bluuebunny/crossref_metadata_2025 huggingface dataset:
Flying Boat Problems Related to Production, Controls and Pressurisation
Authors: Lipscomb C. P. T.
Published: August 2016

This paper was requested to deal with (1) the future relations between designers and production; (2) the special problems to be faced by the production people and the assistance to be expected from the designers; and (3) how such design problems as pressurisation, silencing and the fitment of turbine engines were being tackled.

These terms of reference are very broad and probably can only be touched upon in a general way. I, personally, have been engaged entirely on the design side for the past thirty years and therefore it might have been more fitting if a member of the production organisation had been asked to give this paper.
New Developments of the Autogiro
Authors: Cierva Juan De La
Published: August 2016

It is my privilege to present to the Royal Aeronautical Society a brief summary of the work done and the results achieved in developing the autogiro in the last few years. Many fundamental improvements have been the product of that work, but of still greater importance is the considerable progress in the knowledge of the aerodynamics, dynamics and engineering requirements of the new aircraft. The improvements in the formula have been made possible or practical only because of the painfully acquired technique, which, as is the case in all new arts, is a compound of theoretical developments and empiricism.
A Theoretical Investigation of the Maximum-lift Coefficient
Authors: Von karman TH. , Millikan Clark B.
Published: August 2016

The problem of the maximum lift of airfoils has concerned the authors greatly since there were first discovered in the spring of 1932 serious discrepancies in this characteristic between results obtained in the wind tunnel of the Guggenheim Aeronautics Laboratory at the California Institute of Technology (GALCIT) and those reported from certain other wind tunnels. An elaborate experimental investigation by the junior author and A. L. Klein indicated that the value of CLmax for a given airfoil was strongly affected both by Reynolds number and by the degree of turbulence in the tunnel wind stream.
Catapults and Catapulting of Aeroplanes
Authors: Salmon P.
Published: August 2016

The aeroplane launching catapult is a means whereby in a very short distance the speed of an aeroplane can be accelerated from rest to that at which it becomes air borne.

Fundamentally the aeroplane launching catapult comprises a carriage on which is mounted the aeroplane to be launched, a motive plant which causes the carriage to travel at an increasing speed along a prepared track or structure and a means of arresting the carriage after the aeroplane has attained the necessary flying speed.
Growth of Aviation
Authors: Fairey C. R.
Published: August 2016

The statement that aviation is in its infancy is now the commonest of platitudes and it is possibly not unbecoming in conscientious parents or guardians to take stock of the growth from time to time of the infant they are interested in—to weigh and measure it with a view to ascertaining whether such growth is normal and uniform, and more important still, whether the rate of growth is being maintained, is increasing or diminishing and to try to ascertain what external influences have the most beneficial effect.
A Study of Slots, Rings & Boundary Layer Control by Blowing
Authors: Townend H. C. H.
Published: August 2016

In this paper a study has been made of certain cases of airflow in which various means are employed to control the behaviour of the air so as to prevent breakdown in the flow and the resulting turbulence. It is mainly an attempt to analyse the evidence which exists on such phenomena as slots, rings and boundary layer control by means of blowing through backwardly–directed slots in the surface, and to determine, if possible, the extent to which their apparent similarity corresponds, if at all, to an identity of physical principle.

A great deal of experimental work has been done at various times on such devices, and in this paper some of the published results are discussed and an attempt made to correlate them. In addition, some further experiments have been made to fill up gaps in the data available, or to extend their scope. They include other examples of control of airflow at sharp corners (Part I.); some of the cases considered differ widely from others, but all exhibit the reduction in eddying which results from assisting air to negotiate sharp corners or bluff obstacles with the least disturbance possible.
Tapered Wing Stalling
Authors: Nazir P. P.
Published: August 2016

It has been known for many years that the rectangular wing stalls first in the central region, burbling spreading gradually tipwards with further increase of incidence. This phenomenon is useful in connection with lateral control, because this control is retained for a while (though reduced) past the stall. Increased use of the1 tapered wing to-day raises the question of whether this phenomenon holds good with tapered wings. There is already some doubt on this score.
Tables for use in Aero Navigation by Astronomical Methods
Authors: Everitt P. F.
Published: August 2016

As the subject of the reduction of astronomical observations in the air had been the subject of several conversations with the late Squadron Leader Johnston, who was one of our best exponents of aerial navigation, Mr. A. J. Hughes, O.B.E., suggested to the writer that a short note based on Squadron Leader Johnston's methods would be useful in order that his valuable experience should not be entirely lost, and that some systematic survey of the methods available would be useful in connection with a subject that is becoming of increasing importance now that the range and reliability of aircraft have been so largely extended.
Post-War Transport Aircraft
Authors: Warner Edward P.
Published: August 2016

