SPEAR 3 integration on F-35B a priority, says minister

The immediate priority for the UK is to finalise the integration of the SPEAR 3 missile onto the F-35B, and to accelerate the work where possible, Defence Minister Luke Pollard has said.

Answering a written question from Ben Obese-Jecty, the Conservative MP for Huntingdon, who asked what capabilities were included within the scope of the planned spiral upgrades, Pollard said the focus was on completing the integration of SPEAR 3 and seeking to bring forward the warfighting capability as far as the United States-controlled programme allowed.

He said that once the weapon was in service it would be subject to spiral upgrades to keep it effective as the threat evolved, but that the specific upgrades were classified.

“The immediate priority is to finalise the integration of SPEAR 3 to the F35B, seeking to accelerate where the US controlled programme permits to realise the warfighting capability. Once in service, the already highly capable weapon will be subject to Spiral Upgrades to maintain effectiveness as the threat evolves; specific upgrades are classified to maintain the weapons operational advantage.”

SPEAR 3, developed by MBDA, is a precision-guided air-to-surface missile designed to be carried internally by the F-35 in numbers, allowing a single aircraft to engage several targets at stand-off range. The weapon is intended to strike mobile and defended targets such as air defence systems, armour and command sites, and its small size lets the F-35B carry multiple rounds while preserving the aircraft’s low-observable configuration.

In a separate answer last month, Pollard gave a target date for the weapon reaching the front line. “Fielding this critical F-35 warfighting capability is targeted within the joint programme from financial year 2028-29; spiral capability upgrades across the programme life cycle will occur thereafter,” he said. That target is earlier than the early-2030s estimate the Ministry of Defence has previously given for SPEAR 3’s in-service date.

The integration had been due to be completed during the F-35’s Block 3 software phase, but slipped into the later Block 4 update, the major US-led software upgrade that has itself run late and on which the addition of MBDA’s Meteor air-to-air missile also depends. Because new weapons cannot be certified on the aircraft until that software allows it, the timeline rests substantially on the US-controlled programme rather than on the UK or MBDA alone. The delays drew criticism from the National Audit Office, which reported in 2025 that the UK had not yet acquired an effective stand-off air-to-surface weapon for the fleet.

The delay leaves UK F-35Bs reliant on the Paveway IV guided bomb in the air-to-ground role for the time being, since the decision not to integrate Storm Shadow onto the aircraft means no other long-range strike weapon is currently planned for the type. To bridge the gap, the Ministry of Defence confirmed in May 2026, in a letter from its permanent secretary Jeremy Pocklington to the Public Accounts Committee, that it had approved a Foreign Military Sales purchase of the RTX GBU-53/B Small Diameter Bomb II, also known as StormBreaker, to provide an interim stand-off capability until SPEAR 3 enters service.

The glide weapon offers considerably greater range than the unpowered Paveway IV and can engage moving targets in poor weather, though it falls short of the turbojet-powered SPEAR 3 on range and lacks the missile’s ability to network several rounds together. Unlike SPEAR 3, the StormBreaker is already integrated on the F-35B and has been used operationally by United States Marine Corps aircraft, so the UK purchase does not require fresh integration work.

There have also been signs of forward movement on SPEAR 3 itself. The weapon was carried in flight on an F-35B for the first time in January 2026, and in recent weeks an aircraft carried four inert rounds in its internal bay on a captive-carry test flight at Naval Air Station Patuxent River in the United States, a step intended to inform the next stages of mission-systems integration and jettison trials.

Spiral development describes an approach in which a capability is fielded and then improved in successive increments rather than waiting for a single finished standard, allowing upgrades to be introduced over time as technology and threats change. Pollard’s answer indicated that while SPEAR 3 would follow that path once in service.