bluuebunny/crossref_metadata_2025 huggingface dataset:
The War in the Ether
Authors: Addison E. B.
Published: August 2016

A few months ago I was asked to deliver a lecture to the Royal United Services Institution on the Radio War. In the preamble to that lecture I explained that my treatment of the subject would not consist of a description of the various radio devices which were used in the late war for purposes of communication, early warning and air navigation, but rather of a treatise on the methods that were employed to deny to our enemies the use of their radio services. My lecture dealt mainly, therefore, with the use of radio as a weapon; and the tactics that we evolved to exploit its employment for such a purpose not only in the defence of this country, but also in the protection of our bomber forces when attacking targets in enemy territory.
Elementary Aspects of Technical Statistics and Common Fallacies
Authors: Thornton-Bryar W. E.
Published: August 2016

The subject of statistics is so vast that many thousands of volumes have been written on it and it would be lunacy to try to give any complete outline in a brief paper. Even by confining the field to that range of data arising from aeronautical engineering the limit seems to recede into specialist abstractions rather than narrow as generality is jettisoned. At the outset it may be well to consider these apparent platitudes because many (most?) otherwise well-informed people are dogmatic in their belief that statistics are merely applied arithmetic. No doubt the same kind of thing was said before any distinction was drawn between a tally-clerk and a qualified accountant. The assertion contains too much fundamental truth for easy rebuttal: nevertheless there does exist both a science and an art in statistics, and arithmetic is only one important contribution to the exercise of either.
Air Survey
Authors: Hart C. A.
Published: August 2016

The employment of aircraft for surveying has become so usual, and so much has been written about it from one aspect or another, that perhaps the time is appropriate to define exactly what is meant by Air Survey; what the surveyor is trying to achieve, and how he is dependent upon the airman to obtain his objectives. To achieve good results from an air survey, closely integrated team work is required. The airman, photographer, instrument specialist, meteorologist and the surveyor each depend upon the other, any weakness in the chain making results more expensive and less effective. The author, as a surveyor, has worked in harmony for a good many years with the “air” side, and it is proposed in this paper to summarise the surveyor's approach and his requirements, and to explain why he seems never to be satisfied with the accuracy achieved. The greater the accuracy of photography, the simpler, quicker and cheaper become methods of using the results to fulfil the desired specification.
Progress Towards Hydraulic Serviceability
Authors: Bound R. H. , Conway H. G.
Published: August 2016

The 822nd Lecture to be read before the Royal Aeronautical Society, “Progress Towards Hydraulic Serviceability,” was given by R. H. Bound, F.R.Ae.S., and H. G. Conway, F.R.Ae.S., on 15th March 1951 at the Institution of Civil Engineers, Great George Street, S.W.I. Major G. P. Bulman, C.B.E., F.R.Ae.S., President of the Society, presided at the meeting and introduced the lecturers, Mr. R. H. Bound, Technical Director of Dowty Equipment Ltd., and Mr. H. G. Conway, Technical Director of British Messier Ltd.

To be asked to prepare a paper for delivery to the Royal Aeronautical Society on the subject of the serviceability of a product with whose design the authors are closely associated, offers an excellent opportunity for a critical survey of the field, uninfluenced by commercial considerations and with the realisation that the admission of faults, where present, is essential for constructive consideration of the whole problem.

The hydraulic installation of an aircraft is now such an important and integral item of equipment that any steps which may be taken towards improved performance in serviceability would contribute notably to the operational success of transport and military aircraft. The degree of complexity required in modern aircraft hydraulic systems is such as to make impossible a completely fool-proof system. But consideration of factors which keep trouble within very small bounds is of vital importance.
The Application of the Gas Turbine to Aircraft Propulsion
Authors: Hooker S. G.
Published: August 2016

The evolution of bigger, better and faster aircraft of all classes received a great impetus during the War period. Now, when Peace has come and the Air Age is upon us, the development of more modern aircraft both for military defensive purposes and for civil transport uses, remains a matter of urgency if Great Britain is to retain her position as a great transport power. The tempo of development reached during the War must not be slowed down if we are to keep pace with, let alone excel, the United States.
Turbine Compounding of the Piston Aero Engine
Authors: Ricardo H. R.
Published: August 2016

I have been invited to-day to put forward the case for,the compounding of a piston engine with a turbine, and this I propose to do in very general terms.

This is a scheme which we investigated fairly fully, both theoretically and experimentally, some ten years ago, and with which we would have proceeded actively had not the war, and consequent pressure on more immediate problems compelled us, temporarily, to lay it aside.
The Physiological Aspects of Air Safety
Authors: Bergin K. G.
Published: August 2016

Safety in the air in simple terms means a reduction in the number of accidents. There are many factors which influence air safety, some of which are being dealt with by other lecturers; for my part I propose to consider a vital one, namely, the human link in the mechanism of control of heavier-than-aircraft which, for all practical purposes, is the pilot. However much importance is placed, and rightly, on such factors as aircraft structure and performance, meteorological aids, ground traffic control, and the many other details which are concerned with an aircraft's safety, the ultimate factor in this, as in practically every form of transport, is almost always the human one.

