By Kris Osborn - Warrior Maven

(Washington, D.C.) A new generation of stealth technology, unprecedented sensing and computing, long-range precision cruise missiles and air dropped bombs and an ability to strike undetected against the most advanced air defenses in the world .. are all potential attributes of the now-on-the-way Air Force B-21 bomber.

The new platform, which will form the bulk of the U.S. Air Force’s future bomber force cannot come soon enough. Testing, assessments and preparations have for quite some time been underway at Edwards Air Force Base, Calif., in anticipation of some of the aircraft’s first test flights. At least two B-21s are reported to have been built or under construction.

The Air Force-Northrop Grumman program has gone better than expected, inspiring many service leaders and members of Congress to not only push for an accelerated delivery and production of the new bomber but also massively increase the planned number of bombers.

U.S. B-21 Bomber: Urgently Needed

The need for the new bomber is quite pressing for many respects, the principal reasons being the advanced technological capacity of enemy air defenses and the age of the current bomber fleet. Not only that, senior U.S. Air Force leaders have for many years now expressed grave concern about a massive “bomber deficit” in the force, a circumstance putting the U.S. at risk. There simply have not been enough bombers, say Air Force leaders. Bomber Task Forces, are being stepped up around the world as increasingly vital to deterrence operations in the current threat environment. B-1 bombers are arriving in India and Norway to beef up patrols in the Indo Pacific as well as the Arctic

In addition, B-2 bombers arrivals in Portugal plan to contribute to increased bomber patrols on the European continent. Moreover, B-52 bombers are increasingly being armed with newer, more capable weapons to keep potential adversaries at risk. Simply put, there does seem to be an emerging consensus among Pentagon leaders that more bombers and more Bomber Task Force patrols are needed.

“We need North of 220 bombers,” Gen. Tim Ray, Commander, Air Force Global Strike Command, told reporters at the 2021 Air Force Association Symposium.

The path toward this number, Ray explained, is varied, challenged and complex as it involves a crucial balancing act between the introduction of new platforms such as the B-21 alongside concurrent efforts to extend the effective operational life of several upgraded existing weapons systems.

“The road map is well thought out. We need more B-21 and also need to make sure the B-2 is viable until the B-21 comes in sufficient numbers. We are also re-engining the B-52 and bringing on new radar and cruise missiles, a process being expedited through digital prototyping,” Ray said.

U.S. B-2 Bombers  

Equally key variables include the age and size of the B-2 fleet. Many remember that plans for the B-2 bomber were abruptly truncated years ago, resulting in a small force size of 20 B-2s. Also, after emerging during the Cold War years, the B-21 is now 30-years old. 

While looking in retrospect at the exact reasons for the B-2 production stop may be difficult three decades later, it may have been due in large measure to decision makers operating with a short-term threat outlook, thinking that the collapse of the former Soviet Union greatly reduced the need for stealthy B-2 bombers. 

Years later, the opposite became true given the resurgence of a Russian threat and emerging Chinese threat. 

Now it should be said that the B-2 bomber is now quite different than it was years ago, and is still being upgraded. The modern B-2 is not only getting new Defensive Management Sensors enabling it to find and therefore elude next-generation air defenses, but is also receiving 1,000-fold improved computer processing and upgraded weapons.

U.S. Air Force B-2 Spirit Bomber

Northrop Grumman B-2

U.S. B-52s

Then there is the question of the B-52, yet another older airplane sustained into the modern era with a massive amount of unanticipated upgrades to include an internal weapons bay, new communications system and a re-engining, not to mention an entirely new weapons arsenal.

What all of this amounts to is that, despite the fact that several legacy bombers have been upgraded to remain viable, relevant and lethal in a new threat environment, the need for an entirely new platform cannot be understated.

B-52

Boeing B-52

Russian PAK DA Stealth Bomber & Chinese H-20  

The need for the B-21 is also naturally heightened by the fast emergence of the Chinese H-20 and the Russian PAK DA stealth bomber

The first model of Russia’s new PAK DA stealth bomber is expected to be completed at some point this year, an anticipated development expected to lead toward additional prototypes and testing over the next several years.

Russian PAK DA Stealth Bomber 

This timeframe, should it come to fruition, aligns the emergence of the PAK DA with the U.S. B-21 which is also being completed and prepared for its first test flights and early operational assessments. Can it rival the U.S. B-21? Or the Chinese H-20? Those may not be answerable questions at the moment, yet there do appear to be some similarities between the PAK DA and the U.S. B-2 or even B-21. 

