bluuebunny/crossref_metadata_2025 huggingface dataset:
A Resonance Chart for Damped Vibration
Authors: Bishop R. E. D.
Published: August 2016

A convenient method is pointed out for calculating the response of a damped linear system with one degree of freedom to harmonic excitation. Results of such calculations are usually represented by the familiar “ resonance curves ”—one curve being plotted for each intensity of damping. These curves are not particularly convenient to use and Yates has overcome several of their defects by throwing them into a nomographic form. Yates' nomogram is based upon the concept of viscous damping and it does not give the information of a conventional set of resonance curves in that it relates to the velocity of vibration. By changing over to hysteretic damping, a nomogram of somewhat similar form may be constructed such that it gives amplitudes and phase angles of displacements while retaining the advantages, over resonance curves, of this form of representation.
Note on the Bending of a Finite Rectangular Plate under Continuous Non-Normal Loading
Authors: Mckenzie K. I. , Rothman M.
Published: August 2016

The problems discussed here are those of a uniformly inclined and skew loadings on a finite rectangular plate such as would be obtained by the action of wind or rain on a large door of an aircraft hangar or other such building. Such a force may be considered constant in magnitude over the area of the plate but non-normal in its direction with the plate.
Flutter of Propeller Blades
Authors: Inglesby J. V.
Published: August 2016

An analytical study of the flutter of stalled and unstalled propeller blades is recorded. The flutter of unstalled propeller blades investigated is unstable coupled flexural-torsional oscillation, while the flutter of stalled blades is assumed to be unstable torsional oscillation due to aerodynamical hysteresis, which is Studer's theory of stalled flutter.

A method of estimating critical speeds, which is within the scope of Stress Office work, is proposed and examples given.

The observed and calculated flutter speeds of propeller blades are tabulated.

(All statements made and opinions expressed represent the author's own views.)
Eighth Louis Bleriot Lecture: Making Aeroplanes Independent of Runways
Authors: Hereil Georges
Published: August 2016

As technical progress has improved the airborne performance of aircraft, so the difficulties associated with their take-off and landing have increased.

The grass airfields which were still commonplace at the end of the Second World War have now developed into complex arrangements of concrete runways of up to three kilometres (two miles) long, taxiways, dispersal areas, and so on. The main disadvantages of these large airfields, both for military and for civil aviation, soon become obvious: —

(i)

The enormous expenditure in either case; for military aviation this expenditure has to be approved, but it is at the expense of the production of actual aircraft—like Ugolin who ate his children so that they would not be fatherless;

for civil aviation, the high cost of airfield construction has hampered the development of aviation in the remote areas where it would be of particular use in raising the standard of living.

(ii)

The lack of flexibility of air forces operating from fixed bases, thus reducing their efficiency.

(iii)

The increase in vulnerability as destructive weapons become more highly perfected.
Effect of Variations in Weight or Normal Acceleration on the Ceiling of Jet-Propelled Aircraft
Authors: Sutcliffe P. L.
Published: August 2016

The ability to manoeuvre at high altitude has become one of the main requirements in the design of modern military aircraft. Ability to manoeuvre enables the fighter pilot to execute tight turns during the attack on a bomber and the bomber pilot to perform evasive manoeuvres and so make the task of the fighter more difficult.

Normally the main manoeuvre considered is the application of increased normal acceleration, or g, and if we assume that (a) there is sufficient pitching power available from the longitudinal control surface to increase the wing incidence to give the necessary increase in normal force, and (b) that the new wing incidence is below the stalling incidence of the wing, then the degree of manoeuvrability available is a function of thrust and drag alone. In the past the manoeuvrability required at a given altitude has been expressed in terms of the rate of climb available at that altitude and thus we have such definitions as “ the 1,000 ft./min. ceiling ” and so on.
The Influence of Body Forces on the Stability of a Reinforced Rectangular Plate
Authors: Amba Rao C. L.
Published: August 2016

Reinforced rectangular plates find frequent application in the field of aeroplane structures, ship structures and allied fields. The stability of a structural element, if its critical load in compression is rather low, is normally influenced by its own weight. Usually the ratio of the body forces of the stiffened plate to the critical load is a considerable amount and the influence of the body forces of the plate and the ribs on the critical load of the stiffened plate is discussed here.

