But due to failings of both the MoD and the global programme, the level of overall UK F‑35 capability is currently lower than the MoD intended it would be by now at the time of its 2013 business case, and will be for several years.
Since 2010, MoD decisions to meet wider affordability challenges have led to delays in the delivery of aircraft and key infrastructure. The MoD has also failed to address personnel shortages and does not expect to fill gaps until 2028. And the global programme has had a series of issues which have delayed production and hindered logistical support while technology upgrade and support costs have also increased markedly over recent years.
In our view, the capability achieved for the estimated £11 billion spent to date is a disappointing return so far compared with MoD plans, even if other programme benefits have been significant.
UK approves StormBreaker glide bomb as interim F-35B stand-off weapon
The United Kingdom has approved the procurement of the RTX GBU-53/B Small Diameter Bomb (SDB) II (now known more commonly as StormBreaker) to equip its Lockheed Martin F-35B Lightning combat aircraft with an interim stand-off strike capability.
The Ministry of Defence (MoD) disclosed on 14 May 2026 that approval has been given for the Foreign Military Sales (FMS) procurement of the StormBreaker, confirming a Janes report from July 2025 that it was looking to acquire the glide bomb to mitigate delays with the integration of the Selected Precision Effects At Range (SPEAR) 3 precision-guided air-to-surface munition (while the MoD designates this weapons SPEAR 3, the manufacturer MBDA now calls it Spear).
“In the interim, approvals have been given to proceed with an FMS procurement of the precision-guided munition SDB II. This acquisition will provide the F-35 with an interim stand-off capability until the introduction of SPEAR 3 into service,” Permanent Under-Secretary for Defence, Jeremy Pocklington, said in a letter to the Chair of the Public Accounts Committee (PAC), Sir Geoffrey Clifton-Brown, dated 30 April 2026. Pocklington was responding to the PAC report The UK's F-35 Stealth Fighter Capability published in October 2025.
The MoD plans to equip the F-35B with the MBDA Meteor beyond-visual-range air-to-air missile (BVRAAM) in the air-to-air role and the SPEAR 3 in the air-to-surface role. Integration of both of these weapon types, however, has been progressively delayed in the context of the wider international F-35 programme so that neither will be ready until the early 2030s.
Recommendation 2a: The Department should set out in the Defence Investment Plan how it will ensure a standoff capability in the coming years before Spear 3 is fully integrated onto the aircraft.
Finalisation of the DIP remains a departmental priority as it will determine the timing and delivery of capabilities, ensuring that the UK, alongside its Allies, maintains critical operational outputs.
In the interim, approvals have been given to proceed with a Foreign Military Sales (FMS) procurement of the precision-guided munition, Small Diameter Bomb (SDB-II). This acquisition will provide the F-35 with an interim stand-off capability until the introduction of
SPEAR-3 into service.
