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Aviation History
1912
1912 - 1242.PDF
[/jJGHT system, and the effect of this rigid construction upon the lateral control. Should a vertical gust strike the extremity of a wing so that it be driven downward, overcoming the inertia of the body to which it is attached, with ensuing complete displacement of pressure from beneath the wingi, the unbalanced mass falls sideways ; the weight of tin- engine right ahead converts the side fall into a head long dive, and the entire rigid structure tumbles to disaster. Were the wings so mounted that when struck by a vertical gust at either extremity they might have rotative motion, in a lateral sense, alwut the body, this disturbance of their balance would leave the balance of the body, the great mass of the machine, laterally unaffected, and the pilot, through his balancing planes, would more easily control the lateral balance of the minor mass of the system contained in the wings than the lateral balance of the whole mass of the machine. But this does not confer absolute security, because the ready manipulation of the balancing planes would still depend upon the vigilance of the pilot, and he may not always be alert. But if the balancing planes were mechanically connected to the body, this, the main mass of the machine, laterally free of the wings, and stabilised in its normal position by its inertia and connection with the balancing planes, would enable the wings when struck at either extremity by a gust which impelled them to rotative motion about the body to operate the balancing planes instantly, and oppose them to the 33 lbs. per square foot pressure of the hundred and five- mile current created by the forward motion of the swift machine. This would effectively check the impulse to rotative motion, that is the tendency to lofs of the lateral balance of the wings which contain the minor weight of the aeroplane, while the lateral balance of the body containing the major weight of the system would remain undisturbed. Thus stability, laterally, may be automatically obtained. But it is necessary, in order that absolute stability in air may be secured, that automatic stability, in a longitudinal sense, shall also be made effective. In consitlering the methods by which fore and aft stability may be automatically achieved, it would appear that the extended dis tribution of the main masses of the machine, and their rigid fixture to the body-shell, prevent the absolute efficiency of the present longitudinal control. The engine, the chief mass, is usually fixed at the forward extremity, necessitating disposition of balancing muses unduly to the rear of the centre of pressure, this extended distribution of the masses tending to greater danger from their moment of inertia on displacement of the normal attitude than need 1MS incurred. Concentration of the masses at the transverse axis reduces this danger, but will not eliminate it if the masses be rigidly fixed in this position ; for should a gust displace the pressure From l>encath the wings, the aeroplane, wings, body, and the masses contained therein, the whole forming an entirely rigid structure longitudinally, will fall in the abnormal attitude to which it is impelled, and will require space wherein to recover balance. But as there may not always be sufficiency of space, it is vital that means should be devised to prevent at its beginning any impulse to an abnormal attitude of the machine. If the concentrated masses, instead of being rigidly fixed to the body-shell be s<> mounted that the wings and body-shell when struck by a gust may rotate longitudinally about them without being; able to disturb their normal attitude, the danger from the moment of inertia of these masses, the major weight of the system would be eliminated, and the pilot would only have to prevent the assumption of an abnormal attitude of the wings and body-shell, the minor weight of the machine. Hut this does not make for absolute immunity from danger. The longitudinal balance of the main masses of the system has been placed beyond attack ; but there is still dependence upon the pilot for the maintenance, through his control of the elevator, of the normal attitude of the wings and body-shell, and • sudden assault may defeat his vigilance. Hut if the pilot's control of the elevator were connected to the concentrated masses, these, stabilised in their normal position by their inertia, method of mounting, and connections with the elevator and driving-gear, would enable the wings and body-shell when struck by a gust causing them to attempt rotation about the masses, to actuate the pilot's control, and bring the elevator into operation to receive the high-pressure of the machine-created current. This would, in the fraction of a second, check automatically the attempted rotation of the wings and body-shell, that is, their impulse to abnormal attitude, while