<text id=00he2009><title>Development of the Gunships</title>
<history>US Air Force: Events History</history>
<article><hdr>Development of the Gunships</hdr><body>
<p>Perhaps the most significant, and unquestionably the most effective, weapon to come out of the nighttime war on the Trail was the gunship. It reached its wartime zenith in the AC-130E, a multi-sensor, multi-gunned potent package. These gunships had disadvantages as well; they could only be used against targets that were lightly defended against air attack. The big, slow-moving planes flying on a fixed and predictable orbit were easy targets for enemy fire. At night, on the Trail, against rifles, machine guns and an occasional anti-aircraft battery shooting in the blind, they were powerful truck-killers and traffic-stoppers.
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<p>The concept is based on precise pilotage around a circular orbit whose radius of turn and angle of bank are predetermined. Onboard computers take the flight path into account, and calculate impact points for the various weapons, knowing their ballistic characteristics. The armament consists of a mix of automatic weapons from 7.62-mm to 105-mm, and they are fired from the left side of the aircraft by the pilot, who uses a special gunsight. He needs a backup crew of loaders, fire control officers, navigators, a flight engineer and co-pilot to make the whole system work.
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<p>First of the line was the venerable Douglas AC-47 in yet another role. Formally called Dragonship or Gunship One, the AC-47s were informally called 'Puff, the Magic Dragon' or, most often, 'Spooky', their radio callsign. They became operational in Southeast Asia in 1964, and were turned over to the VNAF five years later when updated gunships became available.
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<p>The next, Gunship Two, was the Lockheed AC-130A, an early model with four 7.62-mm Miniguns and four 20-mm M61 Vulcan automatic cannon. It had night observation devices (NOD) and forward-looking infra-red (FLIR) detectors, and was designed to work against trucks. The first of them began operations against the Trail targets during the 1969-1970 dry season.
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<p>Third in the series was the Fairchild AC-119 'Shadow', made in two different models. The AC-119G was intended primarily for close support of friendly forces in South Vietnam. It was armed with four 7.62-mm Miniguns and had NOD. The AC-119K was intended for interdiction missions, primarily against vehicles along the Trail. It was modified by the addition of a pair of jet pods containing J85 engines. Its armament was four Miniguns plus a pair of 20-mm M61 cannon. Its sensors included FLIR. Twenty-six of each model were modified for the Gunship Three program.
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<p>The AC-130 program produced two different end products for combat in Southeast Asia:
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<item>• <hi format=bold>The updated AC-130A</hi>, refitted during summer overhauls in the United States, was built around an armament package of paired 7.62-mm, 20-mm and 40-mm automatic cannon, the LLLTV and FLIR sensors, a laser target designator, a radar tracking sensor, and Black Crow, a new sensor that detected operating truck ignition systems.
<item>• <hi format=bold>The AC-130E Spectre</hi>, which featured greater survivability and to that end had additional armor protection for the crew stations. It had an increased loiter time at the target, and a heavier punch. Its gun battery included paired Miniguns and Vulcans, a single 40-mm automatic cannon, and a single 105-mm howitzer in a trainable mount.
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<p>On a typical mission, the radar was used as the first detection system, because it had a longer useful range than any other sensor. The LLLTV or FLIR or both picked up the details of the target. Black Crow was very effective when the trucks were running; a truck recently shut down still radiated in the infra-red range and could be detected by the FLIR.
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<p>Surprise was important in using the gunships, primarily because of their vulnerability to ground fire. If they could get off a first strike, there was not likely to be enough of the enemy target left to fire back. Visualize a football field; on a single pass overhead, one AC-130E could put a bullet into every square foot of that field. It was an absolutely devastating weapon in its milieu.
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<p>During the 1969-1970 dry season, which ran from November through April, the toll on the Trail was 5,950 trucks destroyed, according to post-combat reports and reconnaissance. One year later, the cost to the North had more than doubled; 14,000 trucks were ruined during the 1970-1971 dry season. Toward the end of the latter time period, the gunships were in full cry, with advanced sensors, heavy artillery, and finely honed tactics. By then, they were accounting for between 75 and 80 per cent of the kills of trucks on the Trail.
