WASHINGTON — In a departure from the dual-service F-35 effort, the Pentagon's sixth-generation fighter jet likely won't be common between the US Air Force and the US Navy, a top Air Force general said Friday.

The next generation of fighters likely will likely be designed as separate aircraft across the services because the Air Force and Navy will have unique mission requirements in future decades, said Lt. Gen. James "Mike" Holmes, Air Force deputy chief of staff for plans and requirements. The sixth-generation fighter jet will replace the Air Force’s F-22s and the Navy’s F/A-18s in the 2030s.

"We will have some different requirements for what we need based on the different things we are expected to provide for the joint force," Holmes told reporters. "We will use common technologies and maybe some common things, but at this point we think it will be a different enough mission that it won't be the same airplane."

This is a departure from recent history, as the fifth-generation F-35 joint strike fighter will be used by the Air Force, Navy, and US Marine Corps. The F-35 was designed as a joint-service fighter, with three different variants built for the various services.

Last year, the Navy and Air Force said they were set to begin a joint analysis of alternatives to explore solutions to ensure air superiority into the 2030s and beyond. While the Navy went ahead with its AOA, the Air Force decided to delay its own effort, Holmes said. Still, the two services are collaborating closely on the project, he stressed.

"We took a year out on purpose to try to bring in a broader picture," Holmes said.

Instead of moving forward with the AOA, the Air Force stood up a Capability Collaboration Team (CCT) to study the possibilities for a sixth-generation fighter. The Air Force worked with industry, the other services, academia, scientists and government research centers to narrow the options down to two, Holmes said. The team will brief Air Force leadership on its findings in the spring, he said.

"With a multi-domain Air Force, we're going to approach problems with multi-domain solutions," Holmes said. "We wanted to open the aperture and take a look at what space, cyber and air capabilities can come to bear to try to regain that capability advantage we had in air-to-air against our potential threats."

The Air Force has included money in various funding streams within its fiscal year 2017 budget request for experimentation and technology demonstration in order to minimize risk for the sixth-generation fighter in the long term, Holmes said. The service’s funding profile for next-generation air dominance — which is not limited to the sixth-gen fighter — includes $20.6 million in fiscal 2017, and about $13 million each in fiscal 2018 and fiscal 2019 for research and development, according to official budget documents. The Air Force also included $75 million in fiscal 2017 through fiscal 2019 for "innovation and experimentation," which could be used for sixth-gen fighters, according to a service spokeswoman.

The Air Force will decide this year exactly how to spend that cash, Holmes said.

"And so in the short term," Holmes said, there "is some experimentation and some technology demonstration that's being done to try to reduce the risk on the kinds of capabilities that we think should end up in that family of systems."

Email: lseligman@defensenews.compswarts@airforcetimes.com

Twitter: @laraseligman@PFSwarts

More In Pentagon