bluuebunny/crossref_metadata_2025 huggingface dataset:
Part I. The Aircraft Viewpoint
Authors: Chaplin R. H.
Published: August 2016

Before embarking upon the business of this paper I should like to make one or two general remarks by way of explanation.

It was suggested by two members of the Council that the present situation with regard to ancillary power services on aircraft was far from satisfactory, and that the question might well form the basis of a lecture before the Society; moreover, that such a lecture might be more interesting and valuable if presented as a joint paper by a member of an engine firm and an aircraft firm respectively. Mr. Nixon and myself have had the honour of being asked to collaborate in this connection and we trust the result will be acceptable to you.
“Dynamic Stiffness and Effective Inertia Methods in Modern Torsional Vibration Theory”
Authors: Manley R. G.
Published: August 2016

The chief aim of the vibration engineer is to prevent the occurrence of structural failure due to excessive vibration. A secondary aim of only slightly less importance is to ensure comfort for personnel by the elimination of physiologically unpleasant vibrations; this consideration is a vital factor in the effective design of operational aircraft. The technique of vibration research is largely a matter of detecting and avoiding resonant conditions, and any method of predicting natural frequencies by calculation is welcome if only because it offers the possibility of reducing the practical testing programme.
The Natural Limits to Human Flight
Authors: Wimperis H. E.
Published: August 2016

The more I think about the subject chosen for this Address, the rasher does it seem. To proclaim limits to human flight is to do two things. To say what can be done, and to suggest what cannot. Now, though there may be little rashness in the one, there is much in the other. If I say that such and such a thing can be done and someone in the distant years points out that actually it has not been done, my shade has the easy reply that achievement requires effort and that my critics should use their brains.

But if I suggest that certain boundaries cannot be crossed, what fun for the coming race of engineers who cross them (if they do), than to poke fun at the memory of your lecturer to-night! And when I use the word flight I mean flying with wings and not the flight of a projectile.
Turbulence
Authors: von Karman Theodor
Published: August 2016

When I received the invitation to deliver this Memorial Lecture, and “Turbulence” was chosen as the subject, I remembered that my good friend, G. I. Taylor, gave a very stimulating talk on the same subject ten years ago. It was his G. I. Symons Memorial Lecture before the Royal Meteorological Society. He succeeded in fulfilling his job without using one mathematical symbol, the President of the Society, Sir Gilbert Walker, insisting very definitely that “turbulence without tears” was what he wanted. I do not think that I can duplicate Taylor's achievement completely; however, I shall try to reduce the mathematics to a minimum.
The Jointing of Materials by Welding
Authors: Dobson R. H. , Taylor R. F.
Published: August 2016

This is a subject which during recent years has aroused considerable interest in all industries and particularly in the aircraft industry and a large amount of investigation work has been carried out. In some industries, both light and heavy, the growth of welding as a “ production tool ” has been phenomenal, and the same growth is at the present time occurring in the structural steel work and shipbuilding industries. If one views this change which is taking place it will be observed that the change is entirely at the expense of riveting and bolting, and before proceeding I will roughly summarise the general disadvantages of these two processes.
The Use of Model Data in Aeroplane Design
Authors: Bradfield F. B. , Ellis D. L.
Published: August 2016

My first reaction to being asked to speak on this subject was that it is the user and not the producer of model data whose views we want to hear, and I am glad to say that Mr. Ellis has agreed to co-ordinate with me, so that I have some inside knowledge to draw on, if I venture to say what a designer does.

I wish in the main, however, to take the title in rather a different way, and to discuss in what sense model tests can be expected to give results useful to the designer.
Some Corrosion Problems Relating to Modern Aircraft
Authors: Sidery A. J. , Willstrop J. W. W.
Published: August 2016

It is well known that, under certain conditions, duralumin and other wrought aluminium alloys are liable to suffer intercrystalline attack, such corrosion being frequently accompanied by little visible corrosion product on the surface of the material. The necessity for careful temperature control during the solution heat treatment of duralumin and the beneficial influence of a rapid rate of cooling after such heat treatment on the corrosion-resistance of this material are now too widely appreciated to need emphasis here.
Definition of Specific Impulse
Authors: Thorne F. W.
Published: August 2016

Your contributors on Specific Impulse in the May journal say, “ The mass definition, on the other hand, gives a value of specific impulse which varies according to the units used.“

It must be realised that the value of a quantity cannot depend on the units chosen. To quote therefore the example on page 371 in gravitational units, namely: —
Definition of Specific Impulse
Authors: Asquith K. , Whitaker J. G.
Published: August 2016

We can agree with Professor Thorne that no physical quantity can be altered by varying the system of measurement, in the sense that the length of a ruler, for example, is the same whether its length be recorded in inches or centimetres. It is of course the numerical value of the length that varies with the system of measurement, and perhaps we should have used the words “numerical value” instead of “value” in the paragraph to which Professor Thorne refers.

