More B-21s? Why the U.S. Still Needs to "Mass" Stealth Airpower

by Kris Osborn, Warrior

Militaries around the globe are doubtless aware that new generations of technology change maneuver formations, tactics and concepts of operation, yet these paradigm-changing systems also need to exist at “scale.”  There is still a need to “mass” force and generate sustained, large-scale “firepower.” New platforms such as the U.S. Air Force’s B-21 can change the balance of power between countries and help ensure air superiority, yet accomplishing this task depends upon “scale” as well, as B-21s  must exist in large enough numbers to propel and sustain a large-scale war effort. 

Operation Epic Fury further highlights the need to “scale” and “mass” power from the air, a current reality which may influence ongoing decisions to flex production and “increase” the planned size of the B-21 fleet.  While Iran’s Russian-built air defenses may  be destroyed, the country has a history of holding aircraft at risk to some degree. Of course Russia and China are also known to operate advanced air defenses, and any large-scale operation would likely require a large fleet of B-21s. 

Why More B-21s?

Alongside whatever stealth technologies the aircraft contains, attributes which likely include radar absorbent materials, embedded antennae, and acoustic signature management, the B-21 is reported to contain unprecedented advantages in the area of weaponry, sensing, and computing

Senior Air Force weapons developers have also been clear that the B-21 will operate with and likely control unmanned systems as “loyal wingmen” in position to advance forward sensing, reconnaissance and targeting.

When it comes to threat information, Austin also made this clear that the bomber will be “multifunctional,” meaning it will perform a wide range of missions beyond simply “attacking” or dropping bombs.

Ground-based air defense radar technologies have become increasingly sensitive and precise, longer-range, better networked through digital processing and capable of operating on a wider range of frequencies. These technologies, as exhibited by Russian S-400 and Chinese HQ-9 air defenses, have vastly increased the risk to stealth platforms in recent years and inspired a need for a new generation of low-observable technology.

Need for Stealth

Russian media claims its new S-400 and S-500 Surface-to-Air-Missiles are able to track and shoot down even “stealth” platforms, an ambitious claim which does not seem to have been verified or corroborated in any substantial way. What is known, however, is that new Russian-built air defenses are networked to one another with much faster computer processing, able to see or detect targets at much greater ranges and capable of operating on a wider range of frequencies.

However, this does not mean that these systems can actually succeed in “hitting” or engaging a stealth bomber, especially an advanced one like the B-21 is reported to be. A given radar or air defense system may succeed in determining that something is “there” or in a general area of operations using low-frequency surveillance radar, however that does not mean the system can actually establish a target track on a moving stealth bomber and actually “destroy” a stealthy platform. This requires a much greater level of precision, track loop fire control and image fidelity to accomplish, and it appears there are likely many “undisclosed” stealth properties built into the B-21.

New Generation of Stealth

Clearly many of its stealth properties and advanced technologies will not be available for public discussion given the secret nature of the program, yet the recent photo does offer an as-of-yet unprecedented side-view of the new aircraft. A quick look at the external configuration would seem to suggest that indeed the aircraft may contain massive “leaps-forward” in the realm of stealth technology.

A key element of the aircraft might jump out at observers, as its “inlets” are smoothly woven into the rounded fuselage-wing-body structure in a way that is flatter, more horizontal, less angular and more seamless than its B-2 predecessor. Simply put it is less vertical and flatter in its integration with the body of the aircraft, something of great significance because any kind of protruding or vertical structure, however rounded or “blended” into the fuselage of the aircraft, introduces the prospect of an increased radar signature. Vertical structures and sharp angles, in pure aerodynamic terms, create shapes, angles and contours electromagnetic radar “pings” are able to bounce off and generate a return rendering. A completely flat aircraft, by contrast, offers few if any protruding structures or angles off of which radar pings traveling at the speed of light can bounce off. Radar and air defense systems, of course, generate a picture or rendering of a threat object by virtue of bouncing electromagnetic signals off of a structure and analyze the return, thus creating a rendering or image of some kind of the size, shape or even speed of the object. This is why the F-35 and F-22, while quite stealthy and believed to be effective against many air defense systems, are ultimately less stealthy than a fully horizontal blended wing-body aircraft such as the B-2 or B-21.

This makes sense, as a B-21 is not designed to “dogfight” or vector in the air per se but instead actualize “broadband” stealth and “penetrate” defended enemy airspace without an enemy even knowing it is “there” at all. B-2 and B-21 bombers therefore, are said to present as a “bird” or small airborne animal to enemy radar, given the absence of detectable “shapes,” “structures,” and angles contained on the fuselage. Vertical structures, such as tails and fins for example, decrease stealth properties to some extent while simultaneously enabling maneuver, speed and air-to-air combat. At the same time, an ability to maneuver at high speeds and “vector” in the air are things which in and of themselves are stealth enhancing, radar signature reducing attributes, something capable of presenting challenges to ground-based radar seeking to establish a “target lock” or “track” on a threat object.

The intent of broadband stealth is to be entirely “stealth,” meaning the aircraft can elude both lower-frequency “surveillance” radar able to detect something is “there,” and higher frequency engagement radar able to establish a track and lock on the target and actually “engage” and destroy the aircraft.

Kris Osborn is the President of Warrior Maven – Center for Military Modernization. Osborn previously served at the Pentagon as a highly qualified expert in 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 Masters Degree in Comparative Literature from Columbia University