Hiller Model 360 / UH-12 / OH-23 - 1951

Function Fuel Type Fuel Cap Fuel Cons Load Wt. Empty Wt. Max Crew Maintenanc e Utility AVG 150 240/60 250kg 824kg 1225kg 1+1 6 Power plant(s) Horsepower 1 x Avco Lycoming VO-540-A1B 241kW Length Rotor Height Speed Speed Speed Tr. Comb. Move. Ceilin Range Diam. max Cruise Stall Move. g 8.53m 10.82m 2.97m 153kph 132kph 0 528 15 4025 330km m Armaments Ammo Location

Weapon ROF Damage Penetration Magazine Range

History: The Hiller UH-12, derived from the Model 360 two-seater of 1948 with a 180hp Franklin engine, occupies an important place in the history of the American helicopter industry in the fifties. Stanley Hiller Jr., who built the aircraft, was something of a whiz kid, in that he designed and built his first helicopter, the XH-44, in 1944 at the age of only 18. It was the first efficient American helicopter with coaxial, contra-rotating rotors. The later Hiller 360 leapt to fame in the summer of 1949 when it made the first transcontinental commercial flight. With an uprated engine and new UH-12A rotor blades, it was purchased by the US Army and Navy for battlefield evacuation and observation tasks, with the designation H-23 Raven, whilst the Navy ordered the same basic model as the HTE-1 for training. Its successor, the H-23B, powered by a 200-210hp Franklin engine, was the first version used by the US Army as a trainer. A considerable number were built: 216 were assigned to the Primary Flying School at Fort Walters and another 237 were used for various tasks. The UH-12B normally had skid or flotation gear, but a wheeled undercarriage was fitted to a batch ordered by the US Navy (the HTE- 2). In 1955 a new variant, the UH-12C, appeared. It retained the 200hp Franklin engine, but had all-metal rotor blades and a "goldfish bowl" cockpit canopy. From 1956, 145 were delivered to the US Army as the H-23C. A purely military version, the OH-12D, flew on 3 April 1956 and 483 went to the US Army. The Franklin engine had been replaced by the more powerful 320hp Lycoming VO-540, and the transmission had also been changed to increase the service life of the helicopter. The commonest version of this sturdy little helicopter was the UH-12E which had a more powerful engine. The US Army replaced nearly all the OH-23Ds by Hiller 12Es, designated OH-23G. In 1960 the Model E4 was developed from the Hiller 12E, with a longer cabin to seat four and an anhedral stabilizer on the tail boom. Twenty-two of these were acquired by the US Army as the OH-23F, for geodetic research. The last civil variant, which appeared in 1963, was the Hiller 12L-4 which was also used as a test-bed for a PT6 turbine, but the project was taken no further.Total sales of the Hiller 12E family exceeded 2000; more than 300 were exported. Operators of the Hiller included Argentina, Canada, Chile, Colombia, Great Britain, Guatemala, Japan, Morocco, Mexico, the Netherlands, Peru and Uruguay.

Two-seat helicopter based on UH-5 of all-metal construction with fixed tricycle u/c, fully enclosed cabin and rear fuselage, overhead mounted 360 control stick attached to Hiller rotor control, powered by one 175hp Franklin 6V4-178-B32 engine. Prot. N68940. Developed 360 with framed 'bubble'-type cabin, no fuselage structure round engine, skid u/c and 175hp Franklin 6V4-178-B33 engine. 1015kg UH-12 TOGW.

Production two-seat UH-12 with collective pitch ballast system and UH-12A Raven wooden rotor blades for civil and military customers. 1082kg TOGW.

UH-12A with skid/wheel u/c, 200hp Franklin 6V4-200-C33 engine and UH-12B 1128kg TOGW.

UH-12B UH-12B for USN with wheel u/c. Also HT Mk.1 for Royal Navy.

UH-12C UH-12B with moulded bubble canopy, 3 seats and metal rotor blades.

Military UH-12C with 250hp Textron Lycoming VO-435-A1C engine, UH-12D new transmission system, 1240kg TOGW. Prot. FF 3 Apr. 1956.

UH-12D with 305hp Textron Lycoming VO-540-A 1 A engine. OH-23G UH-12E is 3-seat dual control trainer.

UH-12E retro-fitted with Ham-Standard rotor stability augmentation UH-12EL system, stainless steel rotor blades and 1400kg TOGW.

Revised designation for Hiller Aircraft Corp. production UH-12E with 3 UH-12E3 seats.

UH-12E3T Revised designation for Hiller Aircraft Corp. 3-seat UH-12ET.

UH-12E with inverted rear tail planes and lengthened cabin to UH-12E4 accommodate pilot plus rear bench seat for 3 pax.

UH-12E fitted with Soloy conversion to 400shp Allison 250-C20B UH-12ET turboshaft.

UH-12E4 fitted with Soloy conversion to 400shp Allison 250-C20B UH-12E4T turboshaft.

UH-12E4 fitted with five seats and 340hp Textron Lycoming VO-540 UH-12E5 piston engine. Prot. flown but design not further developed.

UH-12E5T Proposed turbine-powered UH-12E5 with Allison 250-C20B. Not built.

UH-12J-3 Unofficial designation for Soloy-converted UH-12E.

UH-12E with supercharged Textron Lycoming TIVO-540 engine and 'L' UH-12SL series rotor head with gyro-controlled stability augmentation system. UH-12L UH-12SL with unsupercharged VO-540 engine.

UH-12SL4 UH-12L with E4 four-seat cabin.