In this note (following Timoshenko), the extensional deformation of the middle surface during buckling is neglected, which greatly simplifies the analysis. Although it leads to an under-estimation of the critical load (of the order of 10 per cent at most) it is not likely to influence the general conclusions. Strain energy method of analysis is used.
Flying and Maintenance from the Owner's Point of View
Authors: Probyn H. M.
Published: August 2016

I realise that many readers of this paper know more about private flying than I do; on the other hand, many may not be so experienced or have even flown. I have tried to put in things of interest to both and hope I shall be forgiven if I have put in too much elementary detail, or that my simple suggestions appear childish. I find that often it is the small and simple things which go to make for safety, comfort, and efficiency. I have no technical knowledge other than that gained by sitting behind internal combustion engines, which I have done during a great part of the last twenty years.
Comparison of Various Methods for Determining Flight Speed at Great Altitudes
Authors: Schmidt R.
Published: August 2016

The speed of flight of an aircraft at high altitudes is still usually determined by the indirect method of measuring the dynamic pressure in flight. The acknowledged defects of this method—the effect of interference by near parts of the aircraft on the static pressure at the tapping point, the necessity of calibration of the pressure readings by tedious quadrilateral flights over measured ground distances or a suspended static head, the indeterminate effect of the Mach number at high speeds, inaccuracy of the ‘air temperature measurements owing to stagnation of the flow at the instrument, errors of the elastic pressure capsule owing to hysteresis and temperature variations, and the inaccuracy of the mean values obtained by averaging the measured dynamic pressures—have all contributed to raise a demand for a simpler and more accurate method of airspeed measurement.
The Influence of Reynolds Number at High Mach Numbers
Authors: Ferri A.
Published: August 2016

The experiments were carried out in the high speed wind tunnel at Guidonia on three brass spheres of 40, 60 and 80 mm. diameter, supported on rear spindles and on two steel cylinders of 15 and 30 mm. diameter respectively, which passed through the air jet.

Both the total drag and pressure difference between the front stagnation point and a variable point at the rear were measured.

The pressure distribution on similar models which could be rotated and which were provided with pressure holes was also determined.
Stresses Due to Internal Hydrostatic Pressure in Thin-Walled Vessels of Stream-Line Form
Authors: Binnie A. M. , Ward J. C.
Published: August 2016

Tanks in the form of a surface of revolution are sometimes employed for carrying fuel. The purpose of this paper is to show how the stresses, due to the internal hydrostatic pressure, in a shell of this kind can be calculated when the equation of the generating curve is given. The acceleration imposed on the shell and its contents will be assumed to be at right angles to the axis of revolution, hence shear as well as direct stresses are set up. It will be supposed that no longitudinal bulkheads are fitted, and the shell will be taken as very thin so that the bending stresses in it are negligible. No attempt will be made to examine the stress distribution in the neighbourhood of a relatively rigid supporting ring; as shown by Timoshenko these ‘ end effects ’ are appreciable only in the immediate vicinity of the support. Nor will the stability be considered of those portions of the shell which are subjected to compression. Thus attention will be confined to what are commonly described as the membrane stresses.
Flutter and Stability
Authors: Duncan W. J.
Published: August 2016

The theme of flutter has not often been the subject of lectures before this Society, but the earliest of these was given as long ago as 1929 by my friend and former colleague Dr. R. A. Frazer. At that time a secure foundation for flutter theory had been laid and the principal methods for flutter prevention were already known. However, both theory and practice have developed much since 1929 and flutter has become of greater relative importance.
Fatigue of Aircraft Structures
Authors: Walker P. B.
Published: August 2016

The 776th Lecture was read before the Society on the 31st March 1949 at the Institution of Civil Engineers, Great George Street, London, S.W.I. Dr. H. Roxbee Cox, B.Sc, D.I.C., F.R.Ae.S., F.I.Ae.S., President of the Society, introduced the lecturer, Dr. P. B. Walker, M.A., F.R.Ae.S., Head of the Structures Department at the Royal Aircraft Establishment.
The Stress Analysis of the Circular Conical Fuselage with Flexible Frames
Authors: J Goodey W.
Published: August 2016

This paper is concerned with the problem of the skin–and–stringer–covered conical fuselage of circular cross section, having flexible frames and being subjected to an arbitrary distribution of loads applied in the planes of these frames or on the end cross sections. The skin thickness and stringer cross section may vary from bay to bay but are assumed to be constant in a bay, i.e. between any two consecutive frames. The stringers are assumed to be uniformly spaced round the circumference. The frames are assumed to be of uniform cross section (circumferentially) but their stiffnesses are arbitrary, as is also their spacing along the fuselage.

This paper is a sequel to one previously published in the Journal, but the method of analysis is now by minimum strain energy instead of by deflections. Owing to the generality of the investigation it is impossible to present the solution—in terms of the known loads and stiffnesses—in any explicit form, and attention has therefore been concentrated on the technique of numerical computation. A scheme of tabulation has been evolved, and its use is illustrated by a fully–worked numerical example of a moderately complex type.
A Chart for Steady Circling Flight
Authors: Sponder E.
Published: August 2016

For horizontal, or nearly horizontal, steady straight flight there exist some charts from which can be determined the speed at any altitude, the inclination of the flight path, and other quantities. This can be readily done, for instance, by a graphical comparison of the forces of drag and thrust, or by a corresponding representation of the powers, required and available. These charts, however, always involve the polar of the particular aeroplane, and are thus valid only for that aeroplane; they must therefore be replotted for each example. To avoid this and obtain a generally valid chart, the effect of the aerodynamic characteristics of the particular aeroplane must be eliminated; it is thus possible to prepare a chart even for the steady circling flight at any inclination of the flight path.

