bluuebunny/crossref_metadata_2025 huggingface dataset:
Servicing the Miles Aerovan
Authors: Cooper F/Lt. S.
Published: November 2014

SERVICING plays no small part in the successful operation of an aircraft, since, apart from reliable running, an aircraft which is easily maintained offers a considerable saving in time, labour and cost. In the design of the Aerovan, particular attention has been given to the servicing aspect which is outlined in the following notes.
Servicing the Miles Aerovan
Authors: Cooper F/Lt. S.
Published: November 2014

BEFORE commencing an inspection obtain the pilot's report on the previous flight. In the course of the following inspections, as with all inspections, components which are found to be damaged or defective must be repaired, if possible, or replaced. However, before repairing a component, the relevant repair instructions must be consulted. Unless otherwise stated, these inspections are carried out every 40 hours.
Naval Aviation and Instructional Technique
Authors: Hutchings A.C.G.
Published: November 2014

AT the outbreak of World War II, all three services found themselves confronted with one outstanding problem—expansion. This involved the enlargement of the existing nucleus to many times its original size, without the loss of efficiency.
A Survey of Plastic Materials for Students
Authors: Fitzgerald‐Lee G.
Published: November 2014

ALL ‘plastics’ are generally divided into two groups: the ‘thermoplastics’, which are formed by heating, can be re‐heated after forming, and re‐formed almost ad lib, such as celluloid, xylonite, rhodoid, cellophane, and perspex; and the ‘thermosetting plastics’, which are also formed by heating but cannot yet be re‐formed by the application of heat or any other means, probably the best‐known example of which is the thermosetting variety of bakelite.
Release Process in a Four‐Stroke Engine
Authors: Kastner L.J.
Published: November 2014

THE problem of silencing the exhaust of a piston engine requires that attention be given to the two main sources of gas noise; firstly, relatively low frequency vibrations in the exhaust column itself, excited by a pressure pulse produced by the rapid rush of gas from the cylinder into the exhaust pipe, and, secondly, high frequency vibrations resulting from eddies in the gas stream.
Turning Errors of a Monitored Directional Gyroscope
Authors: Price H.L.
Published: November 2014

IT is readily understood that no instrument or measuring device can be entirely free from errors duo to physical imperfections of manufacture. Gyroscopes in particular are affected in this way, requiring, as they do, complete absence of bearing friction if use is to be made of their property of preserving fixity in space of the direction of their spin axis when free from external forces. The impossibility of achieving this ideal condition results in a small degree of drift of the gyro‐axis, and detracts from the value of a gyroscope as a direction indicating device. In spite of this deficiency, in cases where steadiness of pointer reading is of prime importance, standard gyroscopic directional instruments serve a very useful purpose, provided the necessity of applying corrections at appropriate time intervals is recognized and observed. Latterly, development along the lines of automatic compensation has overcome this defect, and has led to the advent of the ‘monitored’ gyroscopic compass.
The Identification of Aircraft Timbers
Authors: Fitzgerald‐Lee G.
Published: November 2014

EXAMINATION of the cross‐section of a tree‐trunk shows the following details of structure: Covering the trunk is the corky bark, the outer layers of which serve to protect the trunk from extreme variations of temperature and humidity, and from mechanical injury; the inner layers, called the bast, serve to conduct the food manufactured by the leaves to actively‐growing parts of the wood and to places of food‐storage in the tree. The bark and the bast together form the rind.
Disk Brakes for Aircraft
Authors: Waring‐Brown R.
Published: November 2014

THE various systems of braking are still undergoing intensive investigation, particularly covering schemes of control, methods of operation and design of brake units. While considerable improvements have been effected all round, the actual brakes offer much scope for advancement and, as in automobiles, the attention of designers has recently been focused on the construction of disk type brakes and on the advantages that may accrue from their adoption.
Discharge Coefficients of Chamfered Orifices and Nozzles
Authors: Collacott R.A.
Published: November 2014

REFERENCE has frequently been made to the increase in the discharge coefficient of chamfered orifices and nozzles, yet few investigations have been made to study these variations in detail. The experiments described in the following were carried out in an attempt to clear some of these points.
Calculation of Frequencies of Truncated Pyramids
Authors: Conway H.D.
Published: November 2014

IN a previous paper by the author (‘The Calculation of Frequencies of Vibration of a Truncated Cone’, AIRCRAFT ENGINEERING, Vol. XVIII, July 1946, pp. 235–236) expressions for the fundamental frequencies of longitudinal, flexual and torsional vibrations were obtained. The methods used have now been extended to include the vibrations of truncated pyramids encastré at one end and free at the other, and the results obtained are given in this paper. Special attention is given to the pyramids having equilateral triangle and square cross‐sections.
Performance Changes with Design Variables
Authors: Williams J.A.C.
Published: November 2014

