The U.S. Marine Corps is pressing ahead with plans deploy the stealthy F-35B jump jet to frontline fighter squadrons this July despite flawed software and very limited ability to maneuver. That’s despite fixes to the software that are already available to the $400 billion Joint Strike Fighter program.

“They plan on declaring IOC [initial operational capability] with the older version of the software that doesn’t have all the fixes in it,” said Air Force Lt. Gen. Chris Bogdan, Pentagon’s program manager for the Joint Strike Fighter. “They can do it because they have work arounds. They have [concepts of operation] and they have ways of mitigating those problems.”

Bogdan said that frontline Marine Corps pilots would have to get around the problems by turning off some systems and maneuvering the jet carefully to avoid the issue.

“That is not the way we want to fix this problem. We want to fix this problem inherent in the airplane,” Bogdan said. “As much as we want to correct these deficiencies … the Marine Corps feels—it is their call—and I support them in this—[that] this software is good enough for IOC and they believe it is.”

The problem lies with the F-35’s complex software, which will ultimately have about 8 million lines of computer code. The jet’s computers have to correlate data produced and shared by multiple jets, Bogdan said. Sometimes, depending upon where each jet in a formation of four aircraft are located, the computer isn’t able to match up each target correctly, he said. That means that sometimes the same object can show up as a duplicate “ghost” target—causing confusion in the heat of battle.

Imagine, Bodgan said, that there’s a group of four F-35s with their sensors on and sharing their data. Now let’s say there’s a single surface-to-air missile below. Ideally, all four pilots would see one enemy. However, right now, with the current state of the F-35’s software, that is not happening.

“What we have found is that when have two, three, or four F-35s looking at that same threat, they don’t all see it exactly the same,” Bogdan said. “When there is slight difference in what those aircraft might be seeing, the fusion model can’t decide if it’s one threat or more than one threat.”

Right now, when there are only two F-35s, the problem is not that bad, but it’s not perfect, Bogdan said. If there are more than two jets, then situation becomes more problematic. What the Marine Corps hopes to do is get around the issue by only linking pairs of F-35s and then connecting those groups of two to each other, Bogdan said. That works a lot better than connecting the planes directly—but that’s not how the Pentagon wants to do things long term.

The Joint Strike Fighter program is working on fixes—and made a lot of progress, Bogdan said. Early testing of the software fixes are looking promising, but it is not yet complete. “We have some work to do, but we are on the right path,” he said. “Sometimes when you fix one problem, and it goes away, another problem that was masked behind it shows up.”

Meanwhile, Bogdan told reporters that the F-35B’s structure is showing a tendency to crack. It’s a problem that stems from earlier efforts to reduce the jet’s weight. Because the program switched from extremely strong titanium parts to aluminum to save weight, problems are showing up.

As if the software and structural problems weren’t enough, the F-35B will also be severely limited in its weapons capabilities. It will carry a pair of AIM-120 AMRAAM long-range air-to-air missiles and a pair of bombs. Initially, it will be able to carry 1,000-pound satellite-guided bombs or 500-pound laser-guided weapons.

That’s not considered to be enough firepower, especially if the Joint Strike Fighter goes up against jets from an advanced foe like Russia or China.

F-35 inability to carry enough air-to-air missiles is a huge concern for Air Force officials. “The biggest issue is that they will not have a large enough air-to-air load [of weapons] to be on the leading edge,” said a senior Air Force official.

Further, new Russian and Chinese jammers are able to jam the AIM-120’s radar, and service officials expect that it will take many more missiles to hit a target than they had expected. “Even with my six AIM-120’s in the F-22 [Raptor, the stealth fighter now in service], sometimes it is not enough,” said a senior Air Force official.

And things won’t be changing soon. According the Joint Strike Fighter program office, the stealthy jet will only be able to carry four missiles once developmental testing is completed in late 2017. The program office didn’t address when the capability will be afforded to frontline squadrons, but military sources tell The Daily Beast that the “combat air forces” won’t receive that ability until 2019.

The F-35B, when it becomes operational on July 1, won’t be able to go as fast or be as maneuverable as advertised, either. Bogdan said that “not a whole lot” of the jet’s full flight performance will be available, but it will have what the Marines are willing to live with.

A plane’s ability to move is measured by how many “Gs”—units of gravitational force—it can function under. The steeper the climb, the tighter the turn, the more Gs the plane pulls. The F-35B was supposed to be capable of 7 Gs. But for now, it will be able to pull between 4.5 and 5.5 Gs, Bogdan said. By comparison, a present-day F-16 can pull 9 Gs. It will also be supersonic—just barely. “I think the Marine Corp at IOC will be able to go supersonic,” Bogdan said. “It might be like 1.1. Mach.”

It’s won’t be able to go its promised 1.6 times the speed of sound until later—but even then, other modern aircraft are capable of flying at more than twice the speed of sound.