The F-22 and F-35 were intended to succeed the F-15 and F-16 as USAF’s high-low fighter mix. But program choices and the emergence of unmanned technologies, as represented here by the remotely piloted XQ-58A Valkyrie, threaten that vision. Courtesy
Photo Caption & Credits

Strategy & Policy

March 26, 2021

End of the High-Low Mix? 

The Air Force is launching a new tactical aviation study in an attempt to rationalize its swelling portfolio of manned and unmanned combat aircraft programs. The goal is to harmonize its efforts with those of the other services across the spectrum of joint combat,  from high-end fighters that can take on peer competitors to cheaper airplanes for fighting in uncontested skies. It’s also supposed to be an affordable plan, and will inform the fiscal 2023 budget request.

While details are still limited, it seems clear the Air Force is moving on from the “high-low,” two-fighter mix it has maintained since the 1980s in favor of an assortment of capabilities tunable to the conflict at hand.   

Chief of Staff Gen. Charles Q. Brown Jr., revealed plans for the study on Feb. 17, telling reporters he needs a decades-long roadmap for “tactical aviation” that balances near- and long-term needs.

The “high-end fight” warrants today’s 5th-generation fighters and the Next-Generation Air Dominance (NGAD) fighter, he said, but “there’s also a mix for a low-end fight,” which could include a “fourth-and-a-half/fifth-gen-minus” fighter and an array of unmanned aircraft.

USAF must get both the capability mix right as well as the numbers, “to assure we are going to be successful in future conflicts,” Brown said. Modeling and simulation will play heavily in the study, which he also said would be conducted in partnership with the Pentagon’s Cost Assessment and Program Evaluation (CAPE) shop. The CAPE will put data rigor to the study, he said.

“If I just do an Air Force study, it’s just an Air Force study,” he said. With CAPE, it will gain credibility with the Office of the Secretary of Defense and the other services. CAPE has been critical of Air Force fighter programs in the past. 

“I’m all about numbers and facts,” Brown said. “That’s what I expect from our Air Staff and that’s what I’m holding them accountable to.” He won’t accept “emotion” from staffers who want to retain a system just because “that’s what they grew up in.”

During the Air Force Association’s virtual Aerospace Warfare Symposium (vAWS) in February, he told reporters the study will also involve the Joint Staff, and that USAF’s fighter mix will be harmonized with the capabilities of the other services. The Navy also flies the F-35 and is pursuing its own sixth-generation fighter. 

It will also be informed by the Global Posture Review that Defense Secretary Lloyd Austin is conducting. Brown said he doesn’t want the TacAir study to be done “in a vacuum,” and “not listening to the other things that are happening inside the Department” would be naive, he said.

“As we really get into … the budget for FY23, that’s where …we’ll really make some key decisions,” Brown predicted. The study will be the jumping-off point for “a good conversation” with key stakeholders—Congress and combatant commanders—about “that right force mix.”

The Air Force’s air superiority model, unbeatable since the 1980s, called for a high-end capability—the twin-engine F-15—dominating the skies, with the less-costly, single-engine F-16 purchased in volume to be the “backbone of the force.” When the F-22 arrived in the mid-2000s,  it was supposed to become the next-generation high-end capability, while the single-engine F-35 was to succeed the F-16, extending the high-low mix well into the 21st century. But the F-22 program was terminated after only half the required numbers were built, and the F-35, though operational year five, has yet to reach full-rate production.

In recent years, the Air Force has invested in  the NGAD, the F-35, new-build F-15EXs, several unmanned systems—the Low-Cost Attritable Aircraft System (LCAAS); the Valkyrie; Loyal Wingman; and Longshot—and potentially a light attack aircraft. For the latter, USAF has looked at a turboprop and/or a weaponized version of the new T-7A jet trainer.  

“You’re going to have to make some tough choices,” Brown said, suggesting not all the programs will move forward. 

Brown insisted the Air Force will not “take money from F-35” to fund NGAD; and will find the cash elsewhere in the fighter portfolio.  Bringing down the  age of USAF’s fighters from today’s average of 28 years is essential, he added.   

The Chief isn’t interested in buying new F-16s, preferring “a clean-sheet design,” with new avionics, and agile software updates that would rapidly update code in response to changing threats and requirements.  Open mission systems—which the 1970s-era F-16 lacks—is “where we need to go.” 