The three equations for the description of the flight path may be derived on the simple assumption that the thrust acts almost along the direction of flight, i.e., that the angles of attack and of sideslip are negligibly small.
The Weight of Seaplane Floats
Authors: Rosenthal L. W.
Published: August 2016

Although floatplanes were not popular during the war years, new types have made their appearance since, and presumably, for certain classes of work, more will be seen in the future. With this in mind, this paper is presented in the hope that it may help in assessing the float weights on any new designs that are contemplated. Some suggestions are included concerning geometry and design which, if adopted, may help to show a higher weight efficiency than existing practice.

The paper is based upon an analysis of the weight and geometrical data relating to a large number of floats, although since the number built during recent years is small, a certain amount of data, which might possibly be considered old by some standards, has been incorporated. As will be seen by the curves, recent practice shows no radical departure from earlier years and the inclusion of the early data to establish design trends would appear to be warranted.
Coefficients of Friction
Authors: Pike E. C.
Published: August 2016

A summary is presented of information collected on coefficients of friction (rolling and sliding) between rubber tyres and road or runway surfaces. Nearly all the data collected are from tests on automobile tyres and are limited to speeds of about 40 m.p.h. In some cases the primary object of the tests was to distinguish between good and bad roads, and not to determine absolute values of friction coefficients.

The reasons for the importance of the information for aircraft design use are discussed and distinctions are made between coefficients measured in different ways.

The results show the variation of sliding friction coefficient with various parameters at speeds up to 40 m.p.h. There is a set of American tests at speeds up to 110 m.p.h., and some estimates made by the Dunlop Rubber Company up to 120 m.p.h.

It is concluded that for sliding friction coeficients differences in surface texture (as distinct from surface material) are significant, and that information can be given only in the form of limits within which the values can be expected to lie.

Few results are available on the variation of rolling resistance coefficient, but it is felt that the approximate values quoted for different types of surface are sufficiently accurate.
Redux Bonding of Aircraft Structures
Authors: Moss C. J.
Published: August 2016

That synthetic glues for wood were used extensively for making Mosquito and Hornet aircraft during the 1939-45 War, and are now used for making Vampires in many European countries, is well known to aeronautical engineers, but not so well known is the fact that, since 1944, synthetic glues for metals have been used in the production of many hundreds of military and civil aircraft. A glue for metals, which gives joints stronger than can be obtained by riveting and which is also resistant to the severe conditions to which aircraft are exposed in service, offers the possibilities of savings in structure weight and of aerodynamically cleaner wing and fuselage surfaces. Such a glue may also be expected to be of value in the manufacture of pressurised fuselages, because it will avoid the large number of small leaks occurring at the rivet heads and may also help to solve the difficult problem of making integral fuel tanks in aircraft wings.
A Note on the Time Required to make a Level Speed Measurement with a Turbine-Jet Aircraft
Authors: Lush K. J.
Published: August 2016

It was desired to confirm quantitatively pilots’ impressions that on turbine-jet aircraft in the region of 40,000 ft. the level speed stabilised very slowly.

The time required to make a conventional level speed measurement has been examined, for a representative turbine-jet aircraft, over a wide range of air speed and height. The results are compared with those for a typical piston-engined aircraft and their implications discussed.

It is concluded that the time required to make a conventional level speed measurement increases rapidly with height, in the absence of compressibility effects on drag, and is about five times as great at 40,000 ft. as at sea level. It is inconveniently large at high altitude and level speed measurements there will require very long runs, unless it is arranged that each run is started at an air speed near the steady level speed.

This increase will be present in most level speed tests, especially those in the region of the best speed for range. In maximum level speed measurements, however, compressibility effects may be present and the air speed may then be expected to settle down quickly.

The need for long runs at high altitude is not peculiar to jet aircraft, but has come into prominence concurrently with them.
The Human Factor in Aircraft Accidents
Authors: Newton J. A.
Published: August 2016

Recently published statistics give the impression that an excessively high percentage of non-carrier aircraft accidents investigated during 1948 were primarily due to human error. Further, an examination of available data covering the past decade gives the same impression in respect of all aircraft accidents occurring during that period. The figures quoted convey in fact the unpalatable implication that, although in nearly a half century of aviation great strides have apparently been made in increasing the reliability of the aeroplane, very little has been accomplished in reducing the element of human error in aircraft accidents. Why is this?

