USMC F-35B Completes First Developmental Flight Carrying Four MBDA SPEAR 3 Cruise Missiles

Technical Summary

The F-35 Joint Program Office (JPO) released imagery on 21 May 2026 documenting the first developmental test flight of an F-35B Lightning II configured with four MBDA SPEAR 3 small-diameter stand-off cruise missiles. The sortie was flown on 20 January 2026 from the Pax River F-35 Integrated Test Force (ITF) at Naval Air Station Patuxent River, Maryland, by Lieutenant Commander Nick Baker RN of the Royal Air Force’s Air and Space Warfare Centre, who is currently deployed to the F-35 ITF. The airframe used was a US Marine Corps F-35B test aircraft. The missiles carried were inert, consistent with a first captive-carriage developmental test point.

The test is the opening developmental event in the F-35B / SPEAR 3 integration sequence and was conducted jointly by MBDA UK (weapon design authority), Lockheed Martin (airframe integrator) and BAE Systems (UK industrial partner and integration software lead). Subsequent test points have been publicly indicated as mission systems integration and jettison trials, with eventual live-firing and operational test still to follow. The 21 May 2026 imagery release is the JPO’s first public confirmation of a four-missile F-35B captive carriage configuration.

What SPEAR 3 Actually Is: the SPEAR Programme Context

SPEAR stands for Selective Precision Effects At Range. It is not the name of one weapon. It is a UK Ministry of Defence portfolio of air-to-surface precision-guided strike capabilities, formalised in the mid-2000s as part of the UK’s Complex Weapons strategy and structured into numbered Capability increments. Each Capability addresses a specific operational gap. The miniature cruise missile that flew at Pax River on 20 January 2026 is the deliverable for SPEAR Capability 3.

The SPEAR Capability set

Why the “3” exists, and why it is often dropped

The “3” is a programme designation, not a version number of the missile itself. It identifies that this weapon was developed to satisfy Capability 3 of the broader SPEAR requirement set. The MoD introduced the Capability 3 requirement around 2009 for a roughly 100 kg-class weapon with turbojet propulsion, folding aero-surfaces for internal F-35 carriage, and a two-way datalink for in-flight retargeting: capabilities that neither Paveway IV nor Brimstone could provide. The £550 million Demonstration and Manufacture contract to MBDA UK in 2021 took the SPEAR Capability 3 requirement from concept into production representativeness, leading directly to the Typhoon launch in November 2024 and the Pax River carriage flight in January 2026.

MBDA markets the missile as simply SPEAR: clean product branding, similar to how the company markets Brimstone or Meteor. UK MoD, JPO and parliamentary documents retain “SPEAR 3” or the full “Selective Precision Effects At Range Capability 3” for contractual and technical precision. When the F-35 Joint Program Office released the Pax River imagery on 21 May 2026, the official caption used the long form: “four Selective Precision Effects At Range Capability 3, or SPEAR 3, missiles.” Media and analyst coverage consistently use “SPEAR 3” to avoid confusion with the wider SPEAR programme.

Naming convention by audience (2026)

The most accurate professional description is therefore: SPEAR (Selective Precision Effects At Range) Capability 3 missile, a turbojet-powered miniature cruise missile developed by MBDA UK to meet the UK MoD’s SPEAR Capability 3 requirement, intended as the primary future stand-off precision strike weapon for the UK F-35B fleet. The “3” has never been part of the missile’s physical designation or part number. It is purely a reference to which line of the SPEAR requirement the weapon satisfies.

SPEAR 3 Weapon Architecture

SPEAR 3 (Selective Precision Effects At Range, Capability 3) is a small-diameter, network-enabled stand-off cruise missile derived from the Brimstone air-launched anti-armour missile family. It substitutes Brimstone’s solid-propellant rocket motor for a Hamilton Sundstrand TJ-150 turbojet engine and adds a folding wing kit and three deployable tail fins, extending the engagement range from Brimstone’s ~20 km to a published range in excess of 140 km, depending on launch altitude and flight profile. The TJ-150 is the same engine used in the AGM-154C-1 JSOW-ER and the ADM-160 MALD, providing a mature expendable-turbojet supply base.

SPEAR 3 Technical Data Pack: verified MBDA / open sources, May 2026

The SPEAR family also includes the SPEAR-EW variant, a SEAD-optimised electronic-warfare jamming and decoy payload that shares the SPEAR 3 airframe and launcher footprint, allowing mixed kinetic-and-non-kinetic loadouts within the same internal bay.

F-35B Internal-Bay Carriage Significance

The 20 January 2026 test demonstrated four SPEAR 3 missiles carried on a single F-35B airframe in the imagery released by the JPO. Open-source reporting from The Aviationist and FlightGlobal indicates the eventual carriage objective is up to eight SPEAR 3 missiles across both internal weapons bays, alongside a complement of AIM-120 AMRAAM air-to-air missiles. This is enabled by SPEAR 3’s sub-90 kg mass and 180 mm cross-section, which permits multi-missile carriage where larger weapons such as the 1,000 lb-class Paveway IV are restricted to single carriage per bay.

