bluuebunny/crossref_metadata_2025 huggingface dataset:
Variation of Power with Height
Authors: Jennings W.G.
Published: November 2014

THE influence of the surrounding atmospheric conditions on the power developed by an internal combustion engine has been the subject of a number of experimental investigations and theoretical discussions. The mass of experimental data dealt with and the rather involved arguments employed have, in some instances, tended to obscure the main issues of the problem.
High Altitude Flying
Authors: Stewart C.J.
Published: November 2014

IN the later stages of the War, aerial maoœuvres at high altitude became increasingly frequent for well‐defined reasons, and, since the War, the tendency has been to provide certain types of aircraft capable of a rapid climb to heights in excess of 25,000 ft. Much work on high‐altitude flying has been done in this and other countries, and notably in the United States, where the present height record of 43,166 ft. is held. This climb was achieved on June 4, 1930, by Lt. Soucck, U.S.N. in an Apache aeroplane. The previous record of 41,794 ft. was held by a German pilot, Willy Neuenhofen, flying a Junkers monoplane. What these figures mean and how they were calculated need not be discussed, for the heights are so huge as to make any comment unnecessary, and when the difficulties of maintaining engine power, effective breathing, necessary warmth of the pilot, and the freedom of controls in temperatures approximating to 90 deg. F. of frost are considered, the performances stand out as unique in technical skill and physical endurance.
Free Model Spinning Researches
Authors: Stephens A.V.
Published: November 2014

THE problem of the spinning nose dive has been the subject of much experimental work in recent years. These researches have been chiefly prompted by the fact that the spin has existed as a potential source of danger since the earliest days of flying. Innumerable accidents have been caused by machines getting into a spin near the ground, generally as a result of engine failure while climbing steeply. Modern tendencies in design have also led to certain types of aeroplane being unable to recover from prolonged spins under adverse conditions of loading. Accordingly, the immediate object of this work is to gain a sufficient knowledge of the principles underlying the motion to enable designers to produce aeroplanes which will not fall into an involuntary spin, however careless or inexperienced the pilot may be; and further, to ensure that an immediate recovery from any spinning motion will be possible without an undue loss of height. There is a growing body of opinion that the spin is no longer necessary as a tactical manoeuvre for fighting aircraft. The ultimate object of research on spinning may thus be the evolution of an aeroplane which will not be capable of spinning in any circumstances.
The Theory of Aircraft Performance
Authors: Hutchinson J.L.
Published: November 2014

IT has been the practice at the official Air Ministry Testing Establishments at Martlesham and Felixstowe to issue with each complete performance report an analytical picture of the performance. This picture is commonly called “Figure 4” because it appeared as Fig. 4 of R. & M. 1140. It is reproduced in Fig. 1. Its physical significance is by no means apparent, and to the practical engineer who appreciates physical significance mainly through his visual imagination it must sometimes have been more mystifying than simplifying. But, as is shown in what follows, the physical significance can be explained naturally and elegantly in terms of the “unit plane” of unit size and wing loading.
Drawing Office Practice
Authors: Dyment John T.
Published: November 2014

EVERY manufacturer is constantly on the alert for methods of increasing efficiency at reduced costs. The drawing office, which is responsible either directly or indirectly for a very large proportion of the cost of an aeroplane, should receive more attention than it usually does. This article deals with a number of simple points which have proved the value of their adoption.
The Estimation of Performance
Authors: Clarkson Richard M.
Published: November 2014

Example 4 A COMMERCIAL aircraft is to be designed whose Absolute Ceiling must not be less than 12,500 ft. The machine is to be a biplane and both wings are to have the same span, which is 48 ft., the gap being 8 ft. However, the possibility of utilising existing stock, and thereby reducing design and manufacturing costs, make it desirable to use a gap of 5 ft. 4 in. What will be the effect of this change on pay load and maximum speed ? (We shall assume the wing structure in each case to be the same weight, which is a fair assumption since it means that with the small gap machine the saving of weight on strut length and cross section is approximately equal to the increased weight of spars necessary to deal with the higher end loads.)
Longitudinal Stability in Aeroplanes
Authors: Bryant L.W.
Published: November 2014

