UH12E4T - One 315kW (420shp) Allison 250C20B turboshaft driving a two blade main rotor and two blade tail rotor. UH12E3 - One 255kW (340hp) Textron Lycoming VO540C2A flat six piston engine.
UH12E4T - Max speed 154km/h (83kt). Range with auxiliary tanks 565km (305nm). UH12E3 - Max speed 154km/h (83kt), cruising speed 145km/h (78kt). Initial rate of climb 1290ft/min. Service ceiling 15,000ft. Hovering ceiling out of ground effect 6800ft. Range with reserves 278km (150nm), or 585km (316nm) with optional fuel.
UH12E4T - Main rotor diameter 10.80m (35ft 5in), length overall 12.41m (40ft 9in), fuselage length 9.08m (29ft 10in), height 3.08m (10ft 2in). Main rotor disc area 92.0m2 (990.0sq ft). UH12E3 - Same except fuselage length 8.69m (28ft 6in).
Seating for three on a bench seat, or for four (two forward and two behind) in UH12E4 and 12E4T.
Over 2300 of all versions built, including military H23s.
Light utility helicopter
The UH12 series of light helicopters has one of the longest and most sporadic production runs in history.
The UH12 first flew in 1948. The initial variant was the Model 12 which was powered by a 133kW (178hp) Franklin 6V4178B33 engine. The Model 12A followed from 1952, it introduced a semi enclosed cockpit, while the distinctive goldfish bowl cockpit first appeared on the 12C, which also introduced all metal rotor blades (the 12C, plus the 12A and 12B were powered by a 150kW/200hp or 155kW/210hp engines). The definitive UH12E was first delivered from May 1959 and differs little from the UH12E3 currently in production.
Developments on the UH12E theme though include the four seat UH12E4 with a stretched fuselage and the Allison 250 turboshaft powered UH12ET and UH12E4T. Kits were offered allowing the conversion of 12Es into 12E4s, while piston powered aircraft could be retrofitted with the Allison turboshaft. Large numbers of military Hillers were also built for the US military as H23 Ravens.
The production history of the UH12 is chequered, with design and initial production undertaken by the original Hiller company. Hiller, and then Fairchild Hiller, built over 2000 up until the late 1960s. The newly formed Hiller Aviation acquired design and production rights in 1973 and restarted UH12E production. Hiller Aviation was then acquired by Rogerson Aircraft in 1984, the first UH12Es manufactured under the new company banner coming off the line in mid 1984. Rogerson subsequently changed its name to Rogerson Hiller, and relaunched UH12E production in 1991.
The final chapter of the UH12 story thus far opened in mid 1994 when the original designer and owner Stanley Hiller, in conjunction with Thai investors, acquired the program from Rogerson. The new Hiller Aircraft Corporation is building small numbers of UH12E3s (the first flew on June 2 1995) for its Thai partners, and has also flown the Allison 250 turboprop powered UH-12E3T.