UK seeks Small Diameter Bombs for F-35Bs

A US Marine Corps F-35B carrying StormBreaker SDBs in an internal weapons bay during trials. The UK is now looking at the same combination as an interim solution until the arrival of the SPEAR 3 in the early 2030s. (RTX)

The United Kingdom is seeking to equip its Lockheed Martin F-35B Lightning Joint Strike Fighter aircraft with the RTX GBU-53/B Small Diameter Bomb (SDB) II (now known more commonly as StormBreaker), it was revealed on 11 July.

In its report titled The UK's F-35 capability , the UK's National Audit Office (NAO) said the UK F-35 programme office has requested SDBs to help mitigate ongoing delays to the integration of the MBDA Selected Precision Effects At Range (SPEAR) 3 precision-guided air-to-surface munition.

“To acquire a more capable interim air-to-surface weapon, the UK F-35 programme has requested funding for Small Diameter Bombs,” the NAO said in its report, adding, “The MoD [Ministry of Defence] has yet to provide this funding.”

The disclosure by the NAO was made in the context of a wider lack of long-range stand-off weaponry that it identified as being a key inhibitor to the country's fleet of 37 F-35Bs (the remainder of the 48 under contract, less one lost in an accident in 2021, are to be delivered by the end of 2026).

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.