THE mathematical theory of longitudinal stability appears to have been adequate to explain the salient features of the behaviour of aeroplanes in longitudinal motion. In general the provision of a stable slope to the static pitching moment curve has been found in practice to fulfil all requirements, and although increasing oscillations do on occasion occur, they are on the whole surprisingly rare. The reasons for this are fairly well recognised and are briefly indicated in what follows. There is little doubt, however, that the designers' principal difficulties centre round the complex interferences between the wings and the tailplane, particularly with the air‐screw running. The downwash from the centre section in many machines, even with no engine on, is quite unpredictable in the present state of knowledge, and the calculation of the downwash due to the slipstream has not yet been successfully made even in the simplest cases. Some attempt is here made to summarise the present position.
The Knock‐rating of Fuels
Authors: Pye D.R.
Published: November 2014

This paper was read before the World Petroleum Congress on July 19, 1933. Mr. Pye acted as chairman of a committee set up by the Institution of Petroleum Technologists to investigate the corelation of knock‐rating as determined in a test engine with the results obtained using aero‐engine cylinders. This paper prepared by him summarises the results of the committee's investigations
A Simplified Explanation of the Spin
Authors: Irving H.B.
Published: November 2014

THE Spinning Panel of the Aeronautical Research Committee received an inquiry from the Society of British Aircraft Constructors as to whether it would be possible to formulate a set of simple rules for the use of aeroplane designers to guide them in making their machines safe from spinning. As a result, a report was prepared by Mr. Irving, of which the following is a summary, which represents the nearest approach that the Panel feels justified in making at the present time towards meeting the request put forward by the Industry. The Report contains a full statement of the aerodynamic and inertial properties of aeroplanes which, according to current views, are regarded as important in their effect on spinning qualities and a statement of the various combinations of properties which are today considered good or bad. Although the formulation of a complete set of rules is desirable, and may ultimately be possible, knowledge on the subject is not yet sufficiently complete to warrant the laying down of quantitative rules in a simple definite form.
Servo Shoe Brake Calculations
Authors: Roxbee Cox H. , Rowlett Jones A.
Published: November 2014

IT appears from published work on brakes that no general theoretical basis has been presented on which the problem of the servo shoe brake can be studied, though empirical procedures have been used and special cases have been examined analytically. In this essay a simple theory is presented for dealing with brakes having any number of shoes; in it the pressure distribution on any shoe is a function of the conditions of equilibrium, of the system and of simple assumptions which it is thought will be generally acceptable. By means of this theory, the effects of variations in the factors involved in servo shoe brake design can be investigated, and it is hoped that it may consequently prove useful to brake designers.
A Drive for Airscrews on Models
Authors: Warden R.
Published: November 2014

THE problem of driving the airscrews on models of large multi‐engined aeroplanes is complicated by the small size of the fuselages and engine nacelles on the model and the consequent severe restriction on the size of the driving mechanisms to avoid undue interference with the shapes of the component parts of the models. Where a motor of the N.P.L. induction type can be fitted into the model fuselage the problem resolves itself into the provision of a suitable gearbox, and method of power transmission from the gearbox to the airscrews.
Aluminium Castings for Aircraft
Authors: Budgen N.F.
Published: November 2014

ALUMINIUM in various forms is used very considerably in the aeronautical industry—even so far back as the end of the war it was computed that in the year 1918 the allied governments employed about 90,000 tons of aluminium and its alloys in aero construction. And it must not be overlooked that it is largely due to the special properties of these materials that the present amazing development of aircraft has become possible.
The Strength of Tubular Struts
Authors: Morris J.
Published: November 2014

THE strength of tubular struts of uniform section and with pin‐jointed or rounded ends is calculated from, the formula
The Phenomenon of Ground Looping
Authors: Klemin Alexander
Published: November 2014

