The History of the Helicopter, 1952

the 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 about all others and established the fixed-wing aircraft but the moving wing 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] in 1907 reggae 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 [Music] 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 directions secondly when the machine moves forward one blade of the rotor is moving with the airflow while another is moving against it the airspeed 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 cierva discovered this and so managed to smooth out much of the irregularity of lift this 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 sear the aircraft like this c19 all use this principle of the 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 aero plane on which the wings were replaced by a rotary the ordinary autogyro could not take off vertically although its takeoff run was very short in later years vertical take-off 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 Florine showed his machine with a new flapping blade to the public at the Brussels Exhibition in the same year d'ascanio established the first world helicopter record with a flight of 8 and 3/4 minutes covering 1,000 years at a height of 59 feet he reached a speed of about 15 miles per hour six years later in 1936 the Pioneer Brigade 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 1/2 miles at a speed of 62 miles per hour Roger 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 the 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 furthest from the camera decreases in pitch and flaps downwards the retreat blade nearest the camera increases in pitch and flaps upwards in effect the rotor is tilted forward it thus 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 Occulus was announced the flexibility and control of this machine were demonstrated when Hana right fluid inside the Berlin sports stadium then another of the pioneers Igor Sikorsky who had been working on helicopter design from the beginning of the century achieved 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 off and lands 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 d'ascanio could only have dreamed 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 horse produced by the Pioneer company started by the late one de la cierva the engine used in this helicopter is so powerful that the three rotors can lift a total weight of just over eight tons this enormous capacity at last fills a gap between usual helicopters with their limited loads and the aeroplane at the other end of this scale the cierva company has produced a small sister to the air horse a neat looking two-seat personal helicopter called the skier the ferry company's gyrodyne is one of the world's fastest helicopters here we see it travelling at 124 point three 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 thrust to drive the aircraft in France Louis breguet one of the leaders of helicopter technique designed this three seater using superimposed contra rotating rotors a development of the pre-war German FACA oculus keeping the original rotor configuration has been made by su DES 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 such devices are not needed jet driven rotors have also been developed in America this experimental single seater built by the McDonnell Aircraft Corporation is called little Henry [Music] the no hands flying of this Hiller Hornet demonstrates well the great stability of helicopters employing jet driven rotors helicopter types and designs are unending the silhouette of the sikorsky s-58 ago into large-scale production is familiar throughout the world it flew the first certificated US helicopter airmail route speeding airmail 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 night 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 down wash from the rotors directs insecticide over and under the leaves rotor downwash 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 piaseki 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 expanse of a storm swept sea Admiral took Helen item 46 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 provided new vantage points for the tourist there is no better way of seeing the Grand Canyon for herding cattle or elk there is the comfort of a helicopter but 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 dam [Applause] yes the helicopter has arrived prehistoric 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 dream 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 engines for more efficient jet engines and for proved airframe designs the helicopter will enable us to fly with the freedom we've never had before [Music] [Applause] [Music] [Applause]