It has been claimed that the possibility of accidents in flying is inevitable by reason of the inherent conditions of flying which necessitate, besides reliance on the technical factor, considerable reliance upon the skill, judgment, memory, and physical and psychological conditions of the human being.
Instrumentation for Testing Aircraft and Aero-Engines
Authors: Jaques C. N.
Published: August 2016

The term Aircraft Instrumentation is used to describe the special instruments which in a variety of circumstances are needed to determine aerodynamic, structural and power plant characteristics. Such circumstances may be flight tests of prototype aircraft, tests in the air or on the ground of the aeroplane, its structure or power plant, or the acquisition of statistical data on the conditions to which aircraft are subjected in civil or military operation. These special instruments therefore are additional to, and usually different from, the instruments needed in an aeroplane to enable it to fulfil its military or civil role.
The Spacing of Aircraft Under High Density Approach Conditions
Authors: Whiteley E. A.
Published: August 2016

The 850th Lecture to be given before the Royal Aeronautical Society was delivered at the Institution of Civil Engineers, Great George Street, London, S.W.1, on 20th March 1952. Major G. P. Bulman, C.B.E., F.R.Ae.S. (Past President) presided and introduced the Lecturer, Group Captain E. A. Whiteley, D.F.C., B.A., A.F.R.Ae.S., Royal Air Force, who was attending the Joint Services Staff College and who, in addition to being a pilot, had qualified as an R.A.F. Engineering and Navigation Specialist and also held a British Civil Airline Pilot's Transport Licence and a Flight Navigator's Licence.
Indication, Measurement and Control of Ice Accretion
Authors: Lucking D. F.
Published: August 2016

The rate of ice accretion on an aircraft depends upon meteorological factors and aircraft characteristics. There are on the one hand atmospheric pressure and temperature; water content; droplet size; electrostatic conditions. On the other hand, there is the collection efficiency made up of aircraft component design characteristics such as size; shape; material; surface finish. Finally, there are aircraft flight variables such as speed; attitude; skin temperature; vibratory state.

Meteorologists are able to define potential icing intensity if they can forecast the ambient factors mentioned. The intensity may be defined as light, moderate, or severe, or by some such broad adjective, with reference to a hypothetical collector. Similarly, the air-worthiness authority, e.g. the Air Registration Board, must be satisfied that an aircraft can be operated safely in the appropriate meteorological conditions. Therefore the probable association of each meteorological factor with the others needs to be known.
A Review of Production Problems in Relation to Aircraft Design
Authors: Fielding C. E.
Published: August 2016

My subject is too big to cover adequately in the time at my disposal and as I have been asked to emphasise the wartime experience in aircraft factories, I propose to confine myself to a few of the most interesting problems.

Because of the urgent necessity to produce aircraft quickly in wartime the production engineer has a greater influence on design than normally, and many design problems are usually settled by a compromise between the requirement of the designer and the production engineer.

The designer attempts to satisfy the aerodynamic requirements at the lowest possible weight and the production engineer has to consider the shop equipment and floor space available, the type and availability of labour and ensure that the aircraft can be built in a minimum of man–hours.
A Note on the Vortex Patterns in the Boundary Layer Flow of a Swept-back Wing
Authors: Black Joseph
Published: August 2016

Detailed investigations of the two-dimensional characteristics of thin aerofoil sections with small leading-edge radius have been made by Gault and McCullough. They found that at angles of incidence well below the stalling angle of the section, the laminar boundary layer separated from the surface near the nose, became transitional away from the surface, and re-attached to the aerofoil as a turbulent layer a little farther downstream. Beneath the separated layer, a “bubble” vortex was formed lying parallel to the leading edge, its rotation being such that the flow adjacent to the surface was towards the leading edge.
Loads on Multi-Wheel Undercarriages During Ground Manoeuvring and Take-off
Authors: Blinkhorn J. W.
Published: August 2016

A few years ago it became obvious that the use of multi-wheel arrangements would become common on future main undercarriages, particularly on large aircraft. Four reasons for such use are: —

(i)

Spreading the load on the runways allows operation of the aircraft from a larger number of aerodromes.

(ii)

Reducing the individual wheel loads and tyre pressures allows operation of the aircraft from natural airfield surfaces.

(iii)

An overall reduction in undercarriage weight may be achieved, particularly for large aircraft.

(iv)

Ease of stowage in the aircraft structure when retracted.

The multi-wheel arrangement could be obtained by having the wheels side by side, in line, by having the wheels side by side, in line, or by a combination of these two methods.
Air Intakes For Aircraft Gas Turbines
Authors: Seddon J.
Published: August 2016

The 837th Lecture to be given before the Royal Aeronautical Society, was delivered at the Institution of Civil Engineers, Great George Street, London, S.W.I, on 6th December 1951. Mr. G. R. Edwards, M.B.E., F.R.Ae.S., Vice-President of the Society, presided and introduced the Lecturer, Dr. J. Seddon, A.F.R.Ae.S., of the Royal Aircraft Establishment.
The Stability in Bending of Slightly Corrugated Plates
Authors: Ashwell D. G.
Published: August 2016

A previous paper was concerned with the uniform finite bending of a flat rectangular elastic plate about an axis parallel to one of its pairs of opposite edges. Expressions were obtained for the shape assumed by sections of the plate containing the axis of curvature, and the applied bending moment. In the present paper the work is extended to deal with a plate having shallow regular corrugations of arbitrary shape running along it at right angles to the axis of curvature. Such a plate may be of interest as it exhibits the type of instability characteristic of curved thin-walled members. Its solution can be derived quickly from the previous work.
Hodgson-Cuthbert Aeronautical Collection
Authors: Pritchard J. Laurence
Published: August 2016

On June 5th 1783, one hundred and seventy years ago, almost to the very day of the Coronation of Queen Elizabeth II, the first public “aerostatic experiments” were made which were to herald the dawn of a diuturnity of human endeavour.