We maintain our assertion, however, that in recording specific impulses, there is more likelihood of confusion as to numerical value, and as to the nature of the unit, if the mass definition is employed
Notes on Power Operated Controls for Large Aircraft
Authors: Gouge A.
Published: August 2016

A Study of the air routes of the world brings out almost at once the fact that some of the most difficult route are also the most attractive. For instance, the North Atlantic route which couples North America with Europe is certainly one of the most difficult in the world, but also by the fact that it couples two of the most densely populated, as well as the most wealthy groups of people in the world, one of the most attractive.
Value of Weight Sating in Air Liners
Authors: Green F. M.
Published: August 2016

The value of 1 lb. of weight saved in an air liner has been given as equal to 1 lb. of gold in an American paper. This figure has been calculated in a more complete way, and on the assumptions made is reduced to £16 10s. or near enough to one guinea per oz. saved.

(1)

It is almost always possible to reduce the weight of any component of an aircraft or engine by refining the design. This can be done in many ways, but chiefly by improved material, by reducing dimensional tolerances, by more accurate stressing and by development by mechanical testing. These processes increase the cost and time of manufacture, and as the value of an air liner starts only when it is put into service, and its useful life is settled by obsolescence rather than by wearing out, there is always a practical limit to the time that can be spent on design, development and manufacture. During wartime the resources of the country are pushed to their limit and it is often impossible to get a big enough production of the best materials, o r i o work to fine tolerances; hence we accept an aircraft a good deal short of the ideal. The life of the aircraft is comparatively short and is governed largely by factors outside our control, so that an assessment of the value of weight saving is nearly impossible.
On the Solution of the Numerical Simultaneous Equations Arising in the Analysis of Redundant Structures
Authors: Turton F. J.
Published: August 2016

The application of strain energy or slope-deflection methods in the analysis of redundant structures leads to a number of simultaneous linear equations with numerical coefficients; the equations may be obtained in such order that each successive equation contains one new unknown, until all the unknowns are so included. This is the only condition essential for the method to be described in the present paper, but the labour is much reduced in slope-deflection and strain energy applications by the fact that most (or all) of the equations contain very few of the unknowns. The method to be given reduces the solving of these equations to a column of successive evaluations, followed by the solution, by algebraic methods, of a small number of simultaneous equations; and a final column of evaluations. In the remaining paragraphs a number of problems are examined to show how the equations may be obtained in suitable sequence for the method to apply. Following an application to the determination of secondary stresses, the operations involved in the moment-distribution method and in this method are compared. A numerical example is worked out in the simple case of §2, and it is shown how any order of mathematical accuracy in the roots may be ensured, provided that sufficient figures have been retained to permit that accuracy.
Aircraft Circuit-Breakers
Authors: Flurscheim C. H. , Nott J. A.
Published: August 2016

The electrical power demand in aircraft has shown a very marked increase in recent years consequent on the development of many new airborne electrical devices in the field of armaments, communications and the control of flight. Whereas not many years back the total demand on the largest aircraft could be supplied from a small windmill driven generator of fractional kilowatt output, designs are now in existence requiring 24 kW. generating capacity, while larger loads are projected for future types.

The power distribution problem has therefore been widely modified and the increased importance of the electrical services performed has considerably raised the status of a onetime Cinderella.
A Comparison of Valve Mechanism (Poppet and Sleeve) as Regards Limiting Values of Compression Ratio, Mean Effective Pressure and Specific Fuel Consumption
Authors: Hoock Th.
Published: August 2016

The performance of large aero-engines is limited by the weight of the charge that can be inspired at the high speeds and by the tendency to knock, which is due chiefly to the hot exhaust valve. The performance can be considerably increased when a valve control system is employed, which offers small resistances and large passages for the gas flow. Besides this, the walls of the combustion chamber must be kept at a low and uniform temperature, in order to ensure freedom from knocking even with high compression.

As tests show that the knock resistance and the piston pressure in engines with rotary valves are sensibly greater than in the same engines with poppet valves, measurement results are used in order to ascertain the possible limiting values obtainable for the compression ratio, the mean piston pressure and the specific fuel consumption of large aero-engines.
A Note on the Determination of the Drag of Retractable Undercarriages in Flight
Authors: Williams J. A. C.
Published: August 2016

Upon occasion it is required to find the drag of aircraft components which are normally retracted in level flight, such as flaps and undercarriages. The usual method of obtaining this drag from flight tests, is to measure speeds in level flight under known engine conditions with the component retracted and then with the component down. The difference of speed so obtained, together with the known test conditions then yields an answer. The disadvantage of this method is that, as the difference of speed is usually large, incidence changes and airscrew and engine assumptions cause discrepancies in the results. The difference of power between different engines of a type can be ± 5 per cent. A method is proposed which will enable most of the disadvantages of the older method to be overcome.
The Buckling of an Elastically Encastred Strut.
Authors: Prager W.
Published: August 2016