Although there may be, and usually are, contributory causes leading up to an accident, subsequent enquiries frequently record an error of judgment on the part of the pilot as being the final precipitating factor.
The Application of Plastics to Aircraft
Authors: Black R. A. R.
Published: August 2016

The object of this paper is to indicate briefly the suitability of plastic materials to aircraft construction and design. Attention is focused on the mechanical properties of the materials, and the types of design. At the same time, the general engineering worth of the materials under service conditions is indicated.
The Principles Underlying the Dynamic Stressing of Aeroplanes
Authors: Williams D.
Published: August 2016

The purpose of this paper is to explain the principles governing the behaviour of structures under transient dynamic loads, such as those encountered by aircraft structures during landing or flying in gusty weather. The paper is intended mainly for the young aeronautical engineer who may not be particularly well versed in this aspect of stress work.
Production Research on Aircraft
Authors: Bunnett L. E.
Published: August 2016

In choosing a title for this paper, the words “ operational research ” might have been preferable to “ production research ” in the sense that “ operations ” refer to the strategic deployment of all the forces at the disposal of management, but to most engineers they would imply research into manufacturing processes only.
Some Operating Problems of Future Transport Aircraft
Authors: Dykes Christopher
Published: August 2016

To judge by the newspapers, the day of the turbine powered transport aircraft is already here. This is not to say that the piston engine is no longer required; probably it will be in use for many years to come, particularly for small aircraft, but new major designs must certainly be planned so as to take advantage of this revolutionary new form of prime mover.
Structural Problems of Advanced Aircraft
Authors: Gardner H. H.
Published: August 2016

In assessing the true extent of technical development of any kind the mind naturally seeks a standard for comparison. When considering structural development the standard chosen could well be that associated with the end of the Second World War. In preparing this paper, therefore, it appeared profitable, and certainly it has been extremely interesting for the author, to review the structure of some of the aircraft then in quantity production.
Lifing of Aircraft Equipment and Instruments
Authors: Tye W. , Cundall H. B.
Published: August 2016

The practice of removing aircraft items for overhaul at specified periods has gradually extended in recent years, so that most types of equipment and instruments have come to be dealt with in this way. The period between overhauls is often called–somewhat inappropriately–the life of the item and, for the sake of brevity, this is the word used in this paper.

The primary object of this procedure is to remove the items for overhaul before defects occur. If this is achieved, two benefits accrue:–

(a)

the defect rate is minimised, with consequent improvement to safety.

(b)

the operator does the work at convenient times at the overhaul base instead of being driven to do work when and where defects occur.
A Simple Rolling Method for Ip
Authors: Fink P. T.
Published: August 2016

Aerodynamic theory may be used with reasonable confidence to estimate the low-speed value of the stability derivative Ip for wings of most plan forms under quasi-steady conditions so long as viscous effects are unimportant. Wind tunnels tests are made to cover other cases such as the partially stalled swept wing, but the writer has heard of a difficulty encountered by a firm when using the free-rolling method. A variant of that technique in which this difficulty is avoided and which has been used at Imperial College for some years may be of interest.
Fatigue
Authors: Cox H. L.
Published: August 2016

In opening this discussion on fatigue it seems that my first duty should be to state what fatigue is – I wish I knew. Just as Alice knew that if you drank much from a bottle marked “Poison” it was pretty sure to disagree with you sooner or later, so do we know that if a component be subjected too often to too high a load it is pretty certain to develop fatigue cracks sooner or later.

It is important to remember that Lewis Carroll was by profession a mathematician, because in a mathematical sense even these heavily conditioned statements should in fact convey a great deal. “Too often to too high a load” infers range of loading, and furthermore it implies a connection between range of load S and cycles N, by which in general N may be expected to increase as S decreases. “Sooner or later” indicates that N is not a unique function of S, and “pretty certain” provides for those pieces which, like certain batteries, obstinately go on long after the others have stopped. Then, lastly “to develop fatigue cracks” is a careful avoidance of a direct reference to failure.
Optimum Conditions for the Operation of Airline Aircraft
Authors: Stratford Alan H.
Published: August 2016

The Conventional method of assessing the direct costs or the aircraft type costs on a passenger mile or ton mile basis does not necessarily give a sufficient indication of the economic merit of a particular type of transport aircraft. It can be misleading when comparing aircraft of widely different design, and it does not indicate the best routes for effective airline exploitation.

The profit margin in relation to the fundamental cost or investment unit of the individual airline must be the ultimate yardstick of transport aircraft selection and this is here analysed with a view to providing further insight into the optimum conditions for potential profits. This study of the subject draws attention to the primary factors involved and suggests a criterion which can be simplified into a form valid for most airline economies.
Two-Dimensional Stress and Inertia Combinations
Authors: Godfrey D. E. R.
Published: August 2016

A Similarity in properties will be demonstrated between the moments and product of inertia of a lamina and the components of plane stress. It is now a well established fact that in two-dimensional stress theory it is advantageous to use certain combinationsof the stress components.