I have been deeply appreciative of the action of the Council in inviting me to deliver this lecture. No one could be otherwise. The Wilbur Wright. Lectureship has been illustrious in the qualifications of the thirty speakers who have been my predecessors on this platform ; but it is illustrious also in itself, in the manner of its founding, and in the manner in which the Royal Aeronautical Society has carried it on in an unbroken series through two wars and the years between.
Note on the Wings of Gliding Birds
Authors: Walker Gilbert T.
Published: August 2016

The recent revival of interest in gliding in this country is my excuse for drawing attention to a feature in the wings of birds whose gliding depends primarily on ascending currents, mainly raptores (eagles, vultures, hawks, kites, etc.), especially in the tropics.
A Study of the Phenomenon of Spin in Aeroplanes
Authors: Wimperis H. E.
Published: August 2016

The spin is a mode of motion of which we know very little. The general public are inclined to look upon it as necessarily dangerous, but this we do know it is not. It is only in rare circumstances and under fortunately rare conditions that danger arises. Nevertheless there is ample warrant for its study, and for that study to be treated as one of high importance. New conditions of aeroplane operation are continually arising, the very increase of speed itself would ensure an entry into regions never before penetrated. Hence it is ever necessary to seek for remedies even before serious difficulty has arisen; this anticipating action always seems to me to be absolutely essential, and I am comforted by support in this view from no less an authority than Francis Bacon, who, in his essay “ On Innovations,” wrote: “ Time is the greatest innovator; and if time in course alters things to the worse, and wisdom and counsel shall not alter them to the better, what shall be the end?”
Injection, Ignition, and Combustion in High–Speed Heavy–Oil Engines
Authors: Davies S. J. , Giffen E.
Published: August 2016

Although there is one successful high–speed heavy-oil engine employing aif injection, it will not be disputed that the present rapid development of this type of internal combustion engine would not have taken place if a high-pressure air-compressor were an essential accessory. It is perhaps well to emphasise that from the beginning designers of engines of the pure “compression-ignition” type have striven after airless injection of the fuel, the first successful application in this connection being that of Sir James McKechnie, of Vickers, Ltd., in 1910. Subsequent development work by Professor Hawkes and others under the Admiralty brought this method to practical success on submarine engines, and it is interesting to note that as late as 1920 almost all experience with airless injection had been gained in this country.

Engines which are the lineal descendants of these early engines, namely, those in which the fuel is injected directly into a combustion chamber of simple form, and known conveniently as the “direct–injection” type, constitute an important section of those engines working successfully at high speeds.
Recent Developments in Engine Cooling
Authors: Swan Andrew
Published: August 2016

Aircraft engines are classed as air-cooled or water-cooled, accordingly as they are cooled directly by contact with air or indirectly by air through the intermediary of the water which surrounds the cylinders. The method of cooling used has been a cause of wide divergence in design and arrangement between the two types. The air-cooled engine, except for the smaller powers, appears in the radial form in which exposure of each cylinder to the air stream is simplified at the expense, however, of a large frontal area while, with obviously greater latitude, the water-cooled engine can take a form having a smaller frontal surface.
Controllable-Pitch Propeller
Authors: Turnbull W. R.
Published: August 2016

Confusion has arisen regarding just what is meant by adjustable variablepitch and controllable-pitch propellers, and the matter should Be more clearly defined in the following way:—Fixed-pitch propellers to apply to both (a) the ordinary fixed-pitch propeller, made up with the hub and blades integral, and the material the same throughout, and (b) the detachable-blade or ground-adjustable type that will usually have the hub and blades of different materials, and in which the blades will be clamped in the hubs on the ground to an angle that is assumed, usually by experiment, to give the best general or some specially desired performance results.
The Design Approximation of Skin Thickness from Stiffness Criteria
Authors: Hall A. H.
Published: August 2016

A general approach and tentative solution has been indicated to the problem of estimating wing skin thickness from preliminary design data. The solution is presented in a form that permits calculations to be made quickly and with a minimum of effort.

In deriving the empirical formula relating perimeter and area of the aerofoil section, only symmetrical sections were considered. The amount of camber normally employed, however, should not alter the results appreciably.

