THE ART OF GLIDING

Taranaki Daily News, 25 July 1931, Page 13 (Supplement)

THE ART OF GLIDING

INTRODUCED TO DOMINION

(By

“Senex.”)

The recent decision of a group of interested enthusiasts to form an organisation to further the sport of gliding will introduce to New Zealand an activity that has for long had many followers in the older countries of the world whose persistent efforts to improve and perfect their machines have resulted in the acquisition of many data of value to the theory of aeronautics. That a keen interest in gliding is still taken in Europe was seen by the offer by an English daily paper of a prize for the first person to glide across the English Channel and back. Almost immediately after the offer was made several pilots were in the race for tho prize. On the day it was won by the German, Kronfeld, five other pilots waited all day long to make the attempt. Gliding is the art of flying heavier than air machines which are not provided with an engine. The whole oi the art depends upon the skill with which up-draughts and helpful eddies of air are used. It requires great skill on the part of the pilot in _ manipulating the controls of the machine so as to maintain the proper equilibrium. The pilot often is able to gain altitude by guiding Ins machine into localities calculated to supply rising air-currents. Ths skill that may be attained may be seen from the fact that one German pilot made a trip of 282 miles without the least outside assistance. The unassisted altitude record is 11,000 feet. The double crossing of the English Channel was made with the assistance of an aeroplane, which towed the successful competitor’s glider to a height of 10,000 feet before the glider cast off. There seems little merit in this performance, for even an aeroplane is capable of gliding for one mile for every 1000 feet of altitude it has- attained, and some Moth machines can perform even better than that. But the use of aeroplanes to give gliders an initial altitude has not in Europe and America been a part of gliding as it is practised by enthusiasts. Machines have generally been launched from the slope of a hill, with only the power of man to give them the initial impetus into the air. A glide across the 22-mile channel from a height of 10,000 feet is not to be compared with a flight of 282 miles begun from a hill only a few hundred feet high. Modern gliders are equipped with all the controls of an ordinary aeroplane. There arc controls for ailerons, rudder and tail surfaces, and the machine is carefully stream-lined. The length of ■wing is generally between 25 and 30 feet, though the machine that Kronfeld used had a 98-feet span, the largest in the world. The requirements for gliding are not simple. In the first place there is necessary a hill from 100 to 300 feet in height which slopes from the level plane at first slowly and then more abruptly to a rounded crest. Some districts of New Zealand may find these conditions difficult to fulfil. The hill should also face towards the prevailing wind, as aircraft may only take off the ground into the wind, and the slope of the hill should preferably be several miles long. The experience of pilots of gliders has taught that there are many other air conditions to be observed. Heavily wooded country, it has been found, is difficult to negotiate in a glider on account of the down currents that are generally present, whereas it is up currents that the pilot seeks. Certain types of cloud, such as cumulus clouds, however, supply glider pilots with - consistently reliable source of up currents. An experienced pilot can remain aloft for hours if he can find a suitable specimen of cumulus, and on several occasions gliders have 'been kept in the air for between 10 and 14 hours.

Though for centuries the mind of man has dwelt often on the possibilities of flight, it was not until the 70’s of the last century that the first significant glider work was carried out. This was done by Captain Le Bris, a French sailor. Like the first aeronauts he attempted to copy the birds in the construction of his machine, basing the shape of the body and wings upon those of the albatross. He was actually successful in remaining aloft for short periods in several remarkable glides, 'but he had no scientific knowledge of the principles of aeronautics. His success depended more upon his good fortune than upon his skill. Nevertheless he had glided, even if he contributed little of value to the science of flight. Tn too, interest was aroused by the studies in aerodynamics of - John J. Montgomery, who for about 10 years engaged almost continuously in experimentation that was full of results. For his first glide he chose a hill sloping gradually at an angle of about ten degrees for a mile. He jumped into the air from the top of this hill without even running and executed a glide of 600 feet, no small feat in those early days of experimentation. Montgomery, however, was not satisfied with gliding under the conditions of the day. He obtained the services of a balloonist, who hoistad him 4000 feet before releasing him. \iie skill Montgomery had attained in control is aptly illustrated in a description of the event by one of his pupils, who wrote: “In the course of the descent the most extraordinary and complex manoeuvres were accomplished—spiral and circling turns being executed with an ease and grace almost beyond description, level travel accomplished with the wind and against it, figure eight revolutions performed without difficulty, and hairtaising dives terminated by abrupt checking of the movement by changing the angles of the wing surfaces. At times the speed as estimated by eyewitnesses was over 68 miles per hour, and yet after a flight of approximately eight miles in 20 minutes, the machine was brought to rest upon a previously designated spot three-quarters of a mile from the place where the balloon had been released so lightly that the aviator was not even jarred despite the fact that he was compelled to land on his feet, not on a special alighting gear.” From ’then on the popularity and value of gliding was firmly established. Lately Germany has come into the field and her pilots have won considerable success. For one thing the construction of large planes in Germany was forbidden 'by the Versailles treaty, and for another the meteorological conditions in the Rhine Valley proved peculiarly suitable for long soaring flights. No one yet knows how suitable New (Zealand may prove to be. There are all types of country and all types of weather conditions, Unheard of feats may yet be performed.