Country of origin:

United States of America

Description:

Three-seat light utility helicopter

Power Plant:

One 194 kw (260 hp) Lycoming TVO-435-A1A six-cylinder horizontally-opposed air-cooled engine

Specifications:

History:

Probably one of the most, if not the most, produced helicopters in the world, the Bell 47 series began when the Bell Aircraft Corporation commenced the development of helicopters in 1941 and flew the first of five experimental two-seat prototypes in 1943, the first being known as the Model 30 powered by a 123 kw (165 hp) Franklin engine. Variants were built with both open cockpits and enclosed cabins. The Model 30 design was the forerunner of the Model 47, which became the world’s first mass-produced helicopter.

By the end of World War II, Bell had set in train the production of the Model 30, and an initial batch of ten machines was laid down, these receiving the designation Model 47. The first of this batch, the prototype for the series, flew on 8 December 1945 and, by the following March, the Type Certificate had been issued.

The Bell 47 series was designed along what is known as classic Sikorsky lines, with a single main rotor and anti-torque tail rotor, but a feature of the 47 was the use of a stabilising system for the rotor which acted in such a way as to keep the rotor in the horizontal plane regardless of the angle of the rotor shaft.

Subsequently orders were received from civil and military operators and some thousands were built during its production life at the Company’s Fort Worth facility in Texas, USA, as well as under licence by Agusta in Italy, and Kawasaki in Japan.

As with most types, the Bell 47 was developed to meet customer requirements, variants being built with a variety of engines. Models built included the Model 47, 47A, 47B, 47D, 47E, 47G, 47G-1, 47G-2, 47G-3, 47H-1 and the 47J series, the latter “being dealt with elsewhere. Until the arrival of the Robinson R-22, the Bell 47 was the most populace helicopter in this region.

In 1960 the type entered service with No 16 AOP Flight of the Australian Army at RAAF Fairbairn, ACT and subsequently continued in service until 1977, when it was replaced by the Bell 206B Kiowa. Other units which used the type were No 161 Recce Flight in Vietnam, where eight aircraft were lost over six years of operations, and Nos 162, 171 and 182 Flights.

The first batch received were Bell 47G-2 Sioux (serials A1-560 to A1-570 – c/ns 1560 to 2570). In 1962 three 47G-2A Sioux were obtained (serials A1-660, A1-672 and A1-721 – c/ns 2660, 2672 and 2721). From 1965 to 1969 a further 51 were obtained, these being Bell 47G-3B-1s (serials A1-394 to A1-410 – c/ns 3394 to 3410; A1-635 to A1-648 – c/ns 6635 to 6648; A1-673 c/n 6673; A1-720 – c/n 6672; and A1-721 to A1-738 – c/n 7401 to 7418). The survivors of the 47G-3B-1 series later were re-serialled in the A1-201 to A1-252 range.

After withdrawal from service a few found their way on to the Australian Civil Aircraft Register. The type has been used extensively in the training role, as well as for cropdusting, utility work, charter work, cattle mustering, etc.

Work has taken place over the years to extend the life of the type and Soloy Conversions Ltd of Washington in the United States has supplied aircraft already converted, or conversion kits, for Bell 47Gs to be fitted with a 313 kw (420 hp) Allison 250-C20B turboshaft de-rated to 201 kw (270 shp), permitting an increased max take-off weight of 1,451 kg (3,200 lb). Examples of this model have been registered in Australia and New Zealand. US, Italian and Japanese-built examples have been registered, and some remain on the Australian Register. A few ex-military machines are preserved in museums.

The Bell 47G series has also seen much service in New Zealand, with more than 60 examples imported over the years. Airwork demonstrated the type to the NZ Army at Trentham in July 1961 but no order was forthcoming at that time. In 1964 six 47G-3B-1s were imported for the RNZAF (serials NZ3701 to NZ3706) and were operated by the newly formed No 3 (Battlefield Support) Squadron at Hobsonville from December 1965.

In June 1968 seven Model 47G-3B-2s were ordered (serials NZ3707 to NZ3717) and these were also delivered to No 3 Squadron during 1970. During that year three were attached to the Pilot Training Squadron at Wigram. Of a total of thirteen machines received, only five survived. Those lost in accidents over the years included NZ3711 (c/n 6813), NZ3707 (c/n 6809), NZ3703 (c/n 6516), NZ3701 (c/n 6514), NZ3708 (c/n 6810), NZ3709 (c/n 6811), NZ3710 (c/n 6811), and NZ3704 (c/n 65170).

The type has also seen much civil service in New Zealand on a variety of duties. In 1956 James Aviation obtained a Bell 47G ZK-HAC (c/n 1511) and some of its early work included carrying supplies and surveyors to isolated points of the Whakatane River in early 1957 during investigations into the future use of hydro-electric power, followed by further work on the survey of the Motu River. Later the machine was taken to the south island where it flew uranium prospecting teams into the mountains of North West Nelson province. On 7 May 1957 it was damaged when a skid hit a rock and the aircraft had to be abandoned, a salvage team only being able to recover some items before it was washed away by floods.

The first Bell 47 seen in New Zealand was a US Navy HUL-1 on board the Icebreaker ‘USS Atka’ in Wellington in January 1946, the vessel being destined to operate in the Antarctic. During its Wellington visit it was flown to and made a landing at Wellington Zoo, causing a few problems to some animals.

Rudnick Helicopters was another operator with Bell 47D-1s, the first ZK-HAA (c/n 35 – ex N181B) entering service in 1956, followed by ZK-HAD (c/n 20 – ex N166B), ZK-HAG (c/n 46 – ex N192B) which later became VH-UTR, ZK-HAI (c/n 43 – ex N189B, TG-C-HOH, N189B) which later became VH-UTT, and ZK-HAJ (c/n B20 – ex N100B) which later became VH-UTU, being used for spreading fertiliser, spraying and conveying supplies.

The Bell 47 was used for a variety of tasks, including the recovery of deer carcasses as part of the NZ industry of exporting venison. In the 1960s, when the venison industry was operating at its peak, some 50 helicopters were being operated by The Helicopter Line and the Alpine Deer Group. ZK-HAA was retired in 1963 and exported to Australia where it was rebuilt and became VH-UTL in 1966.

Other operators included Airwork, which used Bell 47s to carry out Government contracts lifting pylons, masts and cables for the Electricity Department along the Kaikoura coast, lifting material for the construction of buildings in the Abel Tasman National Park, carrying Land and Survey teams, etc. In the 1960s, as the RNZAF had no helicopters, the civil operators were regularly called to assist in mercy flights, rescues, etc.  A few soldier on and a couple are flown as warbirds.