The Sikorsky UH-60 black colored Hawk is a "twin-turbine" engine, single rotor, semimonocoque fuselage, rotary wing helicopter. The "Black Hawk" originated to meet up with a US Army requirement of a UH-1 Iroquois replacement in 1972. Three prototypes were constructed, the first (YUH-60) traveling in October 1974, and evaluated against a rival (YUH-61) Boeing-Vertol design. The Black Hawk was chosen for manufacturing together with UH-60A entered service with all the US Army in 1979.