While the problem has been dealt with only partially and as yet only tentative empirical coefficients have been suggested, it is hoped that the author’s considerations of the problem will be of some interest and use at this stage.
The Berlin Air Lift
Authors: Merer J. W. F.
Published: August 2016

Introducing the paper Air Commodore Merer pointed out that the Americans, the French and the British were concerned in a close partnership in the Air Lift, but the Americans carried by far the larger portion of the load delivered into Berlin. The spirit of comradeship and endeavour which that joint task engendered was one of the heartening experiences of the operation and beyond all praise.
Introduction to the Theory of Photoelasticity and its Application to Problems of Stress Analysis
Authors: Arthur R. E.
Published: August 2016

Many problems arise in stress analysis which are not reasonably susceptible to mathematical treatment. Recourse may then be had to experimental methods. One of the most useful of these is the photoelastic method. This method is based upon the fact that transparent materials when stressed undergo changes in their optical properties which can be measured and related to the applied stress.
Some Notes on the Shear Centre of Thin-Walled Open Sections
Authors: Haas T.
Published: August 2016

Advanced textbooks of strength of materials dealing with the shear centre give examples of the simplest sections only (e.g., Ref. 1, Art. 8). Numerous articles in the technical press are devoted to the subject, and the method to find the shear centre of any open section is now well established (Ref. 2). However, the number of readily usable solutions for sections common in practice, is small. Consideration in this paper is given to a more complicated section, fairly common in practice, and a formulae is derived for the location of its shear centre. The section is a lipped channel, symmetrical about one axis, and the paper is followed by a diagram that enables the shear centre position for various ratios of lip to leg and leg to web to be read off.
Modern Methods of Testing Aero-Engines and Power Plants
Authors: Lovesey A. C.
Published: August 2016

In the early days of aero-engines the test equipment was limited to little more than a brake or dynamometer, a fuel flow meter and a few thermometers, and the development of these engines in the direction of better performance and reliability, to a large extent, was an art, built up of experience aided by instinct, of deducing the happenings inside an engine from the few meagre measurements obtainable.

Nevertheless, the aero-engine made healthy progress, became more complicated in the process, and introduced many more problems.
On the Elimination of Structural Discontinuities
Authors: Argyris J. H.
Published: August 2016

The effect of discontinuities on the analysis of structures is discussed by W. J. Goodey in a Technical Note in the October Journal. He quite rightly points out that a structure with cut-outs is more difficult to analyse (especially for routine calculations) than a structure without cut-outs. Subsequently he indicates a procedure for obviating the former complications by introducing fictitious members in place of the cutouts. Using then the variational method of arbitrary multipliers he derives the stress distribution in the structure with cut-outs from the simpler analysis of the structure without cut-outs.
Recent Developments in the Hydrodynamic Design of Flying–Boats
Authors: Paterson J. H.
Published: August 2016

During the past few years numerous developments in the hydrodynamic design of flying-boats have been brought about mainly by systematic model research. Although Germany deserves the credit for initiating research on the forces on planing plates and Vee wedges, we are indebted to various estabhshments in the U.S.A. for the multiplicity of data on both flying-boats and simple planing surfaces, which are now available.
The Conjugate Load Method in Structural Analysis
Authors: Schwalbe W. L.
Published: August 2016

The problem of analysing the behaviour of a structure as a combination of members joined together, may be stated in the form of a question—What system of loads must be applied to a single member of the combination so that its behaviour as an isolated member is identical to its behaviour as an integral part of the structure? The question becomes clearer upon defining some of the terms used in stating the question.
Response in Yaw
Authors: Archbold E. J. N. , McKenzie Kieran T.
Published: August 2016

If the motion of an aircraft is restricted, near the ground, to zero bank, comparatively simple solutions to the resulting equations of motion can be obtained, enabling the response to an applied yawing moment to be calculated rapidly. In this paper the analysis is made for three simple forms of applied yawing moment. From the results obtained in a particular case it is possible to judge the suitability of the fin and rudder design chosen on the basis of maximum sideslip reached. A general curve of overswing, in terms of the aerodynamic derivatives of the aircraft, enables the maximum sideslip to be calculated rapidly in a particular case.

Because of typogiaphical difficulties the symbols ^ have been replaced by ° with v, r and t throughout the paper.
The de Havilland Wing Test Rig
Authors: Hampton W.
Published: August 2016

A description of a test made recently in this test rig should prove of interest to those engaged in the design, stressing and structural testing of large aircraft structures, particularly wings, in that it would appear to represent a considerable advance over any previous test of this nature made in this country, and opens up new fields in simplicity and speed of application of the loads. The full load was applied to the wing in this test by one operator in approximately 50 seconds, thus approaching much more nearly than on any previous test made here the conditions which occur in flight.
Aeronautics and the Metallurgist
Authors: Aitchison Leslie
Published: August 2016

When first I was approached to lecture to the Society it was suggested that I might speak to you on “Modern Aircraft Materials.” I did not choose this subject, firstly because I felt it was much too comprehensive to be susceptible of compression within the period of any ordinary paper; and secondly, because the relevant data (in so far as it is known) is enshrined in the official specifications, in the catalogues published by the metal manufacturers, and in a large number of papers presented to this and other learned Societies.
The Design of Small Jet Engines
Authors: Rainbow H. S.
Published: August 2016

The whole process of designing an aero engine, from the original concept to the production of the first of the type, called a prototype, normally takes about two years.

