F-35 fighter jets’ wings clipped by complacent MoD’s short-termism, PAC report finds

- Procurement and management of UK's best-ever jet beset by significant problems

- PAC calls for more radical plan to address personnel shortages affecting plane's ability to fly with questions over forecast cost of operating new nuclear-capable F-35A

The F-35 is the best fast jet the UK has ever had – but the Ministry of Defence's (MoD) cost-cutting approach has caused significant problems in its use. In a new report on the UK's F-35 capability, the Public Accounts Committee (PAC) calls for a more radical plan to address an unacceptable personnel shortage, while raising questions over the costs of introducing F-35As in their nuclear weapons role.

The PAC report lays out a pattern of short-term decision-making from MoD impacting the F-35's capability, availability to fly and value for money, including:

• A delayed investment in the facility which assesses the F-35's stealth capability. In the short-term £82m was saved by 2024-25, but inflation from building later will have cost MoD £16m more than that by 2031-32;
• In 2010, the MoD chose to delay the delivery of some aircraft to make short-term financial savings, reducing the number of aircraft available today – a situation exacerbated by a delay of seven aircraft by a year in 2020 for financial reasons;
• The delay of 809 Naval Air Squadron's infrastructure, delivery of which MoD decided to put off till 2029 to save money, knowing it would cost more long-term and reduce capability. Costs here have now increased from £56m to a forecast £154m.

The programme suffers from an unacceptable shortage of engineers, which poses an obstacle to the jets flying more often. While this shortage reflects wider challenges across the armed forces, the MoD worsened the situation for F-35s by miscalculating how many engineers would be needed per plane, through failing to take into account staff taking leave and performing other tasks. Though this mistake has now been identified and new funding provided, it will still take several years to resolve.

There are also questions over the additional costs of operating nuclear-capable F-35As, and how long the necessary arrangements will take to prepare. Becoming certified for the NATO nuclear mission will add new requirements to training, personnel and possibly infrastructure, but discussions in this area are at an early stage, and no indication of forecast costs has been provided by MoD.

The report also highlights the substandard accommodation at RAF Marham, the F-35's main operating base. The MoD accepted to the PAC's inquiry that Marham's living quarters are currently not good enough, with frontline personnel revealing that it is shabby, sometimes lacking hot water, and lacking bus access to a local town. Given already existing recruitment and retention issues in the programme, MoD should urgently look to prioritise investment to bring forward completion of improvements on a much earlier timescale than the currently-planned and very complacent date of 2034.

Sir Geoffrey Clifton-Brown MP, Chair of the Public Accounts Committee, said: “Making short-term cost decisions is famously inadvisable if you're a homeowner with a leaky roof, let alone if one is running a complex fighter jet programme - and yet such decisions have been rife in the management of the F-35. During our inquiry, the MoD told us that they viewed these kinds of decisions costing the taxpayer many millions more in the long-term than the money saved in the short term, as a “conventional consequence” of budget management. This is exactly the sort of attitude that our Committee exists to challenge.

“There are basic lessons here that MoD has been worryingly slow to learn. Its appraisal of the F-35's whole-life cost is unrealistic, which it currently gives as at almost £57bn through to 2069. But this figure does not include costs for personnel, fuel and infrastructure, which the MoD will struggle to operate a successful programme without. Moreover, the MoD is due to declare the jet's full operating capability, despite unresolved personnel shortages. It will also not have the ability to attack ground targets from a safe distance until the early 2030s – the aspect of the F-35's capability which the Chief of the Defence Staff told us worried him most. The F-35 is the best fighter jet this nation has ever possessed. If it is to be wielded in the manner in which it deserves, the MoD must root out the short-termism, complacency and miscalculation in the programme identified in our report.”

PAC report conclusions and recommendations 

The Department is set to declare Full Operating Capability (FOC) for its F-35 fleet based on a subjective judgement and taking no account of a likely reduction of aircraft availability when the Carrier Strike Group has returned from deployment. The Department states that this declaration is based on a combination of applied military judgement and science. The deployment of 2 squadrons on the Carrier Strike Group is part of these criteria. However, the FOC criteria do not account for capability limitations such as the lack of a standoff weapon to attack ground-based targets from a safe distance or the lack of an independent ability to check that aircraft retain their stealth capability. Moreover, the FOC criteria do not require that FOC should be met sustainably over time. To meet the criteria during the Carrier Strike Group deployment the Department has received extra support from the global programme that it will not receive afterwards and reduced the number of aircraft available to the training squadron, resulting in the squadron having less flexibility over when it could fly. There will also be a period of maintenance impacting availability following the deployment.

Recommendation 1. The Department should ensure that for future major programmes it adopts a more robust and objective definition of Full Operating Capability that takes account of capability gaps and the ability to sustain that capability consistently after its declaration.