IN the following notes the phenomenon of ground looping (which may be defined as an uncontrollable fast turn on the ground) is briefly analysed by semi‐technical methods. The analysis has been restricted to a condition which in the opinion of experienced pilots causes trouble most frequently: namely, a landing with dead stick, when there is no slipstream available to make the rudder more effective. The equations of lateral motion for an aeroplane in contact with the ground have been written clown as an introduction to more thorough study. Finally, certain tentative conclusions have been drawn for application in aeroplane design with a view to eliminating or at least reducing ground loop tendencies.
Welding in Aeroplane Construction
Authors: Sutton H.
Published: November 2014

WELDING has been employed in the manufacture of aircraft parts in Great Britain for some considerable time, and the use of welding has in recent years increased both as regards the amount of welding and the scope of application.
The Articulated Connecting Rod
Authors: Evans W.J. , Butcher E.M.
Published: November 2014

VARIOUS methods have been devised for dealing with the effects of the articulated rod in aero‐engines. In an article by E. J. Fearn, published in the Journal of the Royal Aeronautical Society, 1927, a method is given which involves the representation of the piston displacement as a Fourier series. This can be twice differentiated to give the acceleration. Later in the same journal a graphical method is quoted by W. S. Farren. In the 1928 volume Fearn derives a somewhat involved series for the inertia torque on the crankshaft due to the reciprocating mass.
Aeroplane Loading Conditions
Authors: Osborne S.P.
Published: November 2014

IT is well known that the loading of aeroplanes is required to conform with certain design limits of C.G. travel and maximum permissible weight, which are governed by aerodynamic requirements.
Lateral and Directional Control
Authors: Alston R.P.
Published: November 2014

FROM the early clays of flying, aeroplanes have been provided with surfaces intended to give separate control about the rolling and yawing axes. In practice, however, the control surfaces themselves and the stability characteristics of the aeroplane combine to defeat the independence of rolling and yawing control. Recognition of this fact has lately resulted in attempts to arrange the stability characteristics of the aeroplane so that a combined rolling and yawing motion, of the type required in normal flying, is produced by only one control surface.
Research on Model Airscrews
Authors: Douglas G.P.
Published: November 2014

I WISH to thank the President and the Royal Society of Italy for the honour they have conferred by inviting me to read this paper before the 5th Volta Congress as part of a discussion on high speeds in aviation. The contributions which General Crocco has made to this subject have been valuable and stimulating. In the present paper the general question of high airscrew tip speeds is considered and the results obtained from model airscrew tests are reviewed.
Longitudinal Control
Authors: Metcalf A.G.B.
Published: November 2014

THE function of the longitudinal control in an aeroplane is to provide at the will of the pilot a pitching moment of the necessary magnitude and the proper sign, to maintain (a) equilibrium throughout the range of angles of attack at which it is desired to fly the aeroplane; (b) a given angular velocity in pitch.
Aeronautical Progress 1930–1936
Authors: Relf E.F.
Published: November 2014

I CAN hardly say how much I appreciate the honour your Council has conferred on me in asking me to deliver the James Forrest lecture this year. I realise fully the difficulty of the task that has been set me, for it is no easy matter to follow in the footsteps of the illustrious men who have previously addressed you on aeronautical subjects. I will, however, do the best I can to give you some idea of the development of aircraft since Professor R. V. Southwell delivered his excellent review in 1930†, and in doing so, I will not fail to bear in mind the “leit motif” of this series of lectures, which is to trace, wherever possible, the interdependence of abstract science and engineering. My lecture is, in fact, arranged with that object mainly in view, for I shall endeavour to point out the advances that have been made in the technique of research methods, and the nature of the new knowledge of aerodynamic phenomena which has resulted from them, and to show, as far as I can, how this new knowledge has reacted on the practical design of aircraft.
Body and Tail Moments in Spin
Authors: Irving H.B.
Published: November 2014

