The doubtful future of the US Air Force’s planned NGAD fighter
28 Jun 2024|

US Air Force chief of staff General David Allvin handed a surprise to industry on 13 June by suggesting that the service might not proceed as expected with its next combat aircraft, the one planned in the Next Generation Air Dominance (NGAD) program.

Asked whether the USAF could go ahead with NGAD, Allvin said: ‘We’re going to have to make those choices, make those decisions, across the landscape.’

The USAF has been extremely secretive about NGAD, including about the testing of at least one demonstrator at the air force’s covert flight test base in Nevada (popularly known as Area 51). Nonetheless, selection of a single contractor had been hinted at for this year. NGAD and its precursor, the Aerospace Innovation Initiative (AII), have been under way for nine years and the closely associated variable-cycle Next Generation Adaptive Propulsion (NGAP) engine for longer than that.

The outcome of many billions of dollars in investment, by government and industry, is in doubt. It follows the Navy’s removal of $1 billion in money for its new strike fighter, F/A-XX, from the 2025 budget.

Some background: Air Force Secretary Frank Kendall launched AII when was the Pentagon’s acquisition boss in 2015. It was run by the Aerospace Projects Office within the Defense Advanced Research Projects Agency.

AII paralleled the Air Superiority 2030 effort led by Air Combat Command chief General Michael Holmes to define a future combat aircraft. It was nominally a replacement for the F-22, because the F-35 was (and is) the program-of-record replacement for all other USAF fighters.

The new aircraft became known as Penetrating Counter-Air (PCA). It was not a classic fighter: it was intended to operate against all counter-air threats, including integrated air defense systems and airborne radars; it was designed to operate in conjunction with stand-off weapons, unmanned vehicles, electromagnetic warfare and cyber; and maneuver and close combat would be de-emphasised. It became clear that PCA would be large, acquired in the low hundreds of units at most. Unit procurement cost, not including research and development, was expected to be nearer US$300 million than US$200 million.

It was disclosed in late 2021 that a prototype had flown, and the associated project office was closed in early 2022. By then the aircraft came under the NGAD program. Late in that year, Northrop Grumman focused its future air dominance activity on the navy’s F/A-XX, a decision formally announced in June 2023. (It is likely that the company is teamed with Lockheed Martin for the F/A-XX, as it is on the F-35.)

There are various explanations for Allvin’s comments. It may be a ploy to get industry to lobby Congress for more money. After all, Congress keeps reinstating aircraft that the USAF wants to retire and attempting to restore orders for F-35s that the air force would like to defer. Both draw on the accounts that would pay for NGAD.

The budget is being stressed by the F-35, now in disarray from the latest in a series of development problems, as described in a May report from the Government Accountability Office (which I comment on here and here). The USAF now faces a longer, costlier path to getting what it has focused on since 2015: Block 4 avionics fixes and improvements, plus engine and subsystem changes to alleviate cooling problems.

Also, with the future of the F/A-XX looking dubious at best and a modified Pratt & Whitney F135 engine selected over a new NGAP for future F-35 versions, NGAD was left carrying all the cost and risk of a high-tech new engine.

Given China’s rapid modernisation and war in the Ukraine, PCA/NGAD might be looking late relative to the need for it, delivering no capability until the early 2030s. Some observers speculate that the USAF could consider the option—raised by former Northrop Grumman analyst Chris Bowie, just after the company quit NGAD—of arming the B-21 Raider bomber with long-range air-to-air weapons.

Drones, too, have moved to front and center of force planning since 2016. That could feed into a reappraisal of requirements.

The USAF may not be seeing attractive NGAD bids. Boeing has no option but to be conservative, given its dismal performance on the air force’s tanker, trainer and presidential transport programs. Lockheed Martin has little incentive to bid aggressively on a program that might compete with F-35: chief executive Jim Taiclet said in January: ‘We don’t have any must-win programs anymore.’

Perhaps the USAF is taking a pause to reconsider its requirements. It may be significant that NGAP continues for now. Whether NGAD is just resting or is an ex-parrot is an active discussion in Washington.

If NGAD is gone—and not much in US planning can be considered stable until after the presidential election—then Australia, like other forces in the Pacific, will be considering options for aircraft with more reach than those designed before the rise of China.

The Global Combat Aircraft Programme being pursued by Britain, Japan and Italy emerges as a possibility. It is not overtly advertised as a longer-range aircraft, but its transonic delta wing is highly reminiscent of Boeing’s losing X-32 candidate for the JSF program. Although much smaller than GCAP, the X-32 had a wing that would could hold 9 tonnes of fuel, a large quantity for a fighter. GCAP will have legs.

There is another, more radical possibility: grow beyond NGAD into a true supersonic-cruise aircraft. If the B-21 has one limitation, it is sortie rate over a long distance.

A high-altitude supercruiser (Mach 2+) can survive with moderate reduction in radar cross section, combined with speed, altitude, and stand-off launch. Rocket or glide weapons launched at high speed and altitude will easily fly more than 100 nautical miles (180km), while ramjet weapons released in such conditions can dispense with the complexity and weight of a rocket booster.

A large enough aeroplane could carry its own unmanned adjuncts and release them outside the adversary’s defended zone. Response time would be 2.5 times shorter than a subsonic aircraft, and the sortie rate would be at least twice as high.

Sounds expensive? Risky? We have been proving for 40 years that reliance on stealth alone is expensive and risky, more so when combined with high speed or agility. Some low-profile programs indicate that a supercruise engine could be developed using commercial technology, and aerodynamics, structures and systems were proven in the 1960s.

More than 60 years ago, General Dynamics briefed Australia on the B-58 Hustler supersonic bomber, and brochures showed the Mach 3 B-70 Valkyrie intercepting an invasion fleet headed for Taiwan. Supersonics briefly got attention in the early 2000s under the dual-use Quiet Supersonic Platform project. It may be time for another look.