FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1922
1922 - 0156.PDF
MARCH 16, 1922 Society by Maj.-Gen. Sir Frederick Maurice, printed elsewhere in this issue. In his career Sir Frederick has had ample opportunity of getting experience of the War Office and of. the old-fashioned. military mind, and he stated as his firm conviction that, had the R.A.F. been under the_ control of the War Office it would never have been allowed to prove of what it is capable in the manner in which it has been allowed to do so under independent control. He expressed the view that under no circumstances must we allow the R.A.F., which is as yet in.a stage of evolution, to be hampered and probably killed by being made subservient to the older Services. As we have repeatedly pointed out in these columns, forces are constantly at work attempting to under mine the R.A.F. and the Air Ministry as a separate service and ministry, and we must never relent our vigilance if these forces are to be kept in check and the R.A.F. allowed to develop untrammelled towards its ultimate destiny of being our principal fighting force and our first line of defence. And that is precisely why we are pleased with the matured steps announced by Mr. Churchill. So long as we have men with the courage of their opinions like the Colonial Secretary7, who possesses the necessary imagination to take a broad view, and so long as the R.A.F. remains loyal to its chief and does its best to deserve the trust thus placed in it, we need have no fear for the future. The ultimate victory of the new air arm over the older Services is certain. If there is any one item which, more TGuideth than any other' affects the utmtv and Cable safety of aircraft it is the capacity to fly in the dark and in fog. Over very long routes, such as for instance England to Australia, the capability to fly at night as well as in the daytime is practically equivalent to doubling the speed of an aeroplane. It is not, of course, quite so, as there must be delays in transferring passengers and/or mails from one machine to another, but for practical pur poses the speed is very nearly doubled. To do so by any other means would be out of the question. Or, looking at the matter from another point of view, to be able to fly by night is the means of drawing full advantage of the speed of the aeroplane, when otherwise this could not be done. On the long routes it is of little use to be able to do 100 m.p.h. for 12 hours, and then having to stop for another 12 hours. The practical speed is then only 50 m.p.h. But by flying at night an average speed of, say, 70 or 80 m.p.h. could be maintained, which would be so vastly ahead of any other means of locomotion as to give aircraft an enormous advantage. Any means which can be taken for rendering safe flying by night and in fogs is therefore entitled to serious consideration. In this connection, the Loth guide cable described elsewhere in this issue is of more than ordinary interest, and appears to promise great things for the future. Already the French Government has decided to equip le Bourget with such a cable, and there is more than a possibility that the cable will be extended from le Bourget to the French coast, as a first step towards introducing this means of guiding aircraft over the French portion of the London-Paris route. It now remains to be seen whether our Government is ready to co-operate by similarly equipping our modest 60 miles or so of route between Croydon and the English coaat. «»•<•» According to the American National American advisory Committee Report for 1921 on Thick (Administrative Report without Tech- Aerofoite nical Reports), a large number of tests on thick aerofoils have been carried out, with the object of studying the pro perties of aerofoils suitable for internal bracing. The Report states that the tests were made at air speeds of 35 metres (115 ft.) per second, and in some cases at a speed as high as 60 metres (197 ft.) per second. Several very interesting facts were brought to light. For instance, it was found that thick wings improve in efficiency with speed more rapidly rhan thin wings. In other words, the scale effect was considerable, and thick wings, when applied to modern high-speed aeroplanes, may be expected to have a better L/D ratio than would be indicated by model tests at relatively low speeds. It appears from the Report that an efficient thick wing was sought, rather than one having a high maximum lift coefficient. Thus it is stated that some of the sections developed had at all angles a higher efficiency than the R.A.F. 15 section tested under the same conditions, and yet were more than three times as thick as that section in the centre. The maximum lift coefficients were approximately the same. The Report does not contain any figures relating to these tests, but no doubt the technical reports dealing with the experiments will be published in due course. We are looking forward to seeing them, as the reference to them appears to indicate a very great improvement. Thus, while having a wing as efficient as the R.A.F. 15, a much lighter wing would result from the greater depth of wing spars ; or, if an internally braced cantilever wing is required, the section should be deep enough to allow of building such a wing without undue wing weight. Hitherto it has been customary in certain quarters to dismiss the thick wing as being hopelessly inferior, as regards efficiency, to the thin wing. This report indicates that the thick wing may have been sadly misjudged on its model figures, and no doubt the new wind tunnels which are being constructed in America will be used for determining the scale effect on such wings at speeds giving a truer indication of the properties of the actual full-size wings. In this connection it is also of interest to note that experiments on several heavily-tapered wings indicated that wings of this type had the same centre of pressure travel and practically the same efficiency as wings of uniform section. This is all in favour of the cantilever wing, since for structural reasons it is an advantage to taper the wing from root to tip so as to get the greatest stresses where the section is of greatest depth and where, conse quently, the spars are better able to resist the bending moments imposed upon them. Another advantage of the tapered wing is that it usually tends to make an aeroplane very nice to handle as regards lateral contol, the machine responding readily, even to fairly small ailerons, as instanced by several German types having tapered wings. As soon as the technical reports on these tests become available we hope to place them before our readers.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
