Senate panel calls for new F-35A gun system solution

Senate policymakers want the Air Force to start looking for a new F-35A ammunition system that "provides a full-spectrum target engagement capability" after continued deficiencies with the aircraft's current gun.

In the report accompanying its mark of the fiscal year 2021 defense policy bill, the Senate Armed Services Committee highlights known concerns with the F-35A gun, which were raised most recently in Pentagon Director of Operational Test and Evaluation Robert Behler's annual testing report, that deemed the current gun, as installed, "unacceptable."

The provision would require the Air Force to seek a new provider, noting that while the program is working to improve the gun's performance, "the anticipated hardware and software solutions do not adequately address the lethality limitation of the F-35A gun."

"Improvements are necessary in ammunition performance, including the ability to penetrate hard targets as well as the ability to achieve combined explosive fragmentation, and incendiary effects," the report states. "The committee further understands that the currently qualified 25 mm ammunition effectively penetrates semi-hardened armor; however, the ammunition has limited capability against a broader range of target sets."

The committee does not prescribe a path or a timeline for identifying an alternative provider.

In his 2019 testing report, Behler noted that the gun muzzle's alignment within the aircraft is a contributor to the system's accuracy issues. Those issues led the Air Force to restrict gun use for low-rate initial production Lot 9 and newer aircraft.

The F-35A's gun is installed internally, while the B- and C-model variants have external gun pods and have not shown the same issues. Inside Defense reported in February that the Air Force would begin installing upgraded panels to fielded aircraft this spring and to production aircraft in the summer.