Fairchild AU-23 combat record in S.E. Asia

Hi, my first post here.

I’ve been trying to find details on the combat record, in SE Asia, of the humble Fairchild AU-23, with results that are vague (to say the least) and not always consistent.

From the Roden plastic-kit’s instruction-sheet (quote) Soon a new build airplane was sent to Vietnam to conduct military tests in combat conditions, according to the program of aviation development in support of Pave Coin troops. The airplane was intensively used in helicopter escort, combat against mobile partisan groups, and special service operations. In particular it was intensively tested in take off and landing on poorly prepared air strips while carrying various loads. In total, during these tests the airplane executed about two hundred missions. Half of them were conducted by American pilots, the remainder by the USA’s South Vietnamese allies. A notable defect of the airplane which caused much criticism was its considerable vulnerability to enemy small arms fire, even such ordinary Soviet machine guns as the DShK, which Vietcong soldiers had in great quantity. Additionally the aircraft appeared poor at managing quick upward flight with maximum load. Nevertheless, Fairchild received an order for a small series of 15 such airplanes. The order was fulfilled but the Vietnam War was already finished by then. In 1972 all 15 AU-23A machines were sent on to the Davis-Monthan Air Force Base. They could have stayed there forever, however soon after the USA and Thailand signed a mutual military aid agreement, and all 15 airplanes were delivered to this South East Asia country. They were widely used by the Thai military for many years, mainly in the task of border patrol.(end of quote)

From warisboring.com blog (quote) 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. (end of quote)

From Development and Employment of Fixed-Wing Gunships, 1962-1972, by Jack S. Ballard, page 223 (quote) Credible Chase edged forward during June and July 1971, as the Helio Stallion and Fairchild Peacemaker underwent combat evaluation in Southeast Asia. The team discovered quite a few deficiencies in the two aircraft, and recommended further testing after their correction. (End of quote)

The U.S. National Air Force Museum’s AU-23 online factsheet (since removed) stated (quote) The combat evaluation of PAVE COIN, was done in June and July 1971. The AU-23A was tested for eight possible missions: armed escort of helicopters, close air support, hamlet defense, STOL airlift and resupply, armed reconnaissance, border surveillance, forward air control, and counter infiltration. USAF crews flew 73 missions (94 sorties) and RVNAF crews flew 68 missions (85 sorties). Several types of weapons were test dropped/fired including 2.75 inch rockets (explosive and smoke), cluster bomb units (CBU-14), MK 6 Mod 3 flares, and MK 81, 82 and 106 practice bombs. More than 8,000 rounds of 20mm ammunition was also fired, including both high explosive incendiary and target practice tracer types. Several problems were discovered during the PAVE COIN program, the most serious was the extreme vulnerability of the aircraft to all but the lightest antiaircraft fire (below 12.7mm). (end of quote)

From Globalsecurity.org (quote) The Credible Chase program began in May 1971, and was designed to add firepower and mobility to the South Vietnamese Air Force in a relatively short time. The combat evaluation, Project PAVE COIN, of the Fairchild AU-23A and Helio AU-24A was done in June and July of 1971. These aircraft were evaluated for potential use in Southeast Asia as an armed light utility short take off and landing gunship. The AU-24A, like the AU-23A, was found to be unsuitable for combat operations. Major problems identified included a low attack speed of about 135 knots, a low operating altitude below 5,000 feet, no “zoom” escape capability after an attack run, and an extreme vulnerability to antiaircraft fire. Further testing was recommended after the aircraft were updated to combat standards. The location of the side-firing gun in relation to the center of gravity made both aircraft tail heavy. In the Peacemaker, the condition proved so dangerous that forty pounds of lead had to be inserted under the engine cowling to restore some semblance of equilibrium. To overcome the lack of balance required a heavy hand on the controls and forced the small-framed South Vietnamese to wrestle the stick with both hands in performing basic maneuvers. As if this were not enough, neither range nor payload lived up to expectations; a minigunship carrying one thousand pounds and flying a distance of one hundred nautical miles could remain on station just thirty minutes before turning back to refuel.The XM197 Armament System evaluated in this test is similar to the M61 Vulcan 20mm rapid fire cannon. The XM197 consists of three rotating barrels instead of six and has a rate of fire of approximately 400 rounds per minute (rdpm) slow rate, and 700 rdpm fast rate. For the test reported here, the gun was pedestal mounted just behind the pilot’s seat in the Fairchild-Hiller Peacemaker Aircraft. The M61 and XM197 20mm guns are automatic aircraft cannons for use against aircraft and ground or seaborne targets. These guns are electrically or hydraulically powered, belt fed or linkless feed, and electrically fired. A round of ammunition is fired through one barrel at a time, as the barrels and rotor assembly rotate once around the rotor housing. (end of quote)

So it appears that a restricted number of aircraft were hastily sent to S.E. Asia, between May and July 1971, to get a taste of their combat capabilities, under either Pave Coin or Credible Chase Project’s, with less than stellar results.

This was followed, in 1972, by a thorough evaluation, at Eglin AFB, Florida, by US and S.Vietnamese pilots, which confirmed the unsuitability of both aircraft for combat, prompting Secretary of Defence Laird’s decision to deliver the AU-23’s (‘dump’ would probably be a more appropriate term) to the Royal Thai Air Force who was said to have been thrilled to be now able to create its own gunship’s unit.

However, the 1971 combat evaluation was not the end of the association of the AU-23 with USAF pilots and the conflict in S.E.Asia
From Escape to U Taphao, Air & Space Magazine, Jan. 1997 (quote) A few days before the exodus from Saigon, Aderholt had sent Air Force Captain Roger L. Youngblood to Trat Field on the Thai border with Cambodia. Flying a Royal Thai Air Force AU-23 (a derivative of the Pilatus PC-6 Turbo-Porter that could handle the short runway at Trat), Youngblood orbited in the area with a Vietnamese co-pilot. The co-pilot stayed on the radio giving the tower frequency for U Taphao and trying to direct pilots to land there. Not all of the pilots made it. (end of quote)

USAF Capt. Ted B. Hallebeck, on temporary duty with the 1131st USAF Special Activities Squadron, instructor, and a Thai pilot were killed on a training mission on February 5, 1973, when their AU-23, S/N 72-1313 (RTAF S/N JH2-08/15) crashed into rice paddy at Khok Krathiam District, Lopburi Province, near the near Koke-Thiem Airport.

It seems that, even though the RTAF owned the AU-23’s, the USAF was not shy at employing them, to some extent, at their own discretion.
Also, one can’t help considering what a waste of resources it must have been to employ a ‘Special Activities’ unit for training only, with the conflict still ongoing (the ceasefire would go into effect at 8AM, Saigon time, on January 27, 1973). Hence, one can only speculate on the kind of missions USAF pilots were actually flying the RTAF AU-23 in…

Any information and/or detail on the combat record of the AU-23 will be highly appreciated.

Best regards.

Pete1957