1

First, it will be shown that the use of similar combinations of the moments and product of inertia leads to a useful graphical means of obtaining these quantities for awkwardly placed axes and also to some results not normally to be found in the text-books. Secondly, an application to photoelastic analysis is also made.
Some Observations on dr. Coleman's Comments
Authors: Lachmann G. V.
Published: August 2016

The method referred to in Dr. Coleman's notes was developed with the collaboration of my colleague Mr. J. B. Edwards of Handley Page Research Department. The purpose was to obtain a rational estimate of suction quantities and suction distribution, linked up with measurements of boundary layer profiles and suction quantities on wind tunnel models, and also to assess the effect of a certain degree of roughness of the order to be expected on actual wings. Existing theoretical methods ignore roughness which, however, is a most important parameter not only in wind tunnel tests, but also in flight at higher values of the unit Reynolds number; surface roughness obviously limits the intensity of suction which can be applied at a spanwise suction strip.

It was intuitively assumed that the removal of fluid by suction was equivalent to cutting off the lower portion of the boundary layer profile at the upstream edge of the suction strip and that a rapid re-adjustment of the boundary layer profile within a short distance took place.
Estimation of the Fatigue Life of a Transport Aircraft
Authors: Walker P. B.
Published: August 2016

A simple formula is presented for the safe life of an aircraft under reasonably good operating conditions from the standpoint of wing fatigue. Gusts are treated as the main factor in determination of fatigue life, though other factors are allowed for as being secondary. Before the formula can be used a simple fatigue test is required on critical components, and is repeated several times to establish variation of nominally identical specimens. The loading cycle for this test corresponds to a sequence of up and down gusts of 8 ft./sec. equivalent velocity. The life obtained is termed the “Standard Life” and corresponds to normal operating conditions on European air lines. Reservations in the use of the formula and correction for other operating conditions are discussed in general terms.
Structure Weight
Authors: Taylor J.
Published: August 2016

This paper is primarily concerned with structure weight as related to aircraft shape and size, rather than with the saving in structure weight that may be brought about by improved methods of construction. The difference in weight due to differences in methods of construction is a question of structural efficiency, and this will not be discussed here. Structure weight, even when expressed as an overall percentage, is not in itself a measure of structural efficiency. If the depth of an aircraft wing were doubled, without altering the lift distribution on the wing, the bending loads would be unaltered so that the resultant end loads in the top and bottom surfaces would be halved. If the second wing had the same weight as the first the structural efficiency would be less. Conversely, if they both had the same structural efficiency the deeper wing would have the lower structure weight
Maintaining Airworthiness in Operation
Authors: Hardingham R. E.
Published: August 2016

The Eighth British Commonwealth and Empire Lecture was given by Mr. R. E. Hardingham, O.B.E., F.R.Ae.S., M.S.L.A.E., before the Royal Aeronautical Society on 2nd October 1952 at the Institution of Mechanical Engineers, Storeys Gate, S.W.I. The audience included a number of distinguished guests, among them visitors from overseas and representatives of the Divisions of the Society.

Mr. G. H. Dowty, F.R.Ae.S., President of the Society, at whose suggestion the British Commonwealth and Empire Lectures were started in 1945, presided over the meeting. After welcoming the guests Mr. Dowty introduced Mr. Hardingham, outlining his career briefly. Mr. Hardingham was one of the original apprentices at the Royal Aircraft Establishment and in 1921 joined the de Havilland Aircraft Co. Ltd. Later he served for three years with the Air Ministry during which period he was associated with the Aeronautical Inspection Directorate and the Directorate of Technical Development. He joined the Air Registration Board on its formation in 1937, becoming Principal Surveyor in 1945. In 1947 he was appointed Secretary and Chief Executive and that same year became an Officer of the Order of the British Empire. Mr. Hardingham has represented the United Kingdom at a number of International Conferences.
The Design and Construction of Airfield Pavements
Authors: Tomlinson M. J.
Published: August 2016

Before the Second World War there were few airfields in Great Britain with paved runways.

The grassed flight strips of the pre-war years could carry the wheel loads of the aircraft then in use with little maintenance, other than grass cutting and rolling clinker or stone into local soft patches. From 1939 onwards, the increasing weight of aircraft, and more intensive flying, made it necessary to construct airfields with paved runways to permit operation in all weathers.

