Recommendations & Conclusions
14 items
7
Conclusion
51st Report - The UK’s F-35 stealth fig…
Deferred
The Department expects to declare Full Operating Capability (FOC) by the end of 2025. In its 2018 Concept of Use document the Department had expected to declare FOC by the end of 2023 based on two frontline squadrons of 12 aircraft and a training squadron at full capacity. It subsequently …
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The Department expects to declare Full Operating Capability (FOC) by the end of 2025. In its 2018 Concept of Use document the Department had expected to declare FOC by the end of 2023 based on two frontline squadrons of 12 aircraft and a training squadron at full capacity. It subsequently delayed this to April 2025, then to December 2025, and introduced a more qualitative assessment of FOC. The Department expects to evidence FOC in part by deploying two full squadrons during the 2025 Carrier Strike Group (CSG) deployment. However, the National Audit Office’s report notes that “even if the MoD meets its FOC criteria, it will not yet have a force that can deploy sustainably.”11
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Government response AI summary
The government response is entirely unrelated to the recommendation regarding the F-35 Full Operating Capability (FOC) declaration, instead discussing the 'illegal meat crisis' and biosecurity at the border.
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HM Treasury
8
Conclusion
51st Report - The UK’s F-35 stealth fig…
Deferred
The Department told us that its criteria for declaring FOC are based on a combination of hard facts and applied military judgement. In forming its view, it told us that it had considered FOC through four distinct 5 C&AG’s Report, para 9 6 Q 91 7 C&AG’s Report, para 1.19 …
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The Department told us that its criteria for declaring FOC are based on a combination of hard facts and applied military judgement. In forming its view, it told us that it had considered FOC through four distinct 5 C&AG’s Report, para 9 6 Q 91 7 C&AG’s Report, para 1.19 8 Qq 87, 91; C&AG’s Report para 1.10 9 Q 118 10 C&AG’s Report, para 3 11 C&AG’s Report, paras 11, 1.19, 1.21 7 lenses: the state of the programme; the operational capability available; other defence lines of development including personnel, infrastructure, organisation and doctrine; and the contractual and legal situation.12 The Department told us that the decision to declare FOC is ultimately taken by the Chief of the Air Staff following a recommendation from the F-35 programme Senior Responsible Owner which is cleared through the chain of command.13
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Government response AI summary
The government response is entirely unrelated to the recommendation regarding the F-35 Full Operating Capability (FOC) criteria, instead discussing animal vaccine availability and ongoing cross-sector engagement, with an action plan to be published in late 2026.
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HM Treasury
9
Conclusion
51st Report - The UK’s F-35 stealth fig…
Deferred
The Department acknowledged that its definition of FOC excludes a crucial element of capability. It does not include a requirement to integrate Spear 3 onto the F-35 to provide a standoff weapon to attack ground targets from a safe distance, which it does not expect to have until the early …
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The Department acknowledged that its definition of FOC excludes a crucial element of capability. It does not include a requirement to integrate Spear 3 onto the F-35 to provide a standoff weapon to attack ground targets from a safe distance, which it does not expect to have until the early 2030s. This is despite the Chief of the Defence Staff telling us that this was what worried him most about the F-35 and its capability.14 The Department also acknowledged that it will not have resolved personnel shortages that pose a risk to capability before the planned FOC declaration.15
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Government response AI summary
The government response is entirely unrelated to the recommendation regarding the F-35 FOC definition, Spear 3 integration, or personnel shortages, instead discussing Sanitary and Phytosanitary (SPS) agreements with the EU and strengthening resilience to animal disease.
