Maintenance backlogs in Belgium leave over half of Ukraine's F-16 fleet grounded

Maintenance bottlenecks in Belgium

More than half of Ukraine's fleet of 39 F-16 fighter jets is currently grounded due to extensive maintenance schedules in Belgium. The aircraft, supplied by the Netherlands and Denmark, require comprehensive phase inspections after every 300 flight hours to examine engines, avionics, hydraulics, and fuel systems. Under a United States support contract worth up to $235.5 million, Belgian company Sabena Aerospace Engineering performs these overhauls. While standard phase inspections in the United States require between two and six weeks, retired Rear Admiral Mark Montgomery indicated that the turnaround time in Belgium extends up to 40 weeks.

Retired United States Air Force General David Deptula assessed the operational impact:

Regardless of the cause, this is a failure of the sustainment system that is becoming an air defense crisis.

Surging jet drone strikes

The maintenance delays coincide with an escalation in Russian aerial attacks using jet-powered drones. Russian forces launched approximately 2,000 jet-powered drones against Ukraine in September 2026, compared to approximately 350 in June 2026. These aircraft reach speeds of around 604 km/h, making them significantly harder to intercept than earlier propeller-driven models. Ukrainian forces intercept roughly 55% of incoming jet-powered drones, compared to an interception rate exceeding 90% for older Shahed models.

F-16s serve as an essential countermeasure against low-flying aerial targets, neutralizing drones at an estimated operating cost of $25,000 per jet drone interception. In total, Ukrainian pilots flying F-16s have destroyed approximately 2,500 drones of various types and 650 cruise missiles. A Western defense source cited by the Wall Street Journal warned that at current repair speeds, Ukraine risks exhausting its operational airframe inventory before the end of the year.

Delayed Belgian fighter transfers

Belgian Prime Minister Alexandre De Croo pledged Belgium's fleet of F-16s to Kyiv in 2024, but no Belgian aircraft have arrived in Ukraine to date. Initial declarations pointed to deliveries in 2025, but logistical constraints have shifted the timetable. Belgian defense officials confirmed a revised delivery projection: seven aircraft by the end of 2026, five in 2027, four in 2028, and a final batch of 27 in 2029. Four of the seven aircraft slated for 2026 are currently assigned to training Ukrainian maintenance personnel.

General Bernard Phaleg, who oversees material support for the Belgian military, described the physical condition of the airframes:

Most of these machines are at the end of their service life, and some of them can no longer fly. Nevertheless, their engines and other parts can be useful for other F-16s that have been transferred by EU countries.

Dependence on American replacement jets

Belgian deliveries remain contingent upon Brussels receiving new American-built F-35 stealth fighters to maintain its own territorial defense obligations. The Belgian Air Force has received only four of the 34 F-35 fighters ordered from the United States, with final deliveries scheduled through 2030. Belgian defense chief General Frederik Vansina defended the cautious transfer schedule:

Because if we take away the F-16s, we are naked.

To address near-term air defense shortfalls, Ukrainian President Volodymyr Zelensky announced that Belgium will deliver three F-16s under an accelerated track this year. Norway has also promised an additional six aircraft to support Ukrainian operations while domestic teams develop alternative counter-drone systems over the coming months.