The U.S. Army Wants to Blast Drones Out of the Sky With a Huge Chain Gun
Cannon spews guided ammunition to hit low-altitude targets
by JOSEPH TREVITHICK
Just a few years ago, the United States had a near-monopoly on drones. No longer. As the tiny, unmanned aerial vehicles become ubiquitous on battlefields around the world, the U.S. Army is studying how to shoot them down with a chain gun.
Since at least 2007, the ground combat branch has been working on the so-called Extended Area Protection and Survivability program, or EAPS. Originally expected to just shoot down incoming rockets or mortar bombs, killing small aircraft is now a key part of the project.
Drones have “exploded,” Manfredi Luciano, an EAPS project officer, explained to Army Technology magazine. “It has kind of almost sneaked up on people.”
“It’s almost more important than the counter-RAM threat,” Luciano added, using the acronym for rockets, artillery and mortars.
These threats and the EAPS program both fit in with the Army’s new focus on countering so-called “hybrid” warfare. Highlighted in the Pentagon’s 2015 National Military Strategy, this type of war arises from the intersection of conventional military forces, insurgents and terrorists; and less traditional factors such as economic pressure and media campaigns.
The strategy singles out drones as a particularly tricky problem. Unmanned planes are among “technologies designed to counter U.S. military advantages,” according to the official policy.
Since this trend isn’t likely to change any time soon, troops are going to need something to deal with future enemy drones.
To meet the EAPS requirements, engineers settled on a large cannon firing special guided ammunition at relatively short ranges. This is a more practical way to shoot down low-altitude drones, compared to missiles, which need a long lead time to successfully hit their targets.
“The gun system has certain logistics advantages,” Luciano explained. The current prototype uses a readily available 50-millimeter Orbital ATK Bushmaster III cannon. Denmark and the Netherlands already have CV-90 armored vehicles in service toting the 35-millimeter variant of this weapon.
Powered by an electric motor, the gun can fire up to 200 rounds every minute — or single shots if required. The design is basically a larger version of the 25-millimeter Bushmaster used the M-2 Bradley armored fighting vehicle.
Neither Orbital ATK nor the Army have offered any specific details on how far away the gun can hit and kill its targets. Engineers described the weapon’s “battlespace” as reaching out to just over a mile, according to one 2011 briefing.
On the ground, a radar points the guns in the right direction. Then once the shells leave the barrel, a computer beams guidance instructions, telling them where to go and changing their course mid-flight. Once near the target, the shells explode into a cloud of metal shrapnel.
If it works … no more drone.
The Army’s plan is to eventually mount the weapons and gear onto a single truck. Four years ago, the ground combat branch considered strapping everything to a Stryker eight-wheeled armored personnel carrier.
But at its most basic, EAPS isn’t anything particularly new. In the 1950s, the Army designed the first ever radar-directed anti-aircraft gun, the M-51 Skysweeper. In 2005, the Army — in partnership with the U.S. Navy — sent a more advanced gun system to Iraq to protect bases from rocket and mortar attacks. This consisted of Phalanx Close-In Weapons Systems and accompanying fire control radars.
Also known as CIWS, the Phalanx is principally deployed on warships as a desperate, last-ditch defense against missiles. After a successful trip to the Middle East, the Army experimented with the idea of putting this weapon on a large truck.
But combining guided shells with a large gun puts a new twist on this old idea. And unlike most guided projectiles, these shells get their orders from the equipment on the ground. “All the ‘smarts’ are basically done on the ground,” Luciano said. “The radio frequency sends the information up to the round.”
Four months ago, the Army says a 50-millimeter test gun knocked out its first drone with a single shot.
We don’t know what type of pilotless plane served as the target, but unmanned aircraft of all shapes and sizes are potential and widespread threats. The Pentagon’s definition of “hybrid” warfare also pretty much describe tactics in development right now in Russia and China.
The Kremlin’s Orlan-10 drones are flying over eastern Ukraine, helping out separatists fighting Kiev’s troops. Flying over that battlefield at high altitudes is extremely dangerous due to proliferation of anti-aircraft missiles. But at low altitudes, drones rule the skies.
In May 2015, Chinese plane spotters snapped pictures of the new Divine Eagle drone. Beijing reportedly use this massive twin-bodied aircraft to scout for stealthy planes at high altitudes — probably out of range from a short-range gun like EAPS.
With limited resources, smaller nations are making or developing drones, too. Many unmanned aircraft types can be cheaper to build and operate — and require less extensive pilot training — than high performance military jets.
After years of American strikes in its territory, Pakistan claims to have its own armed type called Burraq—after a beast mentioned in the Koran. Iran regularly shows off numerous drones, including some that Tehran claims can destroy enemy planes.
Terrorist groups have also taken to the skies with pilotless craft. Tehran has sent some of their military types to Lebanon’s Hezbollah. Islamic State bought toy-like quadcopters.
For the most part, these are tiny, unarmed spy machines. But they can be dangerous in their own way. On July 17, 2015, officials briefly called off water-bombing planes and choppers fighting a brushfire in California’s Cajon Pass because videographers had clogged the airspace with drones.
“It was the third time in recent weeks that firefighters were grounded because of drones,” the Los Angeles Times reported. “The devices could collide with aircraft that fly at low altitudes.”
So while quadcopters lack the range and other capabilities of military drones, terrorists could just as easily use one to disrupt aircraft landing or taking off at airports or military bases. And while American authorities debate the legal implications, an amateur flyer in Connecticut showed an individual can rig up their own gun-toting version with relatively little effort.
Army engineers hope their gun truck will be able to protect American troops from all of these pilotless enemies, big and small.