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HM Treasury
11
Recommendation
51st Report - The UK’s F-35 stealth fig…
Deferred
Although the F-35 is significantly superior to any previous UK aircraft, the Department has yet to achieve the capability or availability that it wants.19 Most significant is the lack of the standoff weapon.20 This will limit the UK’s ability to conduct certain missions in contested environments.21 The Department also told …
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Although the F-35 is significantly superior to any previous UK aircraft, the Department has yet to achieve the capability or availability that it wants.19 Most significant is the lack of the standoff weapon.20 This will limit the UK’s ability to conduct certain missions in contested environments.21 The Department also told us that it had delayed building its sovereign Air Signature Assessment Facility (ASAF) to measure the stealth 12 Q 83 13 Q 81 14 Qq 88, 109 15 Q 104 16 Q 85 17 C&AG’s Report, para 1.21 18 Q 87 19 Qq 85, 104 20 Q 88 21 C&AG’s Report, para 1.11 8 characteristics of UK F-35 aircraft.22 Furthermore, aircraft availability is poor. The UK F-35 fleet achieved approximately one-third of the MoD target for the time it was able to fly all its required missions in 2024, and achieved only two-fifths of the level of availability of the global F-35B fleet between October 2024 and January 2025.23 The Department acknowledged that it was not getting the F-35 availability it wanted.24
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Government response AI summary
The government will set out its approach to delivering the Strategic Defence Review and the investments required to deliver the Integrated Force in the forthcoming Defence Investment Plan, including details on the standoff capability requirement.
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HM Treasury
12
Conclusion
51st Report - The UK’s F-35 stealth fig…
Deferred
The Department set out why these capability limitations have occurred. It told us that its ability to integrate new weapons was dependent on the global F-35 programme run by the United States Department of Defense. It requires the major software enhancements provided by Tech Refresh 3 and Block 4, which …
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The Department set out why these capability limitations have occurred. It told us that its ability to integrate new weapons was dependent on the global F-35 programme run by the United States Department of Defense. It requires the major software enhancements provided by Tech Refresh 3 and Block 4, which has not yet been fully defined or timetabled and which the UK cannot directly influence.25 The Department acknowledged that delivery of Spear 3 is also negatively impacted by supplier performance.26 The Department also told us that it had delayed building the ASAF to save money for higher priorities elsewhere in Defence, acknowledging that this short-term saving would cost more money in the long-term.27
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Government response AI summary
The government will set out its approach to delivering the Strategic Defence Review and the investments required to deliver the Integrated Force in the forthcoming Defence Investment Plan, including details on the standoff capability requirement.
Read full response →
HM Treasury
13
Recommendation
51st Report - The UK’s F-35 stealth fig…
Deferred
The Department told us that it had plans to tackle these limitations. It is seeking opportunities within the global programme to accelerate the integration onto the F-35 of Spear 3 and Meteor, its preferred air to air weapon. The Joint Programme Office, which runs the global programme, has invited the …
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The Department told us that it had plans to tackle these limitations. It is seeking opportunities within the global programme to accelerate the integration onto the F-35 of Spear 3 and Meteor, its preferred air to air weapon. The Joint Programme Office, which runs the global programme, has invited the UK programme to include a UK weapon in its so-called digital accelerator which it hopes will speed up delivery. In the meantime, the Department told us that as part of its Defence Investment Plan it is considering buying other weapons that are already available and integrated.28 It also told us that it is working with Italy to measure the stealth characteristics of UK aircraft, although this arrangement only accounts for two aircraft per year.29
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Government response AI summary
The government agrees with the Committee’s recommendation and states that the forthcoming Defence Investment Plan will set out the government’s approach to delivering the Strategic Defence Review (SDR) and the investments required to deliver the Integrated Force. This will provide details of the government’s balance …
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HM Treasury
18
Recommendation
51st Report - The UK’s F-35 stealth fig…
Deferred
RAF Marham has been designated the F-35 main operating base since 2013 and now has at least 1,500 people working at the base to support the F-35 fleet, many of whom also live there.38 A 2025 NISTA programme review found that most of the accommodation offered at RAF Marham was …
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RAF Marham has been designated the F-35 main operating base since 2013 and now has at least 1,500 people working at the base to support the F-35 fleet, many of whom also live there.38 A 2025 NISTA programme review found that most of the accommodation offered at RAF Marham was the lowest-quality category of Ministry of Defence accommodation. Frontline personnel told the National Audit Office that accommodation was shabby and sometimes lacked hot water and that RAF Marham needed more amenities, such as bus access to a local town, to make it attractive to service personnel.39 This is completely unacceptable in today’s world. Servicemen and women on long tours of duty deserve decent accommodation for their families and themselves.
