AC-123 Black Spot
The Air Force experimented with a self-contained night attack craft, the NC–123K Black Spot, redesignated the AC–123K. Twin jet engines slung in pods beneath the wing supplemented the original pair of piston engines and improved the performance of this Fairchild tactical transport, which had entered service in 1955.
Combining the Starlight scope’s capabilities with those of the C-123 Provider transports assigned to the 56th ACW, a crewman looking through the scope from an open hatch in the belly of the transport’s cargo bay from an altitude of 4,000 to 6,000 feet over the Ho Chi Minh Trail got an excellent view of any activity taking place under the C-123’s flight path.
By adding an aerial flare capability to the Provider, the “Candlestick” concept was born. C-123K Provider transports belonging to the 606th Air Commando Squadron had a special night mission over the Ho Chi Minh Trail. After observers first detected truck traffic below with a handheld Starlight scope, the C-123 “Candlestick” missions exposed the trucks with six-million candlepower aerial flares. When a totally blacked-out Candlestick detected truck traffic, strike aircraft (also blacked-out) were called over the convoy, which was still oblivious to what was going on above it. With the strike aircraft ready, the C-123 dropped its six-million candlepower flares and “marker bricks” over the trucks and flew out of the immediate vicinity. And like sharks following a blood trail, the strike aircraft followed the reddish-tinted flares to the hapless trucks. The results were dramatic, both at the moment and in the rise in USAF’s end-of-month truck-kill tallies.
In December of 1965, the USAF began Project Black Spot. This test program was designed to give the Air Force a self-contained night attack capability to seek out and destroy targets along the Ho Chi Minh Trail. In early-1966, the concept was approved by the Department of Defense and two Fairchild C-123K Providers (#54-691 and #54-698) were modified by E-Systems of Greenville, Texas. They were redesignated NC-123K, designed as test aircraft not intended as operational, hence the prefix "N", though they are often referred to as AC-123K configuration.
The Fairchild NC-123 Black Spot was not technically a gunship, since the aircraft did not carry side-firing weapons. The two aircraft flew out of the 16th Special Operations Squadron in Ubon, Thailand. This was the same unit that flew the AC-130 gunship. This type had an infrared scanner, low-light level television, a laser range finder and Cluster Bomb Units (CBU) dispensers to attack enemy trucks on the Ho Chi Minh Trail. Depending on the type of CBU installed, the containers had a capacity of between 2,664 and 6,372 one pound bomblets. The two Black Spot prototypes featured equipment that came to be more or less standard for night interdiction—television, a laser range-finder, an infrared sensor, a radar that searched ahead of the plane to track moving vehicles, and in one of the aircraft, a Black Crow ignition detector. A computer determined bomb release, but in Black Spot all the sensors automatically fed data into this device. The cargo compartment contained a dispensing unit, originally designed for possible installation in the bomb bay of a B–47 or B–52 strategic bomber, which held 72 canisters, each one packed with either 74 or 177 bomblets, depending on weight and shape of the individual weapons. The canisters dropped through the dispenser’s twelve vertical chutes to burst open and scatter the bomblets, either a fifteen-ounce cylindrical type or a spherical variety that weighed twenty-six ounces. Both kinds scattered fragments on exploding, inflicting damage on trucks and other equipment and also causing casualties.
An emergency in Korea delayed the arrival in Southeast Asia of the two Black Spot aircraft. During the tense months following North Korea’s capture of the U.S. intelligence ship Pueblo in January 1968, North Korean infiltrators began landing from small boats, bypassing the demilitarized zone that separated South Korea from the communist North. The two AC–123Ks arrived in Korea during August, remained there about three months, trying to intercept gasoline-powered motor boats, and only then flew to Southeast Asia for their evaluation. From November 15, 1968, until January 9, 1969, the Black Spot aircraft attacked trucks in Laos, showing enough promise to cause the Commander in Chief, Pacific Command, Admiral McCain, to retain them until the end of the 1968–69 dry season and use them again when the rains ended in the fall of 1969.
They were used in interdiction missions on the route Ho Chi Minh and the Mekong Delta from the base of Phan Rang, South Vietnam between 1968 and 1970. The launch of the weapons was managed by computer, and some idea of the effectiveness of the system is given by the fact that in 141 outings during the campaign "Commando Hunt III" of 1969-70, the NC/AC-123K destroyed an average of 3.12 trucks per mission. Although Black Spot received credit for destroying 1,128 trucks during roughly fourteen months of action, the kinds of munitions dropped by the converted transports lacked the punch to cause such havoc. Intelligence analysts may not have realized at the time that the bomblets generally did only superficial damage to vehicles, puncturing tires, gas tanks, and radiators. The fragments might wound or kill drivers, but seldom did the weapons start a fire that consumed a truck and its cargo.
The Black Spot aircraft, moreover, proved vulnerable to antiaircraft fire. The best of the sensors, the infrared detector that scanned ahead of the aircraft, could not locate targets from altitudes above five thousand feet. This limitation doomed the project, for during 1969 antiaircraft guns capable of reaching this altitude already were appearing along the major roads of southern Laos. “I have concluded,” declared General Brown, the Seventh Air Force Commander, in June 1970, “that despite past accomplishment and our need for sensor equipped first-pass-capable truck killers, the AC–123’s reduced effectiveness due to vulnerability dictates . . . removal from SEA.”
A subsequent attempt to restrict Black Spot to lightly defended routes, relying on the Black Crow sensor to spot trucks through the jungle canopy, ended in failure, for the ignition detector in the AC–123 indicated only the general presence of gasoline engines; it could not pinpoint individual vehicles. Black Spot had outlived its usefulness; in June 1970, the combat careers of the two prototypes came to a close. The 8th Tactical Fighter Wing, which had flown them, recommended canceling the project and preserving one of the aircraft in the Air Force Museum at Wright-Patterson Air Force Base, near Dayton, Ohio.
Although Project Black Spot was a success, both aircraft were later refitted to back to the C-123K standard to serve as normal transports. The two aircraft returned to the United States to be stored in Arizona where, after two years, they were returned to Southeast Asia to be transferred to the Royal Thai Air Force within the agreements of Military Assistance Program USA. However, by then had become mere cargo planes.
