PENTAGON: The Navy’s F/A-XX initiative has been depicted as an ultra-advanced “sixth generation” aircraft that the Navy would prefer to buy instead of Lockheed Martin’s F-35 Joint Strike Fighter. But Breaking Defense interviews with Navy and industry sources strongly suggest that the service has little appetite for another expensive development program and that the most likely candidate for the F/A-XX is, in fact, an upgraded F-35.

“We’re not chasing the next shiny object,” a Navy official told Breaking Defense. “We’re looking to what is the art of the possible with regard to affordable warfighting capability.”

So while the Navy is considering an all-new design for F/A-XX, he said, “the answer might be a continued buy of whatever legacy platforms are out there at the time.” And the only existing fighter that will still be in production in 2030, he acknowledged, will be the F-35.

The driver here isn’t some Navy desire for a sixth-generation super-plane: It’s the Navy’s need to replace Boeing F/A-18E/F Super Hornets that will start reaching the end of their projected service life after 2025. F/A-XX is simply the Navy’s name for whatever aircraft comes next. The service’s Request For Information sent out to aerospace companies this spring explicitly solicited concepts – no one is at the stage of submitting actual proposals – both for “new design aircraft” and for “concepts derived from legacy aircraft.”

Breaking Defense has learned that Lockheed Martin has submitted one of each: an all-new, advanced, “sixth-generation” design and a derivative of its F-35C.

“If I had to bet,” said an industry source, “[I'd say] what the Navy would do is an F-35C-plus.”

It’s not that the Navy is uninterested in cutting-edge technologies. “We’re pulsing industry currently with the RFI to find out what they are seeing as the art of the possible,” said the Navy official: directed-energy weapons such as lasers, supersonic tailless airframes, advanced fuel-efficient engines able to provide better speed or range, improved forms of stealth, even making the plane “optionally manned” so it can sometimes fly without a pilot aboard. But “you have to sprinkle affordable in there,” he emphasized. “Affordability is a huge concern.”

So can the Navy afford a major new development program for the F/A-XX? Presumably the current budget crunch will end sometime.

“There are people who think that sometime in the next ten years that the R&D cash can be found for a sixth-gen fighter, and technologically there’s a lot you can do,” Teal Group analyst Richard Aboulafia told Breaking Defense. But until F/A-XX actually becomes an item in the budget, he said, “I wouldn’t actually take it seriously from a cash standpoint.”

Loren Thompson – consultant, analyst, and frequent contributor to Breaking Defense – put it more bluntly: “I doubt F/A-XX will ever get beyond the advanced PowerPoint stage,” he said. “A sixth-generation fighter is unlikely to be operational before mid-century, assuming a time lag similar to that between F-15/16 and F-22/35.”

It’s not impossible to field an all-new fighter design by 2030 if the Navy starts soon – but that would require finding significant funding in the next few years, when budgets are tightening. And while some in the Navy would love to raid the F-35 budget to launch a new program, the political odds are against them.

“I don’t think it’s any secret that the Department is committed to F-35,” said the Navy official. “It’s a given: Some level of F-35 inventory at this point has to be assumed.” That’s where planning for the F/A-XX has to start.

So the easiest course, politically and fiscally, is not to launch a new program but to let the F-35 evolve. Not everything envisioned for a “sixth-generation” fighter could fit onto a future version of the F-35, but a lot could. Lockheed has studied making an unmanned F-35, for example. Northrop Grumman explored concepts for putting a laser weapon in the Joint Strike Fighter. Perhaps most important, the existing airframe could be outfitted with more advanced, fuel-efficient engines to get the extra range that’s critical to the Navy’s AirSea Battle concept.

For now, the Navy is simply exploring its options. There are plenty of hurdles to get a program off the ground. Currently, staffers are finishing the draft of an F/A-XX Initial Capabilities Document (ICD) for Navy leaders to review. If the admirals approve, the ICD gets to go before the inter-service Joint Requirements Council; if the JROC approves, then F/A-XX goes before the Under Secretary of Defense for Acquisition, Frank Kendall; and if Kendall approves, the Navy can launch a formal “analysis of alternatives” (AOA) – one set of alternatives being a new design versus an F-35 derivative.

“We’re shooting to get to an AOA by this fall or winter,” said the Navy official. When would that analysis be finished, and the Navy ready to decide which alternative to pursue? Given the complexities, he said, “our initial guess is a couple of years right now.”