THE use of an analytic method of aircraft performance calculation allows certain calculation facilities denied to normal graphical method. The analytic method has to make certain basic assumptions but justification for these can be claimed in that at the design stage the overall drag can never be exactly summed from the individual component drags and in the ‘flown’ stage a normal scatter of results always occurs, the analysis values should always lie within such scatter. Analytical methods have been put forward in the past by Bailey Oswald and R. M. Clarkson amongst others for the airscrew propulsion type aircraft and recently by R. K. Page for use with turbine jet propulsion. The airscrew propulsion case is more difficult to deal with than the turbine jet case as the level speed is derived from the solution of a cubic equation of the powers involved. At the higher speeds possible with jets, compressibility effects may be involved, in which case an analytical approach is not practical.
A Graphical Determination of the Flow in Nozzles
Authors: Mote Lionel
Published: November 2014

THE flow of gases in nozzles has been considered by many authors. The results are usually shown in the form of curves or tables of figures. Practical use of these diagrams or tables is, however, made difficult by the large number of variables concerned and the difficulty of finding convenient scales.
A New American Air Liner
Authors: Evans Stanley H.
Published: November 2014

REPRESENTING America's latest bid for the twin‐engined medium range civil transport world market—hitherto largely monopolized by the ubiquitous Douglas DC‐3 —the Consolidated‐Vultee 300 m.p.h., 40‐passenger, pressurized ‘Convair‐Liner’ is now making its debut in regular airline service. Three basic airline types are now on the production lines, differing mainly in the location and type of passenger‐loading facility and baggage compartments: thus type (a) has an integral stairway, with the door located on the right side, ahead of the wing; type (b) an. integral stairway, with the door located in the after belly of the fuselage; and type (c) the more conventional door arrangement located on the left side, aft of the wing. Executive versions are also being produced to meet individual customer preferences.
The Electric Welding of Aluminium and its Alloys
Authors: FitzGerald‐Lee G.
Published: November 2014

FEW processes have made such an advance during the last two years as has the are welding of aluminium and its alloys. In the 1945 impression of the Second Edition of his Engineering Materials, Machine Tools and Processes (Longmans), W. Steeds states, on page 148:
The Statistical Analysis, of Experimental Data
Authors: Saravanos B.
Published: November 2014

WHILE the introduction of statistical methods into the analysis of aeronautical experimental data, whether for quality control in production, for the interpretation of the results of structural and aerodynamic laboratory experiments, or for airline operation, has been brought about only in recent years, it may by now be fair to assert that their advantages and even their indispensability are no longer in dispute. Hitherto, investigations on these lines have usually involved, explicitly or implicitly, only the ‘normal curve of error’ and allied considerations; owing, it may be thought, to the controllability of the various manufacturing or laboratory techniques, but also perhaps to the scarcity of data hitherto available. It may well be, however, that with the accumulation of information arising out of investigations planned with particular reference to the statistical analysis of their results the whole range of the apparatus for statistical analysis, usually confined to such fields as those of biology or economics, will be called into full play.
The Strength of Jacks in Compression
Authors: Person P. , Saunders D.
Published: November 2014

THE strength criterion for hydraulic and pneumatic jacks usually occurs under compression and the methods for determining this strength and the critical load from stability considerations depend largely upon the construction of the jack and the operating conditions in which the load is applied. Suitable methods for use in particular cases are indicated below and for this purpose jacks may be divided into two classes according to the operating conditions, viz.:
Solution of Simple Simultaneous Equations
Authors: Brailsford G.R.
Published: November 2014

SUPPOSE that we wish to solve the two equations:
Aeronautical Research in Canada
Authors: Parkin J.H.
Published: November 2014

AVIATION has played and is playing an important part in the economic development of the Dominion of Canada. The mapping of huge areas has been accomplished with aircraft and the instruments and techniques of air survey and map plotting have been brought to a high state of development in the Dominion. Geological exploration has been facilitated and greatly accelerated by the aeroplane and air transport plays an indispensable role in connexion with northern mining operations. Aerial forest patrol and timber cruising arc widely used in the protection and development of the vast timber resources. In the far north the aeroplane provides a vital service to outlying posts and settlements, meteorological stations and trappers. In the organized air transport of passengers, mail and express, Canadian operations have developed from modest beginnings to the present continental network and services to the United Kingdom, Bermuda and the West Indies. The operational record of the scheduled services, in traffic, economy and safety, is impressive.
A Simple Approach to Wind Tunnel Constriction Effect
Authors: Duncan W.J.
Published: November 2014

