The helicopters in use today cover a period of time from 1947 to the present. They have gone from being a novelty to being the work horse of the aviation industry, performing tasks of every imaginable description. In this period, the industry developed a large commercial fleet which has exceeded the air carrier and corporate aviation fleets in size. This unprecedented growth did not occur by accident but because of the versatility of the machine and the ingenuity of the operators seeking new possibilities for their use as a fast and efficient method of completing various tasks, including construction, agriculture, forestry, and business. At this time there is probably no area of the economy that is not touched by the helicopter in some manner.
To meet the ever-increasing demand to fulfill the needs of the helicopter operators, manufacturers have increased the reliability, decreased the maintenance requirements, and designed new helicopters. They include three generations of machines, from reciprocating two-place helicopters to those that are turbine powered and carry many passengers. Because of the many different types, it is important to know about those in use today and their capabilities as described in this section.
BELL HELICOPTERS
1. Bell 47
The Bell 47, in 1946, was the first helicopter to receive civilian certification. This helicopter enjoyed a long production life, until 1974, when it became too expensive to manufacture. During this period it was manufactured in a great number of models and its components have been used to build special purpose helicopters. It is also presently being converted to turbine powerplants. This helicopter once enjoyed such popularity that more Bell 47's were in use than any other helicopter in the world. Although this is no longer true, they are still in wide use today, performing numerous tasks such as flight training, agricultural work, traffic control, etc. It will undoubtedly lose its popularity as new and more modern equipment is introduced, but at this time it could certainly be considered the DC-3 of the helicopter industry.
Because of the great number of models manufactured, each individual model cannot be shown. The following is a list of the various models and their major differences. Of course this list cannot point out all the differences of the various models of this helicopter. Because of the great numbers built for civilian and military use, and the continual updating of the older models, no attempt will be made to give the number of them in existence.
2. Bell 204
From its beginning with the Bell 47, the company grew, building several additional, models for civilian and military use. Many of the military models were modified in design and later became civilian models.
The 204B model was a derivative of the U-H1 series of helicopters built for the military. Although the two helicopters appear very similar in appearance, many changes were made between the civilian and the military aircraft, including the length of the tailboom, baggage area, and rotor blades.
The 204B is an 11-place helicopter with turbine power. Although built in small numbers, the 204B paved the way for the turbine-powered helicopter and the use of such helicopters by the petroleum support industry.
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