The U.S. Air Force chief of staff is entertaining a clean-sheet design to replace the F-16 and wants the tactical aircraft mix discussion to extend past the service and into the Office Of The Secretary Of Defense (OSD).

The service needs to determine what the “son of [Next Generation Air Dominance]” will be to replace the F-16, Air Force Chief of Staff Gen. C.Q. Brown told reporters Feb. 17 during a virtual Defense Writers Group event.

Brown envisions a 4.5-generation, or fifth generation “minus,” as the F-16 replacement. This is similar to what the Navy did when the service decided to pursue the Block III Super Hornet. At the time, former Chief of Naval Operations Adm. Jonathan Greenert called the Block III a 4.5 generation fighter.

The most important characteristic for the F-16 replacement is it include an open system that allows the Air Force to perform software updates, he said.

“Let’s actually take a look if there’s something else out there that we can build, and that’s what we’ve learned with our eSeries approach with the T-7, what we learned with NGAD,” Brown said.

Any decision about the future of the Air Force’s tactical aircraft fleet will require buy-in from Capitol Hill and elsewhere in the Pentagon, Brown says. He wants the Pentagon’s Cost Assessment and Program Evaluation (CAPE) office to be part of the future tactical aircraft study that will inform the fiscal 2023 budget, Brown said.

Involving CAPE would bring OSD into the assessment. This is necessary because Brown predicts pushback from various communities, depending on the outcome.

“I don’t think that everybody’s going to exactly agree with what I say, but I want to actually have a starting point as a … departure point and dialogue of what is that best force mix,” Brown said.