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Aviation History
1920
1920 - 1038.PDF
during the winter months when^machine is stored, depreciation should be charged as shown in A. A.—Constant depreciation—3 per cent, per month. The two remaining factors to be considered are B (i) Crash risk and B (ii) Deterioration. B (i)—Crash risk. It is obvious that since under B (ii) the aeroplane is to be written off in 700 hours. it will be un- necessary to insure it against crash risk beyoad that period. It is also obvious that it is unnecessary to insure a machine against crashes right up to its full value if the machine has done say 699 hours' flying. B (i) should, therefore, be estimated on a sliding scale, or, for the purpose of averaging, the figure of one-half of one-sixth, or one-twelfth, per cent, per flying hour may be taken as an equitable basis. B (ii)—Deterioration.—This factor may be considered as stated, one-seventh of one per cent, per flying hour. In adding the above figures together, we find that on an aeroplane detailed to carry out certain operations lasting six months, and entailing 300 hours' flying, the cost of the machine being $10,000, depreciation should be figured as under :— B (i)—Crash risk—one-twelfth of one per cent. per flying hour for 300 hours ... ... ... §2,500 B (ii)—Deterioration—one-seventh 'of one per •-•cent, per hour for 300 hours ... ... ... §4,286 Total depreciation $6,786 If the machine is stored in a hangar for the balance of the year we will get the additional cost of:— A.—Constant depreciation—-3 per cent, per month on $10,000 for six months ... ... $1,800 In other words, the total allowance which should be made in calculating cost of operations or insurance and depreciation upon a new machine valued at $10,000 and" used for operations for a period of six months during which it was flown 300 hours jwould be $6,786, or sixty-seven and four-fifths per cent, of the value of the machine. It is particularly emphasised that the above calculations are based Ion War-type machines and with War-time experience. These .figures will unquestionably be greatly modified as the present types of machines give place to these designed for commercial uses, and as the attitude of mind created by war experience is altered under peace-time conditions. SEPTEMBER 30, 1920 The reader of these figures will naturally be inclined to doubt them ; certainly this figure is very large, but experience goes to prove that it is at least approximately correct. The business-man unfamiliar with the use of aircraft will im- mediately state that depreciation is so large as to rule-out aircraft entirely as a feasible mode of transport. This I do not believe to be the case, but the estimating of the cost of operations in various parts of Canada has made it clear that if aircraft has to be used economically, every machine must be flown to its maximum capabilities. In other words, machines must not be allowed to " eat their heads off." For example, in figuring up the cost of operations of six aeroplanes flying in all 120,000 miles, it has been found that the figure for depreciation was as low as 16.6 cents per mile out of a total of 62.7 cents per mile. In another instance, where only 50,000 miles of flying was required, the depreciation amounted to 96 cents out of a total of $2.04 per mile. Various other examples go to show that the more flying that is done the more reasonable both depreciation and operation costs become. During the War no attempt was made to build a machine in such a way that this figure would be reduced. The life of an aeroplane on active service was exceedingly short, whether it came to its end by crash risk, by deterioration, or at the hands of the enemy, few machines on active service lasted much over 100 hours, hence a machine designed to stand 1,000 hours' work was merely a waste of energy. Now that the War is over, however, and aircraft manufacturers are turning their attention to the commercial use of aircraft, serious efforts are being made to design and build machines that will last for upwards of 1,000 hours. Prominent in this direction is the advent of the all-metal machine. Already very satisfactory wings have been made which, while increasing the weight only 10 per cent, over present methods of con- struction, give a factor of safety of 12 instead of 6. In England today the largest machine ever constructed is being built of metal, and it is hoped that in this and subsequent types the life will be very much lengthened. Unquestionably this is the greatest problem facing air- craft manufacturers today, and one that will retard the commercial use of aviation until it has been satisfactorily solved. THE LONDON-CONTINENTAL SERVICES FLIGHTS -'•'.'• ' '.""' Route Croydon-Paris ... ..'*•'" ' ' •••' Paris-Groydon ... Cricklewood-Paris Paris-Cricklewood Croydon-Amsterdam ... Amsterdam-Croydon ... Cricklewood-Amsterdam Amsterdam-Cricklewood Croydon-Brussels Brussels-Croydon Cricklewood-Brussels ... Brussels-Cricklewood ... Totals for week No . o f flights * 25 28 9 8 6 7 5 5 7 7 107 BETWEEN SEPTEMBER 19 AND SEPTEMBER 25, 42 be1 a. "8 0 51 75 5244 59 8 7 7 258 No. of flights carrying Mail s IO 4 6 5 3 3i Good s 16 16 6 5 6 6 3 51 64 No . o f journey s complete d f 22 25 78 6 7 6 88 Averag e flyin g tim e h. m. 2 32 3 13 3 28 3 26 3 26 2 40 2 36 2 45 Fastest time made by ' Westland G-EAJL (ih. 52m.) Airco 16 G-EASW (2h.) ... H.P. G-EALX (2h. 30m.) ... H.P. G-EATM (3h. 7m.) ... Airco 9 G-EAPL (2h. 22m.) Airco 9 G-EAPU (2a. 15m.) Airco 4 O-BALO (2h. 15m.) Airco 9 G-EAUN (ih. 58m.) INCLUSIVE Type and No. (in brackets) of Machines Flying : A.9 (4). A.16 (3), A.18 (2), B. (1), G. (2), N. (1), Sp. (I), V. (1), W. (2). A.9 (5), A.16 (4), A.18 (2). B. (2), G. (3), N. (i), Sp. (1), V. (i).W.(x). ...-• H.P. (6). ..._•: ^;: H.P. (6). ' •:-.•-.. A.9 (3), A.16 (2). :"'4" • . A.9 (3). A.16 (2). *, ^ A.4 (1), A.9 (3). A.4 (1), A.9 (2). A.4 (2), A.9 (3).A.4 (2), A.9 (2). * Not including " private " flights. f Including certain journeys when stops were made en route. ^: A.4 = Airco4. A.9 = Airco9 (etc.). B. = Breguet. G. = Goliath Farman. H.P. = Handley Page. N. = Nieuport. ~ Sa. = Salmson. Sp. = Spad. V. = Vickers Vimy. W. = Westland. The following is a list of firms running services between London and Paris, Brussels, etc., etc.:—Air Post of Banks; Air Transport and Travel; Co. des Grandes Expresses Aeriennes ; Handley Page Transport, Ltd. 5 Instone Air Line; Messa- geries Aeriennes ; Syndicat National pour l'fitude des Transports Aeriens ; Co. Transaerienne. The Air Conference IT has been decided that the conference arranged by thelAir Ministry shall open at the Guildhall at 10 a.m. on October 12, when Sir Frederick Sykes will read his paper on '• Civil Aviation and Air Services." A luncheon will follow at 1 p.m., at which the Right Hon. Winston Churchill, M.P., Secretary of State for Air, will preside. A visit to the terminal aerodrome at Croydon has been arranged for the afternoon of October 13. The only other alteration to the/ programme as announced in our last issue is that Capt. F. S. Barn well will read the paper on " Technical Aspects of Service and Civil Aviation " on September 13. 1040
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