From 1939 to 1945, 444 airfields were constructed with paved runways for the Royal Air Force at a cost of £200,000,000, excluding the cost of building construction. Since 1945 the emphasis has been upon airfields for civil use, and the great airfields at Idlewild, Boston, Johannesburg and London Airport have been built.
Oscillatory Occurrences in Ball Bearings
Authors: Frenkel M. S.
Published: August 2016

In this paper it is shown how, in an angular contact ball bearing, the motion of a ball depends on the dimensions, loading and speed of the bearing. In general, ball motion in an angular contact bearing differs from the simple motion usually visualised by including oscillatory occurrences, shown here analytically, graphically and visually. These oscillatory occurrences are shown to lead to premature fatigue of the bearing metal, as a function of the speed of rotation, thereby imposing the present limitations on maximum speed and “ life.”

It is further shown that only when the dimensions of an angular contact ball bearing are related in a certain way, a motion is produced in which the oscillatory phenomena are eliminated. These relations are given as functions of loading and speed in a system of equations and limiting conditions (hereafter referred to as “ Relations of the Dimensions ”).
Ram-Jets
Authors: Jamison R. R.
Published: August 2016

Ram-jets in Great Britain have, until now, been associated with Guided Missiles and, for this reason, tight security regulations have been in force. In fact, it is only recently that it has been possible to talk about ram-jets at all. Even now, quite a number of features in these engines are classified and, for this reason, some portions of this paper may appear perhaps a little thin and inconclusive, but I have done my best to discuss the subject as fully as possible.

It is now generally known that the work of the Bristol Company has led to the adoption of the Thor ram-jet engine for production by the Ministry of Supply but security restrictions remain and in this lecture I have drawn upon general experience and thoughts in this field and avoided giving information directly related to a particular engine. In these circumstances, of course, the choice of any operating condition for the purpose of giving form to the lecture has had to be a purely arbitrary one.
Spiral and Elliptical Orbits
Authors: R.N. (Retd.) Rear-Admiral Brian Egerton
Published: August 2016

An Artificial Satellite set to start on a circular orbit round the Earth, will have to be given a known velocity, at right angles to the radius vector, which depends upon its distance from the Earth's centre.

It will, from the start, begin to spiral downwards towards the Earth, owing to the resistance of the atmosphere, but if it begins its path at a sufficiently high altitude, the decrease of height after one revolution will be small.

Should the initial “ tangential ” velocity be greater than the value calculated for a circular orbit, the satellite will, according to the text books, describe an ellipse instead of a circle; and, if at a sufficient distance for the air resistance to be at first ignored, will return after one revolution to the distance at which it started, this point being the perigee of the ellipse. It will never return to a point outside the starting point.
Note on the Drag Due to Lift of Slender Wings
Authors: Küchemann D.
Published: August 2016

Several Attempts have been made lately to reduce the drag due to lift of wings by means of camber and twist. Slender wings in particular have been considered and a typical theory is that by Tsien on the supersonic conical wing of minimum drag, where the lift forces on the wing are calculated from conventional aerofoil theory so that the overall lift of a flat wing turns out to be proportional to the angle of incidence. For convenience, this is called a “ linear theory.” It is usual to consider two cases: (1) Wings where the drag is calculated by the same theory so that the full thrust component and the suction at the leading edge are included. (2) Wings where the drag is not calculated by the same theory as the lift but where the thrust at the leading edge is omitted.
Temperature Control of Jet-Engined Aircraft
Authors: Still E. W.
Published: August 2016

The rapid development of the jet engine has been responsible for a complete change of outlook in air transport. The purpose of this paper is to illustrate some of the problems and to indicate ways in which they have been solved. The subjects discussed are those of temperature control of

(i)

Pressure cabins of aircraft

(ii)

Engine intakes (for de-icing) and

(iii)

Aircraft wing surfaces (for de-icing).

The normal control of engine jet pipe temperature has not been included because, until recently, it has been fully covered by the engine companies.

Jet pipe temperature control is a specialised application involving the correction of fuel flow for variations of air flow which may be due to changes in either compressor or turbine characteristics at altitude, or even the incorrect sampling of jet pipe temperature at altitude. The methods of temperature control discussed in this paper are often applicable also to engine jet pipe temperature control.
The Future of the Flying Boat
Authors: Knowler Henry
Published: August 2016

Louis Blériot's epic first flight across the Channel in 1909 was the inspiring inception to a new era of travel. Man's imagination was stirred by the fact that a tiny aeroplane had crossed the sea barrier, thus showing to the least thoughtful that no longer were oceans an obstacle to international communication.

With the subsequent rapid development of aviation the Channel crossing became a matter of course, but it was nine years before a long ocean crossing was made, when, in 1918, Alcock and Brown flew a Vickers Vimy from Newfoundland to Ireland, and it was thirteen years before Lindbergh again captured the world's imagination by his lone flight across the Atlantic.