In a previous issue of this Journal (Vol. 40, pp.663-680, 1936) Mr. N. J. Hoff has investigated the buckling of an elastically encastred strut. The ingenious method used by Mr. Hoff consists in considering portions of various lengths of a rigidly encastred strut which is in a state of neutral equilibrium under the action of its critical compressive load. This load is also the critical load of an elastically encastred strut whose length is equal to the length of the considered portion, if only the rigidities of encastrement are chosen in accordance with the ratios of the slopes of the neutral axis at the ends of this portion to the bending moments there. The total length of the elastically encastred strut does not enter immediately into the formulae derived by this method, there enter only two lengths x1 and xr whose sum is equal to the total length. These quantities are the distances between the ends of the considered portion of the rigidly encastred strut and the middle of its span.
At High Altitude
Authors: Lanchester F. W.
Published: August 2016

In the present paper it is demonstrated that variations in the Reynolds number as due to altitude are unimportant, provided that NR at sea level is in the region of 107.

That under these conditions the law of velocity in relation to altitude, is implicitly contained in the expression W= KLρV2 x area, in which ρ and V only are variables; i.e., the velocity of flight must vary in the inverse ratio of .

That the velocity limit due to the elasticity of air is lower at high altitude, for the velocity of sound is lower, the optimum flight velocity is higher. The facts concerning this are set forth.
Note on the Possibility of Flight by Human Power
Authors: Townend H. C. H.
Published: August 2016

The object of this note is to draw attention to a few facts which, taken together, suggest that, from a purely aerodynamic point of view, the difficulties involved in flight by human power may not be as great as is generally supposed.

Some years ago, in a lecture delivered to the Royal Aeronautical Society, the German soaring pilot, Lippisch, referred to an account of dynamic soaring given by Lanchester in his “ Aerodonetics ” and to some wind tunnel experiments made in Vienna.
Testing Civil Aircraft
Authors: Hufton P. A.
Published: August 2016

When I was asked to give this lecture on Civil Flight Testing, I considered in what way any of my experience might be of general help to the Industry.

The tests which A. and A.E.E. make on civil aircraft are at the moment of three kinds: —

(a)

Tests to prove compliance with Air Registration Board requirements for a Certificate of Airworthiness.

(b)

Development tests for firms in order to suggest modifications to the aircraft occasioned by the results of tests made under (a).

(c)

Tests made for the Ministry of Supply because some of the aircraft are for Ministry of Supply contracts.
Aviation's Place In Civilization
Authors: Wright T. P.
Published: August 2016

The Thirty-third Wilbur Wright Memorial Lecture was delivered before the Society on Thursday, May 31st, 1945, at 6.30 p.m., in the Lecture Hall of the Institution of Mechanical Engineers, Storey's Gate, London, S.W.I, by permission of the Council of the Institution. The chair was taken by Sir A. H. Roy Fedden, F.R.Ae.S., President of the Society.
A Simple Approach to the Wing Flutter Problem
Authors: Lockspeiser B.
Published: August 2016

Let us first consider the oscillations, in still air, of a monoplane wing whose aileron is supposed locked to the wing in such a way that it behaves as though it were an integral part of the wing structure. When the wing is displaced from its position of equilibrium and released it will, in general, vibrate both in flexure and torsion. The initial displacement may be purely flexural, but if the inertial forces called into play, over any wing section, produce a twisting moment about the centre of twist (i.e., the centre about which the wing section twists on the application of a pure torque at that section) torsional as well as flexural oscillations will be set up. Inertia, in general, robs the two kinds of oscillation of their independence, and, when they are interdependent, we may conveniently speak of “inertial couplings” between the two motions. In still air these vibrations must, of necessity, die down. One part of the wing may gain energy at the expense of another, but the store of elastic energy given to the wing by the initial displacement must grow progressively less as the wing does work against the viscous air damping and structural hysteresis forces.
Light Alloys for Aeronautical Purposes with Special Reference to Magnesium
Authors: Aitchison Leslie
Published: August 2016

To deal effectively in the course of a single lecture with the subject of light alloys for aircraft is, to-day, practically an impossibility. Actually, the various alloys of aluminium that are put forward for consideration by the aeronautical engineer do not vary amongst themselves to such an enormous extent as to make one or other of over-riding interest, and much the same might be said of the alloys of magnesium. Despite this position, so much of interest is occurring in both fields, and so many alloys are being put forward having some characteristic or another of real interest, that the aircraft engineer, and in fact any other engineer, could readily be excused if he felt somewhat nonplussed when he surveyed the multitude of materials that are offered for his employment. I am relieved, therefore, that your Council decided that this lecture should give special prominence to the alloys of magnesium. I am assuming that by this they mean those alloys which consist of magnesium in a great preponderating proportion, but I feel that the time is appropriate also to make some reference to those alloys which consist principally of aluminium, but which possess definitely useful properties in consequence of the presence in them of certain relatively small proportions of magnesium. I propose, however, first to consider the alloys rich in magnesium, and will endeavour to provide some data of a rather fundamental type which may be of definite service to the aeronautical engineer when he is engaged in comparing the relative importance and value of the magnesium alloys made available to him in commerce.
Aerial Survey in Relation to Economic Geology
Authors: Gill Donald
Published: August 2016