THE paper reviews the problem of the influence of the walls of a closed tunnel in increasing the velocity in the neighbourhood of a model under test. It is shown that, for a perfect fluid, considerations of continuity suffice to establish an exact value of the mean interference velocity for any cross‐section of the tunnel. This mean interference velocity is expressed in terms of the perturbation velocity which would be caused by the same model in the absence of the walls. The linearized theory of subsonic compressible flow is applied and it is shown that the interference velocity for a small two or three dimensional model is increased in proportion to l/β3, where β=√(l—M2) and M is the Mach number. Interference caused by a body with a long parallel middle body, the influence of the wake from a model and of the boundary layer on the tunnel walls are briefly considered.
The Elementary Theory of. Stressed Skin Construction
Authors: Hemp W.S.
Published: November 2014

A STRUCTURE is, or at least should be, the result of purposive design. It is there‐fore rational and the principles of its functioning should be apparent after a little study. Its purpose is to carry certain types of load and its ‘appreciation’ consists in unravelling all the various ways in which it can achieve its purpose. The appreciation of structures is largely a matter of experience, but the following lines of attack are often useful.
Proposal for a Powered Control System for Aircraft
Authors: Price H.L.
Published: November 2014

THE following paper was written early in 1946 when the writer was a member of the Sperry Gyroscope Company. It discusses in general terms a particular form of powered control system for aircraft, in which precautions are taken against certain types of failure of the system.
The Tenth S.B.A.C. Display
Authors: Huls L.L. Th.
Published: November 2014

THE Flying Display and Exhibition organized annually by the Society of British Aircraft Constructors has rapidly become one of the highlights of the year, not only for the British Aircraft Industry, but for world aviation generally. Aviation people from all over the world come to Britain to sec the results of that country's effort in aircraft design and production—and a magnificent effort it is—thereby providing a welcome opportunity for the exchange of opinions on an international basis between aircraft technicians and operators. The main purpose of the show is, of course, to stimulate the sale of British aircraft and equipment, especially on the export market, but the value of an occasion like this for meeting old friends and making new ones, thereby strengthening the relations between people from different countries who learn to appreciate each other's work and opinions, should not be under‐estimated.
The Study of Strength of Materials
Authors: Hill F.T.
Published: November 2014

THE study and teaching of the subject of ‘Strength of Materials’, in so far as the engineering student is concerned, is in a state of metamorphose much more far‐reaching than most of the other subjects in his curriculum. The problem of the behaviour of materials under the influence of loading has generally been treated as a more or less static one by the engineering designer. Having computed the load occurring upon a member in a structure, he provides the necessary reaction to this by assuming a strength of the material that he proposes to use, and giving the member the needful cross‐section. This assumed strength was found by testing samples under conditions that could quite fairly be described as ideal, and took no account of many effects that inevitably occur in everyday use. The fact that he was able to use large ‘factors of safety’ has undoubtedly covered many cases in which his assumptions of strength of the constructural material were, to say the least of it, optimistic.
The Library Shelf
Authors: A.R.C.
Published: November 2014

The present reviewer was privileged to see the manuscript of this book some three or four years before its publication. It is a pleasure, therefore, to record that in its final form the book satisfies very fully the appetite whetted by the earlier reading. It is a large volume, containing over seven hundred pages, and its cost (57s. 6d.) is high even for these days; nevertheless, it can be whole‐heartedly recommended to all who are interested in aerodynamics and in the application of aerodynamics to aircraft design. Indeed, recommendation is perhaps too weak a term: the reviewer regards this as a book which must be acquired by all aeronautical engineers. Its title, Wind‐Tunnel Technique, represents only the main central theme of the book; but since there is virtually no field of aerodynamics, or indeed of related subjects such as aeroelasticity, which is not nowadays subjected to scrutiny by means of wind‐tunnel experiment, any volume on this subject which pretends to completeness must survey practically the whole field of fluid dynamics. The volume under review very successfully compresses into one small compass just so much of every important branch of aerodynamics as is necessary for an understanding of the application of wind‐tunnel techniques to that branch of the subject.
The Design and Installation of Aircraft Sanitary Systems
Authors: Bowey G.S.
Published: November 2014

There arc few published works dealing with British aircraft sanitary systems and associated equipment and a comprehensive survey of this particular subject should not, therefore, be out of place here. In this article, a history of the development work culminating in the evolution of a modern scries of chemical closets is traced. It is shown that for equipment of this nature . simplicity of design is essential if proper mechanical functioning, satisfactory hygiene standards and good serviceability arc to be assured. Two outstanding features of the modern chemical closet are the closed flushing system, in which one of a scries of special chemical fluids is used as the circulating medium, and the external servicing arrangements. Specific closet design information is presented. Details arc also given of aircraft toilet compartment layout and of representative types of ground servicing equipment.
The Library Shelf
Authors: A.E.J.  , J.R.P.  , H.D.H.  , P.L.T.
Published: November 2014

The collection of thirteen reports in the first volume are concerned largely with theoretical research on the strength and deformation of metals carried out by Doctors Mott, Hill, Lee and others on behalf of the Ministry of Supply.
The Repair and Overhaul of Gas Turbines
Authors: Saeed F/O S.M.
Published: November 2014

