The Nearly Decade-long Story That Led To NGAD Flight Demonstrator

The first confirmation of the existence of a flying, full-scale flight demonstrator for the Next-Generation Air Dominance program by the U.S. Air Force on Sept. 15 dropped like a lightning bolt from the black world of secretly funded military projects.

• Flying full-scale flight demonstrator announced
• “Broken records” claimed, but what kind?

But the exciting, albeit terse, announcement during the virtual Air, Space and Cyber Conference, hosted by the Air Force Association, comes after a long series of revealing statements by defense officials over nearly a decade that point to the existence of such a program and illuminate critical details about the scope and limits of the project.

Most of the Next-Generation Air Dominance (NGAD) program details remain among the Air Force’s most tightly guarded secrets. But two parallel objectives are clear: to revolutionize the air superiority mission by fragmenting the mission set among multiple aircraft types and to disrupt how the defense industry produced most of the state-of-the-art combat aircraft during the past half century.

The NGAD flight demonstrator confirmed by Will Roper, the Air Force’s assistant secretary for acquisition, technology and logistics, plays a critical role as a proof of concept for both objectives.

Senior Air Force officials attending the virtual conference declined to elaborate on the only two statements provided by Roper about the NGAD flight demonstrator.

“NGAD has come so far that the full-scale flight demonstrator has already flown in the physical world,” Roper said during his keynote address. “It’s broken a lot of records and is showing digital engineering isn’t a fluke.”

Pressed for elaboration during two follow-up appearances with journalists, Roper offered only one other direct comment about the aircraft’s performance so far: “All I can say is the NGAD [flight demonstrator] test flights have been amazing. Records have been broken, but I’ve been impressed at how well the digital technology transitions to the real world.”

Before Roper’s comments, the closest hint of the flight demonstrator’s existence came about a year ago. In previously unreported comments, Gen. David Goldfein, the then-chief of staff of the Air Force, offered the most explicit, unclassified description of the NGAD program during a September 2019 press conference.

“Here’s our NGAD strategy: We have five key technologies that we’re investing in that we don’t intend to have all come together on a single platform,” Goldfein said. “They will all mature and accelerate at difference paces. As they become ready, you will see us adapting them on existing platforms, sensors and weapons and also looking at new platforms, sensors and weapons.”

With the exception of an adaptive-cycle propulsion system, the Air Force has not specifically linked other new technologies to the NGAD program. But the new family of systems is likely to require further advances in communications and networking, onboard electrical-power generation, thermal management of waste heat and potentially new types of armament and sensors, such as directed-energy weapons and passive detection systems. Such technologies can be developed and tested on the ground but still must be validated in-flight in a relevant air vehicle configuration. In his comments in 2019, Goldfein hinted about the necessity of a flight demonstrator but stopped short of providing a timeline for the first flight.

“There has to be a test article to be able to take some of these technologies to mature,” Goldfein said. “That’s probably about as far as I can go.”

But the Defense Department’s interest in developing new prototypes to support the air dominance mission goes back nearly a decade. In 2014, DARPA completed an Air Dominance Initiative study, in which leading military and technology experts concluded that “no single new technology or platform could deter and defeat the sophisticated and numerous adversary systems under development,” according to written testimony by a Pentagon official to Congress in March 2014.

That study prompted DARPA to launch the little-known Aerospace Innovation Initiative (AII) in fiscal 2015. The official’s testimony outlined the explicit purpose of AII: “to develop and fly two X-plane prototypes that demonstrate advanced technologies for future aircraft. Teams will compete to produce the X-plane prototypes, one focused on future Navy operational capabilities and the other on future Air Force operational capabilities.”

The Defense Department stopped referring to the AII program shortly after submitting the fiscal 2016 budget request, but DARPA’s website remains active for the Aerospace Projects Office, which manages the AII prototyping program.

In 2016, the Air Force followed up on DARPA’s study by establishing an enterprise capability collaboration team to produce the Air Superiority 2030 flight plan. The unclassified version of the plan released in late 2016 echoed elements of the DARPA study, especially the need for a family of systems. “There is no single capability that provides a silver bullet solution,” stated the 11-page summary of the classified flight plan.

But the Air Force flight plan still appeared to focus on one specific member of the family called the Penetrating Counter-Air (PCA) system. This platform appeared to resemble the sixth-generation fighter concepts released about the same time by major defense companies, such as Boeing, Lockheed Martin and Northrop Grumman. The industry concepts invariably featured a large, tailless, supersonic and highly stealthy aircraft with certain exotic capabilities, such as defensive lasers. The flight plan described the role of the PCA as targeting and engaging other aircraft by itself as well as using the data from its sensors to feed targeting information to standoff aircraft carrying long-range missiles.

The Congressional Budget Office (CBO) has used the PCA concept to project Pentagon aircraft spending. In December 2018, the CBO forecast that the first of 414 PCA aircraft would enter service in 2030, costing an average of about $300 million each. Overall procurement spending for PCA could total $130 billion between 2028 and 2050, CBO reported in January 2020.

The CBO’s cost estimates for PCA appear to be based on a concept of a monolithic weapon system, such as the Lockheed F-22 and F-35. Both of those aircraft are equipped with all the sensors and weapons necessary for the aircraft to perform any mission within its operating role by itself, although they also possess a limited ability to collaborate with other aircraft types in stealth mode.