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Government response AI summary
Following the publication of the Defence Investment Plan infrastructure requirements will be reassessed against departmental priorities. The department will write to the Committee by 31 May 2026 to advise whether the current timescale for RAF Marham accommodation can be brought forward.
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HM Treasury
19
Conclusion
51st Report - The UK’s F-35 stealth fig…
Deferred
The Department accepted that accommodation at RAF Marham is not good enough, reflecting wider problems within the Defence estate, more than half of which is over 50 years old. The Department told us that it had identified the need for increased investment in accommodation in the Strategic Defence Review and …
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The Department accepted that accommodation at RAF Marham is not good enough, reflecting wider problems within the Defence estate, more than half of which is over 50 years old. The Department told us that it had identified the need for increased investment in accommodation in the Strategic Defence Review and is working through investment choices as part of the Defence Investment Plan. The Chief of the Defence Staff told us that the Royal Air Force has committed to upgrading all its accommodation in the lowest two categories so that it meets the criteria for the highest two categories. Across the whole Royal Air Force estate this will cost more than £1.5 billion over approximately 15 years.40
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Government response AI summary
The government agrees with the recommendation, but will reassess infrastructure requirements against departmental priorities following the publication of the Defence Investment Plan and will advise the Committee by 31 May 2026 whether the current timescale for RAF Marham accommodation can be brought forward.
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HM Treasury
20
Conclusion
51st Report - The UK’s F-35 stealth fig…
Deferred
The Department acknowledged that providing poor quality accommodation negatively impacts its personnel. Most significantly, it increases the risk that people leave the service earlier than they otherwise would.41 This is a serious risk given the problems with retention that the Department has set out and the length of time it …
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The Department acknowledged that providing poor quality accommodation negatively impacts its personnel. Most significantly, it increases the risk that people leave the service earlier than they otherwise would.41 This is a serious risk given the problems with retention that the Department has set out and the length of time it takes to train specialist staff such as engineers.42 37 Q 101 38 C&AG’s report, para 3.27 39 C&AG’s report, para 2.13 40 Q 105 41 Q 107 42 Qq 101, 103 12 The Department also told us that it needs to upgrade accommodation so that staff become more engaged and feel more valued, with the implication that poor accommodation reduces personnel engagement.43
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Government response AI summary
The government agrees with the recommendation, but will reassess infrastructure requirements against departmental priorities following the publication of the Defence Investment Plan and will advise the Committee by 31 May 2026 whether the current timescale for RAF Marham accommodation can be brought forward.
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HM Treasury
21
Recommendation
51st Report - The UK’s F-35 stealth fig…
Deferred
The Department told us that it has plans to upgrade accommodation at RAF Marham but will not complete these plans for many years. The Department will upgrade 900 accommodation units and bedrooms across the base. However, the Department told us that the programme for doing so began in 2021 and …
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The Department told us that it has plans to upgrade accommodation at RAF Marham but will not complete these plans for many years. The Department will upgrade 900 accommodation units and bedrooms across the base. However, the Department told us that the programme for doing so began in 2021 and will not be completed until 2034. The Department acknowledged that it would have preferred to have upgraded the accommodation earlier to coincide with personnel arriving to work on F-35. But it said that this was not possible because it needed to make savings and prioritised preserving its operational output over upgrading infrastructure.44 We believe this length of time for refurbishment is unacceptable and have asked the Department to write to us to say how this can be accelerated. The Department told us that it had made significant investment in upgrading single-living accommodation at RAF Lossiemouth, which was a few years ahead of RAF Marham in the programme, and linked that to the workforce there feeling engaged, valued and invested in.45 43 Q 107 44 Q 105 45 Q 107 13 3 F-35 costs and future procurement Costs
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Government response AI summary
The Department will reassess infrastructure requirements against departmental priorities following the publication of the Defence Investment Plan, and will advise the Committee by 31 May 2026 whether the timescale for RAF Marham accommodation can be brought forward.
