UK approves StormBreaker glide bomb as interim F-35B stand-off weapon

A US Marine Corps F-35B carrying StormBreaker SDBs in its internal weapons bay during trials. The UK is set to receive the weapon also, to provide an interim stand-off strike capability until the introduction of the MBDA SPEAR 3 in the early 2030s. (Lockheed Martin)

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.