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Aviation History
1927
1927 - 0804.PDF
OCTOBER 13, 1927 AVIATION Mr. F. Handley Page in Optimistic Mood THAT by making full use of such aids to aerodynamic efficiency as are known at the present time, and by using the most efficient constructional materials, we should in the future be able to produce aircraft capable of taking off and flying satisfac- torily with 25 lb. h.p.and carrying useful loads per horse-power of 14-85 for 4 hours, 14-15 for 6 hours, 9-25for20hours, and 2-25 for 40 hours, was the prediction made by Mr. Handley Page in his lecture to " The Royal Aeronautical Society with which is incorporated the Institution of Aeronautical Engi- neers," on October 6. This ideal state of affairs also pre- supposed a fuel consumption of 0-35 pint per h.p. hr., and an engine weight of 1-75 lbs./h.p., including propeller. A geared engine was also assumed. Col. the Master of Sempill, Chairman of " The Royal Aeronautical Society with which is incorporated the Institution of Aeronautical Engi- neers," was in the chair, and before introducing the lecturer he tendered the congratulations of the society to the Super- marine Aviation Works and to Napiers on the remarkable achievement attained in the Schneider race, and also to Webster and the other pilots, and to the Air Ministry. The meeting was also noteworthy as being the first to be held after the amalgamation of the Royal Aeronautical Society and the Institution of Aeronautical Engineers. He read a letter written to the society in 1907 by a young experimenter by the name of F. Handley Page, who wished to be put in touch with Mr. Weiss in order that he might ascertain whether his (Mr. Handley Page's) work was really of any value. From that modest beginning that evening's lecturer had attained a position of prominence in aviation and his aerofoil slot was one of the greatest contributions to aeronautics ever made. Mr. Handley Page said that with the opening of the present session anew sphere of activity was entered upon in that the society welcomed into its circle the membership of the Institution of Aeronautical Engineers. Itwas. therefore, an appropriate time for reviewing the progress of aviation to date, examine the state of the art to-day, and see if the progress beingmade was as rapid as it might be if they had a clearer conception of what the ideal aeroplane of the future was likely to lie, and had their minds morefirmly fixed on the ideal. The time for such a review was also appropriate in that the influence of war-time development Jwas passing and the moresolid work of basic scientific research applied to practical development and construction was now having a marked effect on aircraft design.With the approach of the second half of the ten years' contract under which State assistance to air transport was now given, it was also appro-priate to consider the progress made in commercial flying and see how near was the possibility of civil aviation " flying by itself." State support mustbe a temporary necessity, warranted only just so long as aviation gave promise of a self-supporting or nearly self-supporting condition.The lecturer then pointed out how, if one examined the progress of avia- tion from its birth in 1903, one saw the slow pre-war progress followed bythe hothouse forcing growth during the war, when the urgent demand for production made impossible the inclusion of any radical experimental develop-ments. Since the war there had remained with us the effects of the deep impressions created by war-time experience, and the memories of war-timeexploits had engendered among pilots a rare and lasting affection for certain types of aircraft and for certain ideas in operation which it had taken yearsof the colder light of peace-time analysis to change. They were now begin- ning to see incorporated in design much that had evidently had its main-spring in technical research, and it was to be hoped that in the coming years they would see an increasing advantage taken of the fundamental scientificprogress which had been made in this country with a consequent rapid development of aircraft design. To illustrate the progress of the past vears, the lecturer showed lanternslides of world's records for speed, altitude, distance and duration. If this progress had been made in 24 years of flying, what limits, he asked, werethey likely to reach, what increases in performance were probable in the near future, and to what improvements in efficiency could they look forward,so that the cost of flying could be reduced to a commercial level In examining the problems the lecturer sub-divided his examination intothe following heads : (1) Structural design ; (2) aerodynamic design ; (3) power unit and airscrew ; and (4) design from the user's point of view. Structural Design Under (1) Mr. Handley Page pointed out that it was a matter of extremedifficulty to obtain accurate statistics as to what was or was not comprised in the structure weight of aircraft. From the academic point of view, theaircraft structure should include nothing except what was required solely from the point of view of carrying the weight into the air. As a ruie, how-ever, the design had to be modified to make provision for special equipment and it became difficult, if not impossible, to separate this from that of thegeneral structure. Surveying the subject on the broadest possible lines, it might be said that for similar types of machines with similar factors of safety-there had been no very striking improvement in structure weight percentages during the last few years. In fact there had been a tendency for structureweight percentages to increase, due to more rigid requirements in regard to factors of safety. One might therefore say that unless further improvementwas made in the materials there was no great hope of a reduction in the structure weight percentage. One fact was certain, i.e., that all-metalaircraft would eventually replace those built of wood, owing to their greater durability and smaller cost of upkeep. The research and development Work made in steel and light alloys duringthe past years gave great hope that the necessary improvement in materials would be forthcoming. Progress in drawn-steel tube might cause tubularconstruction in steel to be an active competitor of built-up strip construction. For instance, solid-drawn tubes could be obtained in 30 gauge which afterheat treatment gave up to 90 tons tensile strength. Steels suitable for Welding could now be obtained which gave 35 to 40 tons per square inchafter Welding, and a particular development which should be watched for its ultimate utility was the use of non-corroding or stainless steels to give astrength