Written questions by Obese-Jecty.

With reference to paragraph 11 of the Fifty-First Report of the Committee of Public Accounts, entitled The UK’s F-35 stealth fighter capability, HC 1232, for what reason the UK F-35 fleet achieved two-fifths of the level of availability of the global F-35B fleet between October 2024 and January 2025.

The Ministry of Defence (MOD) does not release availability data for operational security reasons; the National Audit Office (NAO) reporting of this metric was also appropriately redacted for this reason. The standard availability metric used by the NAO assumes that the assets are available 24/7; which skews the metric when calculating MOD capability usage, particularly Combat Air, as we do not keep the assets airborne 24/7.There were a range of factors in the reported October 2024-January 2025 period including Force regeneration as part of standard Force Readiness cycles, and periods of planned personnel leave. This included a period when both Squadrons were deployed to a Carrier for an Exercise, routine post exercise regeneration with personnel leave and scheduled aircraft maintenance for many of the aircraft, and the Christmas and New Year leave period.

How many planes was the F-35 training squadron reduced by in order to facilitate the recent deployment of the Carrier Strike Group.

The Lightning Fleet operates as a total Force, individual airframes are not permanently allocated to units. They are allocated on a day-to-day basis to meet daily tasking requirements of each unit. Throughout the period of the Carrier Strike Group deployment the Operational Conversion Unit 207 Squadron has operated sufficient airframes to meet all its planned training and course output requirements.

What the timeline is for completion of new service accommodation at RAF Marham.

Four new Single Living Accommodation blocks are under construction at RAF Marham. The first block is scheduled for completion and handover for occupation on 4 December 2025, with two further blocks due for completion by February 2026. The final block is planned for completion in April 2027.There are no plans for the construction of new Service Family Accommodation at RAF Marham.

With reference to paragraph 13 of the Fifty-First Report of the Committee of Public Accounts of Session 2024-26 on The UK’s F-35 stealth fighter capability, HC1232, published on 31 October 2025, what progress he has made in identifying other weapons to purchase for the F-35 which are already available and integrated.

The F-35B Lightning's fifth-generation capabilities are transforming its operational effectiveness. The Lightning uses advanced stealth low observable capabilities and unparalleled sensor fusion and threat detection. When combined with the Lightning Electronic Warfare, Jamming and Electronic Attack capabilities, it provides the capability to dominate a highly contested battlespace.In parallel, its sensor fusion and advanced secure datalinks enable it to share threat and advanced targeting information with other UK offensive assets and those of Allies in real time to coordinate with a wide range of other stand-off weapon systems across maritime, land and air-based systems to achieve a wider decisive Joint Fires effect.The future F-35B munitions strategy is being addressed through the Defence Investment Plan.

When he will set out a timetable for the purchase of the remaining 90 F-35 aircraft his Department committed to purchasing.

The recommendations of the Strategic Defence Review are being taken forward in the Defence Investment Plan.

What progress he has made in building the sovereign Air Signature Assessment Facility.

A revised Business Case for a Sovereign Low Observable Verification Facility will be submitted in 2027. We do not comment on the stealth characteristics of individual aircraft for very obvious operational reasons.

With reference to the Fifty First Report of the Committee of Public Accounts of Session 2024-26 on The UK’s F-35 stealth fighter capability, HC 1232, published on 31 October 2025, what steps is he taking to address the lack of a standoff weapon to attack ground-based targets from a safe distance.

The F-35B Lightning's fifth-generation capabilities are transforming its operational effectiveness. The Lightning uses advanced stealth low observable capabilities and unparalleled sensor fusion and threat detection. When combined with the Lightning Electronic Warfare, Jamming and Electronic Attack capabilities, it provides the capability to dominate a highly contested battlespace.In parallel, its sensor fusion and advanced secure datalinks enable it to share threat and advanced targeting information with other UK offensive assets and those of Allies in real time to coordinate with a wide range of other stand-off weapon systems across maritime, land and air-based systems to achieve a wider decisive Joint Fires effect.The future F-35B munitions strategy is being addressed through the Defence Investment Plan.

With reference to page 3 of the Fifty First Report of the Committee of Public Accounts of Session 2024-26 on The UK’s F-35 stealth fighter capability, HC 1232, published on 31 October 2025, (a) what steps and (b) how long will it take to address the shortage of engineers in the F-35 programme.

