The Army’s Doomed Plan for a Howitzer-Toting Helicopter Gunship
1970s studies were the beginning of the end for the aerial artillery concept
In 1972, Boeing sent a report to the U.S. Army Weapons Command on the possibility of a howitzer-armed helicopter gunship. Despite its positive conclusions, the study marked the beginning of the end of an era for Army aviation.
The Army’s main complaint at the time was that helicopters could still only fly howitzers from point A to point B. In 1970, the Army had outlined requirements for a helicopter with its own externally-mounted artillery piece.
At that point, the ground combat branch had been trying to develop “aerial artillery” for over a decade. The concept envisioned using armed helicopters just like regular howitzers or mortars. Except they could fly.
Early experiments simply treated gunships like self-propelled guns with excellent off-road abilities. Aircraft were expected to land before firing their weapons.
Eventually, the concept evolved to allow aerial artillery gunships to fly in and hit a single specific target. The helicopters would then leave the area immediately.
However, the aircraft would not take off until a request came in over the radio. The arrangement would be painfully slow in practice.
Boeing’s setup, a CH-47C helicopter with two XM-204 howitzers, would theoretically allow for one gun to be firing during virtually any phase of the process. The aircraft would only have to stop shooting while taking off and landing.
The experimental XM-204 howitzer was key to all of this. The new howitzer had a complex “soft recoil” system, where the barrel actually traveled forward when fired.
As a result, the XM-204 was both lighter than other 105-millimeter howitzers and more stable when firing. These characteristics offered a possible solution to a long-standing problem.
In the 1950s and ’60s, the Army tried firing big guns from helicopters numerous times. The recoil from traditional howitzers and recoilless rifles had been too much for the test aircraft to handle.
As far as Boeing was concerned, the XM-204 “reduced the recoil problem
to negligible proportions.” Boeing also manufactured the CH-47C, which it said was “more rugged” than earlier helicopters.
Still, the CH-47C needed modifications to withstand the force of firing the weapons in midair—and protect the pilots from the blast. Boeing proposed adding almost 200 pounds of reinforcements to the aircraft’s frame.
The weapon system itself was a Rube Goldberg machine weighing almost 11,000 pounds. One howitzer would be mounted on each side, along with a device to feed shells into it.
The ammunition feed system involved a complicated combination of pneumatic, electric and hydraulic power. A net hanging under the fuselage was supposed to catch the empty casings as they popped out.
After the aircraft landed, the howitzer on the left side could be detached for regular use. The one of the right was mounted on a special platform so it could be fired by the crew while still attached to the helicopter.
We don’t know if industry ever built a full size prototype, or even a mockup, of this howitzer-toting gunship. Boeing did, however, build a 1/11 scale model of the XM-204 to test the basic physics of the whole thing.
Whether Boeing’s design would have worked quickly became a moot point. By the early 1970s, the Army was rapidly losing interest in the idea of aerial artillery.
In 1973, the ground combat branch issued a new study of what it planned to do with its new attack helicopter battalions. The evaluators decided the final version of the aerial artillery concept was ill-suited to the Army’s needs.
Vietnam had showed that armed helicopters were distinct from howitzers. By the end of the decade, attack helicopters had come into their own.
Today, gunships operate independently of traditional artillery—and transports still schlep howitzers around the battlefield.