Of course, the PAK DA’s horizontal blended wing-body shape is to be expected for these kinds of stealthy platforms, yet available renderings of the PAK DA show rectangular-shaped inlets aligned with or somewhat parallel to the top of the fuselage.

Russia PAK DA Stealth Bomber

PAK DA

Looking at the back of the B-21 and the PAK DA on available images show some potential design similarities as neither model has anything that looks like a protruding external exhaust or visible area from which heat can dissipate. Has one or both of these stealth bombers been engineered with any kind of cooling technology or exhaust management system to manage thermal signature.

While little or nothing is known about the B-21 or the PAK DA in some respects, both appear slated to fire air-launched cruise missiles, weapons with clearly enable a wider range of attack options. 

According to a TASS report from last year. “The PAK DA is expected to deploy Kh-102 nuclear-tipped stealthy cruise missiles, and a number of newer hypersonic designs including derivatives of the Kh-47M2,” the TASS story writes. 

This brings up yet another parallel, as the U.S. B-21 is slated to fly armed with the new Long Range Stand-off weapon, a nuclear-capable, air launched cruise missile intended to hold targets at risk at greater standoff ranges to reduce risk of destruction by enemy air defenses.

As for fuselage shape, the U.S. B-21 does appear to have more rounded and indented inlets when compared with the B-2 or the Russian PAK DA. The B-2 has small, protruding rectangular structures on top of the fuselage for inlets, and the PAK DA looks like it has rectangular inlet built directly into the front end of the wing. 

The new B-21 bomber does appear to have a smaller or more blended incline between the fuselage and wings. Granted, protruding configurations of any kind, if even rounded or covered in a radar-absorbing exterior, are more likely to generate some kind of radar “ping” return from ground-based air defense systems. Vertical structures and uneven contours are therefore more likely to generate radar returns, as electromagnetic “pings” will discern the differences in shape.

The concept with these kinds of stealth bombers is to not only elude surveillance radar systems but also evade higher-frequency, more precise engagement radar, ensuring that the platform will not only be difficult or impossible to hit, but also remain completely undetected. The idea is for adversaries to “not even know something is there.”

Recommended Articles

 A stealthy platform can succeed by appearing as a “bird” or “insect” to enemy radar, yet the precise measure of performance or efficacy against advanced air defenses may not be well known.

Chinese H-20 

China’s emerging “B-2 copycat” H-20 stealth bomber is expected to introduce an entirely new sphere of threat dynamics to the U.S., as it further cements China’s nuclear triad and massively extends its nuclear attack range to include major portions of the continental U.S.

The new H-20 bomber reportedly has a range of up to 7,500 miles according to the UK’s Sun, making it possible for a single sortie from mainland China to reach targets over the U.S. without needing to refuel. 

H-20 Bomber

An artist’s impression of what the H-20 may look like

This is a substantial development, as refuelers can of course help reveal the position or presence of a stealth bomber, and uninterrupted stealth bomber attack missions with that kind of reach raise the possibility of undetected nuclear attack upon major U.S. targets.

An essay in the Asia Times states the following: “According to the South China Morning Post, which cited a London-based Royal United Services Institute for Defence and Security Studies report, the state-of-the-art H-20 can carry a massive weapons payload of 45 tonnes and fly great distances without mid-air refuelling.”

While the exact composition of its stealth properties or radar-signature reducing technologies may not be fully known, available photos and renderings reveal an aircraft which one could say seems in some respects to be indistinguishable from a U.S. B-2. 

There is nothing surprising about this, given China’s well known and well-documented habit of stealing or copying U.S. weapons designs, it seems particularly apparent in the case of the H-20. It features a similar rounded upper fuselage, blended wing body, curved upper air inlets and essentially no vertical structures. There appears to be a fair amount of evidence, simply available to the naked eye, to demonstrate China’s overt “copycat” maneuver.

The B-2 is known for its long-endurance flights as well; during Operation Enduring Freedom in the opening days of the Afghan war, U.S. B-2 flew 44-hour missions from Whiteman AFB, Miss., to Diego Garcia, a small island off of the Indian coastline. From there, B-2s flew bombing missions over Afghanistan in support of U.S. ground forces.While this mission likely required refueling, it does speak to the merits and tactical advantages of long-endurance bombing.