The great interest being taken at present in the use of aeroplanes in connection with mining, shown in the reception given to a recent paper before the Institution, has suggested to the author that a paper may be welcomed which deals with aerial survey as an aid to the geologist and to the prospector, and which attempts to put before members information on the subject, much of which is available but not altogether accessible.
The Meteorology of India
Authors: Field J. H.
Published: August 2016

In an interesting paper on the meteorology of India read before the Society in 1925, Sir Gilbert Walker gave a comprehensive account of the main elements of climate which affect the industrial and social well-being of the country, and dealt with the great question of seasonal weather forecasting, on which he has become the chief authority. I propose to-day to take up some of the newer means of dealing with Indian problems, and to add the consideration of a fresh item, the safeguarding of international aviation.
The Development of Aviation Lighting
Authors: Mealing R. H. S.
Published: August 2016

Prior to 1914 there was no night flying proper, as we know it to-day, and therefore, so far as I am aware, there was no night lighting. I must except, of course, the night flying exhibitions which were given at Hendon in this country and at a few places abroad.
Tail Buffeting
Authors: Duncan W. J.
Published: August 2016

The subject of tail buffeting first came into prominence in this country early in 1931 when the Accidents Investigation Sub-Committee of the Aeronautical Research Committee issued their report on the accident to a Junkers monoplane at Meopham, Kent. The Sub-Committee gave it as their opinion that tail buffeting was the probable primary cause of this accident, and recommended that the phenomenon should be investigated. At this time tail buffeting (Leitwerkschutteln) was quite well known in Germany, where the low-wing monoplane, which is peculiarly susceptible to this trouble, was a popular type of aircraft; and some full-scale experiments on the subject had already been made by the Deutsche Versuchsanstalt fiir Luftfahrt. The findings of the Accidents Investigation Sub-Committee caused an intensive study of buffeting to be undertaken both in Germany and in this country, and the enquiry was also taken up in the United States at a later date. As a result of these studies tail buffeting is now quite well understood, and methods for its avoidance have been established.
Thurston Wing-Tip Rotors Control Beyond the Stall
Authors: Thurston A. P.
Published: August 2016

Summary and Deductions

The accompanying Report No. B.A. 1083 of the Royal Aircraft Establishment demonstrates generally that a moving body or rider plane can be associated with a fixed body or plane for altering the aerodynamic properties of the combination for various useful purposes, and in particular, that rotating cambered rider planes, when associated with the front edge of a fixed wing of standard section (see Fig. 11) “are definitely advantageous” in improving the gliding conditions, and that “by increasing the size of the rotors relatively to the size of the wings, this superiority is increased.”

Previous experiments at the N.P.L. with various types of wings fitted alternately—with optimum wing-tip slots and with rotors—have shown that rotors can give about the same degree of lateral stability as tip slots, but over a much wider angular range. Other experiments with better rotors than used at the N.P.L. have shown that a more powerful stabilising effect over a wider annular range is to be obtained with rotors than with slots.
Extracts from the Aeronautical & Miscellaneous Note-Book (ca. 1799–1826)
Authors: Cayley George
Published: August 2016

Until recently it was believed that Sir George Cayley's note-books had been lost. In 1927 Mr. J. E. Hodgson, the Honorary Librarian of the Society, learnt that a quantity of miscellaneous manuscript papers were in existence in the home of the Cayley family, and permission was obtained to sort out from such papers matter bearing on Cayley's aeronautical and other engineering or technical labours. Among them was the Note-book, which will shortly be published in full by the Newcomen Society, by kind permission of Sir Kenelm Cayley.
The Case for Vertical Flight
Authors: Platt Haviland H.
Published: August 2016

If the man in the street is asked his opinion of the future of aviation, he will almost invariably reply, “ Everyone will have an aeroplane on his roof and go straight up like this.” Whereupon he will go through the traditional motion of the spiral staircase joke.

