What we can learn from the B-21 Raider?

Luminact Insights by Andrew Skinner – 26 April 2022

What can we learn?

At some point this year we are likely to get the first ‘look’ at the new B-21 Raider, the latest US long range strategic bomber in development, and scheduled for introduction into service in the 2026-27 timeframe. In Australia some strategists have even argued a case for local acquisition of the aircraft to fill a long-range strike gap left since the retirement of the RAAF’s venerable F-111C in 2010.

Apart from being the most technologically advanced stealth aircraft in the world, the B-21 will also represent the state of the art in terms of design and development, and from that perspective we can take some lessons from it even before it’s born. The development of aircraft, much like submarines, is one of the most complex projects you can undertake, and with complexity comes technical risk.

Therefore, it’s worth exploring how the B-21 team within Northrop Grumman have ‘de-risked’ the development, what we can learn from those innovative processes, and how they might be used in a local, Australian, defence development context.

We know that technical risk is a key driver of acquisition project cost and schedule overruns, and that it’s more likely to be underestimated rather than overestimated in the early phases of the development lifecycle1. Similarly, it has often been said that ‘a dollar spent at the start of a project is worth ten at the end’ and as the ANAO put it “the more advanced the project the greater the costs of any corrective action”2.
It’s the combination of these two maxims that conspire to drive the high technical risk that has been the source of many historical capability delivery issues. But that’s hardly news to anyone who has worked in the defence industry, so the more important question is how to deal with them?

The Australian context

In the Australian context, the Loyal Wingman (recently designated the MQ-28 Ghost Bat) is the closest program we have to the B-21, however the lessons taken at a high level apply equally to all technically complex development endeavours. That list is somewhat larger and will likely include the future Australian nuclear-powered submarine (SSN), to be acquired within the construct of the AUKUS alliance.

So what can we learn from B-21 development, and how do we incorporate such lessons into Australian programs like the future nuclear submarines? Before we look at that, it’s worth canvassing some of the strategies the Northrop team has used to mitigate risk on the B-21.

Lessons from the B-21 development program

The development of the B-21 has, from the outset, been based around the concept of an open systems architecture3. This means that a common set of open standards and a data model will govern how all sensors and key technologies are integrated into the platform. The move to open architectures allows for much easier integration, evolution, and helps mitigate the risk of vendor lock-in and obsolescence throughout the life of the airframe. The decision to adopt an open architecture is key in terms of the ability to mitigate future technical risk, and is becoming more prevalent in military systems, and systems of systems.

In addition to the open architecture, the development of the Raider has heavily used digital design principles, not just for the structure, but also for the systems and software. Some of the innovative ways of using this technology include virtual reality (VR) environments where maintenance and logistical tasks can be simulated before anything is ever built, helping to design in user-centric and lower maintenance costs resulting in more efficient through-life support.

These VR – and augmented-reality (AR) – technologies leverage the 3D design data to enhance design reviews, ultimately leading to a more effective design, and mitigating the risk of late design changes to address short-falls that become evident during the verification and validation phase. As the sustainment or through life support costs for military hardware often far exceed the acquisition costs, it’s self-evident that a design favouring maintainability, commonality, and upgradeability is incredibly important.

The digital engineering and simulation tools that has become standard in industry are also improving, with the quality and accuracy of simulations becoming much closer to real life environments seen in trials and eventually in operation. A key source of technical risk is the maturation of a novel design, even one that is built on a pedigree of knowns (such as the B-2 airframe, sharing much with the newer B-21). With new geometry, systems and layouts throwing up new challenges, the B-21 design has been no exception – as one article referencing experience clearly states:

“…one of these surprises was discovered in 2018, when some thrust issues related to the bomber’s inlet and serpentine ducting were noticed and promptly solved, after some basic changes to the design.”4

Rendering of the B-21 Raider – Image: USAF

The difference in the B-21 and the lesson learned is that this ‘surprise’ was discovered in the development phase three years before the first flight is even scheduled. The ability to uncover these ‘unknown-unknowns’ early in a product development effort reduces the cost to change the design, reducing the overall risk to schedule and budget, and prevents re-work or modifications later. Advanced computer aided design (CAD) packages, and powerful simulation systems for structural and fluid-based analysis can be coupled with machine learning to iterate a design many times in a short timeframe, based on set parameters. The result of the artificial intelligence (AI) enabled design is greater optimisation, measured in lower cost per part, higher strength and lower mass and mean time between failures.