There is no doubt of the value of pioneer flights such as these in stimulating aircraft development towards greater performance, reliability and suitability.
Control Surface Flutter
Authors: Broadbent E. G. , Kirkby W. T.
Published: August 2016

In recent years it has grown customary for aircraft firms to put increasing effort into the prediction of flutter during the design stage. This design work, however, is chiefly related to wing flutter in which the control surfaces play little part, whereas the cases of flutter which most commonly occur in reality are those involving control surfaces. The reason for this is that the wing stiffness, and hence the wing weight, is often determined by considerations of main surface flutter. Control surface flutter, however, can often be prevented by methods which do not have a serious effect on the aircraft weight and which are often postponed until after the design stage. This paper will discuss what steps can be taken, both in the design stage and during the flight testing of a prototype, to prevent control surface flutter.
Measurement of the Profile Drag of Compressor and Turbine Cascades and the Effect of Wakes in Exciting Vibration
Authors: Stephenson J. M.
Published: August 2016

The Melvill Jones equation for the profile drag of a single aerofoil is adapted to the case of an aerofoil in cascade, where the static pressure may be permanently raised (compressor), or lowered (turbine). A simplified procedure for measuring the drag is then described, assuming that the total pressure wake has the form of an error curve. A table of multiplying factors is given, for compressible flow up to an outlet Mach number of 0·9. Many published measurements of cascade drag have ignored this factor, with a consequent error of up to 25 per cent.
The Dawn of Aerodynamics
Authors: Laurence Pritchard J.
Published: August 2016

As individuals, those who have been born and bred and nurtured in the long, unique and formative tradition of the British people may justly claim a pride in their scientific and technical achievements over the years which cannot be claimed in such measure by any other nation. It is a claim they can make as proudly this very day as they could have done over the past three hundred years.

In the main, this paper is concerned with but a small, although not unimportant, part of the scientific achievement of the Seventeenth, Eighteenth and Nineteenth centuries. It was a period, in Great Britain, of such giants as Isaac Newton, James Watt, John Dalton, Robert Boyle, Henry Cavendish, Michael Faraday, Charles Darwin, Clerk Maxwell, W. J. M. Rankine, Lord Kelvin, Lord Rayleigh, Sir Charles Parsons, Prescott Joule, C. G. Stokes, Osborne Reynolds, Sir J. J. Thomson, C. Babbage, F. W. Lanchester, and so many others whose ideas and achievements have changed the face of the world in this Twentieth century of application.
Effect of Flow Pulsations on Form Drag
Authors: Bayley F. J.
Published: August 2016

Relatively simple theoretical procedures enable the pressure loss of the simpler forms of baffle used for flame stabilisation in combustion chambers to be computed, while tests made under non-burning conditions are available for ad hoc testing of the geometrically more complicated forms. Both these methods, with the appropriate corrections for the momentum changes due to burning, have in the past proved suitable for the prediction of the drag of aero-engine combustion chambers under operating conditions. Recently, however, it has been found that under certain conditions, associated especially with very high rates of heat release, the drag of combustion systems can become very much greater than would be predicted either from simple theoretical considerations or from conventional “cold” tests, and vary in an unexpected manner with the normal flow parameters.
Fatigue of Aircraft Materials with Special Reference to Micro-Structure
Authors: Teed P. L.
Published: August 2016

Of the many kinds of fatigue of materials, this paper deals only with “The fatigue of ductile metals by the imposition of cyclic stresses.” It is the purpose of the paper to show that: —

(i)

Metals have certain very human attributes.

(ii)

They have both memory and temperament.

(iii)

They remember with increasing resentment the stresses which have been imposed upon them.

(iv)

They are extremely sensitive as to the appropriate moment at which to break.

The question arises of why a piece of any ductile metal, other than a ferrous one, free from any abrupt change of section, when subjected to cyclic stresses of any magnitude, however small, ultimately breaks although the maximum stress imposed is one which, if static, it could have borne indefinitely. The answer is—mainly because of its metallographic structure.
Sir Henry Royce, Bart
Authors: Evernden Ivan
Published: August 2016

The 996th Lecture to be given before the Society and the 26th Main Lecture to be held at a Branch of the Society, was also the First Sir Henry Royce Memorial Lecture inaugurated by the Derby Branch. The Lecture, “ Sir Henry Royce, Bart,” was given by Mr. Ivan Evernden, M.B.E., B.Sc.(Lond.), M.I.Mech.E., M.S.A.E., M.S.I.A., on 1st October 1956 at Derby. Mr. A. A. Rubbra, F.R.Ae.S., Chairman of the Derby Branch opened the Meeting and Dr. E. S. Moult, B.Sc.(Eng.), F.R.Ae.S., Vice-President of the Society, presided for the rest of the meeting.
Acoustic Screening by an Experimental Running-up Pen
Authors: Hayhurst J. D.
Published: August 2016

In 1951 the Ministry of Civil Aviation made an investigation into the acoustic screening offered by the use of a running-up pen. Tests at London Airport in which a Viking was run up behind an experimental wall constructed of corrugated cement asbestos sheeting fixed to a scaffolding of steel tubing showed that a reduction of some 25 phons could be obtained throughout most of the geometrical shadow of the wall and over a range of distances probably exceeding one mile. Unexpected acoustic characteristics of the experimental wall precluded the collection of the full design data on running-up pens that were sought, but did not detract from the efficacy that was demonstrated. Auxiliary tests suggested that little noise abatement can be achieved by the use of trees or buildings. A prototype running-up pen is now being built at London Airport to find what operational problems are associated with the use of running-up pens and, if possible, the design data still required.
The Scope and Limitations of the Photoelastic Method of Stress Analysis
Authors: Jessop H. T.
Published: August 2016