The prototype design may originate from proposals put forward by the engine maker from specifications for military aircraft engines, issued in the United Kingdom by the Ministry of Supply, or from the Aircraft Industry.

It is not usual for engines to be designed specifically for civil aviation requirements. More often they are adaptations of military engines de-rated to increase their reliability, and to extend the overhaul period. With the growth of civil transport and the development of guided missiles, it is possible that this state of affairs may be reversed and engines for civil aircraft may become more important than those for Service use. At the present time, it is difficult to foresee a potential civil or private aircraft engine market that would justify the cost of designing and developing a small jet engine on that score alone.
Cold Working of Metals
Authors: Berry J. W.
Published: August 2016

The lecturer adopted the course of explaining the Cold Working of Metals from first stages.

The lecturer first dealt with the cold raising of metals and pointed out that in this case the operator always worked from the outside, and to avoid “ puckering ” of the metal it was gradually hammered concentrically so that “ puckers ” were eliminated almost as soon as they appeared.

The spinning of metals was then dealt with and nearly all cylindrical objects are worked in this way. Commencing as a metal disc the object is placed on a lathe and backed up on to a wooden former block and gradually formed on to the block. By eliminating the sudden bending of the metal round the sides of the block the “ puckers ” are reduced to a minimum and the metal is allowed to “ flow.”
Flight Testing Methods
Authors: Jones E. T.
Published: August 2016

In common with other machines, each new type aircraft must be put through comprehensive and well-seasoned tests. Unlike other machines, however, the aircraft exists to fly and by so doing severs its contact with the earth. Even this would not present a peculiar test difference if the atmosphere were rigidly connected to the earth and had a constant pressure and constant temperature at all heights, for then the engine power would not change with height or place and the speed over the ground would equal the speed through the air. Likewise the rate of climb, the manœuvrability and the behaviour of the controls would be independent of height. In such an atmosphere, tests would be required at one height only and measurements such as speed, rate of climb, take-off and landing could all be obtained accurately and directly from ground apparatus.
Some Aspects of Modern Aircraft Materials
Authors: Sutton H.
Published: August 2016

Wartime experience with aircraft steels emphasised the desirability of a complete revision of specifications for aircraft steels from both the technical and inspectional points of view. This was undertaken in association with the steel makers and the Society of British Aircraft Constructors under the aegis of the British Standards Institution. The aims were

(i)

To reduce the number of basic types of steels to a minimum, consistent with satisfying the demands of aircraft engineers.

(ii)

To transfer as many materials from the D.T.D. series of specifications to the B.S. Aircraft series.

(iii)

To prepare an Inspection and Testing Schedule, which would exist separately from the Materials Specifications, but applicable to all steels in whatever form they may be required.

(iv)

To achieve a degree of economy in alloying elements, again without detriment to the satisfying of designer's requirements.

The Inspection and testing schedule was issued as British Standard S100 in January 1949, but significant difficulties in its full application appeared in practice and it was not until the second half of 1952 that agreement was reached to put into practice the current standard 2 S100.
The Stability of an Axially–Loaded Continuous Beam
Authors: Dobson A. M.
Published: August 2016

The Classical method of solution of the stability of an axially–loaded continuous beam is by means of the three moments equation, using the Berry Functions, which are functions of the axial load. As the axial load approaches a value equal to the critical value for a pin–jointed beam, the Berry Functions tend to infinity, and the use of the three moments equations —(i. e. treating the end fixing moments as the independent variables)—leads to certain difficulties in the complete solution of the problem.

The major difficulty lies in the question of stability. The critical value is determined by the vanishing of the determinant of the coefficients of the fixing moments in the three moments equations. This value could be found by plotting the determinant against end load (c. f. Pippard and Pritchard). However, in a problem involving a large number of bays, the calculation necessary to do this is likely to be considerable, for there may be many branches to the curve.
French Practical Aerodynamic Methods
Authors: Brocard Jean , Hussenot François
Published: August 2016

France, paralysed during many years of a cruel occupation, has been unable to maintain a sustained technical effort, comparable with that of England.

Nevertheless, the work of French engineers was never discontinued. In difficult and sometimes dramatic circumstances, more often than not with only restricted facilities, their work of research continued, stubbornly and in silence.
The Effect of Curvature on the Centre of Shear
Authors: Johnson W.
Published: August 2016

A considerable amount of attention has been devoted to the study of the position of the centre of shear for straight beams but there appears to have been Uttle or no consideration of this position for beams of which the centre line is either shghtly or heavily curved. The reasons are probably twofold. Firstly, no demand for such an investigation has been made by designers, and secondly, and probably not least, any very general inquiry into this problem will lead to complex expressions which would not only be difhult and tedious to evaluate but will also be of uncertain accuracy.

