Country of origin:

United States of America

Description:

Light utility helicopter

Power Plant:

(H-12E)

One 241 kw (323 hp) Lycoming VO-540-A1B six-cylinder horizontally-opposed air-cooled engine

Specifications:

History:

Stanley Hill Jr designed the Model 360 helicopter and offered it for commercial sale in 1948.  Subsequently the designation Hiller 360 was dropped in favour of UH-12, and later models were known simply as the 12C, 12E, etc.

Powered by a 133 kw (178 hp) Franklin 6V4-178-B33 engine, the Hiller 360 had a totally enclosed fuselage containing the cabin and engine bay, with a tail-boom carrying the anti-torque rotor in its initial form.  However, much of the metal skinning was eliminated in the production model.

Type approval was obtained in October 1948.  This model was used mainly for agricultural work, with tanks or hoppers installed on the sides of the engine bay.

In 1950 the UH-12A was introduced, with the main change being new rotor blades.  Either the 149 kw (200 hp) Franklin 6V4-200-C33 or the 156 kw (210 hp) Franklin 6V-335-B engine could be fitted. This model was chosen for the United States (US) armed forces, as the H-23A for the Army and HTE-1 for the Navy. One hundred were supplied, and these saw service in Korea.

A total of 194 UH-12s and UH-12As was built. The UH-12B, of which 453 were built, was mainly for military use, although a number were used in the agricultural role in civil service.

The UH-12C differed from the previous models by having a one-piece moulded canopy and metal rotor blades.  Type approval was obtained on 12 December 1955.

The prototype of the UH-12D, which was flown on 3 April 1956, had a new transmission and drive system, a 186 kw (250 hp) Lycoming VO-335-A1C engine, and could carry two external litters.  Several hundred were built for the US Army as the H-23D (later OH-23D).  Development continued to the H-23D-2 with a 228 kw (305 hp) Lycoming engine; and the UH-12E, which was certificated on 6 January 1959.  At this time the ‘U’ prefix was dropped and the machine became known as the H-12E.

In addition to civil customers, this model was supplied to the Canadian Army, the Royal Canadian Air Force (RCAF), and the Royal Navy (RN).  In 1960 the first major changes occurred in the H-12E-4 model, which had the power plant, etc, of the H-12E, but the cabin lengthened by 63 cm (25 in) and an inverted Vee tailplane added on the tail boom.  This permitted accommodation for four instead of three persons, as with the earlier models.  The H-12L-4 model, released in 1961, was the H-12E-4 with a stability augmented rotor system.

In the 1960s the Company closed down production facilities and only continued to provide service and parts for the 2,200 helicopters that it had already built.

In March 1970 Hiller Aviation, which was a subsidiary of Fairchild Industries, purchased the rights to build the H-12E and, after some minor design improvements, the company began construction of the helicopter as the UH-12E, and later the Model UH-12E4.  The UH-12E was then available with the normally aspirated Lycoming engine, or with an Allison 250 turboshaft.

Hiller Aviation then acquired a company known as Rogerson Aircraft in 1984.  In 1985 Hiller announced it was planning to re-enter the market with four models: the UH-12E Hauler seating three with a 228 kw (305 hp) Avco Lycoming VO-540-C2A engine; the UH-12E4 with seating for four; the UH-12ET with a 225 kw (301 shp) Allison 250-C20B turboshaft; and the UH-12E4T, the four-seater UH-12E4 with the turboshaft engine.  Later the company became known as Rogerson Hiller.

In 1994 Stanley Hiller, with investment from Thailand, acquired the program and commenced building the UH-12E3 with the Lycoming engine, and the UH-12E3T with the Allison turboprop engine.

The type has been reasonably popular in this region over the years, one of the first being a Model 360 (UH-12C – VH-THA – c/n 769)  imported in 1956 for the Australian National Airlines Commission (Trans Australian Airlines).

More than 20 examples of the series have been registered in Australia, the type being marketed in the 1980s by City and Country Helicopters Pty Ltd at Bankstown, NSW, selling examples in Australia and New Guinea.

The first turbine UH-12ET in Australia was obtained by Pacific Helicopters of Goroka and used in New Guinea for fertilising coffee plantations at a height of 1,981 m (6,500 ft).

One, operated by McIver Aviation of Hoxton Park, NSW, was used to inspect the Sydney to Newcastle natural gas pipeline in 1981 during its construction.

In 1954 James Aviation imported a UH-12B (ZK-HAB) to New Zealand for aerial spraying, the machine first flying at Hamilton on 11 January 1955.  It was initially used as a demonstrator and, whilst making a tour of the islands, made the first parachute drop in New Zealand from a helicopter at Hastings on 15 May 1955.

One of the main operators of the type was Helicopters (NZ) Ltd, which was formed at Timaru in 1955 as a commercial helicopter operator.  Like the Bell 47G of similar vintage, the Hiller 12 series was very popular in this region, one role it played in New Zealand being the recovering of deer carcasses from the mountains, after being shot by hunters as part of the venison export industry.

Operators of the Hiller 12 included Whirl-Wide Aviation Ltd, Alexander Helicopters Ltd, Angus Gordon Ltd and Luggate Game Packers.  By 1968 13 UH-12B, UH-12C and UH-12Es were registered in New Zealand, this figure increasing to 25 by 1982.  Of these at least five were known as the UH-12E-J3 Soloy, being converted to turbine power with the Soloy conversion provided by Soloy Conversions Ltd of Chehalis, Washington, USA.  This involved the fitting of the 313 kw (420 shp) Allison 250-C20B engine de-rated to 225 kw (301 shp), this unit being lighter and providing a higher useful load, being able to develop sea level power up to 2,134 m (7,000 ft).