IT was generally believed during early servicing experience of gas turbines that nearly every defect could result in power losses, but the last eight years have provided operational experience which has helped in the design, and improvements have made the gas turbine a trouble‐free and comparatively reliable unit. There are still defects which may arise, but it can safely be stated that they have no bearing on the power output. The customary teething troubles of early days have been overcome and power units are now available having an overhaul life of 500 hours. This figure is being increased rapidly and in the near future, the engine life between overhauls may exceed 1,000 hours. The overhaul of an engine provides an engine with a complete life cycle and the engine goes out into service embodied with improved design details, thus making it more reliable than before. The overhaul procedure consists of stripping, washing, crack testing, inspection, building and testing the engine, and a brief comment on each has been made in these notes, supported by a typical overhaul shop layout. The gas turbine power plant operating costs consist of primary and overhead charges, but in our discussion the overhead charges pertaining to overhaul will not be considered. These notes are a generalization of a variety of gas turbines and do not relate to any particular design.
The Basic Problem of Undercarriage Geometry
Authors: Bialkowski L.S.
Published: November 2014

IF the plane of symmetry of the wheel is the same in both its landing and retracted positions, retraction is achieved by simple rotation about an axis which is perpendicular to the plane of the wheel.
Torsion of a Constrained Rectangular Box Section
Authors: Green W.L , Gill S.S.
Published: November 2014

The paper describes an investigation of the stresses due to torsion of a doubly‐symmetrical thin‐walled rectangular box section with four corner spar flanges. The box section was subjected to a pure torque at the free end. The other end of the box section was constrained to remain plane. The shear stresses in the top and bottom skins and in the vertical webs and the direct stresses in the corner spar flanges were measured. The measured values were compared with theoretical predictions using the ‘linear’ and ‘closely spaced rigid diaphragm’ assumptions. The torsional stiffness was also measured and compared with theory. The experimental results show the marked effect of buckling of the skin covering on the stresses in the flanges. They also illustrate the importance of using the secant modulus in calculations.
Flexure‐Torsion Failure of Panels
Authors: Argyris John H.
Published: November 2014

The methods developed in sections (5)–(7) are now applied to the determination of the torsional cum flexural failing stresses in two panels. The following points should be noted:
Some Remarks on the Structural Analysis of Swept Wings
Authors: Terner E.
Published: November 2014

The problem of stress analysis of swept wings has been approached in different ways. Here a method is briefly surveyed in which swept structures are treated as orthotropic sandwich plates of varying thickness; the resulting non‐linear partial differential equation is linearized by suitable assumptions. Thus differential bending, flexure‐torsion coupling, etc. can be treated with ease, and no virtual elastic axis is needed. Functions derived are regarded as two‐dimensional analogues of the well‐known concepts of one‐dimensional Engineers beam theory.
Modern Aircraft Cable Developments
Authors: Hancock D.C. , Tunnicliff T.
Published: November 2014

IN consequence of the rapid progress in aircraft development in the past decade it has been necessary for cable manufacturers to provide an ever‐widening variety of cables to meet the special needs of aircraft designers.
The Strength of Tubular Struts
Authors: Prizeman R.
Published: November 2014

Curves have been drawn to show the compressive (flexural instability) strength of tubes made from four materials in common use. Although these curves are subject to all the limitations of usual strut analyses, their use eliminates much arithmetical work.
Developments in the Structural Approach to Aero‐Elastic Problems
Authors: Williams D.
Published: November 2014

THE main theme of this lecture is the revolution which the high speed digital computing machine is bringing about in the attitude of engineers to structural calculations, and particularly in the attitude of aeronautical engineers to the calculation of the dynamical characteristics of an aeroplane.
A Descriptive Geometry Solution of Some Undercarriage Problems
Authors: Bialkowski L.S.
Published: November 2014

This Paper presents a few examples of Descriptive Geometry applied to the Undercarriage design:(1) Retraction mechanism geometry.(2) A method of checking clearances between moving undercarriage parts and the surrounding structure.(3) The control by an undercarriage leg, or any other swinging member, of another swinging member, when their axes of rotation are in different planes in space.
Progress in Research on High Speed Flow
Authors: Holt Maurice
Published: November 2014

INVESTIGATIONS into the nature of high speed flow have now been in progress alto‐gether for thirty years, and at a particularly intensive rate during the past ten years. Many of the problems which troubled early workers have now been solved, certain methods of treatment have been developed to a high degree and interest has shifted to new types of problem and new techniques. A stage has been reached when it is appropriate to review the progress made and to point out those fields which remain to be examined. In this and succeeding articles advances in a number of branches of the subject are described. The account is by no means comprehensive and has been limited to those fields in which work remains to be done, which bear some relation to aircraft or rocket design and of which, at the same time, the author has some direct experience, however limited.
Progress in Research on High Speed Flow
Authors: Holt Maurice
Published: November 2014