This problem of taking beam curvature into account starts from the point where it normally ends for most mechanical engineers, who usually require to estimate the bending stresses in members of large curvature such as hooks and chain-links. Now the classical theory of elasticity applied to these latter members has yet to be seen to conform with experimental results to such a high degree as makes the added labour attending such methods worth while.
The Case for the Tailless Aircraft
Authors: Lee G. H.
Published: August 2016

The purpose of this paper is to present the case that can be made for the tailless aircraft on the grounds of improved performance and operational suitability.

The whole field of possible investigation is not treated here with uniform thoroughness and the main reason for this is that I have only quoted detailed results for those cases which I have actually considered myself, so that in some instances the general qualitative arguments can be backed up by actual figures, whereas in others the argument has had to be confined to generalities.
The Separation of Principal Stresses in Photo-Elastic Analysis
Authors: Frankl E. K.
Published: August 2016

The photo-elastic method can be used for either of two main purposes:

a)

As a qualitative design tool to obtain indications of possibly unsuspected sources of stress concentration.

(b)

As a means of obtaining a complete analysis of a two-dimensional stress problem,i.e., the determination of the separate magnitudes of the principal stresses at any point, as well as the direction of the principal planes relative to some axis of reference.

All that is required for (a) is the stress pattern which becomes visible and can be photographed when a loaded model cut from a sheet of suitable material is placed in a field of circularly polarised light.
Aircraft Engine Oil Cooling
Authors: Nixon Frank
Published: August 2016

When at the beginning of the year I was invited by the Council of the Society to give a Paper on oil cooling I had had little more than average contact with the subject, but nevertheless I was startled when I discovered the extent of my ignorance. Inquiry showed that this lack of knowledge was fairly general, and that apart from highly technical articles by specialists, there was remarkably little up-to-date published data.
Supersonic Propellers
Authors: Hilton W. F.
Published: August 2016

A start is made by considering why the subsonic propeller was abandoned when aircraft speeds approached the shock stall. It is true that the shock stall also occurs on the propeller blades under these conditions, causing a loss of lift and an increase of drag, but this is not the predominant effect which produces the marked decrease of propeller efficiency associated with high-speed aircraft. The main aerodynamic difficulty associated with the shock stall on the wings of an aircraft is due to the separation of flow caused by the shock wave rather than the presence of the shock wave itself. This difficulty is reduced on a propeller, as any separation of flow which might occur on a propeller blade due to the shock stall, would tend to cause the air to be stagnant relative to the blade, and would thus experience a large centrifugal force by virtue of the propeller rotation. Thus the propeller shock stall would never develop to the same degree that it does on the wings of an aircraft in steady flight.
The Application of the Gas Turbine in its Forms to the Field of Commercial Aviation
Authors: Clarkson R. M.
Published: August 2016

The development of the gas turbine is so rapid and the thermo-dynamic ingenuity which is being lavished upon it at the present time is so imaginative and varied that the words “ in its forms ” which appear in the title to this paper can mean as much or as little as you please. Partly because I want to limit the scope of this paper to developments which might be expected to be in service within the next five years, and partly because I am frankly not sufficiently acquainted with the characteristics of many of its more advanced forms, I am going to confine myself to a discussion of the effects upon the speed and economy of commercial aviation of the two simplest and immediate variants of the gas turbine— the simple jet-producing turbine and the simple propeller-driving turbine.
The Development of the Armstrong Siddeley Mamba Engine
Authors: Lindsey W. H.
Published: August 2016

The Mamba engine has now been in existence some two–and–a–half years and in that comparatively short period of time it has been developed to the stage of being a type tested engine with over 5,000 hours test bed running and 100 hours flying as a background. The purpose of this paper is to give a brief account of the progress of the development and of the many problems which have been met and overcome during the period. Because of the many aspects of the development work it is not possible to deal in great detail with any particular item but rather to present the over–all picture, from the original design conception to the complete power plant of to–day.
Stability of an Aircraft Structure in a Strength Test Frame
Authors: Walker P. B.
Published: August 2016

The part played by major structural strength tests in aeroplane design is well known. Without such tests the standard of safety for aircraft would soon decline and excess weight, as an insurance against structural failure, would become a general rule. Considerable time and effort are expended therefore in the early stages of each new design of aeroplane to check by actual test whether its strength meets requirements. It is clearly reasonable to devote some little further time and effort to the study of methods and technique for strength testing in general.
Modern Trends in Civil Airworthiness Requirements
Authors: Tye Walter
Published: August 2016

Some liberties have been taken with the contents of the lecture in relation to the title. Firstly, it is proposed to examine safety in general, for only by this means can airworthiness be seen in its true perspective. Secondly, some trends in airworthiness and inter-related operational matters will be discussed. Finally, crashworthiness is dealt with at some length.
The Influence of Tyre Pressure on the Design of Aerodrome Pavements
Authors: Fisher Cassie W.
Published: August 2016