For the F-35B specifically, the short take-off and vertical landing (STOVL) variant operated by the Royal Navy and Royal Air Force from HMS Queen Elizabeth, HMS Prince of Wales and shore bases, the magazine-depth implication is significant. Current internal-bay loadouts for stand-off strike against fixed targets default to one Paveway IV per bay, with low-observability preserved. An eight-missile SPEAR 3 loadout would deliver an eightfold increase in stand-off precision strike magazine depth while keeping the airframe low-observable, opening operationally meaningful options for sustained anti-radiation, swarm-engagement and saturation strike profiles that the current sovereign weapon stack cannot support.

Programme Lineage and Timeline

The SPEAR 3 / F-35B integration test point at Pax River is the latest stage in a multi-platform development pipeline that began publicly with first launches from the Eurofighter Typhoon. The verified open-source timeline runs:

• November 2024: First live launch of SPEAR 3 from a Eurofighter Typhoon at the Vidsel test range in Sweden. Flown by 41 Squadron RAF (the Test and Evaluation Squadron) in cooperation with the BAE Systems flight test team. This was the first all-up missile release of the production-representative weapon configuration.
• 20 January 2026: First F-35B captive carriage test flight at Pax River F-35 ITF. Four inert SPEAR 3 missiles carried internally on a USMC F-35B test airframe. Pilot Lt Cdr Nick Baker RN.
• 21 May 2026: F-35 Joint Program Office releases the official test imagery via DVIDS, providing the first public visual confirmation of the four-missile F-35B carriage configuration.
• Next planned phases (publicly indicated): mission systems integration testing, jettison trials, ground-launched ejection sequencing, and subsequent guided live-firing trials. The Royal Air Force has publicly stated it is preparing for the “first ejections” phase of the test sequence.

The integration software for F-35B compatibility is being developed by BAE Systems’ UK F-35 integration team. This work draws on the UK’s status as a Level 1 partner in the F-35 programme and the country’s second-largest position (after the United States) in F-35 sustainment infrastructure. The Level 1 partner status grants the UK technical access to airframe systems necessary for sovereign weapon integration that is not extended to nations that joined the programme as Foreign Military Sales customers.

Personnel and Safety Considerations

For F-35B armament technicians and weapons load crews, the principal handling departure from the existing sovereign stack is the introduction of a small-diameter, turbojet-propelled missile with deployable wings and tail fins. Carriage on the F-35B internal launcher will require a dedicated stores adapter or multi-missile launcher distinct from the single-station Paveway IV and ASRAAM hardware currently in service. Loading procedures, fuze-state checks and turbojet-engine handling precautions will all require new entries in the Stores Loading Manual and the appropriate Technical Order series, and weapons load crew Authorised Equipment List training will need to be revised before the missile enters operational service.

For Quality Assurance staff operating under AQAP-2110 Edition D and STANAG 4107, SPEAR 3 represents a new UK-origin missile entering an existing US-led integrated stores configuration. Receiving Quality Assurance on UK-delivered articles destined for partner-nation F-35 fleets (Italy, Germany prospectively) will require Government Quality Assurance Representative arrangements appropriate to the UK’s status as the design authority, with corresponding Mutual GQA delegations under AQAP-2070.

For Range Safety Officers and weapons release authorities, the live-firing phase (not yet conducted from F-35B) will need updated jettison envelope data, minimum-arming distances, no-drop zones for the turbojet propulsion section, and revised range hazard arcs that account for the longer-than-Brimstone engagement footprint. The presence of a network-enabled two-way datalink means that range Electromagnetic Environmental Effects (E3) clearances will also need to be reviewed for any test profile that includes mid-course target updates.

Data Gaps

The publicly released material does not specify:

• Whether the four-missile configuration imaged at Pax River represents a single-bay or split-bay carriage layout.
• The specific multi-missile launcher hardware (designation, supplier, certification status) used to enable internal carriage of four SPEAR 3s on the F-35B.
• Software block compatibility: whether SPEAR 3 integration depends on Block 4, Tech Refresh 3 (TR-3), or a later F-35 software release.
• Planned operational test (OT) date and the lead UK frontline squadron for first-of-type training.
• Production-contract value, UK MOD missile-quantity commitment, and the in-service date for SPEAR 3 in operational RAF and Royal Navy F-35B units.
• Italian and German formal commitment status: evaluation, letter-of-request, or contract.
• Performance differences between the Typhoon-launched and F-35B-launched configurations attributable to launch altitude, internal-bay release dynamics and aircraft attitude at launch.
• Network architecture for the two-way datalink in F-35B operational concepts (Link 16, MADL, or dedicated UK sovereign waveform).

The DVIDS asset metadata, JPO imagery release and the public coverage by The Aviationist, FlightGlobal, Naval Lookout and Militarnyi constitute the authoritative open-source record at this stage. Further detail is likely to surface in NAVAIR test-event milestone briefings, UK MOD Defence Equipment and Support disclosures, MBDA press releases, parliamentary questions to the Secretary of State for Defence, and subsequent DVIDS releases as the test sequence progresses.

AI-assisted technical assessment based on open-source material from the F-35 Joint Program Office (via DVIDS), The Aviationist, FlightGlobal, Navy Lookout, Militarnyi, MBDA, Pratt & Whitney, Aerospace Global News, CSIS Missile Threat, UK Defence Journal, and ISC Defence Intelligence archive material. Not a formal intelligence product. Source ratings applied per NATO STANAG 2022 (Reliability A–F, Accuracy 1–6). All content open source and unclassified.