IN the first of these articles it was pointed out that normal supersonic flow can be described theoretically, to a first approximation, by the linearized equation of motion. This has the form of the wave equation and governs first order disturbances to fields of uniform flow; for example, flow past thin wings or slender bodies at small angles of incidence, and flow through ducts of varying cross‐section. In the same way small disturbances in a purely subsonic stream can be described by a linearized equation of motion, which can be reduced to Laplace's equation by contracting the co‐ordinate normal to the direction of flow. Transonic flow, in which regions of both supersonic and subsonic flow occur, is not so easily represented.
Measurement of Skin Friction Using Surface Tubes
Authors: Hool J.N.
Published: November 2014

The report covers an extension of the surface tube technique devised by T. E. Stanton to measure the intensity of skin friction. A simple surface tube is described and a method of varying the surface tube calibration curves to cover other fluids and temperatures is developed. An empirical equation is obtained permitting values of the intensity of skin friction to be determined from surface tube static tapping readings and the width of the opening of the surface tube.
Graphical Estimation of Flow through Orifices
Authors: Gabbay E.J.
Published: November 2014

For compressible subsonic flow through a sharp‐edged orifice, where pressures are measured by static pipeline taps, the Saint‐Venant and Wanzel equation for nozzle discharge, applies as follows:
A Versatile Control Equipment for Fatigue Testing
Authors: Coulshed W.F. , Moore D.S.
Published: November 2014

DURING the design and development of an aircraft it is becoming increasingly important to test components under repeated loading to establish the ‘life’ of these components in service. This is often done by subjecting the component to a programmed sequence of loads which correspond to a given number of flying hours. In many cases this loading programme will contain a relatively small percentage of high loads, particularly in the case of a fighter aircraft which is only required to have a life of one or two thousand hours.
Fitting Curves to Experimental Data by Least Squares
Authors: Head J.W. , Oulton G.M.
Published: November 2014

IF a number n of readings are taken of a dependent variable y for various values of the independent variable x we frequently need to determine a reasonably satisfactory curve to express the relation between the two variables; preferably we should be able to give an equation for this curve. We know that the observations will be subject to random errors due to various causes; we therefore expect the curve not to go through all the points representing the observations, but to lie evenly among these points. If the curve is expected to be a straight line, we may be able to determine it with sufficient accuracy by eye. The ‘least‐squares’ technique for finding the equation of the best‐fitting curve C for which y is a polynomial of degree m in x is well known. If m is small, the curve Cm will be smooth, but may not fit very well; if m=n−1, the fit is perfect, but Cm is likely to have several oscillations which do not correspond to reality. If m has an intermediate value, there will be some oscillations and a fair fit; increasing m rapidly increases the complexity of the equations determining Cm, and the unreliability of Cm from the statistical point of view.
The Bending Stresses in Cantilever Plates by Moiré Fringes
Authors: Palmer P.J.
Published: November 2014

The bending stresses in plate models can be determined by means of the experimentally produced moire fringes, which Rive directly the gradients at all points of the surface of the model. It is shown that this technique can be used for cantilever plates with either uniform or non‐uniform thickness provided that, in the latter case, the thickness is not large. The technique and apparatus is described, details of the experimental technique are given and discussed, and some resultant experimental fringe patterns are shown and analysed.
Tensor Analysis of Finite Rotations
Authors: Bateman E.H.
Published: November 2014

PART III The Motion of a Retractable Undercarriage THE methods developed in Part I, to describe the motion of a body moving on a fixed axis, enable the direction of the axis and the angle of rotation to be determined from two compatible positions of a component relative to a parent body. Graphical methods, such as that devised by Bailkowski, are available for finding the axis of rotation of an undercarriage when the extended and retracted positions are specified, but an analytical method will always give a more accurate solution than a graphical one, and it may at the same time be both shorter and simpler.
The Library Shelf
Authors: A.D.B.
Published: November 2014

This book is described by its publishers as the first in a new and highly important field and also the initial volume in a new series on Missiles and Space Technology. It may be remarked immediately that if the succeeding volumes of the series maintain the standard set by this, they will be very welcome additions to the technical literature.
The Library Shelf
Authors: J.C.  , A.D.Y.  , T.H.
Published: November 2014