The influence exerted by the technical development of a vehicle on the design of the surface on which it travels is of considerable historical and social importance. Technical progress in the design of the road vehicle has never been matched by a similar development of the road, and in the past 50 years the discrepancy between the performance of the vehicle as dictated by road conditions, and the performance of which it is capable has been even more marked. The policy, forced upon society by national and international conditions, of compelling the vehicle to conform to the present standards of road design is highly restrictive and uneconomic, and such devices as pedestrian crossings, traffic lights and speed limits, are all evidences of failure to solve the problems of the simultaneous development of vehicle and road.
Bogie Undercarriages
Authors: Cussons R. C.
Published: August 2016

There has been little practical experience in the United Kingdom on the operation and use of bogie undercarriages, although the de Havilland Comet, the production version of which is fitted with four-wheel bogie main undercarriages, has done enough flying now to give some idea of the snags likely to be encountered.

These remarks are confined mainly to the theoretical and practical advantages and disadvantages of bogie undercarriages in general, with brief descriptions of some of the various types.
On the Stability of the Flow of Gas out of a Compressor
Authors: Stephenson J. M.
Published: August 2016

It is often supposed that the flow of gas from a compressor is, or should be, stable if the pressure-flow characteristic has a negative slope. It is shown here that this is only true if the Mach number is zero, i.e. if the machine is pumping a liquid. As the Mach number is increased towards one, a third regime becomes more and more important, wherein disturbances give rise to damped oscillations. The flow in this regime is stable in the mathematical, but not in the physical sense, since disturbances can occur all the time.

Two conclusions can be drawn. First, although compressors with “flat” pressure-flow characteristics have a wide range of stable flow at low speeds, they are poor at high Mach numbers, where the flat part cannot be used. Next, the actual points on the characteristics at which the flow becomes unstable are not fixed, but depend to a large extent on the steadiness of the entry flow.
Differential Inductance Telemeter Equipment for Force and Moment Measurements
Authors: Gould R. W. F.
Published: August 2016

This note describes apparatus which has been used for remote measurements of forces and moments on models on the Whirling Arm at the National Physical Laboratory. Good short-term stability, independent of mains frequency and voltage variations, has been obtained with simple apparatus. Descriptions are included of the differential inductance bridge, a stable 1 kc./sec. oscillator used therewith, and a regulated power supply for the oscillator. General comments are made on problems involved in the force and moment measurements.
Note on the Application of Busemann's Formula to a Simple Two-Dimensional Curved Aerofoil Section
Authors: Dunsby J. A.
Published: August 2016

The theoretical aerodynamic properties of supersonic aerofoils of polygonal section are well known. This note describes the results obtained by applying supersonic aerofoil theory to a simple curved aerofoil of arbitrary maximum thickness position, the leading and trailing edges of which are pointed.

The results for a symmetrical curved section are compared with the theoretical properties of a symmetrical double-wedge section.
Unsymmetrical Bending and Bending Combined with Axial Loading of a Beam of Rectangular Cross Section into the Plastic Range
Authors: Barrett Anthony J.
Published: August 2016

This note considers two cases of bending beyond the limit of proportionality which have not received a great measure of attention in the past. These are Case(i). A beam subjected to a pure bending moment acting in a plane other than one of symmetry. Case(ii). A beam subjected to a bending moment and an axial load.

A mathematical form is used for the stress–strain curve in order that the results shall be applicable to a large number of materials and to avoid the tedious arithmetical summations which would be necessary if actual stress-strain curves were used. All the results are presented in terms of form factors since this notation is convenient for design purposes and is consistent with current British practice. Although the method adopted in the analysis is applicable to a number of different types of beam cross section, only rectangular cross sections are considered in detail at the present time.

Curves are presented showing the variation of the form factor with respect to the angle of the plane of loading, for Case(i), and with respect to the ratio of bending moment to axial load for Case(ii). These curves are based upon a standardised form of the stress–strain curve which may be taken as representative of a range of aircraft materials. Consideration is given to the automatic satisfaction of present military proof loading requirements when these form factors are used for the estimation of maximum permissible bending moments and axial loads under ultimate loading conditions.

The recommendations of F. P. Cozzone, for dealing with these two problems are examined and comparison is made between the theoretical work of this note and a limited number of test results available for Case(i).
The Normal Functions of Beam Vibration in Series Solutions of Static Problems
Authors: Bishop R. E. D.
Published: August 2016

The normal functions of beam vibration may be used in series to solve statical problems of beam flexure and the recent appearance of tables of these functions has rendered this method practicable. An outline is given of the procedure.

