History of the Helicopter (1952)

[Music] in recent years a new dimension has been added to fly vertical flights by helicopter the very speed on which the aeroplane depends and sometimes be a handicap only a helicopter can hover only a helicopter could reach this storm bound lighthouse vertical movement was Man's first vision of flight for centuries he tried to copy the pre controlled flight of bird and insect he hadn't the eye of the slow-motion camera to follow the subtlety of wing movement of birds such as the hummingbird but his attempts were brave enough not succeeding he gave flight divinity and held it blasphemous to try to reach the Stars but men of vision like Leonardo da Vinci continued to search for a means to fly he experimented with flapping wings and whirling wings it was he who applied the word helix meaning spiral to whirling wings helix combined with Tehran meaning wing becomes helicopter Leonardo da Vinci's whirling wing design was similar to the Chinese top a toy whose origin is lost in early Chinese history the top consists of a pair of wings at the head of a stick about two and a half centuries after leonardo's death an Englishman Sir George Cayley developed a more elaborate top on similar lines his interest had been aroused by a model made by Leno and bien Venu in France the Illinois and Bienvenu top consisted of two sets of wings which rotated in opposite directions it's unusual flight caused a sensation when demonstrated before the academy of sciences at paris by no menit learned that if the blades of a wing or propeller are set level they will only whirl when rotated but if they are set at an angle and then rotated the blades will produce lift kaylee gave to the world the first plans for a man carrying helicopter the aerial carriage his lead was followed by many others throughout the 19th century but they all liked a sufficiently light and powerful engine at the end of the 19th century men like poems on Demi core and fallen Eenie we're trying to adapt steam engines to aircraft but without success others notably the Wright brothers were working on fixed-wing airplanes the development of the gasoline engine which utilizes an easy-to-handle fuel made possible man's first successful full-scale flight in 1903 had the first successful flight been achieved with a rotary wing helicopter the history of flight might have been different the achievement of the Wright brothers overshadowed all others and established the fixed-wing aircraft but the moving wings still had its advocates for the first 30 years of the century they went on trying to make machines which would rise vertically into the air [Music] Oh in 1907 breguet produced the first helicopter to leave the ground with a pilot aboard the machine was unstable but it did prove that the rotating wing aircraft was feasible you but all these early machines were unstable and for safety the aircraft had to be tethered to the ground the stability of a rotary wing aircraft is particularly difficult first the rotation of the blades tends to make the body of the machine turn in the opposite direction this can be counteracted either by a small vertical tail rotor driven by the same engine as the main rotor or by two sets of main rotors revolving in opposite direction secondly when the Machine moves forward one blade of the rotor is moving with the air flow while another is moving against it the air speed of a blade increases as it turns towards the nose this produces unequal lift and therefore instability the answer to this problem was to hinge the blades so that they could flap and could also speed up or slow down relative to each other Juan de la Sierra discovered this and so managed to smooth out much of the irregularity of lift is solved another problem as the blades of the rotor are no longer rigidly fixed they are held in position only by centrifugal force the whole structure is therefore relieved of a great deal of strain they see other aircraft like this c19 all use this principle of a flapping blade but they were not helicopters they were auto gyros in an autogyro the propeller produces forward motion and the rotor is turned by the aerodynamic forces acting on it and not by the engine the autogyro was in fact an aeroplane on which the wings were replaced by a rotary the ordinary autogyro could not take off vertically although its take-off run was very short in later years vertical takeoff was achieved in the autogyro by coupling the engine to the rotor this principle could be used only for the takeoff meanwhile work on helicopters went on in 1930 fluorine showed his machine with a new flapping blade to the public at the Brussels exhibition in the same year Toscani o established the first world helicopter record with a flight of eight and three-quarter minutes covering 1,000 yards at a height of 59 feet he reached a speed of about 15 miles per hour six years later in 1936 the pioneer breguet came to the front with a much improved design in which the problems of control were tackled with considerable success records were established with this machine duration 63 minutes altitude 515 feet distance 27 and one-half miles at a speed of 62 miles per hour breguet used what is today known as cyclic pitch control this means that the angle at which a rotor blade meets the air is altered as the blade rotates with a hub by photographing the blades in slow motion they can be seen to rise and fall with the influence of the airflow and centrifugal forces when the aircraft is taking off the pilot holds the stick roughly central and the lift force is acting vertically the pilot moves the stick forward the advancing blade farthest from the camera decreases in pitch and flaps downwards the retreating blade nearest the camera increases in pitch and flaps upwards in effect the rotor is tilted forward it dust becomes the means