FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1918
1918 - 0541.PDF
MAY 16, 1918. These points are approximately in order of merit. To attain climb and speed, the weight must be kept as low as possible consistent with the minimum safe strength, and the drag must be kept as low as possible, by making every exposed part as small as possible and of the best possible shape. Climb calls for lighter loading than great speed, particularly near the ground. But speed at great heights calls for lighter loading than speed near the ground, so the compromise in loading to suit climb and speed at great heights is not drastic. A point to be remembered is that lighter loading means larger aerofoils and, therefore, probably a rather greater total weight of machine. Field of view is a matter of disposition of occupants, of aerofoils, and of body shape, and is a very vexed question. Multiplanes score because of their small chord, but then there a re more aerofoils to obstruct the view. Manoeuverability calls for small moment of inertia, small stability, for large controlling surfaces, great strength and light loading. Field of fire is much the same sort of trouble to attain as field of view, perhaps worse, for it entails fairly large exposed moving parts, impossible to fair and generally spoiling the fairing of other parts near them. Slow landing calls for light loading, lighter than is consistent with speed ; it becomes a question of what is the maximum justifiable landing speed. Lastly, to consider what we may expect to be able to do with aeroplanes in the future, and to what uses they may be put, apart from war purposes, for which they are already essential. Great speed with comfort, with no danger and no expensive permanent ways is the claim of the aeroplane commercially; probably greatly increased size will be economical. Speed we shall be able to get, for practically everything, in a commercial machine, especially if it be a large one, may be done to attain it. Increased size presents difficulties. If we increase the scale of any aeroplane throughout, the weight will go up as the cube of the linear dimension, the surface as the square, whilst the strength will remain the same for the same stress loading value, by " stress loading " being meant the "loading " per unit area minus the weight of the aerofoils per unit area. So the larger the machine to the same scale, the less the proportion of useful load it can carry, and even- tually it will not be able to lift even itself. But there are facts which make possible much larger machines than our present ones. It is easier in a large than in a small structure to distribute material economically, and thereby save weight. A large machine will not be, nor require to be, nearly so quickly manceuvreable ; nobody will be able to loop it or fly it upside down or spin it or otherwise test its strength in every conceivable position ; so its " factors of safety," and, therefore, its weight, may be made much lower ; the heavy unit weights may be much more widely distributed, as quick manceuverability is not required, thereby reducing stresses and consequently weight necessary for requisite strength. It may be multi-engined. so that risk of forced landings may be enormously reduced. Finally, it will be required, probably, to be a " one-speed " machine only, so the best loading and air screws for this speed may be employed. I shall conclude by quoting figures I have roughed out for two aeroplanes which it would be possible for us to make to-day (Fig. 14). First, a purely speed machine. Using an engine of about 280 h.p. we would be able to make this machine weigh only about 1,200 lbs., including petrol and oil for half-an-hour, and a 140-lb. pilot. The body would be of elliptical cross section, would be totally enclosed and provided with windows. The landing gear would consist simply of a pair of very long skids. The machine could rise with this form of gear as it would have such an enormous power per lb. weight. The landing speed would, unfortunately, be round about 100 m.p.h., for to get the highest possible speed we should have to use a monoplane form of about 40 square feet total wing area, or about 30 lbs. per square foot loading. We could probably attain a speed of about 250 m.p.h. with such SINGLE SEATED RACING MONOPLANE . 28O& EN6INE WEI6HT ABOUT 1200 i*P. WIN6 AREA -4OCJJ WINS SPAN >6 FT. L.O-A. I7FI. AIRSCREW 6?r. O)A xtiFTPVTCH. 2SOO R.P.M.Barn7veu a machine. The air screws would need to be about 6 ft. diam. only, and about 10 ft. pitch. I quote this machine mainly to show the danger of becoming too optimistic about enormous speeds in the near future ; to attain this speed we have entirely sacrificed utility. . Secondly, a two-seated machine to fly the Atlantic. Totally enclosed biplane, again using an engine of 280 h.p. Lightest possible machine to carry two 150-lb. men, 20 lbs. for food and drinks, mascots, &c, sufficient tankage for 360 gallons of petrol and 30 gallons of oil. The machine could be made as light as 1,400 lbs. empty, for we should only use a factor of safety of about 2, for fully loaded condition. 2,600 lbs. of petrol, 300 lbs. of oil, 70 lbs. of wajer, and the two pilots, give a total loaded weight of about 4,760 lbs. The undercarriage would again consist of a pair of long skids, but detachable axle and wheels might be fitted for getting off only, and could be fitted with a disconnecting gear by which the pilot would drop them off the skids after rising. Landing with petrol and oil nearly finished could be achieved on the skids alone at about 40 m.p.h. Such a machine could be made to do a mean speed of quite 150 m.p.h. on 18 gallons per hour mean consumption, meaning a 20-hours' flight of 3,000 miles. Gift of an Aeroplane. THE Secretary of the Air Ministry announces that Lieut.-Col. Sir A. E. Bingham, Bt., has presented an aero- plane to the R.A.F. Sir Albert Bingham is Senior Warden of the Cutlers' Company, Sheffield, and head of the firm of Messrs. Walker and Hall, Vice-Chairman of the Yorkshire Rifle Association, and Lieut.-Col. of the West Riding Division, R.E. (T.). Fonck's Six in One Day. ".*'••- FLIGHT LIEUT. FONCK is the first Frenchman to be credited with bringing down six German machines in one day. He left his aerodrome on the morning of May 9th with a patrol and soon encountered three two-seater machines. Two were shot down in less than 10 seconds, and the third within 2 minutes. In the afternoon while on patrol Lieut. Fonck ran into four Pfalz and five Albatroses and again succeeded in sending down three—one two-seater and two single-seaters. The six machines are said to have been brought down with an average expenditure of ten cartridges per machine. Two Against Twenty.> Against Twenty. AN extraordinary example of_ the superior moral and fighting quality of our flying men is given in an incident which occurred on May 7th, says the Times correspondent at the Front. Two of the two-seater fighting machines fell in with a patrol of seven German scouts, and immediately gave battle. White the fight was on, two other enemy patrols of about equal strength hove in sight, and joined in, until there were either 20 or 21 German machines engaged against the two British. The fight went on for half an hour, in the course of which our two actually shot down eight enemies and sent down others out of control. Of the machines certainly shot down four broke into flames in the air, and four were seen to go straight to earth and crash. Our two only broke off the fight when all their ammunition was exhausted, and then, out of 20 or so Germans originally engaged, only seven were left in the air. On the following day these same two machines again fell in with a party of the enemy, of whom they shot down one and sent three more down out of control, so that the total " bag " for the two machines in two days was nine machines destroyed and apparently an equal number driven down. In another case, on May 6th, one British machine gave fight to five Germans, consisting of four triplanes and one scout, and shot down two triplanes and came home safe. • • 539
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
