Lockheed Martin photo

F-104 Starfighters

The Air Force’s new approach to fighter development harkens back to the Cold War’s Century Series, which created a half-dozen jet designs in less than a decade to gain an edge over improving Soviet aircraft. The new “Digital Century Series,” brainchild of wunderkind acquisition chief Will Roper, aims to use modular “plug and play” hardware and software, computer-aided design, and virtual modeling & simulation to rapidly field new fighter variants, with less of the cumbersome integration and real-world testing that bog down modern R&D.

Will Roper

Roper is right that that the US military needs to accelerate fighter development. In the time it took the Pentagon to fully field the F-22 Raptor, Russian air defenses advanced six generations, from the short-range early models of the S-300 to the latest S-500 that can reportedly shoot down stealth aircraft over 280 miles away. Roper is also right that the DoD needs to innovate through design, speed up introduction of new technology, and increase competition in aircraft development. Pursuing these goals through manned multi-mission fighters, however, is more likely to undermine U.S. airpower than elevate it.

The original Century Series was intended to master the critical emerging technologies of its time: revolutionary improvements in hardware for jet propulsion and supersonic flight, which were central to the Cold War competition between nuclear-armed bombers and defending interceptors. With the advent of long-range missiles, space-based targeting, and cyber operations, manned fighters no longer hold that same strategic importance. The equivalent technologies today might be unmanned aircraft, man-machine teaming, and command-and-control networks to reorganize forces on the fly in real-time. Instead of using the Digital Century Series to marginally improve well-understood technologies for manned aircraft, it should pursue unmanned aircraft designs to master these new advancements.

Wikimedia Commons

F-100 Super Sabre firing rockets in Vietnam

The worst of all possible force designs

Digital Century Series fighters are intended to have brief production runs and short service lives to enable rapid learning, a cycle in which the experience with each variant leads quickly to improvements in the next. By modularizing systems and containerizing software, the idea is to change only a few features in each new variant, while maintaining much of the aircraft common with its predecessors and successors. This approach may be attractive to engineers and weapons buyers, but it will undermine the emerging combat concepts called Joint All-Domain Operations, which aims to create adaptable options for friendly forces and strategic dilemmas for our adversaries.

Unlike a ship or a widebody aircraft, manned fighters don’t have a lot of room for incorporating new capabilities. If the Century Series’ starting point is an aircraft like the F-35, the process of changing features would likely make each successive generation less multifunctional and more specialized. Unless new systems require very little space and power, the only way to fit them in will be to take some existing systems out. The alternative would be to redesign multiple parts of the aircraft simultaneously–an idea which goes against the program’s design ethos.

Wikimedia Commons

F-106 Delta Dart

It’s likely that all the aircraft in the Digital Century Series will share a common airframe, using modularity and containerization to enable easier and faster evolution between variants. But because modular components need to accommodate a range of potential configurations and must be relatively self-contained, they are necessarily less efficient in terms of space, weight, and power compared to fully-integrated systems. As a result, the new aircraft would probably not be able to incorporate all the mission functionality of today’s fighters.

Digital Century Series fighters will therefore be more specialized than their predecessors. That limits commanders’ options – unless the Air Force builds lots of different specialist aircraft, each optimized for a different mission.

With today’s force of multi-mission aircraft, a commander can always choose among different options, even if the range of those choices may be limited and predictable.  With the planned Digital Century Series approach, a future commander may have a few more aircraft, but maybe not enough of the right ones to achieve the mission, and almost certainly not enough to make a truly complicated tactical problem for the enemy.

This suggests there is a bimodal distribution of useful force designs. On one end is a small force of expensive multi-mission platforms, each of which works well in many situations but lacks flexibility and adaptability. At the other end is a large force of cheaper, more specialized units, which collectively can provide a wider range of options and impose more dilemmas on enemies. An effective military should include both kinds of forces.

The Digital Century Series will instead fall right in the middle with the worst combination of attributes: aircraft that are too expensive to buy in the large numbers required for adaptability and complexity, but too limited in their functionality to be effective as a small force. It’s worth remembering that the Air Force bought at least 800 copies of each of the original Century Series variants.

XQ-58A Valkyrie “loyal wingman” drone, built by Kratos for Air Force Research Lab

We need an unmanned Century Series

The Air Force could get the numbers it needs by shifting the Digital Century Series to unmanned aircraft. For example, the XQ-58 Valkyrie is expected to cost $2 million each, a fraction of even an inexpensive fighter like the T-7A Red Hawk trainer, about $20M, let alone a $100-million-plus F-35 or F-15EX. By focusing on unmanned aircraft, the Air Force would be more likely to achieve its goal of opening up aircraft competition to 10 or more U.S. companies, rather than the three or four that can realistically build manned fighters.

Unmanned platforms would make the most of the Digital Century Series approach by placing fewer design and testing constraints on developers. Unmanned vehicles would also enable the Digital Century Series to employ and mature technology for small batch manufacturing. Lying between artisanal prototyping and mass production, engineers using this technique construct a vehicle using off-the-shelf components that are integrated using middleware built from open source code or 3D printing. The resulting aircraft would contain a large portion of existing well-understood components, reducing test requirements and supply chain challenges. A manned aircraft would be less likely to harvest these benefits.

Boeing photo

Boeing MQ-25 Stingray prototype, an unmanned aerial refueling tanker

Unmanned aircraft are due for kind of revolutionary development represented by the Digital Century Series. Relegated to scout and attack missions in permissive environment, they are capable of more, as suggested by the new Air Force Skyborgunmanned wingman” and Navy MQ-25 Stingray refueling tanker. There is a wealth of unexplored operational concepts for unmanned systems including cooperative sensing and electronic attack, that aren’t suited to manned aircraft.

The Digital Century Series methodology has enormous value, and not just for aircraft. New classes of unmanned ships and robotic ground vehicles could also benefit from this approach, forming a force better suited to the emerging combat concept called Joint All-Domain Operations. But applying the Digital Century Series approach to the most expensive, constrained, and tightly-integrated platforms in the U.S. military is likely to kill the idea in its infancy. In a coming era of budget constraints, the U.S. military cannot afford to waste time or money on another failed attempt at disruptive innovation.

Bryan Clark is a Senior Fellow at the Hudson Institute and Director of the Hudson Center for Defense Concepts and Technology; Dan Patt is an Adjunct Fellow at the Hudson Institute.