In the preface it is stated that a need exists for a ‘comprehensive treatment of the subject that will present fundamentals in broad perspective but without emphasis on any one type of system’. The book is written as a single volume introduction to the subject so as to fill this need in part. The missiles dealt with in the book are what, in this country, would be more properly called guided missiles; the author states that the broader description ‘advanced’ was adopted to avoid implying any unintended restriction upon the applicability of basic principles. The book is competently written and a number of diverse technical aspects are handled in a workmanlike manner. There is a refreshing soundness and depth to the book which regrettably is not often found in books on guided missiles from across the Atlantic. To cover a subject embracing so many different techniques in a book of less than 600 pages is, of course, a difficult task. The treatment on the whole therefore has to be concise. This in itself is not a failing as the reader will generally be expert in at least one of the areas and will gain enough from the book to refresh his memory and enough to see what are the main features applicable to guided weapons. In areas where the reader is less well trained it will be necessary for him to supplement the text by reading elsewhere. To aid him in this the book is adequately provided with references (without overburdening the text). The treatment is a formal presentation of the basic theories, emphasising the common ideas underlying, for example, signal detection in the presence of noise and quality control. The reader would finish the book with a sound idea of the fundamentals but with only the vaguest idea of how to set about the design of a missile. What is required is a sequel to this book where the logical design, say, of three or four types of missiles is worked through with a generous number of examples.
Cyclic Stressing Frequency Effect on Fatigue Strength
Authors: Harris W.J.
Published: November 2014

This article concerns the experimental investigations of the effect of frequency of cyclic stressing on the reversed bend fatigue strength of the aluminium alloys 4·4 per cent Cu‐Mg‐Si‐Mn (L.70, L.71, L.72 and L.73) and the 5 per cent Zn‐Mg‐Cu type (D.T.D.687) over the frequency range 10 to 1,000 cycles per second. The central theme of the theoretical analysis of the experimental work has been based on the working hypothesis that the so‐called frequency effect on fatigue strength, as normally measured by fatigue tests in air, contains, in most cases, an appreciable corrosion fatigue factor together with the true frequency effect. The corrosion fatigue factor, being time and frequency dependent, becomes dominant after an appreciable time exposure whilst the true frequency effect recedes to insignificance. This state of affairs becomes reversed when considering fatigue strength on a much shorter time basis. A study of the kinetics of corrosion fatigue, and fatigue under normal ambient conditions where complete corrosion protection has been afforded, has led to a method whereby the true frequency effect can be separated from the net effect of corrosion and frequency as measured by ambient fatigue strength values. The extraction of the true frequency effect by this method has resulted in its formulation thus:
Design for Minimum Weight
Authors: Yusuff S.
Published: November 2014

A new approach to the problem of minimum‐weight design of stiffened compression panels is presented. It is predominantly based on the plate instability mode in which the sheet and stiffeners, having been stressed to the same degree, simultaneously buckle over a long wavelength with the length of a buckle equal to the pin‐ended length of a panel. Charts to determine the buckling stresses of the modes required for the minimum‐weight design are given. Formulae and charts are presented to compute the effective moment of inertia of a stiffener, a most important quantity, over a wide range of panel proportions, for Z‐section and integrally machined unflanged stiffeners. The principles of minimum‐weight design are discussed and illustrated by the lightest Z‐stiffener panels selected from extensive test data. Comparison of the theoretical stresses of the optimum panels and many other panels of different proportions with those obtained by tests shows good agreement. The principle of dimensional similarity, which is implicit in the buckling mode referred to above, eliminates the effects of size. Results obtained either from theory or tests can therefore be applied to different size panels of like proportions.
Design Properties of Aluminium Alloys at Elevated Temperatures
Authors: Taig I.C.
Published: November 2014

WHEN aluminium alloys are subjected to elevated temperatures their mechanical properties arc affected not only by the temperatures but also by the time of exposure. In order to illustrate the effect of such exposure the most widely adopted practice is to describe the change in properties by means of heat factors representing the ratio of property level after exposure to that obtained in the unhcated condition. Typical carpet plots of such heat factors against temperature and time are shown in fig. 1, and represent strength reductions after exposure to constant temperatures for the indicated times. Stiffness data at elevated temperatures arc usually confined to plots of elastic modulus against temperature and time and occasionally a few stress‐strain curves or tangent modulus curves for specific thermal conditions.
University of Bristol
Authors: Collar A.R.
Published: November 2014

THE Department of Aeronautical Engineering in the University of Bristol was founded in 1945, when the Bristol Aeroplane Company generously presented the University with funds sufficient for the endowment of a Chair, to be known as the Sir George White Chair of Aeronautical Engineering. This was the fourth aeronautical Chair to be founded in Great Britain, having been preceded some quarter of a century earlier by the Mond Chair at Cambridge and the Zaharoff Chair at Imperial College, and a decade earlier by the Wakefield Chair, subsequently abolished, at University College, Hull. In addition, before 1945, a number of universities and colleges—in particular, Queen Mary College1—had offered courses with an aeronautical content, but not in independent departments headed by a professor. The present writer was appointed to the new Chair at Bristol in the summer of 1945; but owing to his commitments at the Royal Aircraft Establishment was not able to take up the appointment until January 1946. Meanwhile the first students, to a total of five, had been recruited and, in October 1945, had begun their general engineering studies in other departments of the Faculty of Engineering.
VICKERS VC10
Authors: McElhinney D.M.
Published: November 2014

