NEW FACTOR IN FLIGHT.

Dunstan Times, Issue 3141, 30 October 1922, Page 2

NEW FACTOR IN FLIGHT.

(By Major C. C. Turner.) Unquestionably, a new and very important factor has entered • into mechanical flight, and although it certaunlv does not portend the doom of the motor-driven flying machine, it probably does signify important changes :n design, a great extension of flying, and a new element in training and education for flight. The first question that arises, and demands an answer, relates to the principle: Is 1 there a secret yet unsolved? Do the soarers pierely take advantage of rising currents and of the impact of oncoming gusts, contriving their turning movements and down and up gradiants accordingly, or can a flying machine be so constructed as to obtain not only lift from its speed through the air. but also speed itself, without any propulsive mechanism? It is important to remember that on a, down gradient an aeroplane speeds up to a velocity that can immediately be turned into Climb. The question that must be settled is whether or not a. great new discovery is at hand; and have certain birds and insects the secret ?

Many observers of natural souring flight contend that no principle is involved other than those already expressed in the aeroplane, and that buds and insects perform their marvellous soaring flights with motionless outstretched wings and a sense of the movements of the air to which human beings will only attain alter prolonged, careful study and hard experience. [Jut a new school has arisen, its principal exponent being DrE.H. Hankin, M.A., D.Sc. formerly chemical examiner to the Indian Government. Dr Hankin believes that certain birds and insects obtain from the air some force hitherto unexplained. He discovered that all the more efficient soaring creatures have a peculiar wing formation, the under surfaces being characterised by a series of transverse ridges. and that nonsoaring Hying creatures have not this feature. He further discovered that the seagull soars in descending currents (which confounds orthodoxy), and that when at a. low level it can soar only in a descending current. Dr Hankin's exhaustive observations of soaring birds in India have been compiled, making one of the classical contributions to the subject. . U does not appear that any of the Gorman experimenters have attempted to embody the principle of the transverso ridges in the construction of their wings, but that they have depended rather upon refinement of design and upon an acquired knowledge of '-the internal structure of the wind." Heir Martens speaks of the great strain on his nerves duo to watching the contours of the ground and taking advantage of every ascending current. It would appear, however, if this bo all, that soarers would be to a great extent at the mercy of the ground formation and of the wind so far as the direction of their tlifiht is concerned. It is therefore difficult to explain how some of the flights Mere made ill' windless air, whilst others consisted of numerous perfect figures of 8. Some of the soarers flew as high as (500 ft., and one maintained flight for more than two hours. Beside the German achievements those of French experimenters have been insignificant; indeed, not so good as Mr Orville Wright's gliding flight of 9min 49soc in October. In Great Britain there has been a curious apatliv, and one would have thought a large number of young sportsmen possessed of means and leisure would have been inspired by the German experiments, which first assumed an important .shape two years ago. It is not a question merely of cutting down the weight of the apparatus. The Wright brothers' glider averaged 1 Jib per square foot of wing. Some of the German soaring machines arc; about the same weight. Hut the loading of the albatross, one of the most efficient soaring creatures, is more than 31b to the square foot. It is inevitably suggested that increasing mastery of soaring flight (whatever ma.v be its complete explanation) will lead to the designing of aeroplanes with engines of two or three horse-power, just enough power to allow considerable speed and additional mastery over the air—hence, safety and reliability. In all probability, however, it would be desirable to extend very greatly our knowledge of soaring before attbempiting low-power machines. The addition of an engine at the present stage would merely confuse the issue, and would add to the cost of construction and upkeep. Moreover, ii would increase the danger, since reliance upon an engine likely at any moment to fail might lead to a bad descent, which, owing to the greater weight. would lie at much greater speed than that of the pure soaring machine. Now that several flights exceeding one hour have been made, and one exceeding two hours. it is evident that a very great deal of observation and experience will be possible without the engine; would, indeed, be impaired by the presence of an engine.