The F-35 Is Still Full of Must-Fix Flaws


The Pentagon’s annual F-35 report says that the controversial fighter still has 13 “must-fix” problems.
The F-35’s gun also suffers from misalignment issues, making it inaccurate in air-to-air combat.
The Pentagon decision to start building the jet early has led to an issue where hundreds of older jets still suffer from significant problems.

The F-35 Joint Strike Fighter still suffers from 13 serious flaws, including a gun afflicted with cracking and accuracy issues. The software that runs the jet also has nearly 900 bugs. The problem is complicated by the need to patch nearly 500 jets already built and in the wild.

The Pentagon’s director of operational test and evaluation releases annual reports on the progress (or lack of) on many weapons systems. The F-35’s annual report is particularly interesting given the jet’s controversial past. This year, the report notes several issues with the jet, including 13 “Category 1” deficiencies, which the manufacturer must address, and 873 software deficiencies. The F-35 is one of the most complicated flying computers ever made, running on more than eight million lines of code.

Another problem unique to the Air Force’s variant: the built-in gun is not accurate. The Air Force’s F-35A model has a four-barrel 25-millimeter gatling gun. Janes, in its coverage of the issue, says the problem is due to muzzle alignment errors. “As a result,” Janes writes,”the true alignment of each F-35A gun is not known, so the programme is considering options for re-boresighting and correcting gun alignments.” Furthermore at least two jets have received “unsafe gun” cockpit alerts during air-to-air gun testing for reasons unknown. The F-35A gun mount housing is also cracking, another issue that will need fixing.

The F-35A is the only version of the jet with an internal gun. The Marine Corps F-35B and Navy F-35C carry a gun in a pod mounted to the outside of the aircraft and the guns have “acceptable” levels of accuracy.

Two F-35s over Turin, Italy, 2019.

Perhaps the most worrying problem with the F-35 is a continued lack of aircraft readiness. In 2018, then Defense Secretary James Mattis ordered U.S. warplane fleets to achieve an 80 percent readiness rate within one year. According to the Pentagon report, although individual F-35 units were able to achieve an 80 percent readiness rate “no significant portion” of the U.S. F-35 fleet in any service was able to achieve and go on to sustain an 80 percent rate. Air Force units scored the best in terms of readiness, while the Navy and Marines were significantly worse.

Why does the F-35 have so many problems a decade after production began? The U.S. government and manufacturer Lockheed Martin made a decision early on to use a concept called “concurrency” with the F-35 program. That concept calls for early production of the aircraft before the design is nailed down and the bugs ironed out, so the plane can get into the hands of pilots sooner. Once the plane was finally complete older planes would be brought up to the latest standard.

Concurrency is a mixed bag. It’s why one Marine Corps F-35 pilot recently logged 1,000 hours in the aircraft—but it’s also why every plane the pilot has flown so far has had unresolved issues. None of the 490 F-35s built so far are “complete,” not with 13 Category 1 issues still unresolved.

One major worry is that some of the oldest planes with the most issues may never be upgraded to a combat-capable configuration and spend their lifetimes trapped as training jets. While the Pentagon has committed to upgrading the jets, Congress must still appropriate the estimated $12-40 billion to do so.