Gunning for Missiles

By Kenneth Kesner

When not in flight, airplanes are basically sitting ducks. Adversaries are developing new ways to strike our planes while they’re still on the ground, targeting them with masses of cruise missiles and unmanned aircraft systems (UASs). Soon, the most dangerous place for planes and crews may be at an airbase as they prepare for their next missions.

Sophisticated interceptor missile systems are already effective shields against the fewer supersonic and hypersonic threats. But commanders could never put enough of the complex, costly interceptors in the air to counter swarms of slower, cheaper cruise missiles and drones.

To protect aircraft, ships, and other assets against this growing threat, Northrop Grumman is developing Cannon-Based Air Defense (CBAD), which loads Bushmaster® Chain Guns® and medium- and large-caliber weapons with our innovative guided ammunition.

“We can effectively use cannons with advanced ammunition to protect bases, forces and assets by shooting down those threats.” said Ryan Carlson, chief engineer of CBAD for Northrop Grumman. “We are combatting mass attacks with economics and resilience.”

How it Works

Classic anti-aircraft guns use high rates of fire to throw up a “wall of lead” as threats near the target. Those smaller-caliber weapons are still effective for close-in dangers. But thousands of bullets end up landing somewhere downrange, and the guns don’t have the reach and punch needed for cruise missile defenses.

The CBAD solution loads existing medium- and large-caliber cannons with new ammunition developed by Northrop Grumman. When a round is fired, guidance sensors activate and guide the ammunition toward the target. Each round also includes a proximity fuze, a forward-looking sensor that “sees” the incoming threat. When close enough to the target, the fuze detonates, directing lethal fragments of the warhead into the target to destroy it. 

“CBAD drastically decreases the number of rounds that must be fired to hit the target,” Carlson said. “With cannon air defense we’re not firing thousands of rounds per minute. We’re executing very specific fire salvos – handfuls of rounds – at intended targets with extreme precision.”

Hitting the Numbers

Though packed with advanced technology that must survive being shot out of a cannon, a CBAD round will be far less expensive than an interceptor missile. The cost of fielding a CBAD-enabled medium-caliber cannon battery is projected to be half that of a missile battery. And the cost-per-kill or intercept is 99.5 percent less than with an interceptor missile.

“It gives our customers a much bigger ready magazine to defend themselves against air threats,” said Aaron Martin, director of strategy for Future Concepts, Northrop Grumman. “A truck with a gun can carry a lot more bullets than a missile battery can carry interceptor missiles. Ships at sea could carry more CBAD rounds than self-defense interceptors. CBAD will boast an effective magazine 15 times larger than missile systems.”

That price and size advantage is transformational, giving air defenders more mobility and more shots. Instead of four or six missiles in a launcher, a cannon and hundreds of rounds can roll right off a transport aircraft to quickly set up base defenses. And the cannons can still be used for traditional attacks, using normal ammunition or the advanced CBAD ammunition for increased precision.

What’s Next?

CBAD builds on Northrop Grumman’s experience in smart munitions and command-guided ammunition, such as the Precision Guidance Kit (PGK) that retrofits existing rounds to increase accuracy and capability. PGK and proximity rounds for Counter-UAS defenses have already been fielded or field-tested but, for now, CBAD is being fired in a simulated environment.

“We’re modeling and evaluating which calibers we should use and doing a lot of mission and campaign-level analyses,” Carlson said. “We are also looking at what command-and-control architecture makes the most sense and intend to integrate CBAD into battle managers like Northrop Grumman’s Integrated Battle Command System (IBCS) and Forward Area Air Defense Command and Control (FAAD-C2).”

A demonstration of initial CBAD capability may come within a year, and production could quickly follow. In just a few years there could be a variety of gun kits and rounds available. Eventually CBAD might also defend against faster threats.

“PGK was the first guided projectile that actually works in a spinning environment,” said Rollie Dohrn, a Northrop Grumman Fellow and an architect of the CBAD concept. “CBAD requires survivable electronics, generating your own power, and having people who understand the physics. We have those things, solved those issues, and we’re able to deliver guided projectiles at a very low cost.

“There is a significant threat out there, as we all know – we all watch the news,” Dohrn said. “We believe we have something here that can be affordably delivered, that changes the balance to give us the advantage we need to protect our people.”