The UK Ministry of Defence is exploring the potential acquisition of the GBU-53/B StormBreaker bomb for its fleet of F-35B Lightning II aircraft, according to a new report by the National Audit Office (NAO). The move comes amid delays in the integration of the MBDA SPEAR 3 air-to-surface missile, which had been intended as a key component of the UK’s F-35 armament.
The NAO report, titled The UK’s F-35 Capability, states that the UK programme office has requested funding for the Raytheon-developed StormBreaker bomb as a stopgap. The Ministry of Defence has not yet approved the request. The report notes that the lack of long-range stand-off strike options is currently limiting the operational flexibility of the UK’s fleet of 37 F-35Bs.Although the UK originally committed to purchasing 138 F-35 aircraft, only 48 are currently on contract, with 38 delivered. One aircraft was lost in an accident in 2021. The remainder under contract are expected to be received by the end of 2026. The Ministry aims to deploy up to 24 F-35Bs aboard a Carrier Strike Group in 2025 and plans to keep the aircraft in service until 2069.
While the F-35B’s integration with the MBDA Meteor and SPEAR 3 missiles remains delayed until the early 2030s, the Ministry is also preparing to procure 12 F-35A variants capable of nuclear delivery under NATO’s dual-capable aircraft programme. These are expected to be delivered before 2030.
The report concludes that while the UK’s F-35 programme has enhanced the country’s air combat capabilities, it has not progressed at the pace originally envisioned. Delays in aircraft deliveries, infrastructure development, and weapon integration—compounded by personnel shortages and rising costs—have affected readiness. The NAO estimates that £11 billion has been spent so far, with returns falling short of initial expectations.