The expert pilot or technician of to-day, overhearing this remark, smiles in a superior way. In his mind are two contrasting pictures : That of a city over which whirligigs are springing up from adjacent roof tops; and that of the vast empty spaces of even the busiest airport as he knows it.
The Influence of Atmospheric Humidity and Other Factors upon the Static Lift of Airships
Authors: Bird W. G.
Published: August 2016

The following Paper comprises some of the results of an investigation originally undertaken by the writer to determine the effects of the humidity of the atmosphere and other secondary factors upon the static lift of airships. It is almost invariably found on completion of such a craft that a considerable deficiency is revealed between the designed lift and the apparent value deduced, for example, from a “ lift and trim ” trial. Clearly, it is of considerable importance that the reason for this discrepancy should, if possible, be determined; for whilst the loss may be only a small percentage of the total displacement of the ship, and hence difficult to trace, yet considered in terms of disposable lift, it frequently is very serious.
Turbulence Near the Ground
Authors: Schmidt Wilhelm
Published: August 2016

Turbulent motion in open air must be studied in a way differing from that followed in laboratory experiments. We cannot choose or arrange for the most suitable conditions; we have to make the best of what nature offers; it is nearly impossible to stain air masses sufficiently so that they show streamlines-we have to judge their possible form from complicated effects. The results arrived at will depend upon the means at one's disposal and the way pursued.
Speeds of Commercial Aeroplanes
Authors: Breguet Louis
Published: August 2016

It is a great honour for me to address the members of the oldest learned society devoted to aeronautics, the Royal Aeronautical Society, which was founded in 1866—six years before the Société Francaise de Navigation Aérienne of France was founded for the same purpose.

The choice of a subject nowadays is a difficult matter; great progress has been made in aeronautical science—numerous research workers all over the world are endeavouring to solve the outstanding problems—and the reason I decided to take for my lecture the subject of the maximum speeds of commercial aeroplanes was that it appears to me to be a matter of the utmost importance for the future of commercial aeronautics and for linking up the different peoples of the globe.
Some Engineering Problems of Large Aircraft
Authors: Russell A. E.
Published: August 2016

The scope of this paper is necessarily restricted. A large aeroplane, within the new definition, has not yet flown in this country. This event, however, is not very far off and the preparatory work that makes it possible has brought to light many novel problems. In some cases these could be predicted with normal anticipation, whereas others have only emerged as analysis progressed. These latter are frequently good examples of the dangers of too facile extrapolation.

Some of the reasons for having large aeroplanes are examined and subsequently, the chief technical problems arising are described. These descriptions avoid mathematics, as in many cases this approach is extremely long and involved and merits individual publication.
Fuels for Aircraft Engines
Authors: Banks F. R.
Published: August 2016

There has been a great advancement in recent years in the technique and production of suitable fuels for both aircraft and automobile engines and the author hopes that a few notes on the fuel problem with particular reference to aircraft work may be of help to those engaged on aero engine design and operation.

In the author's opinion it is somewhat surprising that, with the information and data at present available on the subject of fuels, greater use is not made of this when considering the design and operation of an aero engine.
The Development and Characteristics of a Long-Range Flying Boat (The S-42)
Authors: Sikorsky Igob I.
Published: August 2016

Almost a decade ago, with the rapid world-wide development of air transportation, came the demand for new types of aircraft. It became evident that a plane capable of operating from land or water was the logical step needed to open up larger areas for air transportation. The proximity of water compared with the remoteness of available landing fields to the centres of population was the deciding factor in amphibian development.

While the advantages of the amphibian are obvious, the limitations and; difficulties of creating an efficient plane of this type are also evident. Compared to the seaplane or landplane, the amphibian must take care of the extra weight and parasitic resistance, as well as solve various other problems connected with combining the characteristics of the land and seaplane in one aeroplane.
Variable Pitch Airscrews and Variable Gears
Authors: Jennings W. G.
Published: August 2016

The subject defined by the title of this paper is one which cannot be covered completely in the time at my disposal. I propose therefore to confine my remarks to-night almost entirely to the aerodynamic aspects of the problem and to put before you some possible advantages that may be gained by substituting a variable pitch airscrew for the normal fixed pitch airscrew, and in certain cases to compare the results with those given by the introduction of a variable gear airscrew. The mechanical side of the problem is a subject complete in itself and will not be dealt with here.
The C.I. Engine as the Rival of the Petrol Engine
Authors: Dicksee C. B.
Published: August 2016

The petrol engine has become so firmly established as the motive power for aircraft, automobiles and small vessels that a short while ago it would have seemed almost impossible that its supremacy could be challenged. It is no exaggeration to say that it was the petrol engine which made aircraft possible, while on the road, despite the fact that the steam engine is fundamentally more suited for traction work, the petrol engine has practically ousted its rival from the field. Even for the heaviest vehicle, where, owing to cheap coal, the lower running cost at one time gave the steam vehicle an advantage, the petrol engine is nearly universal, while at sea, for launches and small craft, the steam engine has practically disappeared.
Fifty Years Ago
Authors: Manning W. O.
Published: August 2016

