"Afghan resistance forces, in conjunction with American Special Forces and supported by AC-130 gunships, have begun their push today toward…” This quotation could have come from any of a hundred news stories on the war that broke out after September 11. Occasionally one of the 24/7 news networks airs a film clip showing a large four-engine aircraft identified as an AC-130 in a left turn, long streams of flame coming out of guns extending from its side, looking for all the world like a sailing ship from the early 19th century firing broadside.
To most of the world, gunships, along with Airborne Warning and Control Systems (AWACS), precision-guided munitions, and aircraft carriers, have become the ubiquitous symbol of U.S. post-Vietnam military power. Only the gunship, however, is a uniquely American weapon, conceived by a handful of determined individuals in response to a specific combat problem. It evolved despite huge bureaucratic obstacles and intraservice fighting.
Side-firing gunships are “one of the most successful developments arising from our experience in Southeast Asia,” General John Ryan, then Air Force chief of staff, concluded at the end of the Vietnam War. Colonel Ron Terry, a former fighter pilot who led the charge in the early 1960s to develop the AC-47 and its successors, the AC-130 and AC-119, points out today that the gunships have been one of the most “effective things the United States has had for engagements in Panama, Grenada, and Afghanistan.”
The idea of a side-firing aircraft has a long history. The U.S. Army Air Corps mounted a .30-caliber machine gun on a DH-4 mailplane in the 1920s and the French mounted a side-firing 75-mm artillery piece on a bomber, but the side-firing weapon did not seem to offer any advantages over conventional mounts—it was an answer without a question. As Terry puts it, most combat planners felt that “military aircraft should dive at the ground, drop bombs, shoot guns. They don’t fly in circles.”
The first person to come up with the problem the side-firing gun might solve was Lieutenant Gilmour McDonald of the U.S. Coastal Artillery, who suggested one for anti-submarine warfare in 1942. Such an aircraft could orbit a surfaced submarine—
a maneuver known as a pylon turn—as the gun kept up a stream of fire at the submarine, eliminating the need to dive, attack, pull off, then reacquire the target to repeat the attack. The military did not adopt the idea, and McDonald’s work languished for almost 20 years, until the early rumblings of the Vietnam War.
In his book, Deployment and Employment of Fixed Wing Gunships, Jack Ballard tells it this way: In 1963, Ralph Flexman, a friend of McDonald’s and an engineer at Bell Aerosystems, applied the side-firing gun idea to the new problem of transient targets in a guerrilla war. He realized that by firing in a continuous turn the aircraft could keep the targets in sight constantly. Flexman shared his insights with Captain John C. Simons, an Air Force friend stationed at Wright-Patterson Air Force Base in Ohio, who in turn proposed the idea later that year to several groups interested in counter-insurgency warfare.
Analysts in the Air Force’s Aeronautical Systems Division rejected the proposal as unsound because they thought that the bullet drop would make firing from such a flight path highly inaccurate. But Simons refused to give up. He experimented with pylon turns in a single-engine T-28 trainer and found it was easy to keep a target in sight during the maneuver. He got the military interested enough to assign it a name—project Tailchaser—and to give him access to a twin-engine C-131 trainer, the military version of a Convair 240 airliner. Simons put a fixed sight and three cameras on the C-131 to record target tracking, but during the next year only a handful of flights could be made, due to a lack of funds. The program was for all practical purposes moribund when Captain Ron Terry arrived at the Flight Test Division at Wright-Patterson in 1964.
Cometh the hour, cometh the man. Terry, who had flown F-86s and F-100s, had just returned from looking at all aspects of air operations in Vietnam as part of an Air Force Systems Command team. While there he had learned that the Viet Cong had begun regularly attacking U.S. Special Forces outposts and Vietnamese hamlets at night to avoid air counter-attacks and that Air Force fighters had virtually no night attack capability. On the positive side, he noted that the U.S. flare ships—C-123s and C-47s—orbiting over hamlets at night effectively illuminated surrounding areas to protect against night attacks.
When Terry arrived at Wright-Patterson he went through old project reports and found Tailchaser. Intrigued, he flew with Simons on the modified C-131 and found that they could track a fixed point on the ground with ease if they held a steady banked turn. Terry realized that in defense of hamlets and forts, an aircraft with side-firing guns was the next logical step beyond flare ships. “Tailchaser was a real major breakthrough,” he says. “It gave the pilot a much longer tracking time.”