HMM: US Navy’s carrier-based F-35C stealth fighters may not be ready for combat after all.

“The F-35C is ready for operations, ready for combat and ready to win,” Vice Adm. DeWolfe Miller, commander of Naval Air Forces, said last month as the Navy announced that the fighter had achieved initial operating capability. “We are adding an incredible weapon system into the arsenal of our Carrier Strike Groups that significantly enhances the capability of the joint force.”

But the Project on Government Oversight, a nonprofit government-accountability group, warned Tuesday that despite these claims, the F-35C, like the other variants, “continues to dramatically underperform in crucial areas including availability and reliability, cybervulnerability testing, and life-expectancy testing.”

While still secretary of defense, Jim Mattis demanded last fall that the Navy and the Air Force strive to achieve a fleet-wide mission-capable rate of 80% for their fighters by October 2019. The Navy’s carrier-capable F-35 variant is apparently nowhere close to that target, having consistently achieved unacceptably low fully mission-capable rates.

The Project on Government Oversight began life as The Project on Military Procurement, criticizing the cost and design flaws of the M-1 Abrams — which of course went on to become one of the deadliest and durable tanks in history.