F-35 fighter jets can only fly 55% of time, US watchdog says

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The Pentagon’s costly fleet of F-35 fighter jets can only fly a little over half the time, as maintenance issues keep the aircraft on the ground despite the growing reliance on the planes by the US and its allies.

The fleet’s mission-capable rate — or the percentage of time a plane can perform one of its assigned missions — was 55 per cent as of March 2023, far below the Pentagon’s goal of 85 per cent to 90 per cent, the Government Accountability Office said on Thursday.

The report from the GAO, an independent congressional watchdog, was published just days after a Marine Corps F-35 crashed in South Carolina, prompting a search for the plane and raising questions over how it could have gone missing for a day before its debris was located.

The F-35’s share of the US’s overall tactical aviation fleet is expected to keep growing, providing a boon to its manufacturer Lockheed Martin. Each of the fighter jets costs the government about $160mn.

The US military has 450 F-35s — variants are used by the air force, navy and Marine Corps — and the Pentagon plans to buy roughly 2,000 more by the mid-2040s, costing $1.7tn over the programme’s life cycle, including $1.3tn for maintaining the aircraft.

It is the world’s costliest defence procurement project, replacing the main fighter for those three branches of the US military, meaning they are “flying an increasing amount of operational missions”, according to the GAO report.

US allies in Nato and Asia, as well as Israel, have also added F-35s to their air forces. The UK defence ministry is one of the largest customers for the aircraft.

“Maintenance challenges negatively affect F-35 aircraft readiness”, with the poor level “due in part to challenges with depot and organisational maintenance”, the GAO said.

The Pentagon is years behind in establishing enough maintenance depot capacity, resulting in repair delays and a 10 per cent reduction in the jet’s mission-capable rate.

Part of the challenges stem from a heavy reliance on contractors for maintenance that limits the Pentagon’s ability to control depot maintenance decisions. Delays also arise from spare parts shortages, inadequate maintenance training, insufficient support equipment, and a lack of technical data needed to make repairs.

The Pentagon will take over managing the F-35’s sustainment by October 2027, making this a critical time for it to reassess the jets’ underlying sustainment strategy, the GAO said.

“We stand ready to partner with the government as plans are created for the future of F-35 sustainment ensuring mission readiness and enabling deterrence,” Lockheed said in a statement.