The simple equation of free flexural vibration of beams is

1

where v is the displacement, EI the flexural rigidity andAp the mass per unit length. The separation of variables and the application of appropriate boundary conditions at the ends x = 0 and x = l, gives the following normal functions ϕ(x).
Buckling of Simply-Supported Rhombic Plates Under Externally Applied Shear
Authors: Klein Bertram
Published: August 2016

The buckling of skewed plates with clamped edges and under externally applied shear, and skewed plates with simply-supported edges but with both externally applied axial and shear loading have been considered previously. It is the purpose of the present note to consider the buckling of simply-supported rhombic plates under externally applied shear as shown in Fig. 1.
The Use of Radar to Measure the True Air Speed of an Aircraft
Authors: Warner J. , Heffernan K. J.
Published: August 2016

There is at present no thoroughly satisfactory method of measuring accurately the true air speed of an aircraft, particularly at high speeds.

Ground radar can accurately follow a high-speed aircraft but, without the development described here, can only measure the speed of the aircraft relative to the ground. The method developed by the authors makes immediate allowance for wind speed and is capable of giving the true air speed of an aircraft to within one per cent. There is no apparent reason why the method should not be applicable even at very high speeds and there is no limit in aircraft altitude at which the measurement may be made.
Civil Aviation in the Second Elizabethan Era
Authors: Roberts G. N.
Published: August 2016

The thought that the highlights of history four centuries ago will repeat themselves in our time is growing, but the word and the wish are not enough. It will need to enter the heart and soul of the people and the nation, if another prolonged period of prosperity, highlighted by the deeds of the adventurous, is to be ushered in.
Turbo-Prop Performance Analysis and Flight Planning
Authors: Baxter J. R.
Published: August 2016

When Viscount 720 aircraft were delivered to Trans-Australia Airlines it became clear that increased attention would have to be given to performance analysis and the preparation of flight planning data.

Previous operational experience had been restricted to piston-engined aircraft which, for flight planning purposes, could be regarded as cruising at a certain air speed and burning fuel at a certain rate. Temperature effects were negligible because it was the accepted practice to restore power on hot days by slightly increasing boost settings. Altitude effects, although not truly negligible, were certainly small and could be covered by using flight planning figures from the conservative side of the range. With the Viscount, however, the specific range at cruising altitude was found to be almost twice its sea level value and a 10°C. rise in temperature was capable of reducing true air speed by 20 knots.
Measurement of Gust Loads in Aircraft
Authors: Taylor J.
Published: August 2016

Fatigue of aircraft parts due to small but numerous vibrations has been known about for some time, but in 1944–5 cases of structural fatigue were found which were thought to have been caused by loads greater, but less frequent, than the usual vibration loads. Such loads could be ground loads due to taxi-ing, take-off and landing or they could be air loads caused by gusts and manœuvres.

A general study of the fatigue properties of typical structures was made in the laboratory and it became apparent that the loads likely to do the most damage were those occurring about a million times in the life of the aircraft.
Notes on a General Method of Treatment of Structural Discontinuities
Authors: Goodey W. J.
Published: August 2016

A structure with cut–outs or other discontinuities is generally considered to be more difficult to analyse than a similar structure without such features, although it is in fact less redundant. This is largely due to the special conditions which have to be introduced to allow for these discontinuities, tending to make the calculations less adaptable to routine computation . Another and very practical reason is that it is sometimes fairly easy to—dare we say it?—make a reasonable guess at the load distribution in a structure without cut–outs, whereas a much more critical approach is necessary for the treatment of structural discontinuities. Be that as it may, it will be assumed here that the structure without discontinuities, which will henceforth be termed the “original” structure, can be analysed exactly, in the sense that all the effective redundancies are taken into account. It will now be shown how these calculations may be modified to deal with the corresponding structure with discontinuities, which for this reason will be referred to as the “modified” structure.
Part 1 Design and Construction
Authors: Lickley R. L.
Published: August 2016

The development of manned supersonic aircraft in this country suffered a setback at the end of the 1939-45 War, when it was decided that the use of manned aircraft would be too dangerous; however, more realistic views soon prevailed and, as a result, the ordering of such manned aircraft was considered in 1947 by the Ministry of Supply and in our submissions to M.o.S. in 1949, we described the aircraft as having as its primary function “Research Flying at Transonic and Supersonic speeds up to M =1·5.”

The background which led up to this submission is of interest, as it shows a logical line of development within the Company.
Dimensions Required for Inspection
Authors: Parks Albert C.
Published: August 2016

In his technical note on “Dimensions required for Inspection” (July Journal), Mr. G. A. G. Saywell stated that drawings calling up various machined fittings often lack any reference to “practical” measurement by which the operator, toolmaker and inspection department may “set out” and check the work concerned. This statement does not really do justice to the draughtsman who, in preparing the detail drawing for manufacture, has to give attention to all aspects of manufacturing.
Problems of Short-Haul Air Transport
Authors: Brooks Peter W.
Published: August 2016

The first part of this paper discusses some fundamentals of Air Transport and shows how these affect the organisation of airline operators. Against this background, Part II examines some of the particular problems of the short haul operator—the side of the Industry with which the author has been associated in British European Airways.