The problem of determining the distribution of stress over the various components of a structure such as an aircraft frame is one which has always presented considerable difficulty. For a large proportion of the components calculations of the stresses can only be carried out on the basis of assumptions and approximations, the effects of which cannot be estimated with any degree of accuracy and, since considerations of size and weight impose limitations upon the employment of a large safety factor, there has always existed a need for some practical means of checking the results of calculations or of obtaining more reliable estimates of the stresses.
Resolution of Velocity for the Swept-Back Wing at Incidence
Authors: McKoen C. H.
Published: August 2016

The commonly accepted practice of resolving a velocity V at incidence α into components V sin Λ parallel to the leading edge and V cos Λ normal to the leading edge at incidence α sec Λ is only approximately true and the exact method of resolution is developed here.

In dealing with the aerodynamics of swept-back wings the free stream velocity may be resolved into a constant component parallel to the leading edge and a variable component normal to the leading edge. This is only possible if the constant percentage chord lines are all parallel to the leading edge, that is there is no taper, thickness taper or twist on the wing. This note gives the exact form and the small angle approximations of the velocity components and of the incidence of the component normal to the leading edge.
Minimum Comfortable Cruising Speed
Authors: Toms C. F.
Published: August 2016

The minimum comfortable cruising speed of an aeroplane depends on the complexity of characteristics for the design in question, which may be broadly grouped under the headings of stability and control, drag and propulsion.

The store of knowledge relating to such speed is composed, in the main, from experience with aeroplanes powered by supercharged reciprocating engines, for which, at the low powers appropriate to the conditions considered, the brake horsepower and drag horsepower both increase with height at roughly the same rate (constant aeroplane weight and equivalent air speed being assumed). For a turbine-engined aeroplane the brake horsepower (or thrust) decreases with altitude and it might be supposed that this difference would result in a difference between the minimum comfortable speeds of similar aeroplanes driven by turbine engines (either jet or propeller) and by reciprocating engines.
The Importance of Time in Aircraft Manufacture
Authors: Banks F. R.
Published: August 2016

The 999th Lecture to be given before the Royal Aeronautical Society “ The Importance of Time in Aircraft Manufacture ” by Air Commodore F. R. Banks, C.B., O.B.E., F.R.Ae.S. was given on 17th October 1956 at the Institution of Mechanical Engineers, Great George St., London, S.W.I. Mr. E. T. Jones, C.B., O.B.E., F.R.Ae.S., President of the Society, was in the Chair. Opening the meeting, Mr. Jones said:—

This evening marked the opening of the Society's 1956-57 Lecture season in so far as the London district was concerned. Actually, two Main Lectures had already been given at Branches; the first at Derby and the second at Henlow and at both there was a large and appreciative audience. It was gratifying that these early Main Lectures at the Branches had been received so well. He mentioned this because out of nine Main Lectures this session four were planned to take place at Branches, and that was quite an innovation. It was, he thought in 1948 that Council thought it would be a good thing if a few of the Main Lectures each session were held at the Branches and, so to speak, take the Society now and again to the Branches. He was sure they would agree that that was a good thing to do. There might be some present from the Branches and he had no doubt there would be reciprocal response in the Branches' members coming to lectures in London.

Now it was his pleasant duty to introduce their Lecturer. Actually of course he did not require any introduction. Air Commodore Banks, as they well knew, was a Lecturer of some importance. He had lectured many times to this Society and, indeed, to other Societies in other countries. He was a Fellow of their Society, a Companion of the Bath, an Officer of the Order of the British Empire and, what was a little more unusual in their Lecturers, he was a Commander of the French Legion d'Honneur and a Commander of the United States Legion of Merit. He had a particular distinction in respect of the subject he was speaking on tonight. He started life as an engineer. He then became an aviation fuels specialist. Then he became Director-General of Engine Production in the Ministry of Aircraft Production, and later changed from Production to Development and became Director of Engine Development in the same Ministry. He then went back to his first love, fuels, and returned again for sixteen months to the post of Principal Director of Engine Research and Development at the Ministry of Supply, when at that point of time this Ministry was rather hard put to get the right man in the right job. He was now a Director of The Bristol Aeroplane Company and was also on the Boards of Bristol Aero Engines Ltd. and Bristol Aircraft Ltd.
On the Noise from Supersonic Jets
Authors: Richards E. J.
Published: August 2016

In parallel with the work undertaken at the University of Southampton on the study of the noise from subsonic jets, a further investigation has been made into the noise from supersonic or choked jets. Whereas in the former case the noise is due to the turbulent velocity fluctuations and thus contains a wide spectrum of random frequencies, the latter case contains, in addition to this wide spectrum, noise caused by turbulence-shock wave inter-action.