of accelerating the aircraft forward as well as the means of supporting it in the air the pilot decides to turn to the right stick right the blade on the left flaps up the blade on the right flaps down the aircraft goes into a right hand turn in 1937 the first really successful helicopter the oculus was announced the flexibility and control of this machine were demonstrated when Hannah right fluid inside the Berlin sport stadium then another of the pioneers Igor Sikorsky who had been working on helicopter design from the beginning of the century achieve success in America all these discoveries helped to produce the helicopter as we know it today it's still curious to look at but it can fly in a way even surpassing the flight of birds it takes often land vertically hovers in the air and even turns a full circle over the same spot helicopter design is constantly progressing the precision of control is something of which does cameo could only have green the British Bristol 171 a single rotor type carries three passengers as well as the pilot in contrast to the sleek lines of the Bristol is the angular body of the giant air hoist produced by the pioneer company started by the late juan de la sierra the engine used in this helicopter is so powerful that the three rotors can lift a total weight of just over 8 tons this enormous capacity at last fills the gap between the usual helicopters with their limited loads and the aeroplane at the other end of this scale the CEO of a company has produced a small sister to the air horse a neat-looking two-seat personal helicopter called the skeeter the ferry companies gyrodyne is one of the world's fastest helicopter here we see it traveling at 120 4.3 miles per hour the gyrodyne uses an offset propeller to counteract the torque reaction of the main rotor this has the added advantage that the propeller gives additional trust to drive the aircraft in France Louis breguet one of the leaders of helicopter techniques designed this three seater using superimposed contra-rotating Rovers a development of the pre-war German out jealous keeping the original rotary configuration has been made by sudais and is designed to carry six people another French company sued West have developed an experimental helicopter with the rotor driven by jets at the blade tips one of the attractions of the jet driven helicopter is that as the driving force is at the tips of the blades there is no torque reaction to correct and tail rotors and such devices are not needed jet driven rotors have also been developed in America this experimental single-seater built by the mcdonald Aircraft Corporation is called little Henry the no hands flying of this killer Hornet demonstrates weld the great stability of helicopters employing jet ribbon rotors helicopter types and designs are unending the silhouette of the Sikorsky s51 one of the first helicopters to go into large-scale production is familiar throughout the world it flew the first certificated us helicopter air mail route speeding air mail from the Los Angeles Airport to the downtown post office and on to adjacent communities the Sikorsky now being built in England by Westlands has been used for experiments in carrying mail by Knights flying blind between two large towns these services for 10 the day when large helicopters like this Sikorsky s55 and the bell h.h 12 will be in regular service carrying male passengers and cargo between nearby cities and surrounding suburban areas smaller bell helicopters are now being used on the land with great success spraying crops and cattle dusting orchards where the downwash from the rotors direction secta side over and under the leaves rotor down wash is also used for a strange form of harvesting it's a simple way of gathering walnuts which can't be damaged by their forceful descent the helicopter is serving in the expansion of our vital oil reserves transporting exploration parties swiftly and economically to hard-to-reach locations in addition it can also serve as a work platform for precise geological readings a military helicopter the Piasecki or flying banana is like something out of a story by Jules Verne or hg wells the command a military trainer employs twin intermeshing rotors these eliminate the necessity of a tail rotor for emergency rescue the helicopter is unrivaled it can transport the injured to a hospital or the stranded to safety whether the scene of emergency is battle-torn terrain or the expense of a storm swept see Admiral Byrd took helicopters on his 1946 Antarctic expedition for surveys more detail than could be undertaken by a conventional aircraft a good example of a small helicopter with an all-round view is the Hiller 360 with its perspex bubble front it is excellent for police control of traffic aerial inspections and similar work the helicopter has provided new vantage points for the tourists there is no better way of seeing the Grand Canyon for herding cattle or elk there is the comfort of a helicopter with its large field of vision and its ability to fly slowly the helicopter has been used to do work that seemed impossible here it speeds construction materials high up into the Welsh mountains to repair a damn you yes the helicopter has arrived prehistoric to look at but so versatile that it fills an important gap in transport rotary wing flights is now a reality the helicopter is part of a fantastic future in which you and I may fly about in our own private aircraft but we must not be led astray by a brief the helicopter will not supplant the car or the airplane but as chemists and engineers continue their unending search for better fuels and lubricants for flight for lighter and more powerful gasoline engine for more efficient jet engines and for improved airframe design the helicopter will enable us to fly with a freedom we've never had before [Music]