In the End, the Air Force’s Secret New Fighter Jet May Never Actually Fly (2024)

This year, the Air Force was supposed to award either Boeing or Lockheed-Martin a contract to build a Next-Generation Air Dominance (NGAD) sixth-generation stealth fighter to replace its F-22 Raptor jets in the 2030s.

But after investing many years of R&D and billions of dollars, and repeatedly saying NGAD was insensible, Air Force Chief Gen. David Allvin and Air Force Secretary Gen. Frank Kendall both abruptly indicated in June that NGAD might never take to the sky after all. They claim that this is due to a budgetary crunch caused by the hundreds of billions the service has committed to simultaneously field new Sentinel silo-based nuclear missiles and the B-21 Raider stealth bomber.

However, on June 28, Kendall told Defense News that the service might field a cheaper, presumably descoped take on NGAD. He noted that, currently, each NGAD would cost as much as three F-35A stealth fighters (i.e. $255-300 million per plane).

Kendall went on to say that NGAD’s “family of system concept … is alive and well” while adding that the “NGAD platform design concept” was under continued scrutiny to “see if it’s the right concept or not. We’re looking at whether at we can do something that’s less expensive and do some trade-offs there.”

Kendall’s statement requires parsing: the NGAD ‘family of systems’ refers to the planned drone-fighter team, while the ‘NGAD platform’ refers to only the manned fighter. He characterizes the current proposal for the latter as too expensive to build quickly and in adequate numbers.

That means NGAD’s Collaborative Combat Aircraft (CCA) drone and its manned-unmanned teaming technology are here to stay (they were already planned to also accompany in-service F-35s jets into battle). But whether the service also gets manned NGAD fighters may depend on serious unit cost reductions.

Why cutting-edge NGAP engines are in the crosshairs

It seems unlikely that NGAD could achieve price parity with Lockheed’s mass-produced F-35 as Kendall suggested in his interview. But could unit cost be reduced by one-third or even half while retaining NGAD’s most critical advancements?

Kendall indicated that NGAD’s planned adaptive-cycle engines would likely be on the chopping block. These modulate an additional third airstream to adjust the bypass ratio of air sucked into the engines midflight—to maximize either fuel-efficient cruising or high-speed flight performance.

That had the potential to improve fuel economy by 20 to 35 percent, thereby extending maximum range and thrust, and augmenting both electricity generation and thermal cooling (in the latter two areas, the F-35’s F135 engine is experiencing some difficulties.)

By 2023, the Air Force had already spent $4.4 billion developing adaptive cycle engines, beginning with the Advent R&D program in 2007. This morphed into the Adaptive Engine Transition Program in 2016, which funded development of rival engine prototypes by General Electric and Pratt & Whitney. The prototypes were called the XA-100 and XA-101, respectively.

In the early 2020s, the Air Force seriously considered replacing the Pratt & Whitney F135 turbofan in its growing F-35A fleet with GE’s XA-100. But ultimately, it chose Pratt & Whitney’s lower-risk and much cheaper F135 Engine Core Upgrade.

That left NGAD to shoulder the entire burden of developing production-ready adaptive-cycle engines via its parallel Next Generation Air Propulsion (NGAP) program.

How much does NGAD lose by forsaking adaptive cycle engines? On one hand, the Air Force is increasingly skeptical (rightly or wrongly) that the ‘hot-rod’ within-visual-range dogfighting performance it optimized in the F-22 is critical to future air warfare. Instead, the Air Force is coming to believe that stealth, long-range weapons, and long-range sensors will decide 90 percent of fights before dogfighting performance comes into play.

But, more critically, NGAP’s improved fuel efficiency helped extend its range and ability to more fuel-efficiently transit at supersonic speeds (known as ‘supercruising’). Those attributes matter more to the Air Force as it looks for ways to base fighters further back from China’s many conventional tactical/short-range ballistic missiles.

Thus, without adaptive cycle engines, NGAD will require larger fuel tanks. This will lead to increased weight that will negatively impact kinematic performance and operating costs, and necessitate alternate solutions to both increase electrical generation and improve heat management.

But while design-wise, forgoing NGAP is no free lunch, it would subtract a significant source of R&D costs and delay-inducing technical risks.

The Pentagon could also try designing NGAD to support swap-in of adaptive cycle engines after initial procurement using conventional turbofans. Additionally, it could import or license-build the adaptive cycle engines being developed by Rolls Royce for the UK’s sixth-generation Tempest fighter program, which also has buy-in from Japan. But sourcing abroad would be politically unpopular.

It’s likely that the Air Force’s financial deficit is such that even a cheaper NGAD is likely to remain unaffordable without additional funding from Congress, or major cuts to some other capability. Lowering the price tag could improve the service’s odds of selling the additional/reallocated funding to politicians.

Would NGAD’s cancellation spell catastrophe for Boeing?

The evaporation of a manned NGAD jet is also seen as more negatively impacting Boeing than Lockheed, as the latter already has its financial future secured with well over 2,000 F-35s slated for production. Even orders for Lockheed’s modernized F-16 jets (first designed in the 1970s) remain high.

