While glowing in praise for the helicopter's advances over piston-engined helicopters, the Army reports from the service tests of the YH-40 found it to be underpowered with the production T53-L-1A powerplant producing a maximum continuous 770 shaft horsepower (570 kilowatts).

After September 1962, the designation for all models was changed to UH-1 under a unified Department of Defense (DOD) designation system, but the nickname remained. Army name was almost never used in practice. The reference became so popular that Bell began casting the name on the helicopter's anti-torque pedals. The helicopter quickly developed a nickname derived from its HU-1 designation, which came to be pronounced as 'Huey'. In March 1960, the Army awarded Bell a production contract for 100 aircraft, which was designated 'HU-1A' and officially named Iroquois after the Native American nations. Two more prototypes were built in 1957, and the Army had previously ordered six YH-40 service test aircraft, even before the first prototype had flown. Powered by a prototype Lycoming YT53-L-1 (LTC1B-1) engine producing 700 shp (520В kW), the XH-40 first flew on 20 October 1956 at Fort Worth, Texas, with Bell's chief test pilot, Floyd Carlson, at the controls. The Bell 204 and 205 are Iroquois versions developed for the civil market. The UH-1 first saw service in combat operations during the Vietnam War, with around 7,000 helicopters deployed. The Iroquois was originally designated HU-1, hence the Huey nickname, which has remained in common use, despite the official redesignation to UH-1 in 1962. The UH-1 was the first turbine-powered helicopter produced for the United States military, and more than 16,000 have been built since 1960. The first member of the prolific Huey family, it was developed by Bell Helicopter to meet a 1952 US Army requirement for a medical evacuation and utility helicopter, and first flew in 1956. The Bell UH-1 Iroquois (nicknamed ' Huey') is a utility military helicopter powered by a single turboshaft engine, with two-bladed main and tail rotors. Family of American military utility helicopters

Model huey helicopter