THE structural design of the VC10 has been based on well‐established principles and the philosophy of low stress levels in the skins and secondary load paths to meet ‘fail‐safe’ conditions. In general a multiple load path type of structure has been employed. In any one of these load paths a crack may be allowed to develop without fear of catastrophic failure. The operator will, however, be required to maintain a high standard of inspection of the structure in order to prevent cracks developing concurrently in these multiple load paths. The operating economy will be greatly enhanced since major components will not require to be changed until the whole of their useful life has been utilized. This was not the case in structures of the ‘safe‐life’ type owing to the large factors which had to be imposed on life.
Aeronautical Development in Brazil
Authors: Legg K.L.C.
Published: November 2014

Up to a few years ago the work in the aeronautical development department of the Brazilian Technical Centre had failed to achieve one of its major objectives, which was to produce a nucleus of trained aeronautical Brazilian engineers. This was largely due to lack of co‐operation from contracted foreign personnel and from opposition in some quarters where it was considered that the projects undertaken were over ambitious and unlikely to produce a successful production aircraft of immediate national use in a reasonable time period. The failure to achieve this nucleus team was a great disappointment to the Brazilians in their aim towards developing their own stable national aeronautical industry since this team would obviously have been the backbone of the envisaged industry.
Overhaul Life Development and Early Failure Detection of Aircraft Gas Turbines
Authors: Eden J.J.
Published: November 2014

In a modern gas turbine‐powered aircraft, engine material cost is the major single contributor to direct maintenance and overhaul cost. Due to the large expenditures involved, even a small percentage improvement in this field will result in the achievement of large savings. By concentrating on the reduction of both scheduled and unscheduled removals, this cost can be minimized. An analysis of the experience gained with the application (o gas turbine engines, of traditional overhaul life development programmes shows that these are of no benefit in determining the limitations of the engine. Experience and control of the total time or take‐off cycles of components, rather than time between overhaul, is the most important factor in the operational development of gas turbine engines. Overhaul life development can be divided into two phases: the initial programme applied to new engines with little operational background, and the developed programme applied to engines with substantial operating experience. In the initial programme, the sampling of two engines every 100 hours from a declared plateau can provide the required information and produces the required stagger in total time of components. In the developed programme large steps in overhaul life can be declared without further sampling. Life development of critical engine components cannot be done in service and requires manufacturer's cyclic testing ahead of airline experience until fail‐safe designs are achieved. Early failure detection of gas turbine engines is a Held of great potential return which to date has been only barely explored. Both engine manufacturers and operators need to develop tools and techniques for effective early failure detection quickly, to gain the large benefits which this field offers. Examples of the application of some early failure detection designs and techniques in Trans‐Canada Air Lines (T.C.A.) are given. These are in the field of visual examination with increased access to the engine, X‐ray examination of flame tubes with the engine installed in the aircraft, more effective use of the oil system to give warning of failure, engine vibration monitoring and automatic flight performance recording.
The Beagle‐Miles M.2I8
Authors: Miles G.H.
Published: November 2014

THE concept of an ‘all‐plastics’ airframe has been possible of achievement since the early 1940s but, apart from some special applications, such as radar and radio transparencies, bearings, fuel tanks, etc., the introduction of reinforced bonded materials has been extremely slow. Curiously, and despite the intense pressures of technological advances, the aircraft industry is conservative and many innovations which can be seen in retrospect to have been inevitable, have been held back for years until they have been forced on the designers by circumstances. Cases in point are the time taken to abandon the biplane to accept wing flaps and to adopt variable‐pitch propellers. Even the jet engine was, for a long time, squeezed into airframes of obviously unsuitable shape. Nevertheless, it seems surprising that it has taken some twenty years to bring the use of plastics for major airframe components to the stage of practical proof.
Imperial College, University of London
Authors: Taylor‐Russell A.J.
Published: November 2014

THE teaching and study of aeronautics at Imperial College date back to the year 1909 when the first of a series of evening courses in aero‐nautical science was given in the College and a number of scholarships for aeronautical research were founded. The establishment of a separate Department of Aeronautics had to wait, however, until after the first world war. In 1917, Sir Basil Zaharoff, a war‐time industrialist, offered to the University of London funds for the establishment of a Chair of Aviation to be held at Imperial College. Two years later financial backing for a new department came from the Treasury after the publication of the report of a committee set up by the Government to study the future of advanced education and research in aeronautics. This committee supported the idea of a central school of advanced study in aeronautics and thought that it should be built up around the nucleus provided by the Zaharoff Professorship. A few months later, in the late autumn of 1919, the Department of Aeronautics at Imperial College came into being.
Current Developments in All Weather Landing
Authors: Webber G.W.
Published: November 2014