The UK's F-35 does not have a standoff weapon, and aircraft availability is inadequate. The Department states that its biggest concern with its F-35 fleet is the lack of a standoff weapon to strike ground targets from a safe distance. The Department wants to equip its F-35s with the Spear 3 missile but this is not likely to be in place until the early 2030s, partly because of problems with the supplier and partly because of global programme delays to the required software upgrades. The Department is attempting to bring forward Spear 3 delivery and integration and is considering other weapons for the interim as part of the Defence Investment Plan. The Department acknowledges that, in addition to this limitation on capability, the F-35 fleet is not available as often as it should be, in large part because of personnel shortages and a lack of spare parts.

Recommendation 2.

1. a) The Department should set out in the Defence Investment Plan how it will ensure a standoff capability in the coming years before Spear 3 is fully integrated onto the aircraft
2. b) The Department should write to the Committee, alongside its Treasury Minute response to this report, setting out how it intends to increase F-35 availability so that its targets are consistently met.  

The F-35 programme faces an unacceptable shortage of several types of personnel, including engineers, cyber specialists, pilots and qualified flying instructors. The Department acknowledges that there are significant shortages of engineers in the F-35 programme, and that this is an impediment to operating the aircraft more often. This shortage reflects a shortage of engineers across the armed forces, which the Department is attempting to tackle with retention bonuses and increased capacity to train new recruits.  However, the Department accepts that for F-35s this shortage had been exacerbated by its miscalculation of how many engineers are needed per aircraft. Even now that this mistake has been identified and funding provided for the 168 additional posts required, representing a 20% increase, it will take several years to resolve the shortage. The Department also acknowledges that there are significant shortages in other roles including cyber specialists, pilots and flying instructors. In 2025 only 5 out of 16 flying instructor posts were filled.

Recommendation 3. The Department should produce a more radical plan to recruit and retain the highly skilled personnel necessary to work on and operate the F-35. The plan should include reference to accommodation as well as pay and other benefits that together provide an attractive offer over the long term. 

Accommodation at RAF Marham is substandard, exacerbating issues with recruitment and retention. Despite the urgent need to address this, upgrades will not be completed under current plans until 2034. RAF Marham has been the main F-35 operating base since 2013, with at least 1,500 people working there on the F-35, many of whom also live in accommodation at the base. The Department accepts that accommodation at RAF Marham is not good enough and that these failings create a risk that people leave the service earlier than they otherwise would. The Department has committed to removing all the worst grades of accommodation, which includes most of the accommodation at RAF Marham, from its sites. But it does not expect to complete this work at RAF Marham until 2034, albeit with some personnel expected to move into the first new block by the end of 2025. The Department claims that earlier investment was not possible because of the need for savings, and that upgrading accommodation at RAF Lossiemouth has been the higher priority. The 2034 date for relatively simple service accommodation construction is very complacent and should be given greater priority.

Recommendation 4. The Department should urgently look to prioritise investment to bring forward completion of improvements to RAF Marham accommodation on a much earlier timescale than 2034. It should write to the Committee within 6 months as to how it intends to do this.

The Department has taken a narrow and short-term approach to management and costs and has failed to realistically appraise the programme's whole-life cost. The Department acknowledges that it reduced the pace of aircraft deliveries to make short-term financial savings at multiple points in the programme, notably in 2010. In 2021 the Department decided to pause building a sovereign facility for assuring that aircraft retained their stealth capabilities, which is required for its freedom of action policy. The Department similarly delayed providing 809 Naval Air Squadron's infrastructure by 6 years, increasing costs by almost £100 million. It did so despite knowing it would cost more money in the long-term and create a gap in capability. The Department also failed for many years to significantly update its public whole-life cost, which hardly increased from its 2013 estimate of £18.425 billion covering the first 48 aircraft to the then out of service date of 2048. In response to the 2025 National Audit Office report the MoD published a whole-life cost of almost £57 billion for all 138 aircraft to the new out of service date of 2069. But this still does not include non-equipment costs such as personnel, fuel and infrastructure which are included in the NAO estimate of £71 billion.

Recommendation 5. The Department should:

1. a) set out in its upcoming Defence Investment Plan the expected long-term impact on costs and capability of any short-term savings measures, on both the F-35 and other major programmes, and
2. b) build on its recent whole-life cost analysis by including all relevant non-equipment costs to give a more complete through-life cost forecast of the programme.

The Department has not set out its preferred mix of F-35As and Bs, nor forecast the costs of introducing the F-35As in their nuclear weapons role. The 48 aircraft that the Department has contracted for so far are all F-35Bs, which can be flown from land or aircraft carriers. In June 2025 the Department announced that in its next phase of procurement it intended to buy 12 F-35As alongside 15 F-35Bs. The Department told us that the F35As would both act as training aircraft, where its additional range will be valuable in enabling longer training flights, and join the NATO dual capable aircraft nuclear mission. Only the F-35A variant can carry nuclear weapons. The Department acknowledged that becoming certified for the NATO nuclear mission will add new requirements to training, personnel and possibly infrastructure. The Department is speaking to other nations in the NATO mission about requirements for certification. This work is at an early stage and the Department did not provide any indication of forecast costs.

Recommendation 6. The Department should update the committee in six months on what it expects the additional whole-life costs of operating Dual Capable Aircraft will be, and how long it will take to prepare the necessary arrangements.