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Aviation History
1912
1912 - 0767.PDF
para. 14 of the original regulations, which was confirmed by the supplementary communique, says that a desirable attribute is " Flexibility of speed ; to allow of landings and observations being made at slow speeds if required, while reserving a high accleration for work in strong winds." Now it is obvious that if the first condition stood unqualified by any other clause in the document, that the faster the speed the greater the merit in the official eye. This, of course, may be the case for aught I know, but having regard to the expressed desirability of speed-range, and trying to extract the spirit of the law from its written letter, I should certainly be inclined to regard the specified figure of 55 m.p.h. as a sign-post not to be ignored. In a word it is tantamount to saying that 55 m.p.h. is a speed that should be covered by one end or the other of the speed-range of the machine, and that anyone who has designed to do this should not wholly be put in the shade by another who has been solely concerned with getting 55 m.p.h. at hast. On this basis, a capacity for flying 5 m.p.h. below 55 m.p.h. is worthy of as many marks as the ability to fly 5 m.p.h. faster, provided always that the speed of 55 m.p.h. itself is embraced in the range available. Thus, to particularise, let us subtract 55 from the maximum flight- speed, and also deduct the minimum flight-speed from 55 in the various performances already available :— Hanriot 1 ... 75-2 - 55= -f-20'2 ; 59-9 Hanriot 2 ... 75-4-55=+20-4 ; 66'6- Bleriot 4 ... 6i-i - 55=+6-1; M.Farman22 55*2 - 55= +o'2 ; F. Dep. 26... 69-1 - 55=+14-1 CodyB. .. 72-4- 55= + 17-4 Bleriot 5 ... 58-9-55=+3-9; Bristol M. 14 70-5-55= + 15-5 55= -4-9; 20-2-4-9=15-3 55-0= - ir6; 20-4- 11-6 = 8-8 55-52=+3; 6-1 + 3-0 = 9-0 55-37'4= + i7'°; 02+ 17-6 = 17-8 ; 59-55= -4'o; 14-1-4-0=10-1 55-48-5=+6'5 ; i7-4 + 6'5 = 23'9 55-40=+ 15; 3-o+i5-o=i8"9 13-3 = 2-2 68*3-55= -i3"3; 15'5-M.J The final figures would then serve as a basis of marking for speed, and in the same way we may investigate the climbing capacity of the machine by taking the specified 200 ft. per minute as a basii. Thus :— Hanriot No. 2 ... Bleriot No. 4 M. Barman No. 22 Fr. Dep. No. 26 Cody biplane Hanriot No. 1 ... Bleriot No. 5 Bristol No. 14 ... 333 ft- 250 207 333 286 363 235 200 per 1 • ». ) 1 ?. i) ». min. - 200= 133 — 1 -52 m -200= 50= -57 - 200= 7= -o8 -200=133^1-52 -200= 86= -98 -200=163= r84 -200= 35= -4 -200= 0= -o p.h. surplus ,, Mr. Harold E. Perrin, Secretary of the Royal Aero Gtub who Is assisting the judges in the Army Aeroplane Com petitions, and Mr. Arnold Thurston, of the Bristol Co., waiting in the plough for the carrying out of this test by Prevost on the French Deperdussin. "Flight" Copyright. TWO NOTABLE DESIGNERS AT SALISBURY.— On the left, Mr. Coanda, who is responsible for the new Bristol monoplane; on the right, Mr. Handasvde, the designer and constructor of the Martin-Handasyde machines. In the last column, the excess rate of climb over the 200 ft. per min. required has been converted to miles per hour, so that it may be an expression in the same units as the effective range of speed. There is nothing whatever to use as a guide by which the relative advantage of speed and climbing might be reduced to a common basis, that is to say, as to whether an increase of I m.p.h. in the rate of climbing has as much merit as an increase of I m.p.h. in the range of speed. But apart from arbitrary considerations altogether, there is the internal economy of the machine itself to be considered, which makes the power expended on 1 m.p.h. climbing six times as much, or thereabouts, as the power expended on I m.p.h. flying speed, with the same weight in flight. Now the useful load under the rules is 350 lbs., and is common to all machines, big and small, for which reason the weight of the machine itself can be ignored, in this particular investigation, as incidental to the carrying of the useful load. Thus, by regarding the weight as unity, the numerical values assigned to the speeds may be supposed to have the dimensions of power, provided that allowance is made for the difference between lifting the whole weight vertically and flying against one-sixth of the weight as horizontal resistance. The gliding angle of the machines being different, the resistances per unit of load vary also, but, since a good gliding angle is regarded as meritorious according to the regulations, a very simple way of allowing for it will be to ignore it in the calculations by assuming that all machines have the value 1 in 6. Thus, a machine that does better than 1 in 6 will have manifested the difference in increased speed for which it has already received credit; alternatively, a machine with a poor gliding angle will have had to fight against so much the more resistance in flight, and will thus automatically have established its own handicap. If there is any further merit due to a good gliding angle, it can only be assigned arbitrarily and according to some personal opinion. Applying the above basis to the figures available we get:— 767
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