In the Hodgson-Cuthbert Aeronautical Collection the Royal Aeronautical Society possesses a direct link spanning those one hundred and seventy years, a link which joins those wondrous days of long ago when people cried “What on Earth in Heaven is that?” with the present welfare days in which many have learnt how to move Heaven and Earth simultaneously atomically.
Civil Jet Operations
Authors: Majendie A. M. A.
Published: August 2016

The 882nd Lecture to be given before the Royal Aeronautical Society was held under the auspices of the Glasgow Branch on 23rd April 1953. Professor W. J. Duncan, F.R.S., F.R.Ae.S., President of the Glasgow Branch, welcomed the visitors. He expressed regret that the President of the Society, Mr. G. H. Dowty, F.R.Ae.S., was unable to be present and welcomed Mr. N. E. Rowe, C.B.E., F.R.Ae.S., Chairman of the Branches Committee, and the Secretary of the Society, Dr. A. M. Ballantyne, T.D., A.F.R.Ae.S.

Mr. Rowe, taking the Chair for the rest of the meeting, said how much the President regretted not being present; as they knew, he had shown the liveliest interest in the Branches and had made many visits to them during his year of office. This was the twelfth Main Society Lecture to be given at a Branch meeting; the holding of Main Lectures at the Branches had proved a great success and he was sure that the present meeting would be a success also, because their lecturer had been doing pioneering work for the past three years on the development of the Comet. After graduating from Cambridge in 1940 Captain Majendie joined the R.A.F. and served as an instructor for several years; he served with Coastal Command in 1943 and was mentioned in despatches, then served on ferry duties, and in 1946 joined British Overseas Airways. He held a Pilot's “B” Licence, a Navigator's Licence and a Wireless Operator's Licence. Before being appointed to work on the Comet he had been engaged in helping Mr. E. S. Calvert at the Royal Aircraft Establishment to develop the high intensity lighting system. Captain Majendie was one of those rare people who combined a scientific and a really practical ability.
Fatigue from the Metallurgist's Viewpoint
Authors: Gadd E. R.
Published: August 2016

The term “fatigue” is given to the progressive failure of a metal under the repeated application of a cycle of stress. Although investigators have been working for more than a hundred years to determine the mechanism by which fatigue failure occurs, the problem is still not fully understood. The simple slip theories of Ewing and Rosenhain in 1899, Ewing and Humphrey in 1903 and of Gough and his collaborators from 1923 to 1933 appear now to be only partially true, according to some of the modern theories. These suggest that other factors such as polygonisation, deformation bands and crystallite formations, all play an important part.
The Packaging of Electronic Equipment
Authors: Schuler S. C.
Published: August 2016

The problems involved in the packaging of Service radar equipment are reviewed. Information on shock testing techniques, instrumentation and a design procedure for cushioning are given, together with some examples of current packaging methods used by the Ministry of Supply's Radar Research Establishment, Malvern, Worcs. The paper is based on a lecture given to the Royal Aeronautical Society, Gloucester and Cheltenham Branch in December 1954. Received October 1956.
The Fluid Mechanics of Detonation Waves
Authors: Dawson L. G.
Published: August 2016

In a previous paper it has been shown that a general method may be developed for calculating the various changes which take place in a flowing gas. The changes considered were the addition and extraction of heat in a subsonic flow, the addition and extraction of heat in a supersonic flow and sudden changes, such as shock waves. The changes were considered to be stationary and to take place in a parallel pipe. It was of interest to see if a similar approach would produce a general treatment for moving waves. The investigation was limited to moving shock waves and detonation waves.
Rex Pierson An Appreciation and the Lessons of his Work
Authors: Roy Fedden A. H.
Published: August 2016

I consider it a great privilege to have been chosen to give the first Rex Pierson Memorial Lecture, as not only is he an outstanding figure in British Aviation, but he was also one of my close friends.

Reginald Kirshaw Pierson was born in February 1891 at Fransham, Norfolk, his father being the rector there. He was educated at Felsted School. On leaving he was destined to enter the Bank of England, but at the last moment, mainly due to the untiring efforts of his mother, he was allowed to follow his natural bent, and take up engineering instead.

In 1908, therefore, at the age of 17 he entered the Erith Works of Vickers Ltd., as an engineering pupil-apprentice, passing through the various departments and, while there, taking his Bachelor of Science Engineering degree the hard way, from evening classes.
An Approximate Solution of the Laminar Boundary Layer on a Flat Plate with Uniform Suction
Authors: S. J. Peerless  , D. B. Spalding
Published: August 2016

Boundary layer problems may be divided into two classes: (a) those for which similar solutions can be found, i.e. where the boundary conditions are such that similar profiles differing only in scale factor exist at different sections; and (b) those where the boundary conditions do not effect similarity, so that the development of the boundary layer must be calculated in stages. The latter class are known as “continuation problems,” and very few numerical solutions have been obtained because of the labour involved.