Commercial Air Transport has existed for more than thirty years. It has made important progress, but has still a long way to go to fulfil its destiny. Although progress in developing the vehicle since the first aeroplane flew in 1903 has been highly spectacular, Air Transport itself has made a slow start. This is shown by Fig. 1 which compares the increases in passenger traffic that occurred in the first thirty years of British rail and air transport.
Transient Temperature Distributions and Thermal Stresses in Fuselage Shells with Bulkheads or Frames
Authors: Przemieniecki J. S.
Published: August 2016

The temperature distribution and thermal stresses are calculated in a configuration consisting of a cylindrical fuselage shell with bulkheads or frames. It is shown that at supersonic speeds thermal stresses are set up in a conventional fuselage structure as a result of the bulkhead restraint against circumferential expansion of the fuselage skin. The thermal stresses due to restraint by fuselage frames are usually less severe. The relative merits of various combinations of materials for the skin and the bulkhead diaphragm are discussed. Furthermore, the possibility of the use of light alloy bulkheads to alleviate thermal stresses is investigated. Diagrams are given for calculating maximum thermal stresses and stress-time variation for various rates of heat input in the fuselage skin due to aerodynamic heating.
On Obtaining the Shear Stress-Strain Relationship from a Hollow Specimen in Torsion
Authors: Ellington J. P.
Published: August 2016

A method is given whereby the shear stress-strain relationship of a material can be obtained from observations made during a torsion test on a hollow circular specimen. An examination is then made of the corrections necessary when using thin-walled specimens, and some advantageous definitions of the mean diameter of a tube are suggested.

The use of torsion tests to obtain shear stress-strain relationships is now well established and takes one of two forms. A thin circular tube can be used, it being assumed that the stress distribution is uniform across the wall thickness, or a solid circular bar can be used, the results being analysed by a method ascribed to Nadai. Swift has shown that these two methods give comparable results for moderate strains.
Stress Analysis of Circular Frames in a Non-tapering Fuselage
Authors: Dallison K. J.
Published: August 2016

The problem of the stress analysis of circular fuselage frames has been investigated by a number of authors; the analyses are, necessarily, rather mathematical in nature although in some cases the final results have been presented in extremely practical form. The present paper offers, in non-mathematical language, a short account of the fundamentals of the problem and a brief guide to the more important published literature. It also develops an approximate method for the analysis of frames using Lagrange's method for minimising a function of several inter-dependent variables. This method is shown to be particularly suitable for the analysis of frames with large cut-outs, about which little has previously been published. In addition, the underlying parameters which determine the stress distribution are deduced from the theory, and the deductions are compared with previously published work. In general, agreement is good. The paper is written throughout with a view to being of practical use in the actual stressing of frames. Numerical examples and explanations of mathematical methods are included in Appendices.
Synthetic Aids to Flying Training
Authors: Makinson W. , Hellings G. M.
Published: August 2016

The piloted aircraft provides the supreme example of the highly complex machine performing a precise function in which the control loop is still completed through a human operator. Although both physically and mentally his task has been greatly assisted by the introduction of automatic pilots, auto-stabilisers, power controls, flight directors and the like, he still possesses the ultimate advantage over the machine of being able to use judgment in the face of arbitrarily changing circumstances. Thus, until it is possible in advance to define the required tasks exactly, and to measure the subsequent performance of the system in precise and unambiguous terms, the pilot will be saved from the encroachment of automation.

The performance of the human operator is described by the aptness and speed of his reaction to the pertinent stimuli, in effect his transfer function as an integral element of the overall control loop.
The Use of Normal Modes in Problems of Forced Vibration and Impact
Authors: Jones R. P. N.
Published: August 2016

A simple exposition, using d'Alembert's principle and methods of virtual work, is given of the properties and applications of the normal modes of vibration of a linear elastic system. The use of the normal modes in problems of free and forced vibration and dynamic loading is discussed with the aid of simple examples, and it is shown that by these methods dynamical problems for any linear system may be solved without the use of the fundamental equations of motion, provided the natural frequencies and modes of the system are known. In most problems the solutions converge rapidly, so that only the first few modes of vibration need be considered, and in these cases the solution may be modified to give further improvement in convergence. Unsatisfactory convergence may be obtained, however, in problems where there is an exciting force of very high frequency, or an impact of short duration. An approximate allowance may be made for damping, provided this is small.