by JOSEPH TREVITHICK

While a fixture on the modern battlefield, helicopters are especially vulnerable when hovering low to the ground and dropping off troops. For almost 60 years, the U.S. Army and other services have tried out different weapons to protect choppers as they land and take back off again.

Some of these ideas proved better than others. In November 1968, the Army’s Limited War Laboratory began work on a huge shotgun mounted on the front of helicopters, where it blasted out a wall of tiny bullets at anyone unlucky enough to be on the ground.

It didn’t work out. For one, American commanders in Vietnam—where the Viet Cong routinely ambushed helicopters as they descended—weren’t interested in a weapon that might kill as many friendly troops as enemy ones.

“This system will provide troop-carrying helicopters with an immediate, close-in … fire capability during landing and take-off in combat,” stated the Limited Warfare Lab’s progress reports.

At its core, the weapon had four clusters of .22-caliber barrels, each pre-loaded with a single cartridge. Every one of these XM-215 “Multiple Barrel Guns” had more than 300 separate barrels.

At the touch of a button, a crew member could fire more than a thousand rounds in 10 seconds in a 40-degree arc in front of the helicopter.

The whole system resembled a honeycomb. But this scattergun could also shoot its fearsome barrage at a slower pace, for up to 40 seconds of continuous fire.

The four “modules” attached to the front of a chopper. During tests, a UH-1D Huey helicopter served as the host.