I refer the hon. Member to page 15, paragraphs 15-17 of the Fifty First Report of the Committee of Public Accounts of Session 2024-26 on The UK’s F-35 stealth fighter capability, HC 1232, published on 31 October 2025. The Ministry of Defence (MOD) has increased its recruitment of engineers significantly in the last two years; offering joining bonuses and increasing the capacity of its technical training skills to enable more recruits to be trained more quickly. To improve retention the RAF has implemented a Financial Retention Incentive for engineers. The MOD has acknowledged that the F35 programme suffers from a shortage of engineers and that it is crucial that the Department addresses this issue, with significant steps already having been taken to improve the situation. However, training time required for engineers means that it is expected to take three or four years before the programme has the required numbers. The MOD has noted the Public Accounts Committee’s recommendations related to personnel and will be responding through the Treasury Minute Process in due course. The recruitment and retention of personnel remains one of the top two priorities for the Chief of the Defence Staff.

With reference to paragraph 5 of the Fifty First Report of the Committee of Public Accounts of Session 2024-26 on The UK’s F-35 stealth fighter capability, HC 1232, published on 31 October 2025, for what reason the out of service date was extended from 2048 to 2069.

The decision to extend the out-of-service date for the UK F-35B fleet to 2069 was made by the previous Government.

What elements are included within the whole-life cost estimate of £57 billion for the F-35 programme.

The whole-life cost estimate includes procurement and sustainment of 138 F-35 aircraft to 2069, including technical infrastructure, weapons integration, and aircraft upgrades. Within the development of the Defence Investment Plan, F-35A Dual Capable Aircraft costs are calculated in accordance with departmental policy.

How many and what percentage of flying instructor roles are currently gapped within the F-35 programme.

53% of flying instructor roles are currently gapped on the Lightning training Squadron, this is an improvement of some 20% since the publication of the National Audit Office report in July 2025. The shortfall is mitigated by using flying instructors from elsewhere on the Lightning Force.

What estimate has he made of the additional whole-life costs of operating the F-35A as a Dual-Capable Aircraft.

The whole-life cost estimate includes procurement and sustainment of 138 F-35 aircraft to 2069, including technical infrastructure, weapons integration, and aircraft upgrades. Within the development of the Defence Investment Plan, F-35A Dual Capable Aircraft costs are calculated in accordance with departmental policy.

With reference to paragraph 23 of the Fifty First Report of the Committee of Public Accounts of Session 2024-26 on The UK’s F-35 stealth fighter capability, HC 1232, published on 31 October 2025, what progress has he made on delivering new infrastructure for 809 Naval Air Squadron by 2029.

The Department is considering the PAC report in detail and will respond to its findings in detail through the Treasury Minute process. New infrastructure for the Naval Air Programme continues to be progressed with a current completion target of the first quarter of 2030.

What interim solutions he has identified to fill the capability gap left by delays to the SPEAR 3 missile programme.

The F-35B Lightning's fifth-generation capabilities are transforming its operational effectiveness. The Lightning uses advanced stealth low observable capabilities and unparalleled sensor fusion and threat detection. When combined with the Lightning Electronic Warfare, Jamming and Electronic Attack capabilities, it provides the capability to dominate a highly contested battlespace.In parallel, its sensor fusion and advanced secure datalinks enable it to share threat and advanced targeting information with other UK offensive assets and those of Allies in real time to coordinate with a wide range of other stand-off weapon systems across maritime, land and air-based systems to achieve a wider decisive Joint Fires effect.The future F-35B munitions strategy is being addressed through the Defence Investment Plan.

How many and what proportion of UK F-35 aircraft have had their stealth characteristics measured.

A revised Business Case for a Sovereign Low Observable Verification Facility will be submitted in 2027. We do not comment on the stealth characteristics of individual aircraft for very obvious operational reasons.

What assessment has he made of the effect of the order of 20 Eurofighter Typhoons on the timeline of the delivery of the Phase 4 Enhancement Programme for the UK Typhoon fleet.

The order of 20 Eurofighter Typhoons for Türkiye aligns with long term goals of supplying a NATO member with advanced military equipment. A sale of this significance will bring benefits to UK Industry, the Eurofighter Partner Nations and NATO. It has been assessed that there will be no impact on the delivery of the Phase 4 Enhancement Programme for the UK Typhoon fleet.

What tranche of Eurofighter Typhoon has been purchased by Turkey.

Turkey have purchased Tranche 4 aircraft.

What assessment he has made of the potential merits of replacing the L16 81mm mortar.

The L16A2 81 mm mortar remains an effective piece of equipment. The Army is regularly assessing the effectiveness of its capabilities to ensure that soldiers have the best possible range of weapons to help them achieve their mission.

When he expects the Joint Requirements Oversight Committee meeting to take place for Project Grayburn.

On current plans, the Joint Requirements Oversight Committee (JROC) is expected to meet this Autumn regarding Project GRAYBURN.

Pursuant to the Answer of 20 October 2025 to Question 79398 on NATO Countries: Armoured Fighting Vehicles, what recent progress he has made in appointing a new Director General International Collaboration and Exports.

Avril Joliffe is the Director General for International Collaboration and Exports. This is a permanent position with no current plans for recruitment.