In the year 1884 the annual meeting of the Aeronautical Society was held in the rooms of the Society of Arts on the 2nd July. In those days the Society held one meeting only each year, and there were usually three or four papers read. On this occasion, the chairman was Mr. James Glaisher, F.R.S., and in his opening address he referred to the little progress which had been made during the past year, but drew consolation from the fact that there were still many earnest workers actively employed who were working more persistently and more perseveringly than ever. He also stressed the importance of experiment, stating that although the experimenter might not succeed, he could not make any experiment without increasing our knowledge in the way we desire it to be increased.
The Spinning of Aeroplanes
Authors: Scott-Hall S.
Published: August 2016

Apart from the subject of straight normal flight and all the problems of stability and performance concerned with it, more thought has been given to the spin than to any other form of motion of an aeroplane. The reasons for this are not far to seek. The spin is the evolution which, until the recent introduction of certain well known methods of lateral control and stabilisation, invariably followed the loss of control at speeds below the stall, and its occurrence near the ground has been responsible for the majority of fatal flying accidents.

It is the only form of stable uncontrolled motion which is exhibited by an aeroplane other than that which it may possess in straight flight. This stability has in a number of cases proved extremely dangerous, if not fatal, as in prolonged spins on certain aeroplanes it has been found impossible to recover.
Modern Developments in the Helicopter
Authors: Liptrot R. N.
Published: August 2016

The problem of the helicopter is one which has intrigued inventors for centuries, and which has perhaps attracted more attention and effort than any other phase of design of heavier-than-air craft.

Even as far back as the fifteenth century we find Leonardo da Vinci devoting several years of his life to studying- bird and mechanical flight, and he has left many sketches showing- flying machines. Of particular interest to us is a design showing- an aircraft consisting of a sustaining screw driven about a vertical axis.

The first helicopter actually to fly was a small model, little more than a toy, which was shown before the French Academie des Sciences in 1784 by Launay and Bienvenue, and since that time literally thousands of schemes have been proposed by inventors all over the world. The patent files of all countries are full of helicopter specifications, the greater part of them being based on faulty physical principles, and obviously impracticable.
Fuels and Modern Methods of Testing
Authors: Tett H. C.
Published: August 2016

Petroleum as it occurs in Nature is a very complex mixture of hydrocarbons. Imagine a mixture of petrol, paraffin, gas oil, fuel oil and lubricating oil, together with a certain amount of water and other foreign matter, and you have an idea of crude petroleum as it is found in Nature.

It is interesting to note that practically the sole use of petroleum for some time after the first well was drilled was as a burning oil. The object of the refiner was therefore to produce as large as possible a percentage of paraffin from his crude. The lighter fractions were regarded as a necessary evil, and it became a very difficult problem to dispose of them satisfactorily. It was, of course, necessary to keep the flash point of the paraffin high enough to avoid the danger of explosion of the lamps in which it was used. Petroleum inspectors were employed to ensure that the paraffin on sale was not “adulterated” with the then valueless light petroleum spirit. No market other than as a source for lighting gas was found for this light spirit until the advent of the motor car.
The Corrosion of Electron Alloy AM 503 by Leaded Fuels: Part I.—Mechanism of Attack
Authors: Bengough G. D. , Whitby L.
Published: August 2016

Tetraethyl lead is a constituent of most fuels of high anti-knock value, but such fuels cause serious corrosion of magnesium-base alloy tanks and may completely penetrate them in a few months. No work on the mechanism of this attack has been published and no satisfactory method for protection exists, so that magnesium-base alloy tanks cannot be used for leaded fuels. Since tanks constructed from an ultra-light alloy would be of advantage for aircraft, experiments have now been carried out to elucidate the mechanism of their corrosion, this work representing the first stage of an attack on the problem of providing protection against such corrosion.
The Flying School at the Wasserkuppe
Authors: Stamer Fritz
Published: August 2016

The site of the Flying School was selected on a gentle eastward slope about midway between the southern slope of the “ Wasserkuppe ” and the western slope of the “ Weltensegler,” a ridge running at right angles to the former, the slopes of which are most used for training glides. The hangar, 60m. by 12m., was built of timber, with a cantilever roof requiring few supports and with drop doors at each end. The pupils are boarded at the school for convenience and for better supervision and direction of their spare time activities. It was also necessary to provide workshops and offices, and quarters for the mechanics and instructors and for the head of the school. A single building, also 60m. by 12m., adjacent to the hangar contains living quarters below, and a workshop above; a long central passage leads to a hall, on the south side, off which are the quarters of the Director of Research and of the Head of the School, and the kitchen premises; on the north side a woodworking shop equipped with a combined plane and shaping machine, a combined circular saw milling and slotting machine, and a hand saw.
The Theory of Alloy Structures
Authors: Bragg W. L.
Published: August 2016