During the same period, however, the Air Force’s approach to the NGAD program significantly changed. As Goldfein noted, in 2019, the conventional understanding of a PCA aircraft as a monolithic system able to perform a wide set of missions by itself no longer applies. A glimpse into the internal debate that led to the transformation of the NGAD into its current form first appeared in September 2018. Roper had assumed control of Air Force acquisition seven months earlier and spearheaded a dramatic reimagining of the concept.

“I would say [NGAD now] looks more like a portfolio than a single initiative,” Roper told reporters during a September 2018 press conference.

The transition to a federated architecture for the NGAD program carried significant budget implications. Four months later, the Air Force released a spending plan for fiscal 2020-24. The NGAD budget over the five-year period amounted to $6.1 billion. Only a year before, the Air Force had planned to spend $13.2 billion during the same five-year period on NGAD. Air Force officials justified the 50% five-year reduction for one of the service’s most high-profile weapon systems, saying any trace of a traditional monolithic fighter had been eliminated.

“Instead, NGAD is investing in technologies and prototypes that have produced results and demonstrated promise,” the Air Force said in a statement released to Aviation Week in June 2019 (AW&ST June 17-30, 2019, p. 92).

At the same time, Roper introduced a new element of the NGAD strategy. The goal was no longer merely to revolutionize air warfare technology. The NGAD is a critical element of the Air Force’s strategy to disrupt the traditional business model for developing, fielding, modernizing and sustaining combat aircraft. The Digital Century Series effort kicked off in October 2019, seeking to use a new set of digital engineering tools to break the traditional model.

In his indefatigable style, Roper has proselytized his vision for a “digital trinity” of engineering systems that unite the digital models for flight performance, production and sustainment into the same database. In his vision, this approach would allow designers to immediately realize the full impact of even a minor design tweak on the life cycle of a new aircraft, including the effect on the cost of production and the service life of the part.

Moreover, the Air Force—not the prime contractor—would own the underlying design rights and source code for the operating system. The aircraft designer would deliver a set of digital blueprints, but the production, modernization and sustainment of the aircraft could be opened to competition by any company.

Although the concept invokes the Century Series of six fighters that entered service in the 1950s, Gen. Mark Kelly, the newly appointed head of Air Combat Command, says the concept more closely resembles elements of the F-117 program. Lockheed produced only 59 F-117s over the life of the program, a remarkably short production run. The F-117 also ushered a transformational capability into combat in 1991 by introducing an airframe configuration with a very low radar cross-section. Despite the F-117’s record, the Air Force unsentimentally retired the fleet from regular service less than two decades later, although a handful of aircraft continue to be sighted flying on test ranges.

“It was a bleeding-edge technology that was a unique, game-changing product in the field, which we fielded and operated for a specific amount of time and then moved on to another rapidly emerging technology that we just couldn’t adapt to that exact same platform,” Kelly says.

The Air Force’s approach to the NGAD program will be similar. Leveraging the five key technologies referenced by Goldfein a year ago, multiple types of aircraft will be developed and fielded simultaneously in small production runs, then retired within 15 years, Roper said. If realized, his vision poses severe implications for the defense industry. Defense companies are now oriented to capture winner-take-all contracts for major new weapons systems, then wield a monopoly power based on rights to the underlying intellectual property to sustain the platform over a life cycle that can last a half century or longer.

But the success of the Digital Century Series approach hinges on Roper’s “digital trinity” vision. For such a dramatic departure from the traditional system, there seems little evidence that such an approach could be successful. Boeing embraced the digital engineering philosophy for the T-X program. In partnership with Saab, Boeing delivered the first T-7A prototypes within three years of launching the self-funded program during the competition for the contract. But the first production version of the T-7A has not yet flown, and the type is still four years away from the scheduled initial operational capability milestone.

By unveiling the flight demonstrator for the NGAD program now, Roper delivered a message to any critics of his approach in the industry, in Congress or, indeed, within the Air Force. As a digitally engineered aircraft fully reflecting the “digital trinity” philosophy, the NGAD flight demonstrator offered the proof his approach could deliver the next generation of combat aircraft faster and more cheaply than the traditional approach.

As proof, however, the newly revealed NGAD flight demonstrator suffers from some drawbacks. The knowledge of DARPA’s AII program dating back to fiscal 2015 suggests an NGAD prototype could have been developed and flown two or three years ago. All schedule, design and performance details of the flight demonstrator remain classified, so there is no way to verify how close the concept validated Roper’s vision for the NGAD program.

Although Roper declined to elaborate, the suggestion that the flight demonstrator has already “broken a lot of records” may be significant. In a traditional program, the assumption would be that he was referring to performance records, such as an average speed flown between two cities or the amount of time required to climb to a certain altitude. The spirit of Roper’s vision for NGAD suggests the broken records are more likely related to production schedules, development costs and upgrade options.

Even the term “flight demonstrator” appears intentionally vague. It has been loosely applied to full-scale, competitive prototypes, such as the Lockheed YF-22, but the term was also used for the F-16A Advanced Fighter Technology Integration aircraft that played a role as an early testbed in the Advanced Tactical Fighter and Joint Strike Fighter programs.

The budget documents released by the Air Force this year contained another surprise about the NGAD program. For the first time, the Air Force revealed that the Next-Generation Adaptive Propulsion (NGAP) program is scheduled to deliver a certified engine in fiscal 2025. Not all members of the NGAD family of systems may need an adaptive-cycle propulsion system, but the timing of the NGAP program suggests that an application for such an engine is likely to enter flight testing as early as fiscal 2026 and not merely as a flight demonstrator. At that point, Roper’s vision will be put to the next test.