IN the May, 1933, number of AIRCRAFT ENGINEERING there was published an article by Korvin‐Kroukovsky on the uncontrolled tail spin, in which one of the main points put forward was that during a spin both the body and the tail were very largely shielded by the wings. It was then argued from this that danger might be expected more especially in the low‐wing monoplane type and also the biplane with big forward stagger of wings. At the time there was very little direct evidence on the effect of wings on body and tail moment although an early report on the “ Bantam,” an unstaggered biplane which had spun into the ground, had shown pretty clearly that it was the tailplane which was responsible for the complete blanketing or even reversal of the fin and rudder in a flat spin, and that this could be remedied by raising the tailplanc.
Rubber for Aeroplane Parts
Authors: Garner T.L.
Published: November 2014

RUBBER used for aircraft purposes must be of high quality, and this factor must overrule anything else in the production of the necessary parts. The materials used in compounding arc the best procurable, and control tests arc operated at suitable points during the manufacturing process to ensure the maintenance of a consistent standard.
The Measurement of Speeds
Authors: Woodward Nutt A.E.
Published: November 2014

“WHAT is its top speed?” This is the question which is perhaps most frequently asked about any new aeroplane, and it is certainly a question which is usually incorrectly answered. By this is not meant the natural tendency of manufacturers to be optimistic as to the paces of their latest progeny, but merely that the top speed of an aeroplane cannot be stated with accuracy until a number of careful and methodical measurements have been made. In this article a short account will be given of the errors inherent in the ordinary methods for indicating speeds, and descriptions of some of the methods evolved to measure speed—not only top speed but speed generally—to a high degree of accuracy.
Notes on Hardness Tests
Authors: Skerry E.
Published: November 2014

HARDNESS tests on structural materials are usually taken to indicate quickly and cheaply the probable tensile strength; or used in conjunction with tensile tests, when tensiles are taken on the maximum and minimum limits as revealed by the hardness tests.
Aero‐Elastic Problems
Authors: Pugsley A.G.
Published: November 2014

THIS paper seeks to draw from current research work on flutter and related problems results of general design significance ; and, avoiding mathematics, endeavours to set these results out in relation to past and present problems.
Balancing of Flaps
Authors: Serby J.E.
Published: November 2014

TRAILING edge flaps, it seems, have come to stay for some time; the devices that looked almost too good to be true when first investigated have proved invaluable, not only as aids to landing more heavily loaded aircraft, but more recently they have been shown to be extremely useful in helping take‐off. Evidence of the importance they have lor designers is the large amount of experimental work done on them in all the research establishments of the world, and as a result a lot is known of their aerodynamic characteristics so that it is not difficult to choose, from all the types available, a flap to serve any particular purpose. The object of this article is therefore not to discuss the effects of flaps on lift, drag or stability and control, but briefly to examine them, from one particular aspect that has not received a great deal of attention up to the present, that is—balance.
The Air Drag of Hulls
Authors: Coombes L.P. , Clark K.W.
Published: November 2014

THE design of a flying boat hull is a compromise between the usually conflicting requirements of good performance on the water and in flight. For example, from aerodynamic considerations the hull should be without discontinuities, while for low water resistance when planing, discontinuities are necessary in the form of steps and chines, the former to localise the wetted area to that portion providing lift, and the latter to keep the spray as low as possible. Again, though the minimum air drag results from symmetry about the longitudinal axis, it is usual to curve the tail of a hull upwards to give the tail plane sufficient water clearance.
A Stressed‐Skin Problem
Authors: Goodey W.J.
Published: November 2014

Stressed‐skin construction is now almost universally used in modern aeroplane planes. A technique for the stressing of “tubes” of this type, which seemed to offer almost insuperable obstacles a year or two ago, is gradually being evolved. We feel that the article here printed will be of assistance to drawing office staffs in dealing with one particular aspect of the problem. Another point, that of the effect of introducing openings into the covering of a plane, is dealt with on other pages of this issue by Mr. D. Williams, and we hope that the two together will be of help to all those concerned
Fixed Wing Gyroplanes
Authors: Crowe J.H.
Published: November 2014

