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Aviation History
1912
1912 - 0745.PDF
AUGUST 17, 1912. The work of the designer, M. Coanda, inspires all with the greatest respect for his skill, knowledge of the Subject and en- thuaiasm for his work. He has had to produce a machine in record time, and it is one of the best-built and soundest machines, from an engineering point of view, that we have seen, besides showing every evidence of being a good flyer. In our correspondent's report of the proceedings last week, reference was made to a landing by Pixton on the Bristol biplane, which was said to have broken a chassis strut. Actually, the pilot was Gordon England, and the mishap limited to the radius-rod fastening coming adrift from the timber. In the speed trials this morning, the Cody biplane averaged 72*4 m.p.h., which must be very nearly a biplane record for the world, and is in any case a splendid performance having regard to the fact that the fastest monoplane at these trials did only 75*4 m.p.h. and that the Cody biplane couples with its own celerity through the air a wonderful ability to travel slowly when there is need to do so. It has, in fact, an effective range of 30 m.p.h. difference in speed between its slowest and fastest velocities of flight. This and de Havilland's splendid high flight on the R.A.F. " BEi2," which is also a British biplane record, caused Monday morning to be a red letter occasion in these trials, but as the good weather was not maintained during the day nothing of any impor tance took place later, except that the Bleriot No. 4 completed its tests by undergoing its road transport behind the six-year old Thornycroft car that Mr. Strickland has so generously placed at everyone's service for every type of business. Quite apart from the fact that the motor car engine has been the forerunner of the aero motor, the necessity of having first evolved the motor car before proceeding to the development of the flying machine becomes strikingly apparent at any aviation meeting of this sort. Distances are great and the need for rapid movement oftentimes most urgent, and it is then that a trusty machine that can go over any sort of country and carry any sort of load assists one so much to follow events with intelligence and to be somewhere near the right spot at the right time. l/UGHf Salisbury Plain, Tuesday. Another cold and windy morning—really the climatic conditions on Salisbury Plain attain the maximum of eccentricity—has again interrupted the sequence of events and for the present issue of FLIGHT there remains nothing but to bring our account to a temporary conclusion by briefly referring to the machines that have not already come under prominent notice. The Vickers No. 3 appears to be troubled with a misfiring engine, but has made several flights unofficially. The Breguet is also in trouble with its engine and has so far only succeeded in making a kind of glorified hop. Coventry Ordnance, with two machines and one pilot, have been somewhat limited in the scope of their activities on this account and have besides had considerable trouble with the Chenu motor. In the Bristol camp, Gordon England has taken over the Biplane No. 12 and would have been out for his three-hour flight on Monday morning had the engine consented to start. The other Bristol biplane is for the moment without a pilot, Pixton having been transferred to the monoplane vacated by Valentine, who has left. The Flanders monoplane has been without its engine, which hs now just arrived, and the Martin Handasyde monoplane has been flying admirably, and notably in winds, under the expert control of Gordon Bell, during the intervals that are not occupied with repairing the magneto drive, which appears to be an inherent weak ness of the Chenu engines as at present built. The Aerial Wheel, the Handley Page and the Piggott machines are still in process of their assembly test. The Mersey with its 45-h.p. Isaacson came out on Friday morning and again on Sunday evening and those who saw it say that it was quite strong on the wing.* Now that the French Dep. is through its tests, the two British Deps. will come into the field, Mr. Santoni, the British representative, and M. Koolhoven the works manager, having shown excellent management in concentrating all efforts on the proper attendance on one machine at a time. * As we go to press, news arrives of the sad fatality that is recorded elsewhere. FLIGHT SPEED AND ITS MEASUREMENT IN THE MILITARY TRIALS. THE speed tests pure and simple in these trials are measured by stop-watch, the machines being,flagged as they pass over white lines that have been permanently laid down on the Plain for that purpose. Not high speed alone, but range of speed is required of the military aeroplane, and in consequence each competitor has to fly twice with and against the wind, as fast as he can and as slow as he dare. In the former, a speed of at least 55 m.p.h. must be attained to avoid disqualification; in the latter, there is no limit save that of safety. There is no doubt, from all accounts, that the authorities regard the capacity for variable speed as a merit of high value. This is, of course, an important factor from the constructor's point of view, because of the characteristics that variable speed implies. We shall know more about the facts of the case when the weather has been so kind as to allow a few more machines to perform this test; but, from theoretical considerations, it would seem as if the capacity for variable speed is mainly bound up in the question of surplus power, as indicated by the magnitude of our constant X, explained last week. A machine that can fly slowly and fast must either have plenty of sail area, and the means of pushing it through the air at a high speed when necessary, or the power necessary to fly tail down to the limit of safety. Probably, the method that will produce the slowest speed of all is to fly with the tail right down and the engine all out, but it is scarcely commendable on the score of safety, and for this reason it would seem as if very heavily-loaded planes have an inherent disadvantage in this matter, just as has a motor car with a very high gear ratio, when it is called upon to perform a similar feat without slipping the clutch. There is, indeed, an apparent analogy between the gear ratio of a motor car and the loading of the wings of an aeroplane, which fits in very well with the general purpose of the constant X, which, as will \be remembered, consists of the product of loading (lbs. per sq. ft.), and weight per horse-power. Weight lifting in itself is no merit unless the weight is appropriate to the class of machine required by the purchaser, as is, for instance, demonstrated by the fact that any ordinary lorry could win a hill-climb against touring cars on a formula that put a premium on the weight carried. Con versely, high-gear ratio, or loading in the case of an aeroplane, is not necessarily meritorious in itself, as may again be instanced by the fact that the typical racing car is a notoriously awkward machine to use for average touring, because, notwithstanding its immense power, it can so easily be overloaded by a reasonable weight. In an aeroplane, a reduction of the weight carried in flight auto matically reduces the loading of the wings and the corresponding speed of flight necessary to the support of the machine in the air ; which dual effect renders it more reasonable to arrive at the constant X, by multiplying the two factors (loading and weight per h.p.) instead of adding them together. At the moment of writing there is but little data about actual speeds to discuss. The Hanriot, which happens so far only to have been tried for fastest pace, stands highest in speed, with 74'6 m.p.h. ; and the French Dep. second, with 69" 1. Then comes the Bleriot No. 4, with 61 -5 m.p.h., and the Aircraft Co.'s Maurice Farman, M. Louis Bleriot and Mr. Norbert Chereau, the Bleriot representative for Great Britain, watching the flying on Salisbury Plain. 745 D
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