Read full response →
HM Treasury
22
Conclusion
51st Report - The UK’s F-35 stealth fig…
Deferred
The Department acknowledged that it has, on occasion, prioritised short-term affordability over value for money in the F-35 programme, to keep within its overall departmental budget.46 Notably, in 2021 the Department took the decision to delay investment in the Air Signature Assessment Facility (ASAF). Although this decision saved £82 million …
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The Department acknowledged that it has, on occasion, prioritised short-term affordability over value for money in the F-35 programme, to keep within its overall departmental budget.46 Notably, in 2021 the Department took the decision to delay investment in the Air Signature Assessment Facility (ASAF). Although this decision saved £82 million in the short-term out to 2024–25, it will have cost the Department £16 million more than that by 2031–32 because of inflation resulting from choosing to build later. The Department viewed this as a “conventional consequence” of managing an annual departmental budget covering many programmes.47
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Government response AI summary
The government agrees with the Committee’s recommendation and states that as part of the production of the forthcoming Defence Investment Plan, the government is considering the long-term impacts of any savings measures on costs and capability of all major programmes.
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HM Treasury
23
Conclusion
51st Report - The UK’s F-35 stealth fig…
Deferred
In correspondence provided after our evidence session the Department told us that 809 Naval Air Squadron’s infrastructure is another example of short-term savings resulting in higher overall costs. In 2020 the Department forecast that the cost of building the infrastructure would be around £56 million and be completed in 2023. …
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In correspondence provided after our evidence session the Department told us that 809 Naval Air Squadron’s infrastructure is another example of short-term savings resulting in higher overall costs. In 2020 the Department forecast that the cost of building the infrastructure would be around £56 million and be completed in 2023. But to save money the Department decided to delay the delivery of the infrastructure to 2029. As a result of raw material and workforce cost increases, the Department now forecasts that the construction will cost £154 million despite a reduction in requirements.48
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Government response AI summary
The government agrees with the Committee’s recommendation and states that as part of the production of the forthcoming Defence Investment Plan, the government is considering the long-term impacts of any savings measures on costs and capability of all major programmes.
Read full response →
HM Treasury
24
Conclusion
51st Report - The UK’s F-35 stealth fig…
Deferred
The Department also acknowledged that short-term savings impact the capability provided by the programme. The ASAF, which measures the stealth characteristics of the UK F-35 fleet, is needed for the Department’s freedom of action policy so that it can deploy the aircraft at any time or place of its choosing.49 …
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The Department also acknowledged that short-term savings impact the capability provided by the programme. The ASAF, which measures the stealth characteristics of the UK F-35 fleet, is needed for the Department’s freedom of action policy so that it can deploy the aircraft at any time or place of its choosing.49 The ASAF will not now be delivered until 2032.50 Since its formation in 2023, 809 Naval Air Squadron has been using 617 Squadron infrastructure along with recently-provided temporary accommodation until its permanent infrastructure is delivered.51 46 Q 124 47 Qq 120-122 48 Letter from MoD to PAC, 25 September 2025 49 C&AG’s Report, paras 1.11, 2.9-2.10 50 Letter from MoD to PAC, 25 September 2025 51 C&AG’s Report, para 2.12 14
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Government response AI summary
The government agrees with the Committee’s recommendation and states that as part of the production of the forthcoming Defence Investment Plan, the government is considering the long-term impacts of any savings measures on costs and capability of all major programmes.
Read full response →
HM Treasury
25
Conclusion
51st Report - The UK’s F-35 stealth fig…
Deferred
The Department told us that in 2010, facing a reduction in its budget, it chose to delay the delivery of some aircraft.52 This has reduced the number of aircraft available to the Department today.53 This was exacerbated by a further delay of seven aircraft by a year in 2020 for …
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The Department told us that in 2010, facing a reduction in its budget, it chose to delay the delivery of some aircraft.52 This has reduced the number of aircraft available to the Department today.53 This was exacerbated by a further delay of seven aircraft by a year in 2020 for financial reasons.54 It is unclear whether the 2010 delay has caused increased costs since the increase in costs resulting from inflation may have been offset by a decreased unit cost of the aircraft over time.55 In correspondence provided after our evidence session, the Department stated that, in its view, the effect of delay was marginal if not cost neutral.56
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Government response AI summary
The government is considering the long-term impacts of savings measures on costs and capability of all major programmes as part of the production of the forthcoming Defence Investment Plan.
Read full response →
HM Treasury