THE advantages and disadvantages of the fixed wing for gyroplanes are examined. On the simplest assumptions an expression for the percentage load taken by the fixed wing of a gyroplane is derived. The values so arrived at are compared with those found by experiment and the discrepancy between the two is explained in terms of the increased downwash at the centre of the disc of the gyroplane. It is shown that as much as 50 per cent of the weight of the aircraft can be taken by the wing at top speed with moderate wing area and the most suitable setting. The advantages of an adjustable wing from the point of view of rotor speed control are pointed oat. The Lift/Drag of the combination is raised by 2 over the L/D of the rotor alone. The stability of gyroplanes is discussed.
Wood as a Homogeneous Material
Authors: Brenner Ing. P.
Published: November 2014

WOOD, in the natural state, possesses certain great advantages, and some grave disadvantages, as a structural material. The same is true of the untreated metals. But, whereas nowadays the metallic raw products are, in general, transformed into materials of higher quality by careful smelting, alloying, and other processes, wood is still employed to a great extent in its raw state, i.e., as it occurs in Nature. All previous attempts to improve wood have yielded quite inadequate results, judged by the standard of the advances made in this direction in the field of metallurgy.
High Wing‐Loading
Authors: Belart H.
Published: November 2014

IN considering the size of wings, which aero‐plane designers require to lift a given weight, the fact is very apparent that lifting surfaces have become smaller as the art of aeroplane design has advanced. Fig. 1 shows the trend of this development from pre‐war days up to now, expressed by a steady increase in wing loading (lb. per sq. ft.). How is this development likely to go on, and where will it end ?
The Vibration of Aircraft
Authors: Barlow F.G.
Published: November 2014

THE structure of an aeroplane has several natural modes of vibration in flexure and torsion with frequencies within the le frequency range covered by possible forcing vibrations emanating from engine, airscrew and aerodynamic sources. Resonance in any of these modes may give rise to vibration in the structure of a severe nature which, in extreme cases, may be a limiting factor.
Transfer of End Load in Stringers
Authors: Richards E.J.
Published: November 2014

A GENERAL solution is obtained for the diffusion of stress in n equal and equally spaced stringers in a stiffened panel subject to any boundary conditions at the ends of the stringers.
The Reduction of Position Error
Authors: Kenney K.
Published: November 2014

RECENT tendencies in the design and operating conditions of aircraft have laid increasing emphasis on the short‐comings of the generally accepted pitot‐static method of measuring flight speed. The routine use of air navigation over long distances has spread widely during the past ten years, and, as a result of the greater distances involved, the percentage error in measured flight speed which can be tolerated has become smaller. This un‐satisfactory position was not until quite recently relieved by any very clear appreciation of the errors involved in fitting a pitot‐static head in any given position on an aircraft.
Type Solutions
Authors: Owen J.B.B.
Published: November 2014

COMPLEX problems in redundant frame‐works or vibration are usually treated by some form of “least work” or “energy” method, but in recent years some attention has been given to the development of methods of a somewhat different kind. Such methods may be classified into three main groups :
Non‐Magnetic Materials for Aircraft
Authors: Hadekel R.
Published: November 2014

THE existence of compass errors on ships resulting from the presence of masses of iron in the vicinity of the compass and the method of compensating such errors have been known for over a century. In aircraft the problem is essentially similar, but an additional complication arises where there are moving masses in close proximity to the compass, as the effect of such masses in distorting the Earth's magnetic field depends on their position and therefore cannot be adequately compensated by the usual methods.
Openings in Circular Fuselages
Authors: Kittelsen H.M.J.
Published: November 2014

IN order to obtain a clear view of the analysis it is perhaps better first to consider the analogy of a channel section rigidly attached to two cylinders subjected to a shear at their in the plane of the web of the channel (see Fig. 1).
Rotary‐Wing Aircraft
Authors: Bennett J.A.J.
Published: November 2014