up to 60 to 70 tons per square inch and 40 tons after welding. Greater possibilities lay in the use of the light metals and their alloys.Duralumin in particular had been widely used in this country, and future improvements were likely to arise from the use ot the lighter metal magnesiumand some of its alloys. Magnesium had the greater advantage over aluminium as far as this country was concerned that there was a plentiful supply of theraw material available in large deposits in this country and in Ireland. Slides were shown giving characteristics of magnesium alloys, and the lecturerstated that the material could be protected by a treatment similar to the anodic treatment. This treatment was not so effective as in the case ofDuralumin, but formed a good foundation for further protective covering. Another interesting material, if sufficient supplies could be found, was theelement Beryllium, Which, With a specific gravity of 1 -84. had a hardness sufficient to scratch a piece of glass, while its melting point was as high as1,280° C. At present Jthe cost of this element Was rather prohibitive, i.e., approximately £5 per kilogram, or. roughly, the same as the price of silver,so that at present it was somewhat beyond the reach of even the most pluto- cratic Air Ministry or aircraft constructor. Saving in weight of tanks by the use of aluminium and magnesium wasalso prophesied by the lecturer, and in concluding this section of his paper Mr. Handley Page said that in taking into account various developmentsit Would seem that for normal size commercial aircraft a structure weight percentage of not more than 27h should be reached. Aerodynamic DesignUnder (2), aerodynamic design, there was a wider field for improvement. The aerodynamic results obtained from an aeroplane depended, unfortunately,not merely on the characteristics of the wings determined in model size in a wind tunnel, but also upon the resistance due to the body and the projec-tions which were forced upon the design due to the requirements of the user. Very often the user's requirements were based upon equipmentdesigned by specialists who had designed similar equipment for other but slower means ot transport. It took many years to change the fashions ofthe user's requirements, not merely in aviation, but in every other form of transport. To illustrate this the lecturer showed a series of slides of earlyand modern locomotives, motor cars and vessels. If one looked at aircraft of today one thought with wonder of the scientificresearch that had been expended and the mathematical analysis that had been conducted to evolve wing sections and plan forms with the smallestpossible value for minimum drag. etc. When, however, one looked at the fuselage one sometimes speculated whether it must not have been a differentset of engineers, or perhaps even a different race, which were responsible for open cockpits, projecting gun-rings and guns, pumps and other excrescences,which,projecting from the fuselage, added resistance to good and bad machines alike, and tended to reduce all aircraft to one common level of inefficiency. Slides of various prehistoric flying creatures and birds illustrated hownature in the earliest days of bird development had much to learn in air- craft construction, and the diminution of head resistance-. It was seen thatvast improvement had been made by nature in the long million^ of years of natural development.If they really wished to improve performance, whether in commercial or military aircraft, they must produce aircraft with line lims. To achievethat they must reduce as far as possible the overall size. And if this was only possible with equipment of smaller dimensions, then the equipmentmust be designed to lit in with the performance required. Again a series of slides was shown illustrating the progress in refinementfrom the early Wright machine to some of tin latest type. It wa 5, how-ever, evident how far improvement could still be made provided the pilots were content to use other means of view than those employed today. Itwas evident that eventually pilots, as Well as crew or passengers, must be totally enclosed, but given adequate means of vision, either by4seating themwell forward in a closed cabin without obstacles in front of them, or by some periscope device, so that true vision could be obtained without added headresistance. The head resistance of the undercarriage was another item with whichthey had to deal. This component was not required in the air. and was useful only in lauding and taking off. The bird in flight folded it-, legs underits tail. The advantages of the folding undercarriage were so great that the mechanical problr-rn Would undoubtedly be solved. A good modern aircraft had a maximum value of r; >: _ of just over 7. If the interference effect between body and wings could be successfully dealt with, and these excessivehead resistance items be eliminated, it should be possible to increase the maximum r; / _to 10 or even 12 at climbing speed, and a correspondingly increased value at top speed of perhaps 7 or even 8.Another aspect of aerodynamic design which could not be measured in figures, but which was important for the safety and control of aircraft, wasthe problem of what happened at and beyond the stall. He thought the new Handley Page automatic slot at the wing tips represented a markedadvance without any adverse effect on high-speed performance. Power PlantThe lecturer said he sometimes thought that greater progress had been made in the development of aero engines than in the aeroplane itsell, but fortransatlantic non-stop services there was a battle to be fought out between the Diesel engine using heavy oil and the petrol engine with very high com-pression and using social anti-detonating mixtures. The low consumption figure of 0-35 pint per horse-power per hour of the Diesel was somewhatoffset by the heavier type of oil used, but the great advantage was the use of heavy fuel oil which reduced the risk of fire. The most important featureof the power plant Was the propeller, and the lecturer here pointed out the advantage of the geared engine which gave good propeller efficiency evenwhen the high power of the engine was obtained by running at high engine speeds. ., Turning to the subject of the user of the aeroplane, Mr. Handley Page saia that future aircraft must provide more comfort for the passengers. MuseWould only be eliminated when relatively less power was used, with.slow- running geared propellers. The Machine of the FutureBy paying full attention to the improvements outlined, it should in toe future be possible to reduce structure weight to not more than 27'5 per cent. 726
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