UK F-35 fighting jets' performances shamed in damning new report

Only a third of Britain's state of the art F-35 fleet the jets are fully mission capable, with shortages of engineers, spares and weapons integration undermining operations, a new report has warned. According to the National Audit Office, the UK's Lightning Force - based around 37 in-service F-35Bs - is suffering from delayed infrastructure, mounting maintenance backlogs, and a chronic lack of personnel.

Availability rates are "significantly" below global targets, and even that low bar has only been hit temporarily by drawing heavily on training assets to prepare for the HMS Prince of Wales deployment to the Indo-Pacific. Between October 2024 and January 2025, no aircraft were available to perform any mission at all.

The NAO found that Britain's "availability problems are largely driven by slow maintenance activity and a lack of spare parts, as well as an emerging issue with higher corrosion than expected in maritime environments."

The Ministry of Defence has so far taken delivery of 38 aircraft, with one lost in an accident, and has 10 more on order.

But delays in ordering and operating the fleet have compounded costs.

According to the report: "The UK's availability problems are largely driven by slow maintenance activity and a lack of spare parts."

One of the most glaring gaps is in engineering personnel.

At supervisory level, only 58 percent of required engineer posts were filled in 2024, delaying the stand-up of 809 Naval Air Squadron.

Qualified flying instructors are also in short supply, with 207 Squadron operating just five full-time instructors - far short of the 16 required.

At RAF Marham, the F-35's main operating base, modern hangars and high-tech training centres have been built. But basic living quarters are "shabby", with unreliable heating and hot water.

The NAO noted that "much of the accommodation is categorised as the worst quality in the MoD estate." Temporary housing and even hotels have been used to fill the gap.

A second frontline squadron still operates from portacabins, with permanent facilities now delayed until at least 2029.

A key piece of infrastructure - the Aircraft Signature Assessment Facility, used to test the jets' stealth profile - was originally due in 2021, but now may not arrive until the 2030s.

The report also highlighted serious capability gaps in the jet's armament.

At present, British F-35s carry only free-fall bombs, such as the Paveway IV, meaning they must overfly a target to strike - greatly increasing risk, even with stealth.

"The National Audit Office flagged another issue, making the UK's F-35 less formidable fighting machines. It said there has been a delay in integrating missiles onto the jet that will enable it to hit targets from a safe distance," the report said.

Although the UK plans to integrate MBDA's SPEAR-3 standoff missile and the Meteor air-to-air missile, both upgrades have been pushed into the next decade.

The NAO said: "There is a plan to integrate so-called stand-off weapons on to the jets, but not until the 2030s."

The UK originally committed to buy 138 jets but has only confirmed 48 so far.

The government recently announced that its next order will include at least 12 of the longer-range F-35A variant, which can also carry nuclear weapons as part of NATO deterrence.

Gareth Davies, head of the NAO, said: "The F-35 programme offers significantly improved capability and considerable economic benefits to the UK.

"But the capability benefits are not being fully realised due to delays, infrastructure gaps and personnel shortages. The MoD now needs to decide where to prioritise its resources to improve capability in a way that maximises the full benefits of the F-35 programme to the UK."