The aircraft industry is at present at a stage where a number of striking new advances are approaching practical reality. The super‐sonic transport, vertical take‐off and landing, and variable geometry arc the three developments which spring most readily to mind. Slightly less spectacular, but perhaps equally important, is the intensive development work currently in progress which is devoted to making aircraft—particularly civil aircraft—capable of safe operation in all weather conditions.
Rotor Dynamics and Helicopter Stability
Authors: Price H.L.
Published: November 2014

The purpose of the present work is to develop a unified mathematical theory of the steady and disturbed motion of a helicopter with particular emphasis on the dynamical aspects of the problem. The helicopter is assumed to undergo arbitrary small disturbances in velocity and angular velocity from a steady rectilinear flight condition, and the rotor forces are calculated as generalized functions of the initial and disturbed velocities. A high degree of accuracy is maintained both in the retention, where necessary, of products of small quantities and in the retention of high powers of µ in the solution of the trim equations. The steady motion of the helicopter is discussed at length as a preliminary to a study of its dynamic stability. Part I deals with the general features underlying helicopter motion. The importance is emphasized of a three‐dimensional approach to the problem, and it is shown that a complete description of steady rectilinear motion demands the use of fifteen equations in eighteen parameters, the solution of which presents no real difficulty. A start is made on the analysis of rotor blade motion, and the geometrical aspects are discussed by means of a system of rotating vectors.
Recent Developments in Aircraft Ice Protection SYSTEMS
Authors: Greenly K.H.
Published: November 2014

Ice formation constitutes a hazard to aircraft operation both on the ground and in flight. This article deals with the protection of aircraft against ice formation in flight, but does not consider the counter measures which must be taken on the ground in winter conditions. The first part of the paper deals with the atmospheric conditions which give rise to ice accretion on forward facing surfaces and the types of ice which form at various ambient temperatures. A general survey is then made on methods of solving the problem and the weight and power penalties which they entail. Finally some recent developments in the electrical deicing systems arc reviewed.
The Queen's University of Belfast
Authors: Stephens A.V.
Published: November 2014

ORIGINS THE Department of Aeronautical Engineer‐ing at The Queen's University was founded primarily to stimulate the flow of local talent into the aircraft industry of Northern Ireland. With the transfer of the whole of the resources of Short Brothers and Harland to Belfast in 1947 and their subsequent development, the aircraft industry had come to represent a considerable fraction of the engineering effort of the Province. It was thus to be expected that the only University in Northern Ireland should concern itself with the special needs of this exacting branch of engineering. The University had long had a School of Engineering forming part of a Faculty of Applied Science and Technology. The engineering disciplines were civil, mechanical and electrical, and the mechanical courses in particular had been adapted to some extent to meet aeronautical needs. But it was only natural that there remained a demand for a separate department, providing a degree course devised specifically for aeronautical engineers. In the event the Department of Aeronautical Engineering was established in 1956, after close consultation with Short Brothers and Harland, who have given it both generous support and willing co‐operation ever since.
Basic Design Philosophy and Systems
Authors: Carline A.J.K.
Published: November 2014

FOR a number of years now it has been evident that a successor to the well‐tried Vickers Viscount and Convoir 240/340/440 series was required. However, the big problem was to design an aircraft such that its economics and passengerappealweresub‐stantially better than the machines it would ultimately replace. Other important factors which had to be con‐sidered were improved reliability, easier and cheaper maintenance, higher standards of safety and means of reducing ramp times. Furthermore, the difficult choice of passenger capacity and cruising speed had to be made. Probably the easiest decision was to employ the twin‐engine configuration with the power plants placed in the now familiar rear position, one on cither side of the fuselage.
Rotor Dynamics and Helicopter Stability
Authors: Price H.L.
Published: November 2014

The aerodynamic force on an element dx1 of the rotor blade produces a moment about any point, and the component of this moment along the flapping hinge determines the flapping motion of the blade. The air force on an element being i4 dX4‘+Jt d/Y4’+k1 dZ,‘, the moment dG’, say, about the hinge F is given by
All Weather Landing and Take‐Off
Authors: Webber G.W.
Published: November 2014

IT is symptomatic of the rapidly growing interest in all weather operations throughout the world thatthe fifteenth I.A.T.A. technical conference held recently at Lucerne broke a number of records for these meetings.
A Review of Incompressible Diffuser Flow
Authors: Cockrell D.J. , Markland E.
Published: November 2014

A QUARTER of a century ago, in September 1938, this journal published a review of diffuser behaviour by G. N. Patterson1 which, together with one of. its main information sources by Gibson,2 has formed the accepted guide to diffuser design. Patterson's paper was broad in scope and made clear reference to the effect of parameters which were not fully investigated until much later. It is the purpose of this paper to review experimental work, much of it being along the lines formulated by Patterson, and to indicate the improved analytical understanding of diffusers.