Less than 50% of the F-16 fighter jets delivered to Ukraine may be operational, Defense Express reports, citing a Wall Street Journal (WSJ) editorial published on 29 September. On the same day, Ukrainian President Volodymyr Zelenskyy said that Belgium would deliver three F-16 fighter jets this year.

F-16s are used extensively to intercept Russian cruise missiles and drones. As the number of Russian attacks has increased, these aircraft have become particularly important for Ukraine. However, the jets Ukraine receives are old, and keeping them flying takes regular maintenance, extra work, and hard-to-find parts.

Routine inspections are taking as long as 40 weeks in Belgium, retired US Navy Rear Admiral Mark Montgomery told the WSJ.

The maintenance process for these aircraft for Ukraine is lengthy

A likely reason for the problem is the lengthy maintenance process handled by Belgian company Sabena Aerospace Engineering, according to the WSJ, whose questions the company declined to answer. This process, according to Defense Express's estimates, takes 6–20 times longer than maintenance in the United States, which usually takes between 2 and 6 weeks. Ukraine uses the services of the Belgian company, meaning its F-16s are not being serviced quickly enough.

Delivering three additional fighter jets will not significantly help the Ukrainian military until the issue with aircraft maintenance times is resolved, Defense Express notes. The lengthy turnaround may be caused by a large maintenance backlog at the company, limited capacity, or logistical constraints, and older jets may need extra work and scarcer parts.

The delivery is part of an earlier commitment. Belgium plans to provide seven fighter jets this year: three for operational use and four for spare parts, Belgian Defense Minister Theo Francken said in June.

"I'll propose to the government to send all our F-16s to Ukraine in the coming years. It depends on having the F-35s in place because, of course, we have DCA [dual-capable aircraft] capacity. We have our role in the nuclear doctrine of NATO," Francken said.

Belgium has pledged its entire F-16 fleet of 53 aircraft as F-35s replace them, according to Defense Express.

F-16s in Ukraine have already shot down several thousand Russian aerial targets

F-16s operated by Ukrainian pilots have shot down more than 3,150 aerial targets. These include 666 cruise missiles and around 2,500 drones of various types. The aircraft have also carried out more than 650 strikes against Russian ground targets, Lieutenant General Anatolii Kryvonozhko, Commander of the Ukrainian Air Force, said during a meeting between a Ukrainian Air Force delegation and representatives of Lockheed Martin on 29 September.

At the meeting, Conor McGuire, Lockheed Martin's head of F-16 capability development, highly praised the combat use and operation of F-16s by Ukrainian pilots and the entire ground aviation personnel. He also expressed his intention to help Ukrainians enhance the capabilities of the existing platform, the statement said.