The Pentagon's "2019 China Military Power Report" specifies that the new H-20 will likely have a range of “at least 8,500km” and “employ both conventional and nuclear weaponry.”

The report cites 2016 public comments from People’s Liberation Army Air Force Commander General Ma Xiaotian announcing the development of the H-20, and saying the weapon could emerge some time in the next decades. Well, sure enough, the next decade is here and early renderings appear to parallel some of Xiaotian’s comments about Chinese intentions for the bomber. According to the Pentagon’s China report, he said the H-20 will “employ 5th generation technologies.”

An ability to engineer and deliver fifth-generation systems into the bomber may remain to be seen to some extent, as much is still unknown, yet the Chinese have already engineered several potentially fifth-generation aircraft with the J-20 and J-31.

J-20

J-20 displaying weapon bays, missiles and avionics

At the very least, the exterior does appear to be stealthy; it looks like it has an embedded engine, blended wing body, absence of vertical structures and engine air ducts woven into the frame on top of the fuselage. The Pentagon report observes that “a possible H-20 prototype depicted a flying wing airframe akin to the B-2 bomber and X-47B stealth unmanned combat aerial vehicle.”

A reported range of 8,500 kilometers appears slightly less than a B-2 bomber’s range of more than 6,700 miles, Pentagon reports have raised concerns that the Chinese “may also be developing a refuelable bomber that could “reach initial operating capability before the long-range bomber.”

It is also not clear if the H-20 could succeed in rivaling a U.S. B-2 given the extent of upgrades and adaptations the Air Force has undertaken with the 1980s platform. 

U.S. B-2 & B-21

The B-2 will soon have air-defense evading Defensive Management Systems sensors, a thousand-fold faster computer processor and weapons upgrades to include an ability to drop the B-61 Mod12 nuclear bomb

The B-2, which is expected to fly alongside the new B-21 until sufficient numbers of B-21s arrive, will be a much different plane in a few years when compared to its 1980s origins, as the Pentagon hopes to ensure the platform remains relevant and powerful for many years into the future.

As for its ability to compete with a B-2 or B-21, there may simply be too many unknowns. However, a few things do come to mind. 

The B-21 airframe, for instance, appears to have little or almost no external exhaust pipes, raising the question as to whether it incorporates new thermal management or heat dispersion technologies. A key goal, when it comes to designing stealth bomber airframes, is to work toward having it mirror or align with the surrounding temperature of the atmosphere so as to be less detectable to thermal sensors. 

Also, while much of the B-21’s details remain “black” for understandable reasons, senior Air Force leaders have said the platform contains a new generation of stealth technologies and can “hold any target at risk in the world at any time.”

This indicates that there may be a high measure of confidence that the new B-21 will be able to succeed against the most advanced current and anticipated future air defense systems. 

An ability to elude both surveillance and engagement radar in a modern technical environment would be quite an accomplishment, as advanced Russian air defenses such as the S-400 and S-500 contain a new generation of technologies. 

S-500 Air Defense System

Russia says it had successfully test-fired its new S-500 air defence missile systems at a southern training range and hit a high-speed ballistic target.

Not only do they use digital networking to connect radar nodes, rely upon faster computer processing and track aircraft on a wider sphere of frequencies, but they also claim to be able to detect “stealth” to a large degree. This may remain as of yet unproven, as it is something touted by the Russian media, yet it has inspired U.S. weapons developers so seek newer paradigms for stealth technology. 

Also, the sophistication of these advanced air defenses may be one reason why, at least when it comes to stealth fighters, senior Air Force weapons developers describe stealth as merely “one arrow in a quiver” of methods to evade and destroy enemy air defenses. 

Nonetheless, there is no available evidence to suggest a new B-21 would have any difficulty against the most advanced air defenses; debates along these lines are likely to persist for years, at least until much more is known about the B-21. Air Force officials say the B-21 will be virtually “undetectable,” something which may very well be true.

-- Kris Osborn is the Managing Editor of Warrior Maven and The Defense Editor of The National Interest --

Kris Osborn is the defense editor for the National Interest. Osborn previously served at the Pentagon as a Highly Qualified Expert with the Office of the Assistant Secretary of the Army—Acquisition, Logistics & Technology. Osborn has also worked as an anchor and on-air military specialist at national TV networks. He has appeared as a guest military expert on Fox News, MSNBC, The Military Channel, and The History Channel. He also has a Master’s Degree in Comparative Literature from Columbia University.