the normal attitude of the masses containing the major weight of the aeroplane would remain immune. Thus stability longitudinally may be automatically effected. These suggested arrangements also would enable the pilot to exchange the automatic and hand-controls instantly, either one for the other. It has been shown that an aeroplane may maintain its balance and stability, both laterally and longitudinally, in gusty winds of high velocity, these being the chief of conditions dangerous to flight. Therefore it should maintain balance and stability in conditions of DECEMBER 28, 1912. lesser danger, and so be entitled to be described as " an aeroplane possessed of absolute stability in air," thus justifying the definition suggested at the beginning. 1 he judges in the Military Aeroplane Competition remark in their report :—" The flyer's objection to wind appears to be based chiefly upon the fatigue induced by keeping uninterruptedly on the alert. In a flight of a duration as long as three hours, the element of fatigue is an important consideration; improvements in design or mechanism may, however, overcome this difficulty, and allow of prolonged flights in winds of high velocity." From this it would appear that the judges believe that a machine may be constructed endowed with automatic stability. Mr. Ovington, in his last letter (1650) says :—" I still claim that it is the men who have not flown who want automatic stability." But this is against evidence. General David Henderson and Major Sykes, two of the judges in the Military Aeroplane Competition, responsible for the expression of opinion in favour of automatic stability, which has been quoted, have won their flying brevets— Mr. Glenn Curtiss in America, M. Moreau in France—both flyers employ automatic stability devices, and, in England, Mr. S. F. Cody, who also has flown, is of the number of the advocates of this method of obtaining balance and stability. The fact is of exceptional significance in the case of Mr. Cody. In him we have an accom plished pilot, and a constructor of proved eminence, who in the competition referred to, which was open to the world, won the chief prize for a machine made, of the most part, with his own hands. Yet within a few days of this achievement he states that he is desirous of promoting a company to enable him to produce a machine endowed with automatic stability, thus virtually declaring his prize-winning aeroplane to fall short of a practical flyer's ideal. The judges and the chief prize winner in the Military Aeroplane Competition are seen to acknowledge the desirability of this vital principle. The fact should be impressed upon those responsible for the construction of aeroplanes for our Naval and Military services, and incline them to experiment with any suggested method for obtaining automatic stability which offers a fair prospect of success. Neither fact nor reason appeal to the prejudiced, but the evidence now in existence must cause the honest doubter in authority to revise his judgment, because upon his action in this matter the lives of many gallant men may possibly depend. mrm HIM* C. . • Haywards Heath. L. BEAUCLERC GOLDMAN. ® ® ® ® Unique Christmas Presents. ni*> MANY and varied are the presents which' are purchased at this time of the year, but the gifts received by two ladies resident at west London must surely be unique. Their Yuletide presents took the form of tickets for passenger flights at Hendon on Boxing Day or at any other time they pleased, and the recipients look forward keenly to their aerial experience, not a bad example to follow. ® ® ® ® PUBLICATION RECEIVED. Katalog der Historischen Abteilung der Ersten Internationale!! Luftschiffahrts-Ausstdlung. (Ila) zu Frankfurt-a.-M. 1909. By Dr. Louis Liebmann and Dr. Gustav Wahl. Frankfort-a.-m. 1 Dr. Western and Co. Price 30 m. ® ® ® ® Aeronautical Patents Published. Applied tor In 1011. Published December Vfth, 1912. I7i°39- G. ALATHENE. Aeroplanes. a-,8n. W. B. CLEMENTS. Flying machines. 27,007. E. W. F. HERRMANN. Flying machines. Applied for In 1819. Published December iyth, 19x2. 2,316. C. PONCUE AND M. E. PRIMARD. Aeroplanes. 21,001. R. E. PELTERIE. Aeroplanes. F L i a HT~ 44, ST. MARTIN'S LANE, LONDON, W.C. Telegraphic address: Truditur, London. Telephone : 1828 Gerrard. su BSCRTPTTON RATES. FLIGHT will be forwarded, post free, at the following rates :— UNITED KINGDOM. ABROAD. s. d. 3 Months, Post Free . 6 ,, „ 12 3 7 15 3 Months, Post Free... 6 » H 12 s. 5 10 20 d. 0 o 0 Cheques and Post Office 'Orders should be mack payable Z the Proprietors of FLIGHT, 44, St. Martin's Lane, W.Cfand crossed %t£a%7d. "" WtStminSter Ba"*> """'wise no responsibility Should any difficulty be experienced m procuring FLIGHT from local newsvendors, intending readers can obtain each istur kirtrt from the Publishing Office, by forwarding reJttancTas JbZ. 1234
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