Once the critical pressure ratio of a jet has been attained, i.e. that pressure ratio which produces sonic or supersonic flow in the jet pipe just before the orifice, the structure of the jet depends crucially upon the nozzle shape.
The Centre of Shear of Aerofoil Sections
Authors: Jacobs John A.
Published: August 2016

Consider a cantilever beam of uniform cross section whose generators are parallel to thez-axis and whose lateral surface is free from surface tractions. The line of centroids of the cross sections in the unstrained state is taken as thez-axis, and thex- andy-axes are the principal axes of the cross section at the centroid of the fixed endz= 0.

The other end of the beam (z = l) is subject to forces which reduce to a single force with components (Wx, Wv, 0), transverse to thez-axis, acting through the load pointLof this end section (seeFig. 1). The co-ordinates ofLare taken as (p, q, l).
American Methods of Aircraft Production
Authors: Wright T. P.
Published: August 2016

It is indeed an honour to appear before you to address you on the subject “American Methods of Aircraft Production.” We in America have long held the Royal Aeronautical Society in high regard, amply justified by the excellence of its published papers and the example it has set in organisation and in the conducting of an aeronautical society. Indeed, a few years ago when several of us in America decided that we too should have an aeronautical society, we planned our own organisation very largely on yours. We are very much pleased that the relationship which has existed between your Society and the Institute of the Aeronautical Sciences in America throughout the brief career of the latter has been so close and friendly and I can assure you that we intend to do everything possible on our part to continue this highly desirable condition.
A Survey and Tribute
Authors: Laurence Pritchard J.
Published: August 2016

‘Let us now praise famous men’–

Men of little showing–

For their work continueth,

And their work continueth,

Broad and deep continueth,

Greater than their knowing !

Rudyard Kipling.

It is of cardinal importance that the facts of aeronautical history should be placed on record.

The stirring stories of these tremendous first fifty flying years must be told where and when and how they can, but should be told quickly before the mists of time and memory lose them for ever.

Here is set down the story of the unprecedented achievement of the Wright Brothers, their impacts on, and relationships with, those members of the one-time Aeronautical Society of Great Britain who knew them and were aware of the reality of their genius. It is a story of some importance and one which it is fitting should be on record in the Society's own publication, for all to read who may. It is told by the brothers themselves, and by members of the Society.
The Investigation of Aircraft Accidents and Incidents
Authors: Caplan H.
Published: August 2016

Attention is confined to civil aviation and the present scope of investigating procedures is outlined on a world-wide basis. Deficiencies in these procedures are noted and some suggestions are made for possible future developments of technique. In particular it is suggested that there can be little progress in air safety without the assimilation of “ human engineering data” by investigators and the Industry alike. Opinions expressed are entirely personal to the author and are not associated in any way with the official views of The British Aviation Insurance Co. Ltd.
Note on the Problem of an Infinite Wedge under a General Polynomial Law of Boundary Loading
Authors: Rothman M.
Published: August 2016

This note gives the stress distribution in an infinite wedge subject to a general polynomial law of loading along either edge. The method used is that of Complex Potentials, the results of which may be summarised as follows:—

The stress combinations and and the complex displacement are given in terms of two complex potentials Ω(z) and ω(z) by the relations

1

2

3

body forces being assumed absent and pq denoting the stress intensity across a face perpendicular to p and resolved in the direction q, for a body in a state of generalised plane stress, µ is Lamé's constant and k is related to the modified Poisson's ratio σ, by the equation:

.
Derivation of the “Prandtl-Meyer” Expansion Solution from the Linear Approximation
Authors: Lockwood Taylor J.
Published: August 2016

Each small stage of the expansion starts with a uniform supersonic stream and finishes with a similar stream accelerated, expanded and turned through a small angle. We are therefore justified in applying to each stage the linear (Ackeret) approximation for small departures from uniform flow, according to which

where U = air velocity

M = Mach number

α = inclination of flow.
Note on the Minimum-Weight Design of Thin-Walled Cells in Combined Bending and Torsion
Authors: Cadambe V. , Krishnan S.
Published: August 2016

In a recent paper the authors suggested that the minimum weight design of thin-walled cells in combined bending and torsion could be tackled by using the well-known concept of equivalent bending moment and torque. It is now felt that a more rational approach would be to base the analysis on the buckling behaviour of the walls of the cell under combined compression and shear and choose the dimensions such that the cell will just resist buckling. The second criterion for design is taken as a limit on the twist as adapted in the case of pure torsion. Two types of sections, rectangular and circular, are discussed in this note.
A Note on the Mixing Process in the Flow Induced by a High Velocity Air Jet
Authors: Black J.
Published: August 2016

It is well known that when a plane air jet of high velocity blows over a convex surface, such as the upper surface of a lowered trailing edge flap, it flows along the surface, remaining attached for a considerable length; in the case of the flap, it adheres right to the trailing edge. This effect, usually described as the Coanda effect, has been utilised in the attempts to increase lift at constant incidence by “flap-blowing” in which the high velocity air jet is ejected either through slots in the flap shroud, or tangentially out of the flap surface.

