HU-1A or UH-1A
When I arrived for military occupational speciality training at Fort Rucker, Alabama, in July 1957 testing was underway, the production of Hueys began in 1958, with the first one leaving the Bell factory in September. These first production models were designated as HU-1As, a designation that would be contracted into the unofficial name "Huey." The official name was Iroquis, in line with the Army's policy of naming helicopters after Indian tribes. The HU-1A nomenclature was changed later to UH-1A as the result of a change in the way the U.S. military designated its aircraft. In each case, the H stood for helicopter and the U for utility. Eventually the Huey title became part of the aircraft design when Bell started putting the words "Bell" and "Huey" on the left and right rudder pedals respectively.
The first HU-1 was shipped to Alaska for cold weather testing. Other HU-ls were tested with a variety of weapons mounted on them. These included French-made Nord SS11 and Nord AGM-22A wire-guided missiles. In a wire-guided missile, the missile is controlled in flight using wires that are unfurled from the rear of the missile as the weapon travels from the helicopter to the target. Electrical signals are sent along the wire to the missile's control surfaces. Other weapons tested included four Emerson M73 7.62mm machine guns, a General Electric grenade launcher and 70mm rockets. While designed for utility and medical evacuation missions, the Army was already interested in the Huey as a weapons platform.
The HU-1A or UH-1A was essentially the same as the YH-40 except that it was powered with an 860-horsepower Lycoming T53-L-1A engine giving a maximum speed of 130 knots (148 mph), a gross weight of 8,500 pounds and a range of 335 nautical miles (382 miles).
In all, 182 Bell Model 204s were made. These included the UH-1As plus other variants, including 14 fitted with instrument flying equipment and dual controls. The latter were designated TH-1As and were used for pilot training at Fort Rucker, Alabama, the home of Army aviation. The early UH-1As were assigned to light aviation units in Europe and Korea. Four were assigned to Fort Campbell, Kentucky just before I departed for Korea in 1961.
The first A model Hueys shipped to Vietnam were used by the 57th Medical Detachment for air ambulance service, a unit I had been assigned to at Fort Meade, Maryland. While I was in the unit we used Sikorsky UH-19Ds for medical evacuations. As the name of the unit implies, these UH-1As were used for medical evacuation, or medevac as it more commonly came to be known. (They were also later called "dust-off" missions in the slang of the troops in Vietnam.)
I attended an Army Mobile Aircraft Training Program while assigned to the 45th Transportation Company (Aircraft Maintenance & Supply) at Ascom City, Korea, in 1963 and, when the unit moved to Pyong Taek, Korea, I became the chief of aircraft inspections.