By late 1967, the idea of the fixed-wing gunship had been proven so successful, the United States Air Force was having a difficult time keeping up with demand.

The newer AC-130s that had been created under Project Gunship II were effective, but were being mostly used for armed reconnaissance and interdiction of the Ho Chi Minh Trail.

[1] The Fairchild C-119 Flying Boxcar presented an obvious choice, having been phased out of front-line service in favor of the C-123 and C-130, and with the stock of available airframes in U.S. Air Force Reserve being sufficient.

In February 1968, under the USAF program Project Gunship III, 26 C-119Gs were converted to AC-119G standard, initially taking on the name "Creep", but later assigned the callsign "Shadow".

[2] In addition, Fairchild-Hiller, which was contracted for all the conversions, converted another 26 C-119Gs into AC-119Ks, primarily for the "truck hunter" role over the Ho Chi Minh Trail.

Even the TIC AC-119G featured some of the most up-to-date electronic countermeasures and radar equipment, as well as more basic technology, including an AVQ-8 xenon light, a night observation sight, and an LAU-74/A flare launcher.