The U.S. Air Force’s Tiny Gunships Packed a Powerful Punch

The Americans donated the heavily-armed aircraft to needy allies

The U.S. Air Force’s Tiny Gunships Packed a Powerful Punch The U.S. Air Force’s Tiny Gunships Packed a Powerful Punch
In the early 1970s, the U.S. Air Force briefly operated a small fleet of small, fixed-wing gunships. The military meant to export the heavily-armed... The U.S. Air Force’s Tiny Gunships Packed a Powerful Punch

In the early 1970s, the U.S. Air Force briefly operated a small fleet of small, fixed-wing gunships. The military meant to export the heavily-armed planes to allied air arms battling insurgents in their own countries.

At the time, the Pentagon figured a light attack aircraft could be a boon to America’s friends and allies around the world. But the planes also would have to be easy to fly and repair.

In 1971, the Air Force’s Aeronautical Systems Division explored a number of different aircraft that could meet the requirements. Designs from Fairchild and the Helio Aircraft Company seemed to hold the most promise.

Fairchild’s Peacemaker was a licensed copy of a successful Swiss plane, the Pilatus PC-6. On the other hand, Helio’s Stallion was a variant of the company’s earlier Courier design.

The Air Force picked the Peacemaker and the Stallion because they were both fairly simple and could take off and land from short, primitive runways. American airmen also already had experience with both firms and their products.

In fact, the PC-6 had been shuttling troops and cargo around Southeast Asia—but for the Central Intelligence Agency, as depicted in the photograph above. Both the Air Force and the CIA also purchased Helio’s Courier for secretive missions around the world.

A Fairchild Peacemaker with side-firing Minigun. Photo via San Diego Air and Space Museum Archive

The new planes could carry 7.62-millimeter Miniguns or a 20-millimeter cannon rigged up inside the main cabin. The Peacemaker and Stallion could also carry bombs, rockets and other weapons.

The aircraft could spot enemy forces, haul cargo, drop propaganda leaflets and more. And the Pentagon wanted the designs to perform these counterinsurgency missions with few modifications.

In May 1971, Tactical Air Command was still hashing out what criteria it would use to grade the aircraft. But Secretary of Defense Melvin Laird was eager to see how the new planes would handle actual combat.

Before the Air Force even had selected a design, Laird had ordered the flying branch to prepare a trial by fire in Thailand. On June 1, American crews ferried one Peacemaker and one Stallion to Bangkok.

After fewer than 10 days of training, the Americans transferred the aircraft to Royal Thai Air Force crews. The two planes quickly went into action against communist rebels in the country’s north.

This combat evaluation, codename Pave Coin, lasted nearly two months. Thai airmen flew 83 combat missions, according to the Air Force’s official report.

The RTAF especially was thrilled to have its own small gunships. The planes also escorted helicopters and searched for enemy encampments.

At the same time, the Americans were putting the finishing touches on a larger program. The information from the experiment in Thailand guided the Credible Chase project.

The flying branch would grade the aircraft based on their ability to perform the kind of missions they’d flown in Thailand. The first Peacemakers and Stallions—which the Air Force now designated AU-23 and AU-24, respectively—began arriving at Eglin Air Force Base in Florida the next year.

A Helio AU-24 Stallion in storage in 1972. Photo via San Diego Air and Space Museum Archive

But this time, the flying branch brought South Vietnamese aircrews to Eglin to train. Army Special Forces troops played the role of both friendly and enemy forces during the exercises.

After months of tests, the Credible Chase Task Force’s final conclusion was that the aircraft were functional, but would be of limited use in Vietnam. The flying branch thought the planes were too vulnerable to enemy anti-aircraft guns and missiles, according to the project’s final report.

In June 1972, all of the Credible Chase aircraft—15 AU-23s and 15 AU-24s—flew into storage at Davis-Monthan Air Force Base in Arizona. But the story doesn’t end there.

The next year, the Pentagon pulled all but one of the Stallions out of storage and sent them Cambodia. The Khmer air force was in desperate need of aircraft and quickly threw the planes into battle against the Khmer Rouge.

The Khmer Rouge shot down three of the AU-24s, according to the excellent information that Dr. Joe F. Leeker at the University of Texas at Dallas has compiled. Another plane crashed in the Gulf of Tonkin trying to escape the country as it fell to the communists.

Another three Stallions escaped to Thailand and eventually were sold on the civilian market. The Khmer Rouge captured the remaining aircraft, Leeker’s notes explain.

Bangkok eventually purchased the stockpile of AU-23 aircraft. The Thai air force continues to fly these planes—complete with shark mouth paint jobs—along with other PC-6 variants.

The U.S. Air Force itself still is interested in the idea of small starter gunships for allied air forces. Air Force Special Operations Command tested a new design just last year.