Boeing, by contrast, is shutting down its newer FA-18E/F Super Hornet production line in 2027. Meanwhile, orders for its heavily modernized F-15EX twin-engine fighter were downsized from 144 to just 80 by the Air Force—though the 2024 proposed defense budget may see the USAF order tick back upward to 104.

Boeing’s management has also been in the doghouse for years due to multi-year delays and technical lapses affecting its KC-46 Pegasus tanker, and (less severely) its T-7 Red Hawk training jet—the costs of which have been largely borne by the corporation. The infamous quality control problems affecting its commercial 737 jetliners haven’t helped either, and have attracted increasing ire from Federal regulators. Boeing also lost a bid to Sierra Nevada in April to convert new Nightwatch nuclear command post planes.

While both Lockheed and Boeing are competing for NGAD, Boeing invested $1.8 billion in a new production facility in St. Louis, Missouri (measuring 1.1 million square feet) for an advanced and classified combat aircraft—clearly hoping to prepare for and improve odds of winning the NGAD bid.

The Pentagon might lean toward Boeing’s offer simply to ensure that Lockheed doesn’t end up swallowing the entire fighter-production industrial base, leaving it without competitors to build land-based fighters. Some suggest that even if Lockheed’s design won, the Pentagon might negotiate for Boeing to undertake production, just as the Navy often requires rival shipbuilders to build each other’s designs in order to maintain the health of the shipbuilding sector. But both scenarios depend on NGAD’s survival.

That said, other analysts argue that the Air Force now deeply distrusts Boeing’s managerial competence, yet also feels that Lockheed has little incentive to offer an attractively priced NGAD due to its investment in the F-35 program. NGAD’s abrupt limbo, then, may be intended to signal dissatisfaction with the cost-competitiveness of both company’s offerings.

What are the alternatives to fielding NGAD?

As Air Force officials downgrade a manned NGAD fighter from ‘necessary’ to ‘nice-to-have,’ they have articulated an alternate air superiority strategy that doesn’t require a new manned jet.

The idea is that the combination of new CCA drones (currently competed by General Atomics and Anduril) operating semi-autonomously with manned jets carrying new longer-range air-to-air missiles (AIM-260, the bigger LREW or, hypothetically, the Navy’s newly-minted AIM-174) could reduce the importance of specialized air-to-air duelists like the F-22 Raptor.

The services particularly believe CCA drones offer a cheaper way to rapidly develop, deploy, and iteratively improve aircraft able to operate at the dangerous forward-edge of air-combat, reducing risks to flesh-and-blood pilots. Of course, this is a never-done-before strategy—one defense industry think tanker argues that Air Force officials may be getting carried away in estimating CCA’s capabilities prior to operational testing, leading to over-tuned performance in wargames at NGAD’s expense.

Regardless, if NGAD exits the picture, than more drones, 4.5^th-generation fighters, and stealthy 5^th-generation fighters will likely end up filling the gap.

One possible beneficiary could be Boeing’s twin-engine F-15EX Eagle II. Though not a stealth fighter (meaning it’s vulnerable when closing with enemy fighters and air defense systems like NGAD was planned to do), it does boast excellent speed, range, and payload, and has an especially powerful APG-82 radar and EPAWSS self-defense system.

It theoretically could support stealthy F-35s and risk-taking CCA drones—loitering further back at the limits of enemy engagement range and contributing both long-range scanning and missile shots to the fight while relying on speed, distance, and EPAWSS to evade long-range return fire.

The Air Force might also modernize and extend the service life of its F-22 fleet, which was formerly slated to retire in the 2030s as NGAD entered service. Raptors remain impressive air-to-air duelist, and likely boast the lowest radar signature of any stealth fighter in service.

However, they are short-ranged (problematic in a Pacific conflict), difficult to network with and upgrade (due to outdated software architecture), and their 90s-era stealth technology is extremely maintenance-intensive. These factors made substantial modernization of F-22s excessively costly. But the Air Force may reconsider paying if NGAD falls out of the picture.

NGAD’s cancellation could also open a gap for a hypothetical range-extended F-35D—possibly incorporating some of the technologies already prototyped for NGAD, and perhaps with larger internal payloads and/or a second crewmember to help better command CCA drones.

However, the Pentagon has already found the costs of fielding three different types of F-35s higher than expected, leading it to prefer collective Block upgrades affecting all F-35s (which has also proven more expensive and time-consuming than hoped) rather than developing a fourth submodel requiring yet another stream of unique parts.

Another out-there solution could see the Air Force trying to merge its NGAD program with the Navy’s identically named NGAD, which also had its funding iced in 2024. However, the compromises and disappointingly limited cost savings of co-developing the F-35 jet likely killed the appetite for such complex interservice projects.

Besides, the services already prioritize subtly different air-combat missions; the Navy focuses on defense of its carriers from enemy bombers and missiles, while the Air Force thinks more about offensive counter-air (OCA) missions, aggressively hunting other enemy fighters.

Regardless, Air Force leadership clearly believes that new drones, missiles, and battle networks have opened a pathway to maintaining air superiority that doesn’t depend on procuring manned NGAD fighters (much as those may be helpful). That has apparently empowered the service’s leaders to throw the gauntlet down before industry: devise a more affordable super fighter, or risk losing the opportunity completely. But in that event, Boeing would have much more to lose than Lockheed.