THE flow of air relative to a blade element during translational flight of a sustaining rotor periodically varies, the speed normal to the blade tip being Rω + V sin ψ, i.e., Rω + V in the transverse upstream position and Rω − V in the opposite position downstream (Fig. 40). This dissymmetry of relative air speed produces a corresponding dissymmetry of lift, unless the blade angle is sinusoidally varied or feathered (see ref. 41), and if there were no flapping hinge at the blade root the dissymmetry of lift would produce a rolling couple increasing with forward speed. The rolling couple could, of course, be balanced by controlling the rotor lift vector laterally with respect to the aircraft's centre of gravity or by aileron control, but the flapping hinge, besides suppressing this couple, relieves the blade from excessive bending at its root.
The I.Ae.S. Annual Meeting
Authors: Klemin Alexander
Published: November 2014

Howard W. Barlow, assisted by Henry S. Stillwell and Ho‐Shen Lu of the University of Minnesota, in their paper “Strength Investigations of Thin Stainless Steel Sections,” described an improved test technique which has been very favourably received by the American aviation industry.
Rotary‐Wing Aircraft
Authors: Bennett J.A.J.
Published: November 2014

ONE of the most troublesome problems associated with the development of rotary‐wing systems in which flapping hinges are utilized to compensate for the aero‐dynamic dissymmetry of forward flight has been the rotational oscillation of the blades. To accommodate the horizontal plane dissymmetry (Fig. 4, Ref. 42) due to flapping, vertical “drag hinges” are usually provided, but an alternating bending moment is produced at the blade root due partly to the displacement of the blade about its drag hinge being out of phase with the displacing moment and partly to the necessity for some form of restraint to prevent instability of the oscillating motion of the blade about this hinge.
Modern Wooden Construction
Authors: Weyl A.R.
Published: November 2014

As the most common aeronautical timber is SITKA or silver spruce, its main deficiencies will be of special interest. The essential properties and defects appearing in converted timber, i.e., at planed surfaces (rough portions are unsuitable for timber selection) are as follows:
Rotary‐Wing Aircraft
Authors: Bennett J.A.J.
Published: November 2014

IN last month's article, the simple case of an articulated rotating system in which the whole mass is concentrated at a single point is discussed. An approximate method will now be described of obtaining the natural vibrations of a two‐bladed rotor in which the drag hinges are inclined downwardly and outwardly. This approximation requires the solution of fourth degree equations. Later a more accurate method is considered in which eighth degree equations have to be solved, and it will be seen that an accurate analysis of a three‐bladed rotor would be extremely laborious owing to the increased number of variables and therefore of simultaneous differential equations.
Control‐Surface Mass‐Balancing
Authors: Walker P.B.
Published: November 2014

THE importance of control surface mass balancing does not need to be emphasized, and it is well known that the faster aeroplanes fly, the greater is the care and attention which the designer must give to this question.
Materials of Aircraft Construction
Authors: Teed Major P.L.
Published: November 2014

MAN'S increasing power over the physical world has been largely due to his ever‐growing knowledge of the chemistry and physics of materials. From the end of the Stone Age until almost the present, this developing mastery has largely depended on the metallurgist, who first by empiricism and then by the same means, leavened to an increasing extent by Science, has found means of producing, with but little regard to their specific gravity, substances possessing in greater or less degree those two outstanding qualities, hardness and ductility, on which progress, prior to the flying era, so much depended. In a world of over ninety elements, three quarters of which arc metallic, the combinations and permutations open to the experimentalist arc almost infinite. That these possibilities have not been neglected when the urge existed, is shown by a single example, aluminium. This metal, the discovery of which dates back little over one hundred years, now possesses over 600 alloys whose genesis dates from that of mechanical flight.
Atomic Hydrogen Welding in Aircraft Production
Authors: SMALLMAN‐TEW R.
Published: November 2014