Approximate methods of solving continuation problems are known, using the Karman momentum integral method (e.g. Ref. 1) or variants. Some of these methods make use of velocity profiles calculated for “similar” boundary layers. This note presents a new approximate method which uses “similar” profiles but avoids using the momentum integral. Instead of characterising the boundary layer thickness by the “momentum thickness,” which needs to be calculated yet is of less direct interest, the wall shear stress is used; this stress usually has to be calculated in any case and the present method is therefore comparatively simple.
Instability of Integral Panels
Authors: Kelsey S.
Published: August 2016

In a recent article in the Journal Dr. Syed Yusuff complains of a lack of “analytical work on compression panels of integral construction … . to provide an insight into the mechanism of the various instabilities involved and also to enable the designer to evaluate its advantages more precisely.” It may therefore be pertinent to point out that there is no fundamental difference between the modes of instability of integral panels and those of conventional panels with riveted or bonded stringers, except in so far as certain modes such as inter–rivet buckling cannot arise. Consequently the analyses discussed by Argyris and Dunne in the Handbook of Aeronautics and the more recent paper by Argyris on flexure-torsion panel failure are immediately applicable to integral panels; indeed with an enhanced degree of accuracy due to the monolithic character of the integral panel. Thus, such uncertain factors as the rivet stiffness need no longer be considered. In fact, in the last mentioned paper the analysis is illustrated by application to an integral panel with flanged stiffeners.
Tables of Characteristic Functions for Uniform Beams with Sliding Ends
Authors: Bishop R. E. D.
Published: August 2016

Tables of the characteristic functions of certain types of uniform beams were published by Young and Felgar in 1949. The functions concerned represent (to suitable scales) the principal modes of free flexural vibration, although their uses are far more extensive than is implied by this. Some of the uses to which they can be put are mentioned in Ref. 1 and others are discussed by Felgar and Bishop; they cover both statical and dynamical problems and relate to beams, plates and shells and include problems of elastic instability. In fact these functions can be used in series representations in the same way as circular functions are used in Fourier series.

One of the main uses to which these characteristic functions may be put does not appear to have been described in print, although the relevant formulae are quoted in Ref. 2. The functions can be used in vibration analysis to shorten calculations, sometimes leading to very considerable savings of labour.
Bending Moments in Fuselage Frames Obtained by the Photoelastic Method
Authors: Benham P. P.
Published: August 2016

The experimental work described in this paper, which was divided into two sections, was done to determine the usefulness of photoelasticity as a method for analysing fuselage frame problems. In the first part, a series of tests was made by the photoelastic method on models without any supporting shell, which were in equilibrium under the applied i loads, to determine the bending moment distribution in various types of frames and rings.

In all cases the theoretical bending moments were calculated from the principles of minimum strain energy. The experimental results agreed with theory to within 5 per cent, except close to the null points and joints.

The second part was devoted to shell-supported models, and the shear loads were reacted out through the skin to firm supports at the end of adjacent bays. Again the bending moments were determined for the entire frame from the isochromatic fringe pattern.

The shell-supported tests proved to be of considerable interest when compared with the theoretical curves of Ref. 4 for the corresponding relative stiffness parameters. In some cases agreement was good but in others there were marked differences. A possible reason for this was that compression effects in the skin were altering the distribution and value of the bending moments in the frame.

It was felt that there was plenty of scope for more interesting work on fuselage frame analysis, from the standpoint of shear flow determination, intermediate frame reaction, and skin-to-frame relative stiffness effects. All of these might feasibly be examined photoelastically with a certain degree of advantage over lengthy and laborious theoretical investigations.
Types of Flow on Swept Wings With Special Reference to Free Boundaries and Vortex Sheets
Authors: Küchemann D.
Published: August 2016

This is a discussion of the various types of flow which may occur on thin swept wings when the air stream is not attached to the wing surface everywhere. In particular, the behaviour of vortex sheets which arise from such mixed flows is examined.
London Airport
Authors: D'Albiac John
Published: August 2016

