More than half of Ukraine's F-16s grounded by Belgian maintenance delays

Why it matters

F-16s are described as Ukraine's most effective current means of intercepting Russia's new jet-powered drones, which are being launched in sharply increasing volumes and fly too fast for interceptors that previously worked against older Shahed-type drones. With more than half the fleet grounded at a single Belgian facility under a U.S. contract, Kyiv has become strategically dependent on one maintenance pipeline far from the front line, and a Western source warned the country could lose the rest of its F-16s within a year if usage and repair rates do not change.

What happened

On 30 September 2026, The Wall Street Journal reported that more than half of Ukraine's F-16 fighters are non-combat-ready because their phased technical inspections — required every roughly 300 flight hours to service the engine, avionics, hydraulics and fuel systems — are being carried out in Belgium by Sabena Aerospace Engineering under a U.S. Department of Defense contract worth up to $235.5 million signed in January 2026. Retired U.S. Navy Rear Admiral Mark Montgomery told the paper the same inspection that takes two to six weeks in the United States can run up to 40 weeks in Belgium. An unnamed Western source warned that, at current usage and repair rates, Ukraine could exhaust the rest of its F-16 fleet within the year.

President Volodymyr Zelensky confirmed to the Financial Times that about half the fleet is currently in Europe for long-term repairs and announced an agreement for Belgium to transfer three more F-16s to Ukraine by the end of 2026, along with urgent ammunition deliveries from Belgium, Spain and other partners. He said Ukraine wants to relocate most F-16 maintenance onto Ukrainian territory with Western support so aircraft can return to service faster. Bloomberg separately reported that Ukraine is seeking to buy tens of thousands of 20mm shells — roughly 150 per drone intercepted and around 10,000 rounds a day — because Patriot interceptors are in short supply.

Ukraine's Foreign Ministry spokesman Heorhiy Tykhyi pushed back publicly, saying reports of catastrophically low readiness do not reflect reality, that partners continue to return aircraft after overhaul and that turnaround times are shortening. Retired U.S. Air Force Lt. Gen. David Deptula, by contrast, called the situation a readiness failure turning into an air defense crisis. The dispute coincided with a sharp rise in Russian jet-powered drone strikes — roughly 350 in June, about 2,000 in a recent month, and 2,800 in August 2026, according to Ukraine's Air Force — and a drop in Ukraine's interception rate against such drones to roughly 55%, compared with over 90% for older Shahed-type drones.

How Ukrainian sources describe it

Ukrainian coverage centers on Zelensky's confirmation that about half the F-16 fleet is in Europe for repairs and on his call to bring the work to Ukrainian soil with Western help, presenting the problem as a logistics bottleneck that can be solved with the right support. Outlets stress the operational stakes — fast-growing Russian jet-drone salvos, a falling interception rate, and the math of using 20mm shells as a cheaper alternative to scarce Patriot missiles — to show how critical the grounded aircraft are. Several Ukrainian voices, including Foreign Ministry spokesman Heorhiy Tykhyi, push back on the 'catastrophically low' readiness framing, accusing foreign reporting of exaggeration and stressing that turnaround times are actually improving. Ukrainian pieces highlight parallel steps at home: an announced operational audit of partner commitments on F-16 munitions, urgent ammunition deliveries from Belgium, Spain and other partners, and the 19 September footage of a new domestic interceptor downing jet-powered Shaheds.

How international sources describe it

Western reporting frames the story around a single Belgian contractor under a U.S. contract as the bottleneck, quoting anonymous Western officials and retired U.S. flag officers who describe the situation as a readiness failure becoming an air-defense crisis. International outlets stress the strategic risk for Kyiv, citing the Western source's warning that Ukraine could run out of usable F-16s within a year if usage and repair rates do not change. Bloomberg and other foreign coverage focuses on Ukraine's response in procurement terms — the plan to buy tens of thousands of 20mm shells and the calculation of about 150 shells per drone intercept — while noting that 20mm ammunition exists in much wider global supply than Patriot missiles. Reporting outside Ukraine also places the issue in the wider context of U.S. Air Force maintenance strain, citing a spring 2026 GAO warning on delays and a U.S. Air Force general's $14 billion spare-parts shortfall as evidence that the problem is not unique to Ukraine.

Where reporting differs

Sources disagree on how bad the readiness problem really is. An unnamed Western source cited by The Wall Street Journal says more than half of Ukraine's F-16s are non-combat-ready due to maintenance delays and warns the rest could be exhausted within the year. Ukraine's Foreign Ministry spokesman Heorhiy Tykhyi publicly disputes that readiness is catastrophically low, says partners continue to return aircraft after overhaul and that turnaround times are shortening, and warns against spreading information that could undermine international maintenance funding. Western outlets including WSJ also quote retired U.S. Air Force Lt. Gen. David Deptula calling the situation a readiness failure turning into an air-defense crisis.

There is also no consensus on the 'end of the year' timeline in which Ukraine might lose the rest of its F-16s: WSJ leaves the year unspecified, some Ukrainian outlets write 'end of 2025,' and others write 'end of 2026.' A third disagreement is over how long the Belgian inspection actually takes — most sources, citing retired U.S. Navy Rear Admiral Mark Montgomery, give up to 40 weeks, while one outlet paraphrases the same figure as up to nine months.

Background

Ukraine received its first F-16s in the summer of 2024 and additional aircraft from the Netherlands in February 2025. U.S. policy channels F-16 maintenance for Ukraine through a contract with the Belgian company Sabena Aerospace Engineering worth up to about $235.5 million, signed in January 2026. F-16s require a phased technical inspection after every roughly 300 flight hours; such inspections typically take two to six weeks in the United States but, according to a retired U.S. Navy rear admiral, can take up to 40 weeks in Belgium. The maintenance delay coincides with a sharp rise in Russian jet-powered drone strikes — from roughly 350 in June 2026 to about 2,000 in a recent month and 2,800 in August 2026, according to Ukraine's Air Force — and with Ukraine's interception rate against such drones falling to roughly 55%, compared with over 90% for older Shahed-type drones. Patriot interceptors are in short supply, raising the stakes of keeping F-16s operational, and Ukraine is also seeking tens of thousands of 20mm shells to use its fighters more economically against jet drones. U.S. military aviation faces its own maintenance strain, including a roughly $14 billion spare-parts shortfall cited by a U.S. Air Force lieutenant general and a spring 2026 GAO warning of growing delays.