The latest Pentagon assessment of the F-35 program has reached the media, and with the long-delayed fighter finally entering combat operations with the Marine Corps late last year, one would think the report would offer some good news for the most advanced fighter on the planet. Unfortunately, it doesn’t. In fact, those first F-35s to carry an American flag into combat operations are among the worst off of any.

According to the report, which Bloomberg first gained access to, the first batch of Marine Corps F-35Bs are actually plagued with structural issues that promise to limit their operational lifespans to just 2,100 flight hours, or about one-fourth the service lifetime expected of them. When America first took delivery of F-15s and F-16s, for instance, they were also both rated for 8,000 and 9,000 flight hour lifespans, respectively.

The F-35B is unique among Joint Strike Fighter variants because the Marine Corps wanted to be able to leverage short-take off and vertical landing capabilities. This allows Marine Corps F-35s to operate from much smaller vessels than just America’s fleet of Nimitz and Ford class carriers, dramatically increasing the aircraft’s combat capabilities. However, because the Department of Defense began taking deliveries of F-35s before testing on the air frame was complete, and the issues were only discovered far later, the early F-35Bs delivered to the Marines now face a dramatically-reduced lifespan, despite also being the most expensive fighters purchased.

Structural cracks in the Marine Corps’ jets aren’t the only problems this new report highlighted. It also pointed to cyber vulnerabilities in the two primary networked systems operated by the F-35, as well as concerns about the cloud-based network’s performance outright.

Perhaps worst of all, the report states Air Force testing of the F-35’s air-to-ground attack operations indicate an “unacceptable” level of accuracy. Considering the platform was purpose-built with air-to-ground engagements in mind, including operating as a close air support aircraft, this may be the most damning issue of all. It also may explain the decision to release a video showing the F-35 engaging multiple ground targets at once in recent weeks, as the F-35 program office attempts to get out in front of the critical accusations leveled in this report.

This is far from the first report to offer serious concerns about the most expensive weapons platform in history failing to live up to its (admittedly high) expectations. Repeated setbacks and delays have made the F-35 into something of a case study in government spending, with much of the aircraft’s woes attributable to the Pentagon’s concurrent testing strategy (or purchasing completed aircraft before testing was completed).

Feature image: An F-35B aircraft approaches a KC-130J Super Hercules aircraft to re-fuel as it flies over the North Sea having taken off from RAF Fairford on July 1, 2016 in Gloucestershire, England. (Photo by Matt Cardy/Getty Images)