The low velocity air stream approaching the flap over the wing upper surface, which in the absence of “blowing” would tend to separate at the flap shroud, is entrained by the high velocity jet, and the incipient flow separation over the flap thereby suppressed. The energy contained in the “blowing” jet can, in addition, also produce “supercirculation.“
Aerial Systems For Aircraft
Authors: Burberry R. A.
Published: August 2016

The range of frequency for which aerial systems for aircraft are required is immense: the highest used frequency is over one hundred thousand times the lowest. Very differing techniques are required throughout this range and this lecture will be chiefly concerned with the principles on which these techniques are based, rather than on individual aerial systems.

One method of classification of aerials is by their operating frequency or wavelength range.
Reciprocation of Triply-Partitioned Matrices
Authors: Duncan W. J.
Published: August 2016

A method is given for finding the reciprocal of a matrix which is triply partitioned horizontally and vertically in such a manner that the sub-matrices in the principal diagonal are square, but these matrices need not be of the same order. A preliminary rearrangement of the matrix may be helpful.

In theoretical work it is sometimes required to find the reciprocal of a matrix which can be so partitioned that some of the sub-matrices are of simple types, e.g. triangular or nul matrices, and the calculation of the reciprocal may then be facilitated by using formulae for the inversion of partitioned matrices. The same method will be often advantageous in numerical work also. In an earlier paper the reciprocation of doubly-partitioned matrices was treated in a general way and a method was given for triply-partitioned matrices subject to the restriction that the sub-matrices in the principal diagonal are square and of the same order.
Loss Due to Leakage in Unshrouded Radial Impellers
Authors: Valdenazzi L. G.
Published: August 2016

Unshrouded impellers of centrifugal compressors and centripetal turbines manifest an increase of the flow losses in comparison with the shrouded ones. Assuming that the controlling factor in such increase of loss is the leakage through the gap between wheel and casing, the author develops a simple theory leading to a formula for the volumetric efficiency. Only one experimental quantity is required for applying the formula; and tentative values, based on some experimental evidence, are presented.
The Lift on Wings at Sonic Speeds by Means of an Electrical Resistance Analogue
Authors: Palmer P. J.
Published: August 2016

This note shows how a pure resistance analogue can be used to find the lift on low aspect ratio wings travelling, with small incidence, at speeds close to the sonic velocity.

The method is applicable to flat, twisted or cambered wings and is simple in operation; the results obtained being in close agreement with those obtained by calculations based on the same theory.

The solutions given in this note are essentially those corresponding to the Jones theory, which is applicable to low aspect ratio wings at small incidence, travelling with velocity close to the sonic value. Under these conditions it has been shown that the three-dimensional problem reduces to a series of two-dimensional problems in planes perpendicular to the direction of motion. Thus the wing can be considered as a series of spanwise sections, the solution for each section, in terms of the velocity potential, being considered in turn.
Air Conditioning in Aircraft
Authors: Still E. W.
Published: August 2016

The general requirements for the complete air conditioning of aircraft are discussed in the light of the complete system concept. The author takes into consideration safety, differential pressure, weight saving, power and air supply, passenger comfort, cooling and humidity. Particular systems are then described and there is a section on the test equipment required for the laboratory testing of air conditioning equipment. Cooling systems are taken first and divided into the air cycle system embodying bootstrap, turbine fan, and regenerative applications of cold air units–the vapour cycle system employing a boiling tank and that using proprietary refrigerants; properties of liquid refrigerants are discussed. Regulation of cabin temperature, air flow, humidity, pressure and oxygen is done by control systems and the equipment used is described. Four appendices give (1) suggested detailed requirements for air conditioning equipment and user requirements, (2) sample data and calculations for air conditioning a 100-seater civil transport, (3) some notes on the definition of refrigeration terms and (4) data on pressure losses in aircraft ducts.
Buckling at High Temperature
Authors: Hoff N. J.
Published: August 2016

High temperatures affect buckling because the properties of the materials change and because thermal stresses and creep develop. A survey is given of the known solutions of problems arising in consequence of these phenomena and new theories of the creep buckling of columns and of thin circular cylindrical shells are presented.
Leakage Rates from a Pressurised Aircraft at Altitude
Authors: Jenkins L. R.
Published: August 2016

Flight tests were made to verify a method of predicting pressure cabin leakage rates at altitude from ground test results proposed in a Technical Note published in The Journal in August 1954 The results showed very good agreement with the theoretical treatment of the problem.

It is therefore recommended that the method of the Technical Note be used to estimate the change of leakage rates with altitude and also to estimate the time for the excess pressure to fall during a descent with no pressure supply.