THE HELICOPTER.

Ashburton Guardian, Volume XLI, Issue 9543, 23 June 1921, Page 3

THE HELICOPTER.

PROGRESS IN AVIATION

POSSIBILITIES OF DEVELOPMENT

If recent reports from Europe are to be credited, it would seem that**- still another forward step has been made m the development of the aeroplane (says the Melbourne "Age"). It is said that a " helicopter ". machine is being completed for the British Gov- • eminent, and that another similar machine has been actually built successfully m Austria. Sliould these * machines give perfect results mankind will be m a position to surpass the birds m practically every branch of ; the art of flight — *a remarkable development, m view of the fact that it is only some 18 years since the Wright * brothers made their first free flight "m ' a motor-driVen aeroplane — and a very ' tiny flight at that. Already man, m < his powerfully engined aeroplane, can ' fly faster than the swiftest bird, he i can rival all the seagull's tricks of - gliding and " banking " m lazy curves, ( he can perform other tricks which no bird ever attempted. Whoever heard of. a bird " looping the loop" or whirling . earthwards m a spiral nose dive ? But up to the present the birds have had one triumph left to them. They knew the art of hovering motionless m the air, and of rising and descending vertically. And ' now man, with his helicopter, threatens to equal even that feat. v ] The helicopter is, m fact, a "direct lift " machine, which ■ can be lifted _ vertically from bhe ground by the pull 1 of '.whirling screws or propellers, and < can ' soar skywards without *ny forward ' movement. If perfected it should be . able to hover motionless at any height, . descending again vertically at any de- ] sired speed and sinking gently to the - very spot from which it rose. Af the same time, the fully developed helicop- , ter, for which inventors have sought * m vain m the past, should also be capable of forward movement m. the or- i dinary way when once it is m the ' air. Details of the experiments m ; Europe have not been made public, but it is to be presumed that any machine : which is attracting the serious attention of governments and military authorties gives promise of development : m this direction, and if the difficulty of combining the power of forward flight with that of hovering and of rising, and descending vertically at slow speeds has been overcome the results may be far- reaching. The lifting pressure which enables the modern aeroplane to fly is created by its forward rush through the air. Hence it is that the aeroplane requires a considerable stretch of open ground over which to run before sufficient speed has been attained to enable it to rise ; once m the air it must continue to move, and when landing it is always travelling at a considerable speed, and * again requires a clear run before it stands motionless. To some extent these handicaps can be overcome by skilful piloting and \by the construction of powerful machines, which rise from the ground at an astonishingly sharp angle. But their existence makes ' the construction of elaborate aviation grounds necessary, it renders a forced landing on any wild, or congested spot disastrous, it makes night flying dangerous. Will the helicopter remove these disabilities? A vertical Lift. As long ago as 1874 two French scientists, Launoy and Bienvenu, conceived the, idea of a flying machine lifted vertically by whirling screws', and a learned body of French scientists witnessed the flight of a toy ma- I chine, lifted by means of screw propellers, fashioned from feathers and corks. About the same time an English scientist. Sir George Cayley, who wrote widely upon problems of aerodynamics, constructed a very similar model ; and his little machine, of corks, feathers and whalebone rose successfully from the ground. These experiments were trivial m their way. But for long years afterwards inventors dreamed of helicopter machines, capable of lifting men from the ground, and imaginative artists and writers by the score have pictured /such machines with humming screws, mounted upon long shafts, like umbrellas, plying above the earth's surface. The practical engineering difficulties m the way of the development of the machine, however, were insuperable. It was impossible *to produce sufficient lifting power, for one tiling, to raise a heavy machine. Presently the pioneering work of the German, Otto Lilienthal, with gliders, turned men's thoughts to the perfection of machines with planes, and eventually the air propeller was used, not to lift these planes vertically but to force them forward at high speed through the air, thus producing the "lift" necessary for the machine to rise. Nevertheless, at various times hopeful "inventors attempted to perfect the helicopter, and during the. past fifty years several machines of this description were exhibited at European aeronautical shows. Needless to say, they never rose from their stands. An inventor nayed Lorenzon experimented with peculiar screws, somewhat like electric fans, testing their lifting power according to the ."pitch" of the blades. There was a machine called the Mumford machine, with six two-bladed screws, mounted upon a ' wheeled framework, and driven by a motor, the screws being so disposed that, m theory, a forward pull as well as a vertical * lift' would be obtained* 1 Another quaint machine the Cornu helicopter, mounted two big propellers something like canoe paddles, about a spidery framework. Somewhat similar inventions were turned out m France and America towards the close of the last century, the screws m all cases being driven by small motors. Apparently none of the machines ever left the ground ; and the development of the modern aeroplane put them altogether m the shade. Experts Divided.

But the idea of the hoyering machine has not it seems, been forgotten. It remains' to be seen whether the inventions' now reported m Europe have solved the problem, by means of the developments of modern science m engineering aiid aviation. Experts are divided as to the usefulness of the helicopter, now that the aeroplane has reached such a stage of perfection. But m some respects the yalue of a ma-

chine which would, at will, hover motionless m the v air, and which coma descend or rise gently, and vertically, and at the same time hy forward wlieii required, is unquestionable. Such a machine would probably be of great value m war for reconnaissance and artillery observation purposes. It could remain motionless for any required time, while its occupants mapped, or bombed, the ground immediately beneath, but could escape when attack threatened., or move on to another portion of the front. It could land on, or rise from, the smallest of aviation "grounds, perhaps from a clearing m the midst of a forest, or from a narrow sea beach, surrounded by precipitous cliffs. At night, or m thick fog, it could descend gently earthwards, and maybe hover .a while to allow its pilots to study tiie landing ground beneath them, or to search for a clear area. In exploration it might be of yalue, hovering just above wild or dangerous country, while the navigators photographed, sketched, and studied the country beneath them at their leisure, and more easily than would be possible m a fast-moving aeroplane, continually circling over the same spot.