1. I wish in the first place to express my warmest thanks to the Council of the Royal Aeronautical Society for the honour they have done me in inviting me to read this paper on alloy structures. I have no claim whatever to be considered a metallurgist or an expert in any way on the technical uses to which alloys are put. I only venture to give this lecture because nowadays a physicist has a finger in most pies. The discoveries of physics concern all sciences interested in the structure and properties of matter. Since ultimately the properties of matter are dependent upon its atomic structure, and this is the field in which physics has made such rapid recent advances, its findings have become of especial importance.
Jet Propulsion for Aircraft
Authors: Richardson E. G.
Published: August 2016

The idea of using the reaction of a jet of water pumped sternwards from a ship is endowed with a respectable antiquity, but tests on the efficiency of such propellers, whether model or full-scale, have not been extensive. Perhaps the most thorough tests were those of S. W. Barnaby (Thornycroft and Co.) in 1880, described by him in the Proceedings of the Institute of Civil Engineers, Vol. LXXVII, page 1, 1883. This investigator measured the reaction on a nozzle delivering water under pressure into still water by a force balance connected to the nozzle itself. As a result, the “ Waterwitch,” a vessel of 1,160 tons, was constructed to work on this principle, the jet being supplied by a centrifugal pump which took water from a scoop amidships. The efficiency of the jet itself worked out at .71, but with the pump the combined efficiency was only .38.
Wing Flaps and Other Devices as Aids to Landing
Authors: Alston R. P.
Published: August 2016

It has long been recognised that landing and taking—off are the most hazardous periods of the average flight. In this respect an aeroplane is similar to a boat being launched or beached at high speed; the change from one medium of support to another is bound to involve possible damage especially if speeds are high.

So far as risk of mechanical damage, due to uneven aerodrome surface (or swell in the case of a seaplane), is concerned, the speed of landing should be the minimum practicable. Very low landing speeds have a possible disadvantage in that one may not have sufficient aerodynamic control to compete with gusts, etc., but there are few aeroplanes of to-day which have landing speeds so low that this objection can be raised.

The trend of design in recent years has been to increase aerodynamic efficiency by streamlining and to increase the wing loading.
The Aerodynamic Characteristics of Aircraft Skis and the Development of an Improved Design
Authors: Green J. J. , Klein G. J.
Published: August 2016

Existing information on the aerodynamic characteristics of aircraft winter landing gear is very meagre and it was therefore desirable to test as many full size skis as possible in order to collect data concerning the various types of skis in actual use.

It was known that the air resistance of existing types is quite high and the experiments were intended to explore the possibilities of producing an improved type of ski having considerably lower air resistance.

The large pitching moments on present types of skis give rise to serious problems in trimming gear design, especially on high performance aircraft. The experiments aimed at producing a ski on which the pitching moments would be considerably reduced in order that the use of exterior trimming cables might be avoided.
The Importance of the Boundary Layer
Authors: Glauert H.
Published: August 2016

When we consider the physical properties of the air, the most noticeable features are its low density and its compressibility, and a student new to the subject might be excused for doubting whether the air were not too light and yielding to support an aeroplane in flight. The air is indeed very compressible, but this property of the air becomes important only when the speed of motion becomes a fairly large fraction of the speed of sound, and in practice its influence is felt only in the behaviour of airscrews with high tip speeds.

A more important property of the air is its viscosity or internal friction, and this property is of fundamental importance in flight, either by its direct frictional action or by its indirect action in determining the type of flow round a body. As an example of this indirect action we may consider the lift of a wing.
Research Work of the “DVL”
Authors: Hoff Wilh.
Published: August 2016

In the later part of autumn last year, I was invited by your President, Colonel the Master of Sempill, to read a paper about the work of the “ Deutsche Versuchsanstalt fur Luftfahrt ”( i.e. “ German Aeronautical Research Institute ” ) . The Royal Aeronautical Society can look back to a long and successful development. Your Society has always aimed at the promoting of the technical work of your country and at the fostering of close scientific relations between air–minded countries. It is therefore a great honour for me to lecture before your Society.

I regard co–operation in discussing areonautical matters between the various countries as very necessary. Representatives of aeronautical science have, during the past year, held international congresses at Stockholm, in the Hague and finally in Paris. Common problems were treated at these congresses by the representatives. New personal relations were formed during the meetings held there.
The Resistance of Air-Cooled Engines
Authors: Green F. M.
Published: August 2016

An internal combustion engine divides the heat energy obtained from its fuel into three fairly equal parts. About one-third of the energy becomes useful work; rather more than one-third escapes into the atmosphere in the exhaust gases : and rather less than one-third gives its heat to the cylinders and pistons. As its name implies, an air-cooled engine is one in which the cylinders are cooled directly by air. While the engin.e can and does part with a small amount of its heat by radiation, the bulk of the heat is carried away by air moving more or less rapidly over the surface of the cylinders and cylinder head, which are provided with fins in order to increase the surface in contact with the air. As the loss of heat is nearly proportional to the velocity of the cooling air the faster the aeroplane goes the better will a given engine be cooled; consequently, on a high-speed aeroplane it would be permissible to reduce the area of the cylinders in contact with the air; that is to say, we might save weight by reducing the size and number of fins or, alternatively, the velocity of air over the cylinders need not be equal to the speed of the aeroplane.
The Effect of Accelerations on Human Beings
Authors: Nayler J. L.
Published: August 2016

