The UH-1 is a military helicopter powered by a single, turboshaft engine, with a two-bladed main rotor and tail rotor. The helicopter was developed by Bell Helicopter to meet the United States Army 's requirement for a medical evacuation and utility helicopter in 1952, and first flew on 20 October 1956. Ordered into production in March 1960, the UH-1 was the first turbine-powered helicopter to enter production for the United States military , and more than 16,000 have been produced worldwide. The first combat operation of the UH-1 was in the service of the U.S. Army during the Vietnam War . The original designation of HU-1 led to the helicopter's nickname of Huey . In September 1962, the designation was changed to UH-1, but Huey remained in common use. Approximately 7,000 UH-1 aircraft saw service in Vietnam.