GLIDING.

Hokitika Guardian, 2 November 1922, Page 4

GLIDING.

HOW IT IS DONE. 11E -\ IAUKA BE E IMtOGH ESS. Considerable good limy conic to aviation from the interest which is now being taken in what is commonly called gliding, though in it s present stage of development the operation m igh t more truly he called soaring (writes C. G. Grey, editor of the “Aeroplane,” England). 'the difference between gliding and soaring may be briefly denied thus: Jn gliding the aeroplane, which may or may not have a motor in it, descends from a high level to a lower level, whereas in soaring a machine maintains or increases its height. AGAINST WIND.

The type of glider in which public interest is being taken at the moment is to all intents and purposes an aeroplane without an engine, the weights being adjusted by putting the pilot further forward so that his weight corrects the balance in the absence ol an engine. These gliders are launched from the top of a Gill in the face of a wind blowing up the hill, and are borne on the upland current of the wind, and, so to speak, “coast” down the hill. FIRST AEROPLANE.

The Wright brothers’ first powerdriven machine was the outcome of gliding experiments from the tops ol sandhills in Florida, up which the wind was blowing straight- from the Atlantic. Numerous other people experimented wtli gliders at about this period, but none of them tve.r reached the soaring stage because the machines were all so inefficient. , CAUSE OF REVIVAL. During the war gliding practically ceased to exist, and its sudden 1 1vival is due entirely to the fact that the Jnter-Allicd Aeronautical Commission prohibited for a long time the manufacture in Germany of aircraft. Then, when tho Germans were again permitted to build aeroplanes, they were restricted by rules and re-

gulations of the Commission, which forbade them to build a single-seater aeroplane of more than (X) horse-pow-er, and forbade them to build machines of other types with more than certain horsepower, certain limited height, and so forth. The natural result was that German scientists turned their minds to discovering the most efficient possible form of wing and controls for aeroplanes. MURE EFFICIENCY.

If they were not allowed to lly with engines they resolved to lly without during the period of prohibition, so that they might thus discover how to make tho most ellicient aeroplanes »f

limited horse-power. Thus it is evident that tho foolish policy of the Allies ill prohibiting the manufacture of aircraft in Germany has merely forced

tho Germans to work for ellicicncy. whereas hitherto their tendency lias always been to (ram on more ami more horse-power and achieve high performance bv sheer brute force. GREAT PROGRESS.

flow efficient these gliders have become i.s shown by the recent wonderful performance m the Rhone Hills. They have now reached the stage

where practically no lip-eiiiTeiit is needed to start soaring. A slight fall of ground is sufficient to give the machine its initial impulse; in fad, some of them have started from flat ground, merely by Iceing towed along by handlines, which are let go as .soon as the machine leaves the ground. HOW TO SOAR.

Apparently actual soaring can only ho done in a gusty wind. 'I lie process consists in gliding forward and slightly downward till a. gust'hits the machine, whereupon the pilot, with the skill horn ot long practice, throws the nose of tlui machine up slightly and is lilted by the gust. As he feels the gust dying away he puts the nose of the machine down and gathers forward speed by gliding till he feels another gust hit the machine, when he cnee more throws the nose up and receives another lilt, the • motive power being the momentum of the machine gathered on the glide. USE OF EXPERIMENTS.

Naturally people ask, “What is the usefulness ol these gliding machines Y' Obviously they cinnot he of actual commercial value themselves in that they depend entirely on the quality ol the wind. Their real usd illness, there lore, consists in permitting aeroplane designers to study precisely the wing forms and lardy forms of aeroplanes which givt the highest cllicicnry. If a given type of glider is loimd to he extraordinary ellicient then ii i.s a fair assumption that n large aeroplane designed on the same lines, and fitted with an engine, will be more ellicient than an aeroplane of less ellicient type fitted with the same engine. FOR. YOUNG MEN.

Apart from that gliding may hecoiiu an exciting and comparatively cheap sport for adventurous young men who a.s the result of thou* gliding experience will naturally become expert aeroplane pilots if later they choose to learn to lly on a power-driven machine.