of aircraft up to the latest standard had been made.

“I can confirm the [MoD] intends to upgrade the UK F-35B Lightning fleet with Technology Refresh-3 [and] Block 4 modifications,” Cartlidge said.

TR-3 is a suite of hardware and software built around an L3Harris core processor, a new memory system, and an open mission systems architecture. It includes a new cockpit display, with increased computing power being required for the upcoming F-35 Block 4 standard aircraft.

The UK has to date received 30 of 48 F-35B aircraft ordered (with 29 in service, following one loss), and is expected to sign for a second tranche of 27 jets (including a loss replacement airframe) to bring the final fleet up to 74.

The government had earlier been non-committal on upgrades to its earliest received F-35Bs, in particular with the new distributed aperture system (DAS). In 2018 the then Minister for Defence Procurement, Guto Bebb, said a decision on whether or not to swap the current Northrop Grumman AN/AAQ-37 DAS with a new system to be developed by Raytheon would be made “once [the government] understand[s] the time and cost implications”.