In the early part of last year, the author was asked to examine and report on a number of welded test pieces. These test pieces were cruciform joints in T.45 tube, and had been oxy‐acetylene welded by skilled aircraft welders using DTD. 82A (soft iron) filler rod and had been tensile tested. The tubes were rather larger than are commonly met with in aircraft practice, being 1½ in. o/d and 16G. and 10G. in thickness. Some of the test joints comprised tubes of equal thickness and others of unequal thickness. The lighter gauge tubes were generally satisfactory, all failures occurring in the tube away from the welds, but the heavy gauge tubes all failed in the welds and showed that difficulty had been experienced in obtaining adequate penetration without the welds becoming over‐heated and of excessive size. These indications were still more pronounced in the joints comprising tubes of unequal size in that, in spite of all failures occurring in the lighter gauge tubes, the latter suffered from excess penetration and some oxidation, and the welds on the heavy tubes lacked penetration and were in parts defective. These findings suggested that oxy‐acetylene welding was not suitable for this particular application.
Blade Stall During Take‐off
Authors: Andrews E. John
Published: November 2014

TO facilitate airscrew performance calculations an entirely new series of charts have been developed embodying wider use than hitherto of the term solidity ratio. These charts are applicable to airscrews with any number of blades. Whilst the number of blades is incorporated in the solidity ratio no further inclusion has been made of their tip speed effect on the interference velocity through the actuator disc. This effect has been investigated by Lock in conjunction with tip speed losses, but it was felt that its inclusion did not justify the added complication to the charts. In fact it makes their simple presentation impossible. The effect, however, can be incorporated with a correction factor to the power input to the airscrew. This factor is not dealt with in detail in this article and would form the subject‐matter of a separate work.
Liaison Between Design and Production
Authors: Schroeder A.J.
Published: November 2014

THE manufacture of any goods can be divided into two mental actions: that of contriving and designing, as pure brain work; and of production, as a combination of mental and handicraft processes. Invention and design signify intellectual “construction” in the same way that production deals with material “construction.” The engineer, no matter whether designer or production engineer, is, therefore, the “constructor” in the truest sense of the word.
German Aircraft Instruments
Authors: Postlethwaite F.
Published: November 2014

DISTANT READING COMPASSES ONE of the most interesting German aircraft installations is centred around the distant reading compass.
Air‐line Engineering Management
Authors: Lusty Ivor
Published: November 2014

VI.—OUT‐STATIONS IT has already been pointed out that the engineering maintenance department is a minor factor to the major factor of flying operations and, therefore, for maximum overall efficiency it may be necessary to run the engineering side of the work on a basis of over‐suitability. Admitting this state, it becomes expedient to arrange the work so that as little as possible is done by the more inefficient, i.e. the more over‐suitable, sections. Inefficiencies of the kind which will occur in the organization envisaged are caused principally by the necessity for rendering good service under conditions of peak load, and this entails the availability of labour and equipment in excess of normal requirements. This is particularly so at stations on the routes where aircraft stop for traffic and carry on according to a published schedule. The work done at such stations is principally refuelling, re‐oiling and perhaps some attention to cabin conditions. The personnel, however, must be prepared, and able, to attend to any complaint made by the pilot, or to do a daily inspection overnight with whatever preventative maintenance that may entail. In the case of larger aircraft, assistance may be rendered by the flight mechanic, though this assistance should not be counted upon to too great an extent, as the mechanic's flight duties may be heavy on that day or the next, and his alacrity should not be compromised by work which may demand his mental or physical labours during what should be his rest period.
The Prevention of Eye Injuries
Authors: Meyer Rupert G. , Bowers J.T.
Published: November 2014

The Significance of this Class of Injury THE vast and far‐reaching effect of an eye injury is seldom fully realized, either by the worker or by the management, a fact which, no doubt, explains much of the prevalent disregard of preventive measures. A worker who sustains an eye accident, and goes off duty, disappears for a varying period of time from the ken of his shop manager and workmates in much the same way as one who has sustained a simple laceration of the hand or arm, yet to the medical and compensation departments his case may present far greater problems.
Practical Workshop Classification of Steels
Authors: Skerry E. , Hicks L.W.
Published: November 2014

THE purpose of this article is to describe two methods, which may be employed independently of chemical analysis and within their limitations, to classify steels.
SAMPLING INSPECTION & QUALITY DETERMINATION
Authors: Rissik H.
Published: November 2014

