DOT&E says F-35A gun accuracy issues remain

The Lockheed Martin F-35A Lightning II Joint Strike Fighter (JSF) conventional variant’s gun accuracy issues from fiscal year 2017 (FY 2017) remain to the point that the Pentagon’s chief weapons tester, based on testing through September, considers them unacceptable.

The FY 2018 report by the Office of the Director, Operational Test and Evaluation (DOT&E), released on 31 January, said that F-35A gun accuracy during system design and development (SDD) failed to meet the contract specification. Although software corrections were made to the F-35 mission system software to improve the stability of gun aiming cues, no software or hardware corrections have been implemented to correct the gun accuracy issues.

Gun accuracy issues on the F-35A continue, the Pentagon's chief weapons tester said in a new report. (Lockheed Martin)

Investigations into the gun mounts of the F-35A revealed misalignments that result in muzzle alignment errors. As a result, the true alignment of each F-35A gun is not known, so the programme is considering options for re-boresighting and correcting gun alignments.

F-35A operational test pilots received intermittent “unsafe gun” cockpit alerts while attempting gun attacks during air-to-air gun testing. These alerts occurred with two different aircraft and the root cause is under investigation.

The air-to-ground accuracy results from the gun pod on the US Marine Corps (USMC) F-35B short take-off and vertical landing (STOVL) variant and the US Navy (USN) F-35C aircraft carrier variant have been consistent and meet the contract specifications. They do not show the accuracy errors of the internal gun on the F-35A.