The one-thousandth-and-fourth Lecture to be given before the Society, " London Airport," by Air Marshal Sir John D'Albiac, K.B.E., C.B., D.S.O., was given on 6th November 1956 at the Institution of Mechanical Engineers, London, S.W.I. Mr. E. T. Jones, C.B., O.B.E., F.R.Ae.S.. President of the Society, presided. Introducing the Lecturer, Mr. Jones said that they were to hear from the most competent man in England to give it, a talk on what he would say was the finest airport in the world. He did not think they had had a lecture on a modern airport before and it was worth while reflecting on previous means of transportation. Every previous vehicle of transport before the aeroplane had had to have tracks made for it to take it from one place to another, as well as terminal stations built for it on long distance journeys. Soma people commented on the costs of airports, the amount of concrete, etc., but when one realised that the air was provided free of charge and itself provided the means for the aircraft to go from one concrete patch to another, one appreciated that the airport was cheap compared with previous forms of transport. Air Marshal Sir John D'Albiac had, he thought, possibly one of the most interesting jobs in London; he met all the personalities, film stars, and so on. He had been there since 1946 when London Airport was converted from a small airfield. He therefore knew every little bit about it, control, runways, buildings and everything. Sir John started his career in the Army. He found that a little too slow for him and so he transferred to the Royal Naval Air Service. Whether he found that still not quite fast enough he did not know, but he later transferred to the Royal Air Force and he remained in that Service until about 1946 when he retired with the rank of Air Marshal.
Design Criterion for Fatigue of Wings
Authors: Walker P. B.
Published: August 2016

Exactly what constitutes a design criterion is a matter on which there may well be differences of opinion. For practical purposes design criteria may be taken to be empirical numerical rules to aid the designer in forming his initial conception of a design. The formulation of such rules for aircraft fatigue is still a matter of some difficulty. Not only is the subject of aircraft structural fatigue still in its infancy, but its study has to be linked with systematic experiment in a somewhat unusual way.

In the criteria described in this paper, the structure has first to be subjected to a standardised laboratory test. This test is itself a gross simplification since it has to represent in a rough way a diversity of conditions occurring in flight.
Training of Test Pilots
Authors: Clouston A. E.
Published: August 2016

Never before in the history of aviation has the test pilot been so important as he is today. Now that military aircraft are travelling faster than the speed of sound and climbing to over 50,000 ft. in a matter of seconds, with powered controls, pressurised cabins, ejector seats, special oxygen equipment and such like being the order of the day, it is little wonder that the human being whose job it is to fly in these modern high-speed missiles requires more than ordinary Service flying experience if he is to take his place successfully in the team with today's technicians and designers. The day has long since passed when any good pilot could set himself up as a test pilot. The term “test pilot” covers a large field of work, testing aircraft and the complicated equipment fitted in the new revolutionary designs being produced.
Buckling and Vibration of Isosceles Triangular Plates having the Two Equal Edges Clamped and the Other Edge Simply–Supported
Authors: Cox Hugh L. , Klein Bertram
Published: August 2016

Approximate Solutions obtained by the method of collocation are presented for the lowest critical buckling load of an isosceles triangular plate loaded as shown in Fig. 1. Also, the fundamental frequency is given. The base of the triangle is simply supported and the other equal edges are clamped. The usual assumptions regarding the bending of thin plates are made. The governing differential equation for the plate loaded as shown in Fig. 1 is

1

whereDis the plate stiffness,Nis axial load per unit length,wis deflection, positive downward, and the quantitiesaandhare dimensions shown in Fig.1.
Shock Load Tests of Anti- Vibration Mountings
Authors: Hammond Rolt
Published: August 2016

There are two types of shock loading to which aircraft components are subjected, namely: medium shock loads which can heavily damage equipment; and shocks of high impact, such as those imposed during crash landing, causing the equipment to be torn loose from its mounting, with danger of injury or even death to aircraft personnel.

An impact shock machine has been installed recently in a laboratory for studying this important problem. The machine is capable of providing calibrated shock tests up to a maximum peak acceleration of llg, and of simulating the shock loads normally experienced under everyday operating conditions. Apparatus being tested is mounted on a frame bolted rigidly to the table of the impact testing machine, which has been designed to take specimens up to a maximum weight of 400 lb., with maximum overall dimension equivalent to a cube of 30 inches side. A specimen under test is dropped from a maximum height of 5 ft., falling freely.
Note on a Short-Cut Method for Estimating Aircraft Direct Operating Costs
Authors: Robertson Frank H.
Published: August 2016

In the early stages of preliminary design, it is essential to have a method for the comparison of aircraft on an operating cost basis. The standard S.B.A.C. method is too lengthy and, in any case, demands a greater amount of data than is usually available in the early design stages.

The formulae presented in this note were evolved by the author some years ago and the general method was quoted in a paper entitled “The helicopter—has it a future?” which was read to the Belfast Branch in January 1955. (See Journal, November 1955.)
An Introduction to the Helicopter
Authors: Sibley J. D.
Published: August 2016

The helicopter, because of its complicated nature, provides the mathematician with a delightful set of problems on which to exercise his ingenuity, but the purpose of this paper is to interpret the functioning of the helicopter in terms of its physical aspects.

The paper is divided into three main parts: —

1.

General Performance

2.

Control and Stability

3.

Rotor Vibration Problems.
The Problems of Jet Transport Operation
Authors: Dyment J. T.
Published: August 2016

All of us who are intimately connected with aviation appreciate that the introduction of a new era of air transportation—the jet age—will not be accomplished without a tremendous effort in almost every field of the Industry.