The verification of the B-21’s fuel system software is another example of how the program leverages digital design methods to de-risk the complex system development, and is explained concisely by Maj. Gen. Jason R. Armagost, Director of Strategic Plans, Programs, and Requirements, Headquarters Air Force Global Strike Command, quoted as saying:

“We are capitalizing on the revolution in digital—models-based systems engineering, open mission systems architecture software,” Armagost said.
“As an example, the software for the fuel control system, which is a pretty complex thing, is completely done on an aircraft that hasn’t even flown yet as a test article, because of how we’re able to do models-based systems engineering. And they actually built a fuel systems model and tested the software, and the software is ready to go.”5

The use of this kind of innovative approach is enabling the development of an incredibly complex machine to proceed at a comparatively fast pace. It also acknowledges that new capabilities, and particularly software-intensive ones, don’t follow a traditional waterfall design process. Rather, they evolve and iterate from an initial capability, adding functionality and improving performance as they mature, and continuing to do so throughout their life-of-type.

Never before has the delineation between acquisition and operational sustainment been so grey. The traditional approach of specify, design, test and build has morphed into a hybrid model, with significant influence from the technology sector and various agile ways of working that have become embraced in software development. This is a good thing, and we need to embrace it as well, even if it doesn’t always fit as neatly into less contemporary procurement templates.

Another important aspect of the B-21 development we can learn from is the judicious use of commercial and military off the shelf (COTS/MOTS) components. Whilst the B-21 will no doubt be at the cutting edge of technologies like stealth, there is no need to reinvent every wheel, a point illustrated in the choice of existing F-35 engines (Pratt & Whitney F135s) to power the B-21. Not only does this negate the need for a clean sheet design of a bespoke engine (noting there will no doubt need to be modifications for the B-21), but it also improves the economy of scale for the Joint Strike Fighter, potentially saving cost to maintain the engines as well.

We know from experience that the more bespoke requirements there are, the higher the technical risk, perhaps exponentially so. Therefore, it makes sense to concentrate design and development effort of the aspects of a new system required to meet a new capability need; not the ones that can be satisfied with existing, mature technologies. The focus of design effort and reduced complexity of this approach also de-risks development and achieves the best ‘bang for buck’ in the non-recurring engineering phase of the program.

This concept holds true at a higher echelon as well. The initial requirement for a long-range global strike capability was to be filled by the ‘Next Generation Bomber’ or NGB, however this was scrapped in 2009, following a decision by then US Secretary of Defence, Robert Gates, as NGB costs spiralled, and complexity soared. The NGB was subsequently replaced by the Long Range Strike – Bomber (LRS-B) program in 2011, with the differences described below in a congressional report:

[NGB] was far more ambitious and expensive, in part because of the assumption that the aircraft would operate nearly independently, which drove requirements up. NGB would have needed to be capable of its own intelligence and other functions that LRS-B will get through support from a network of already fielded Air Force platforms.”6

Artist Rendering of the B-21 at Ellsworth Air Base – Image: USAF

By concentrating on a simpler, more specific set of requirements, the B-21 is able to concentrate its design effort on a smaller number of very complex challenges and trade-offs, without the unnecessary burden of being all things to all people – a phenomenon that has afflicted F-35 development for decades as it tried to fill the role of at least three (very) different aircraft it replaced. The result is a platform that does one mission well, as opposed to a compromised design that does everything, but nothing well.

This outsourcing of some complexity is supported by one of the key characteristics of contemporary defence platforms; that is their connectivity to a wider network of systems and sensors, sharing real time intelligence and data to enable a common, enhanced operational picture. This is a trend being more and more important, and on a network level, each platform acts as a ‘node’ – something that is acknowledged explicitly in the B-21 program:

“Air Force officials have emphasized that B-21 is part of a family of systems, implying that it is the node of a larger, distributed network of sensors and communications, not all of which may have been publicly disclosed. Connectivity with this family of systems has been included in the B-21 design from the start…”6

Be it an advanced stealth aircraft, a military vehicle, or even a solider operating on the battlefield, connectivity is key, and interoperability between systems and platforms is paramount to enable it. This requirement needs to be acknowledged and built into the design from the start; not shoe-horned in later at greater cost.

