Essentially all side-firing gunships utilize the same principle. An aircraft flying a fixed altitude banking turn around a point on the ground (read target) can deliver fairly accurate firepower to that target from side-mounted guns firing perpendicular to the line of flight. This concept was first proposed way back in 1926 and demonstrated the next year. However, the concept languished for many years but never completely disappeared. Several airmen later advanced the idea but it didn’t come to fruition until the early 1960s with the Project Gunship I program.
The Douglas AC-47D Spooky gunship, better known as Puff the Magic Dragon, proved its usefulness right from the beginning of its use in Vietnam during 1964. In late 1967 the development of the gunship continued with the Fairchild AC-119G Shadow and AC-119K Stinger– both developments of Fairchild’s C-119 Flying Boxcar tactical airlifter.
The Project Gunship II Lockheed AC-130A Spectre was also in use at the time, but was in short supply due to the Air Force’s need for standard C-130 Hercules airlifters to process the war in Vietnam and meet worldwide airlift commitments. Therefore, the Wright R-3350-powered AC-119 was also selected for the gunship role. 26 of them were converted from Air Force Reserve C-119Gs to AC-119G standard, and heavily utilized in Southeast Asia beginning in 1968.
Project Gunship III AC-119Gs took over the combat role of the majority of the AC-47D Puff gunships, which were turned over to the South Vietnamese as they were replaced. A more advanced aircraft than the AC-47D to begin with, the more heavily armed AC-119G Shadow mounted four side firing 7.62 millimeter six-barrel GAU-1/A miniguns as well as an AVQ-8 xenon light, night observation sighting equipment, and an automated LAU-74/A flare launcher. Shadows primarily provided support to troops in contact (TIC) and airborne base defense.
The AC-119G was also equipped with a General Precision fire control computer as well as a TRW fire control safety display prevent friendly-fire accidents. Internal power for all the new equipment was supplied by a Garrett Industries 60 KVA auxiliary power unit (APU)- the same model used in the Boeing 727 commercial airliner. Ceramic armor was added and APR-25 and APR-26 electronic countermeasures (ECM) gear installed for enhanced crew survivability. The AC-119G carried 31,500 rounds of ammunition and 24 flares on a typical night interdiction mission.
Fairchild-Hiller converted another 26 C-119G airlifters into AC-119K Stingers. These gunships were heavily utilized as truck hunters and as such flew long interdiction missions over the Ho Chi Minh Trail. Two side-firing M61 Vulcan 6 barrel 20-millimeter cannons were added to the four side-firing 7.62 millimeter six-barrel GAU-1/A miniguns mounted in the AC-119G. The AC-119K also added a pair of General Electric J85 turbojet engines mounted in underwing pods, which helped improve the somewhat sluggish loaded performance of the Shadow.
In addition to heavier firepower and additional available engine power, the Stinger was equipped with more sophisticated electronics to support its added weaponry. The AN/APN-147 Doppler navigation radar, AN/AAD-4 Forward Looking Infrared (FLIR), AN/APQ-133 side-looking beacon tracking radar and AN/APQ-136 search radar were all added to the AC-119K. These sensors required modified housings which added external identification cues.
The 71st Special Operations Squadron (SOS) of the 14th Special Operations Wing (SOW), based at Nha Trang Air Base, began operating AC-119G Shadows in November of 1968. The personnel were from the Air Force Reserve (AFRES) 71st Troop Carrier Squadron, 434th Troop Carrier Wing and based in the States at Bakalar Air Force Base near Columbus in Indiana. When the 71st SOS rotated back to the continental United States (CONUS) in 1969, the gunships were taken over by the newly formed 17th SOS.
The AC-119K Stingers were operated by the 18th SOS. Between the AC-119G, the AC-119K, and its other aircraft the 14th SOW operated eight different aircraft from ten different bases in South Vietnam for a portion of 1968 and 1969. After a distinguished combat tour the 14th SOW was inactivated in 1971. A few AC-119Gs and AC-119Ks were operated by the 56th SOW from Thailand through 1972, but except for a few examples operated by the South Vietnamese Air Force the Shadow and Stinger were phased out of service by the end of 1973. During the Vietnam War, only five AC-119 gunships (both models) were lost to all causes.
The Lockheed AC-130 Spectre was utilized and developed more or less continually since its inception during the 1960s. It became clear that the C-130 provided the best airframe to be used as the basis for continued development the side-firing gunship. Still in service today as the AC-130U Spooky, AC-130J Ghostrider, and AC-130W Stinger II (Dragon Spear), the original Spooky, Stinger, and Shadow live on in these heavily armed and highly capable 4 turbine powered gunships.