From the Manufacturer
The Sikorsky UH-60 “lack Hawk”is a “twin-turbine engine, single rotor, semimonocoque fuselage, rotary wing helicopter. The “Black Hawk” was developed to meet a US Army requirement for a UH-1 Iroquois replacement in 1972. Three prototypes were constructed, the first (YUH-60) flying in October 1974, and evaluated against a rival (YUH-61) Boeing-Vertol design. The Black Hawk was selected for production and the UH-60A entered service with the US Army in 1979.