The United Kingdom has resumed receiving F-35B Lightning II fighter jets from Lockheed Martin after a delivery pause of more than a year. On May 8, two aircraft — tail numbers 037/ZM171 and 038/ZM172 — were flown from the company’s production facility in Fort Worth, Texas, to Royal Air Force (RAF) Marham in England, supported by an Airbus Voyager tanker.
These are the first F-35B aircraft to be delivered to the UK built to the new Technology Refresh 3 (TR-3) configuration, following delays in the broader international F-35 programme. The last UK F-35B delivery took place on March 20, 2024, under the previous TR-2 standard.
TR-3 provides the enhanced computing architecture required for the upcoming Block 4 configuration, also referred to as Continuous Capability Development and Delivery (C2D2). Block 4 will bring a range of upgrades to sensors and weapon systems. For the UK, this includes integration of the MBDA Meteor beyond-visual-range air-to-air missile (BVRAAM) and the Selected Precision Effects At Range (SPEAR) 3 air-to-surface munition.
With the arrival of these two jets, the UK now operates a fleet of 32 F-35B aircraft. While one was lost in a 2021 incident and four remain with the 17 Test and Evaluation Squadron in the United States, deliveries of the initial 48 contracted jets are set to conclude later in 2025. An additional 27 aircraft are planned under a second tranche, with the UK’s total F-35B fleet expected to reach 75 by the early 2030s.
The F-35B remains a key asset in the UK’s defense strategy, offering short takeoff and vertical landing capabilities, advanced stealth, and multi-role functionality for both land-based and maritime operations.
📌The UK received two new F-35B jets with TR-3 upgrades from @LockheedMartin, marking the first delivery since March 2024.
📎https://t.co/9IatwH3mxB pic.twitter.com/2ZEIIeV9LN
— Defensehere (@defensehere_en) May 9, 2025