The F-35 “Cornerstone”

House Armed Services Committee Chairman Adam Smith (D-Wash.) echoed Brown’s call for a new fighter study, saying in a March 5 Brookings Institution event,  “I’m going to try to … figure out how we can get a mix of fighter/attack aircraft that’s the most cost-effective.” A “big part of that,” he said, is “finding something” that will make the services less reliant on the F-35. Regarding the Lightning II, he said, “I want to stop throwing money down that rat hole.” Smith acknowledged there’s “no easy way out of” the F-35, though, and doesn’t anticipate a sudden halt to the program. Nor does his Senate counterpart, Sen. Jack Reed (D-R.I.), who said he’s concerned about the F-35 but not looking to slash fighter programs. 

As for Brown, he told reporters during AFA’s virtual Aerospace Warfare Symposium on Feb. 25, the F-35 is “the cornerstone” of USAF’s fighter program and praised its performance in combat deployments.

The Air Force still plans to buy 1,763 F-35s, but the timeline to do so remains sketchy.  At the present rate, it will take until the 2040s to get there. Brown acknowledged the challenge, and suggested the Air Force  may “need to accelerate” the buy, a reference to his own slogan for the force: “Accelerate Change—or Lose.” 

“I can’t [decide] this myself,” he said. Congress and DOD would have to go along, and industry would have to demonstrate it can surge production.  

Brown suggested the calculus could change based on how the F-35 is used. Recent F-35 engine problems can be traced to “the high-use rate,” given the F-35’s frequent overseas deployments to the Middle East and Europe. “That extra time on the engines is causing them to fail a bit sooner,” he said Feb. 17.

“I want to moderate how much we’re using those aircraft,” he continued. “You don’t drive your Ferrari to work every day. … We want to make sure we don’t use [the F-35] for a low-end fight when we want to save it for the high-end fight. … We don’t want to burn up that capability now and wish we had it later.”

The head of Air Combat Command said he’s doubtful that the F-35 will ever get to its target operating cost, however. Gen. Mark D. Kelly told reporters at a Feb. 26 vAWS press conference, “I’m not brimming with confidence” that USAF can reach its goal of $25,000 per flying hour by 2025; the cost today is about $36,000, according to the Air Force and Lockheed Martin, the F-35’s prime contractor.

While “I haven’t lost confidence,” Kelly said, “as I sit here today, I’m not overly confident we’ll get there.” Lockheed told reporters in February that the Joint Program Office rejected the company’s pitch of a broad performance-based logistics (PBL) contract, which it said was the best bet to reach the $25,000-per-flight-hour target by 2025. Company officials said a slimmed down performance-based logistics deal could still get them there, though. Such a “skinny” PBL contract would not include authorities the company sought to make long-term economic orders for some parts and materials. Lockheed officials said they expect a sole-source request for proposals this summer, likely a five-year contract with options to extend.

Ken Merchant, Lockheed F-35 sustainability vice president, said the “skinny” PBL won’t save “anywhere near what we had hoped for” with the original proposal, but said sustainment performance will match the earlier forecast. He’s optimistic because flying hour costs have been almost halved since the program began.

A push is on to keep parts bins full, repair parts faster, and reduce the demand for spares by improving repair capacity “across the enterprise,” Merchant said. Lockheed has assumed risk by committing to years-long deals with some of its own suppliers, even though F-35 sustainment is still on an “annual contracts” basis with the government, he said.

You Snooze, You Lose

Kelly is worried that the U.S. is moving too slowly on NGAD. “I don’t know … if our nation will have the courage and focus to field this capability before someone like the Chinese fields it and uses it against us,” he said. “We just need to make sure we keep our narrative up and articulate the benefit” of air superiority. The U.S. military is optimized to function with control of the air, Kelly said; “It’s less designed to operate without it.”

If the Air Force wins the NGAD race,  Kelly said, adversaries who challenge the U.S. will “suffer a very tough day, and a tough week, and a tough war.”

Brown said NGAD will need to have longer range than current fighters to be effective in the vast Pacific theater, and to be less dependent on aerial refueling. The goal “is to provide … as much range as possible,” he said. 

Asked about Brown’s idea of a “fifth-gen-minus” airplane for less-taxing missions, Kelly said it makes sense not to apply the best aircraft to undemanding missions. Using high-end fighters against low-end missions incurs “a significant jump in investment, as well as cost-per-flying-hour.”

Lt. Gen. Duke Z. Richardson, military deputy to the Assistant Secretary of the Air Force for Acquisition, Technology and Logistics, said the Air Force and Congress must have the “courage” to adopt a rapid-refresh model for fighter technology, as put forward by Will Roper, the former assistant secretary. Richardson said  buying new aircraft in quick succession—but at less cost, because they’re only meant to last less than a decade—requires a shift in mindset. The Air Force and Congress have to be willing to  have “another one right behind it” each time a new jet ends its service, he said. If either fails to follow through, the Air Force may surrender its long dominance of the air.