SNOWSTORMS AND AIRCRAFT.

Pukekohe & Waiuku Times, Volume 5, Issue 229, 24 November 1916, Page 7 (Supplement)

SNOWSTORMS AND AIRCRAFT.

SEVERE TESTS OK ENDURANCE. A number of De Haviland machines ascended from their English aerodrome in the early Spring. They set course for the shores of France. Unfortunately, a severe snowstorm was encountered en route, and several came to grief. So much was learned from the official inquiry into the state of our air services. It is 110 light task that confronts tin aeroplane suddenly thrust into an impenetrable wall of snow in mid-air. Heavier than air machines, observation kite-balloons, rigid, semi-rigid, and non-rigid dirigibles of the Zeppelin, Astra-Torres, and Silver Queen types respectively, are all in varying degree affected by this potent menace to aerial progress. It not infrequently resolves into a do or die effort of men and machines against the vagaries of oiir "equable" climate. Should human endurance and contrivance come out victors many a thrilling tale is attached thereto. Ther are two distinct classes of snowstorms. The hurricane blast carries on its wings myriads of vicious ice particles. The steady, settled fall of giant, feathery flakes is usually accompanied by appreciable air currents. In the latter case especially the sources of supply. snowclouds themselves, are banked up at relatively loiw .altitudes. Their vast depth and extent, however, often render nugatory any attempt at navigation to higher and clearer spheres beyond. FIGHTING THE SNOW. Early in the month of February last a naval seaplane was scouting far out over the North Sea. There had been a calm, if somewhat threatening, sky :w along. When ninety minutes' journey from the coast, however, a thick grey mantle, of snow seemed to drop from the clouds and interpose between the seaplane and its base. _ The petrol gauge showed a supply in the tanks which did not allow of a sufficient margin to justify circuitous manoeuvring in search of openings. There was nothing for it but to head through the storm. Falling snow swiftly encompassed the machine. Clouds and sea became illseparable to the eye. It was very dark. The atmosphere, was singularly oppressive. Once a. free ''pocket" was reached, but again the snowy pall closed in and completely enveloped the 'pi me. The st;rm was ultimately left behind. and although the aerokl registered l,oflO feet to commence with it. the finish only 200 feet showed. All through the flight the pilot had endeavoured to keep the machine 011 the upward grade, but despite this the reverse had oceured. The density and weight 0! the falling flakes and the resultant 'ow atmospheric pressure had combined forces to this end. The main plan and fuselage hugged the snow with incredible rapidity. All icy film ei.llected. notwithstanding the speed f the machine and heat radiated from the engine. Tiiis a etc I instantaneously on the 1 irge span of wing such as our heavy waterplanis necessarily possess. The add mi resistance of the bulky floats pas-iiie through snow as compared with a r alone. :■ n,I similarly ice-coated. ;!>() r.iO!i:<-'".t.iri'y increa-od the total weight of the scapian- 1 . Til I-! V Ai.t'K UK A DRY PROPELLER. Apparently iJie hiuhly-pol-shrd liardw ood tr.u t 11 cnti'd noi maintain H - norm..! "grip" on the air strata. 'lh> low prr--iirc oi the atmosphere partly accounted for this. ;.nd the blade wa«, of n.'iirrc, wet. A bone dryness in this important unit is in itself e-sential to top-notch eliic'eney. Conscqu ntlv the required ''revs' were not obtained from the engine. "The machine was forced by that combination of circuinsf'Miees gradually downwards, the actual drop being I ..iOO ftvt in a 20-mile flight- when the storm was passed a stern. Greater personal discomfort is experienced bv the pilot and observer 111 llu* oilier type of snowstorm owing to the wind. A biting, razor-edged blast drives lot drops stinging against, the planes tn the deterioration of the fabric and the annoyance of the airmen. The cold is sub-antarctic in its intensity. Sudden, impulsive gusts hitting

the wings, strain stays fifty different i directions a minute. Struts are mmutely tested, and over all strength is not infrequently taxed to its utmost. One moment the machine is lifted bodily; another, and she "pancakes' 1 perhaps thirty to litty feet like a parachuta. Even if there is 110 question of the aeroplane itself withstanding such conditions it is a searching endurance test for the occupants'. Be they ever so well muffled up by thick woollens and sweaters lieneath their leather suits the cutting wind seems to pierce through everything and chills the marrow. Face and gnuntletted hands ' grow benumbed with cold. Freezing snow duns the outside of the goggles, and gathering moisture within necessitates constant thawing or removal. Control wires have, to be incessantly worked to prevent jamming, owing to frozen drift in the fairway leads and tubes. If the machine is fitted with wireles . apparatus, as is the rule, the aerial — a long-stranded wire trailing hundreds of feet behind —has to be wound in. 't presents a considerable amount r -f drag, a.nd acts as a brake or hindrance, to both speed and " lift"' in these circumstances. Furthermore, the wireless would be, in our high-power sets, none too safe to operate, owing to "shorting," or the running amok of the high-tension oscillatory currents across the semi-conductive ice film. This, in conjunction with the presence of petrol vapour, practically constant in the vicinity of aero-motors, would be liable to cause fire and probable disaster. FURTHER PROTECTION EOR AIRMEN. When a scheme of covered, and full; protected, cabin accommodation is substituted lor the generally open seat 111 'planes to-day, the human element will be enabled to better perform its functions in extraordinary conditions of this nature. Zeppelins were operating over the Eastern Counties on at least one occasion last winter during a snowstorm. This, however, was comparatively slight, and almost purely of a localised character. The first thing a Zeppelin would do if doubtful of the storm's extent, would Ik? to rid itself of as much superfluous weight as possible. As in wartime bombs take the place of waterballast, then naturally bombs would be dropped, probably hurriedly and indiscriminately at that, as would all ballast. An airship having such a vast surface area could not effectively operate in a prolonged and extensive fall of snow, even if totally unhampered by wind. Even if it did soar above the clonids, its position would be absolute guesswork, relative to bombing any particular spot. Otherwise, irrespective of the speed 40-GO knots the dirigible might have, the snow would collect to an appreciable depth 011 the vast surface of the envelope. It would not unlikely be down by the nose, owing to the warping of the aluminium framework within the fabric. The prow packs hard with snow and ice to a greater extent than the remainder of the hull by reason of its very position—heading through the snow. About an eighth of an inch of snow on the upper surface alone is calculated to weigh more than the airship s earn ing capacity. Should the Zeppelin in such straits be favoured by good luck and manage to get out of this country again, it would he in a sorry plight indeed. Crippling aloiTg at little more than water-level, it would fall an easy prey to our auxiliay patrols, or crock up into the waste of waters of the North Sua.