How can these be applied locally?

On the back of the AUKUS announcement, speculation about a potential Australian acquisition of the B-21 arose7. This would potentially fill a gap left by the F-111 and not sufficiently plugged with either Super Hornets or F-35s, for a longer-range strike capability to defend our norther approaches.

The argument being that if the US is willing to share nuclear submarine technology with us, why not stealth bombers as well? Whilst the numbers would be lower in comparison to the US, an increased in total airframes would offer both countries with lower unit acquisition and through life support costs.

Adding weight to the argument for Australian B-21s is the possibility of air teaming with the MQ-28 Ghost Bats8, which could accompany the bombers into enemy territory, creating an unmanned tactical advantage, and leveraging the advanced networking and sensor fusion capabilities.

But the lessons of the B-21 are not limited to bomber aircraft, they can be applied to any complex defence capability or system. For example, modern military vehicles are more and more seen as platforms for other systems, operating in a complicated and contested battlespace, and part of a wider network that shares real-time data to establish a common operational picture. The development of future vehicles will also leverage open architectures, and use common data models, allowing for them to be easily upgraded, and networked into a joint force comprised of ground, air and maritime forces all working together.

The use of agile ways of working, and iterative or spiral design models are also relevant, especially as we see increasingly software-centric systems, such a battle management and electronic warfare systems.

If the development of the Raider teaches us anything, it’s that we must embrace contemporary ways of working, adopt more digital design practices, and with them the project and procurement frameworks that support them must evolve too. Defence as an industry can be slow to adopt sometimes, but it must. We can learn a lot from Silicon Valley in terms of how to iterate and be Agile in product development. Similarly, the aerospace and automotive sectors show how the digital ecosystems can be expanded throughout manufacturing and into support systems.

Innovation waits for no industry, and as we move into more uncertain and geopolitically unstable times, now more than ever we should ask what can be done better, faster, and for less? Asking these questions, and more importantly, implementing what we learn from their answers, will take some measure of intellectual curiosity combined with the courage required for change. We need to look outside the box, innovate, and evolve – in the words of William James:

“Genius, in truth, means little more than the faculty of perceiving in an unhabitual way”

About the Author

Andrew Skinner is the co-founder and director of Luminact Pty Ltd, a professional services and engineering company based in Melbourne, Australia. Andrew holds an honours degree in mechanical engineering, as well as a master’s degree in project management. He has worked extensively both below the line in large prime defence contractors, as well as above the line in consulting roles within the Department of Defence.

Andrew is the author of a thesis titled Small to Medium Enterprise Risk Management Practices in the Australian Defence Industry, which has been adapted to a chapter featured in the book Perspectives in Project Management (Chapter 10), published by Cambridge Scholars Publishing.
Andrew is a registered and charted engineer, and member of Engineers Australia and member of the Australian Institute of Company Directors.


  1. Costin, A. A. (1980). What makes large projects go wrong (and some suggestions on what to do about it) Project Management Quarterly, 11(1), 28–30.
  2. Auditor-General Report No.31 2018–19, Defence’s Management of its Projects of Concern, paragraph 3.6
  3. https://www.reuters.com/article/us-lockkeed-fighter-upgrades-idUSKCN0WP2XB
  4. https://theaviationist.com/2021/01/17/second-b-21-raider-under-construction-as-the-first-one-approaches-roll-out-in-early-2022/
  5. https://www.sandboxx.us/blog/the-air-force-has-6-b-21-raiders-in-production-1-in-ground-testing/
  6. Congressional Research Report, Air Force B-21 Raider Long-Range Strike Bomber, September 22, 2021
  7. https://www.aspistrategist.org.au/getting-the-most-out-of-aukus-could-require-plan-b-21/
  8. https://www.flightglobal.com/military-uavs/us-air-force-commits-to-fielding-loyal-wingman-uavs/146802.article

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