Ukraine’s F-16 fleet faces major maintenance crisis ahead of winter

A new report suggests that over half of Ukraine’s F-16 fleet is currently in maintainance limbo, while the other half may need maintenance by the end of the year.

Fighter jets are famously maintenance-heavy, and it’s common for air forces to have around a third available at any one time.

Ukraine’s F-16 fleet in need of ‘phase inspection’ maintenance

A new Wall Street Journal article has sounded the alarm about Ukraine’s F-16s this coming winter. Not only is Ukraine facing a shortage of interceptor missiles (e.g., Patriot), but its F-16s are now facing increasing downtime due to maintenance.

This is nothing new; analysts have previously sounded the alarm that Ukraine’s high tempo of F-16 operations would accelerate the need for maintenance.

Over half of Ukraine’s F-16 fleet is out of commission according to an unnamed official. The news comes as Belgium is reportedly preparing to send the first three operational F-16s to Ukraine alongside four retired airframes to be used for maintenance.

According to the Wall Street Journal, Ukraine’s fleet of F-16s has shot down around 2,500 drones of all types and around 650 cruise missiles.

It states, “but after 300 hours of flying time, F-16s require what’s known as ‘phase inspection’ to keep the engine, avionics, hydraulics, fuel lines, and other systems in working order.”

Sabena Aerospace Engineering, a Belgium-based contractor, has the contract for maintaining Ukraine’s F-16s.

While phase inspection generally takes two to six weeks in the US, it can take as long as 40 weeks in Belgium, according to retired US Navy Rear Adm. Mark Montgomery.

It is unclear if the 40-week period is exceptional and has any usefulness when assessing typical turnaround times.

While AGN can’t verify that claim, this isn’t the first time reports have emerged of F-16s taking a long time to be serviced at Sabena. In 2025, it was reported in April that six Norwegian F-16s were stuck in prolonged maintenance limbo with the contractor.

F-16s effective at countering jet-powered drones

Ukraine has become incredibly effective at shooting down Russian propeller-driven Shahed-style drones, often downing around 90% of them. At the same time, Russia is transitioning over to the more advanced jet-powered drones designed to outrun Ukraine’s interceptors.

For these, the interception rate is reported to be around 55%. It is known that Ukraine is developing interceptor drones to tackle these faster drones, as footage has been released multiple times showing interceptions.

Still, these modified interceptors appear to remain in an experimental stage and are yet to be ramped up. The F-16 Fighting Falcon remains one of Ukraine’s most effective platforms at countering jet-powered one-way attack munitions.

Other issues with Ukraine’s fighter jet fleet

Yet another issue appears to be that Ukraine is experiencing a shortage of munitions for its F-16s. Ukraine has said it is receiving munitions from Spain and Belgium.

The first batch of Belgian F-16s is due to arrive shortly, followed by another batch of five in 2027. Most of Belgium’s 53 pledged F-16s will be delivered in 2028 and 2029. Ukraine is negotiating to expedite this.

The first batch of ex-Swedish Saab Gripen C/Ds are also expected to arrive in 2027. But this may be too late to assist in what is expected to be a very tough winter.

AGN has previously reported that negotiations to acquire Poland’s final nine retiring MiG-29s broke down. It appears negotiations are ongoing, although it remains unclear if or when they will be transferred.

Ukraine’s remaining legacy Soviet-era fleet continues to suffer attritional losses.

Overall, the Ukrainian Air Force has continued to be effective and is slowly rebuilding as Western fighter jets are delivered and new pilots are trained. The Russian Air Force has its own suite of less publicised issues.