There are current problems for which solutions are available but not implemented, current problems requiring new solutions, and new problems associated with the unique characteristics of the jet aeroplane.
Line-Squalls
Authors: Giblett M. A.
Published: August 2016

The subject of “Line-squalls” is one which has not been entirely neglected in the proceedings of this Society, but it has not hitherto been treated in any degree of detail. Sir Napier Shaw, in a lecture delivered on January 7th, 1914, on the subject of “Wind Gusts and the Structure of Aerial Disturbances,” briefly cited the line-squall as a phenomenon involving a violent commotion in the atmosphere, illustrating his remarks by sketches and meteorological records relating to a well-marked instance on October 14th, 1912, at Aberdeen.
Pilot Training
Authors: Courtenay William
Published: August 2016

The advent of the jet transport age both for commercial and military aircraft will require conversion to jet training for pilots of all types of transport aircraft. This is the time therefore when consideration ought to be given to some comprehensive scheme on an Empire-wide basis for future recruitment and training of Pilots to a common standard.

It is not enough to assume that the needs of commercial aviation will be supplied by the Royal Air Force. There are two sound reasons why reliance on such a flow will prove erroneous. Firstly the training of the R.A.F. Transport and Bomber pilot is much akin to the requirement for the commercial airline, and once Air Forces have trained their long distance pilots they will make a career sufficiently attractive to induce the pilot to stay. Transport Command of the R.A.F. has already inaugurated such a scheme.
Traian Vuia—A Little-Known Pioneer
Authors: Orna Bernard
Published: August 2016

March 18th is the 50th anniversary of a free flight of some 40 ft. made at Montesson, near Paris, by Traian Vuia credited by L'Aérophile (September 1906) with being “ the first person in France to have really attempted, with a machine able to carry a man, the direct take-off of an aeroplane having a wheeled undercarriage.”

Vuia, a Rumanian, submitted a paper to the Academy of Sciences in February 1903 which included a description of what he called an “ aeroplane-automobile ” which was a light weight monoplane with wheels and an engine driving a single tractor propeller; it was to be controlled by a rudder and by altering the incidence of the wing.
The Design and Operation of a Hydraulic Systems Functional Test Rig
Authors: Lewendon J. M.
Published: August 2016

This note describes the design and operation of the rig used to test and develop the Canadair CP 107 “Argus” hydraulic systems. The Argus is a maritime reconnaissance version of the Bristol Britannia, redesigned and built in Canada for the R.C.A.F. by Canadair Ltd., Montreal.

It is common practice on both sides of the Atlantic to test as thoroughly as possible before flight the various systems of a new aircraft. This is usually accomplished by the construction of space frames on which the systems are assembled and subjected to simulated flight conditions.

It was decided during the early stages of the design of the Canadair Argus that the deviations from the original Britannia hydraulic systems were great enough to warrant a full scale hydraulic systems test rig, in as compact a form as possible, which would give the desired test conditions and results.
Empirical Equations Jor the Thrust Generated by an Ideal Supersonic Nozzle
Authors: Rowe P. N.
Published: August 2016

The dimensionless thrust generated by supersonic flow through a convergent-divergent nozzle is given by Ref. 1,

1

which takes its optimum value, bmax when pe = pa.

For ideal one-dimensional flow, the relationship between Ae and pe is given by

2

and the optimum dimensionless thrust by

3

Where4

From equations (2) and (3), the constant D in equation (1) can be evaluated and thence the thrust of an ideal nozzle at any pressure ratio provided that no separation occurs.

Equations (2) and (3) are tedious to evaluate and it is not easy to estimate the effect of changes in γ.
The Testing of Adhesives for Timber
Authors: Douglas WM. D. , Pettifor C. B.
Published: August 2016

Mr. Douglas : From very early days adhesives have played an important part in the joiners’ trade. The necessity for consistent high quality in glues and cements became acute when they were used under conditions of high stress in aircraft structures. It is natural, therefore, to find that aeronautical interests have been largely represented on research committees which have investigated the use of adhesives. At the end of 1919 the Adhesives Research Committee of the Department of Scientific and Industrial Research was formed to continue the work of the Adhesives Committee of the Conjoint Board of Scientific Societies. It was realised that one of the obstacles to the study of adhesives was the unsatisfactory nature of the tests which determine their strength in timber joints. Many properties of glue (such as viscosity, jelly strength, etc.) have been used to control variation during manufacture or as an indication of probable relative strengths in timber joints, but it has never been generallyadmitted that any simple property of the glue itself can be accepted as representative of the ability of that glue to effect a joint with timber. In the present state of our knowledge, therefore, it appears to be necessary to make final appeal to the timber glue test piece.
Tests on Model Propellers
Authors: Hodgson John L.
Published: August 2016

In the July Journal a number of figures from the reprint of the above paper read before the Institution of Automobile Engineers in March, 1917, were unfortunately omitted. The figures are printed below. In the reprint of the paper by Signor V. Isacco (Reprint No. 43) these figures have been placed in their proper position in the text.