The helicopter as an over-battlefield commodity was proven for the Americans during the fighting of the Korean War (1950-1953). This showing propelled the United States Army to investigate broadened use of the type in, particularly in contested areas where helicopters proved a life saving measure for the wounded. The war resulted in greater investment by the service in rotorcraft that could respond to casualty evacuation and other roles where Vertical Take-Off and Landing (VTOL) was required.
Against this backdrop in 1955, Bell Helicopter, funded by a U.S. Army contract, began work on a prototype helicopter design that was to be powered by a turbine engine. This powerplant was already trialed through a Model 47 (as the "XH-13") to prove the basics of the arrangement sound. The step up to using the larger, heavier "Model 204" offered its own challenges but success was already within reach. As a military prototype, the Model 204 was designated as the "XH-40" and went to the air for the first time on October 22nd, 1956. The following year, two more prototypes were added to the development stable and, in 1958, no fewer than six helicopters - with lengthened cabins - under the developmental "YH-40" designation were delivered for further testing by the Army.
The design was refined after feedback from the service but Army authorities were convinced in the new helicopter, and its more capable turbine arrangement, that it adopted the YH-40 into service as the UH-1 "Huey" - the symbol of the American involvement in the Vietnam War (1955-1975) and the first mass-produced turbine-powered helicopter anywhere in the world.
As finalized, the aircraft had a two-person crew with side-by-side seating in the heavily-windowed cockpit and room in the cabin for additional personnel. The passenger cabin was accessed through sliding side doors while the pilots had access through hinged, automobile-style doors at front. The engine was mounted over and behind the passenger cabin and drove a twin-bladed main rotor unit overhead and a twin-bladed tail rotor unit set to starboard. A shaft connected the powerplant to the rear rotor under the framework of a tail stem. The engine exhausted from a circular port over the tail stem itself. Ground-running was handled by a simple twin-landing skid arrangement which allowed the helicopter to take-off and land from virtually anywhere.
For its time in the air, the XH-40 stood as the progenitor to one of the most well-known and successful rotorcraft in aviation history, its form and function influencing a long-standing line of helicopters that is embodied today by such types as the United States Marine Corps' UH-1Z "Venom" (detailed elsewhere on this site).
Status Retired, Out-of-Service
[ 9 Units ] : Bell Helicopter - USA
- Medical Evacuation (MEDEVAC)
- Search and Rescue (SAR)
- X-Plane / Developmental
55.12 ft (16.8 m)
48.06 ft (14.65 m)
14.44 ft (4.4 m)
(Showcased structural dimension values pertain to the Bell XH-40 production model)
3,307 lb (1,500 kg)
7,716 lb (3,500 kg)
(Showcased weight values pertain to the Bell XH-40 production model)
1 x Turbine engine driving a two-bladed main rotor over the fuselage and a two-bladed tail-rotor unit set to starboard.
(Showcased powerplant information pertains to the Bell XH-40 production model)
124 mph (200 kph; 108 kts)
16,404 feet (5,000 m; 3.11 miles)
217 miles (350 km; 189 nm)
1,200 ft/min (366 m/min)
(Showcased performance values pertain to the Bell XH-40 production model; Compare this aircraft entry against any other in our database)
(Showcased armament details pertain to the Bell XH-40 production model)
XH-40 - Base prototype Designation; three constructed for testing in 1956-1957.
YH-40 - Six pre-series helicopters used for additional testing; delivered in 1958.
* Ribbons not necessarily indicative of actual historical campaign ribbons. Ribbons are clickable to their respective campaigns/operations.
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