FLYING HIGH FOR GREATER COMFORT

Wanganui Chronicle, Volume 79, Issue 181, 5 August 1935, Page 10

FLYING HIGH FOR GREATER COMFORT

More Speed: Less Power

NEARING THE STRATOSPHERE

The true stratosphere plane is not yet, writes Mr Reginald M. Cleveland in the “Scientific American.” Nevertheless, air line operators are looking to higher and higher levels, and actually sending their big transports with supercharged motors and controllable pitch propellers into altitudes of 12,000 to 20,000 feet lor regular flying. Only a year or two ago these strata would have been considered no place for a passenger aeroplane except when necessary to hurdle a mountain range. They are doing this for two reasons—first, economy and regularity of operation; second, comfort for the passengers. Discussing the first motive, Mr Clove land says it is well known that at about 18,000 feet one is normally above the cloud area, and has perfect visibility. Through the rapidly developing science of air mass analysis or “polar front’’ weather predicting, definite strata of favouring winds can be selected with surprising accuracy, especially at high levels. Furthermore, cruising speeds with modern supercharged engines, and with adjustable propellers, can be maintained around 200 miles an hour in thin air, using only about 75 per cent, power, although the throttles may actually be wide open. The newest propeller development, the Hamilton automatic “constant speed” propeller, is destined

lo aid materially in such operation. It maintains any chosen engine revolution by automatically changing pilch of the blades through the action of a simple governor controlling oil pressure. ]t Ims been determined that on a journey of (iU() mill’s with a specific 200-mile-an-huur aeroplane, equipped with modern engines and propellers, 26 minutes <aif be saved by climbing at once to J3,-100 feet, and then cruising at. this level for most of I he journey before beginning the landing glide, ns compared with Hying the .same distance with the same aeroplane al or near sea level. Regular transport Hight over long dis tanc.es at altitudes from 15,000 feet upward, however, will inevitably mean the use of fully sealed cabins supplied automatically with oxygen to compensate for the rarity of the atmosphere. Oxygen in flasks is already supplied when such journeys are in contemplation. It has been used regularly on

Van American Airways over tin: Andes for a number of years, ami on spoctacu lar t rans-eont incut a I Hights. But this is nut scaled cabin operation. It is but n .stop, however, from furred and sound proofed ventilation, already a feature, of modern transport planus, to the .scaled cabin w ith controlled oxygen supply. Hurh equipment would appear to be a necessity in the nature of things if I he high lev els are lobe continuously used, since human reaction to altitude is a. matter of heart, lungs and nerves Disturbing or even tragic incidents might well occur vvliicn could readily be prevented if the sea-level oxygen con tent of the cabin were maintained, no matter how thin the air which the plane was cleaving. The whole question of passenger comfort is one. which the airlines are finding of growing importance. Creature comforts in the main have been well provided. Notable advances in soundpnrooling ami in the elimination

of libration murk tire most recent typos of air liners. Temperature control is already satisfactory.

While a high speed aeroplane is enabled by its very swiftness lo avoid many storms and turbulent areas, it is also true that when it does get into rough air, tho impacts or gusts and bumps are much more severely felt than lat lower speeds. The plane structure maw be of such strength as to be able safely to withstand the stresses invol veil in these impacts; it may bo able with complete security to plough through the storm and thermal currents oxer broken terrain, mountains, quickly alternating land and water, and the like. But the passengers uro duo for a very unpleasant ride under these coudit ions. Much icutaiiis to be learned, of course, in the realm of the relation of w (father lo flight from Hit' point of view of smoothness. The development of air-mass-analysis weal her-forevust ing holds out immense promise of much more delinil:: and accurate long-range prediction. It, is sure to play an important role in the economies of air transport, and there are those who believe that 10 or 15 additional miles an hour average cruising speed, without increase in horse power <>r design modification, may bo its gift 1o air travel. It is quite possible that it can do much also to iron out (he bumps for the. traveller.