The amount of information on the effect of accelerations on human beings is scanty and somewhat rudimentary with the single exception of observations made on aeroplanes. Aircraft in general have to be built to certain factors of safety so as to keep the total flying weight as small as possible, and for this reason accelerometers have been carried to measure the resultant forces experienced in flight. In this way a measure has been obtained of the forces likewise impressed on the human pilot directing the craft. The practice of flying has gradually developed by the careful training of the pilots so that undue stress is not placed on the aircraft structure and as a corollary this has been made possible by the pilot using his physical sensations to limit the violence of any aerobatic manœuvre. But the practice in this respect differs in various countries and so an attempt is here made to collate what information exists on the effect of accelerations on the human body and to consider whether the stresses experienced in flight can be increased with safety. It is, however, realised that the subject is a very open one and that the experimental data are very scanty.
The effect of Aeration of the Oil on the Behaviour of an Engine Lubricating System Under High Altitude Conditions
Authors: Giffen E. , Mills H. R.
Published: August 2016

The work described in this paper was done during the war, at the suggestion of the aircraft engine firms, as a result of difficulties with lubricating oil systems at high altitudes. Failure of oil pressure, seizure of bearings, or excessive loss of oil sometimes occurred and these defects were attributed to air in the lubricating oil, this air being greatly increased in volume at high altitudes because of reduced atmospheric pressure.

The behaviour of air-oil mixtures therefore was studied to obtain fundamental information which could be applied to engine lubrication at high altitudes. The present paper deals with that part of the research which was done on a complete lubrication system under simulated altitude conditions.
The General theory of Cylindrical and Conical Tubes Under Torsion and Bending Loads
Authors: Hadji-Argyris J. , Dunne P. C.
Published: August 2016

Parts 1 to 5 of this paper (February, September and November 1947 issues of the JOURNAL) investigated the stresses and deformations of closed tubes in which the thicknesses were governed by the ts* and t* laws. In the present part, the analysis is extended to multi-cell tubes with openings, open tubes with or without St. Venant torsional stiffness, and to tubes formed by joining elements of different cross-sections. To illustrate the theory a numerical example of the stressing of a four-boom wing consisting of seven joined elements is fully worked out. Finally, an appendix gives practical methods of dealing with tubes which do not conform to the ts* and t* laws, and of finding approximate solutions for four-boom tubes with direct stress carrying covers.
Ernst Mach — Pioneer of Supersonics
Authors: Black Joseph
Published: August 2016

It is a curious reflection on the progress of science in our time, that a term which has only come into common use in aeronautics in the last decade commemorates the name of a man who carried out his researches some fifteen years before the Wright Brothers first flew in 1903. The obscurity surrounding Ernst Mach, whose name is given to the ratio of the speed of flow of a gas to the speed of sound under the same conditions, is ill-deserved, for there can be little doubt that he was one of the outstanding scientific personalities of the nineteeth century; this distinction arises not so much from his experimental work, which was extremely valuable, but more from his original conceptions on the philosophy of science which helped to lay the foundation for modern developments in physics.
Clear Air Turbulence and Civil Jet Operations
Authors: Chambers E.
Published: August 2016

How much is known about high altitude clear air turbulence? Sufficient to show that aircraft may, with little or no warning, experience bumpiness which the pilot would describe as “ moderate ” or, on occasions, “ severe,” at altitudes up to at least 40,000 feet, thus including altitude bands where commercial jet aircraft will be flying during the next few years. The phenomenon, therefore, is of significance to airline operators and the requirement is for the aircraft commander to be supplied with sufficient information to enable him to avoid such turbulence, or to provide him with adequate warning so that crew and passengers can be properly prepared for it. This does not imply that there is evidence to suppose that clear air turbulence may be of such severity as to affect the safety of a flight. It is important, however, to take good care of the passengers and their comfort is an essential consideration.
Stability of Axially Loaded Continuous Beams
Authors: Bolton A. , Owen J. B. B.
Published: August 2016

From Mr. A. M. Dobson's Note (July 1955 Journal, page 506) which dealt with the stability of an axially loaded continuous beam, and other contacts we have had with the Aircraft Industry, it would appear that the very considerable developments of structural theory which have taken place in relation to continuous beams subjected to axial load, as employed in normal structural steel work, are not well known in aircraft stress offices. The list of references appended may then be found helpful.