THE first part of this article, published in last month's issue of AIRCRAFT ENGINEERING, outlined the operation of the non‐statistical method of sampling inspection commonly met with in purchasing specifications, and explained the inability of such a sampling clause to discriminate effectively between good and bad quality product. The present issue describes the practical applications of statistically designed sampling inspection procedures, giving adequate quality assurance wherever 100 per cent inspection of the product is either inapplicable or uneconomic.
The Lateral Stability of Aeroplanes
Authors: Price H.L.
Published: November 2014

IN the previous articles the lateral stability of an aircraft has been considered mainly from an analytically qualitative and quantitive point of view, without any particular emphasis on the physical aspect of the nature of the disturbed motion. It is now proposed to discuss the possible types of motion in greater detail, always bearing in mind the analytical basis upon which the descriptions are founded.
Airscrew Stress Coefficients
Authors: Day T.H.
Published: November 2014

IN the design of hypothetical airscrews an4 general investigations on performance thc calculations are often based on values of torque and thrust coefficients from a family of airscrews or by the use of Lock's method assuming an elliptical grading. It is sometimes desirable to ascertain whether the corresponding stresses in thc blades are satisfactory. This is a laborious process as far as the aerodynamic bending stresses are concerned, since before calculating thc bending moments at each section, it is necessary to calculate the aerodynamic forces.
Wing Lift Distribution
Authors: Morse W.L.
Published: November 2014

THE present article is the application of Schrenk's approximate method to two cases, one a wing without twist and the other the same wing with twist, the nomenclature of Schrenk's article having been altered to conform to British usage, and a certain amount of explanatory matter added in order to make the method more easily understood.
Screws and Airscrews
Authors: Day T.H.
Published: November 2014

BEFORE dealing with the airscrew, it is proposed to compare the systems of forces acting on an aerofoil section with those acting on an inclined plane.
The Design of Struts
Authors: Grundy R.H.
Published: November 2014

TO check the suitability of a given strut cross‐section, for a given length and safe concentric working load, is a simple matter provided that a working stress curve or formula is available, but the reverse process of obtaining a suitable cross‐section, for a given length and load is under normal circumstances a tedious trial and error task, unless comprehensive tables of the properties of the required section arc available. The author's method permits a very close first approximation to be obtained, which is frequently sufficiently accurate to enable the required cross‐section to be laid out without further trial.
Two‐Spar Wing Stress Analysis
Authors: Goodey W.J.
Published: November 2014

IN previous articles by the writer on the subject of Two‐Spar Wing Stress Analysis, it has been assumed that flexibility of the ribs has no appreciable effect on the distribution of stress in the wing. Using the method of minimum strain energy, this assumption is equivalent to neglecting the strain energy stored in the ribs. Other writers have, in effect, made this same assumption by neglecting change of shape of cross‐sections under load.
Tailless Aircraft and Flying Wings
Authors: Weyl A. R
Published: November 2014

DURING the past 40‐odd years or so, a number of experimental aeroplane types have been invented, visualized, designed, constructed and even flown which, in a quite unorthodox manner, had neither behind the wing nor in front of it any sort of stabilizing and/or controlling surfaces.
Conditions in Diving
Authors: Krzywoblocki Zbigniew
Published: November 2014

ASSUME an aeroplane in pure dive, i.e. the motion of the centre of gravity of the aeroplane is purely vertical. The airscrew is stopped and the diving aeroplane may be treated like a diving glider. The only difference is in the value of drag. It is assumed that the aeroplane is infinitely stiff, wings are not subject to twisting, etc. The aeroplane starts to dive from a certain height h with a certain initial velocity vi which in a special case may be equal to zero. To calculate the velocity which the aeroplane will reach at the height x the Neumark formula is applied:
Tailless Aircraft and Flying Wings
Authors: Weyl A.R.
Published: November 2014

Even in these days of long development periods of conventional metal structures and of huge production orders for orthodox aeroplanes the interest in the Flying Wing type and in tailless designs is by no means asleep.
The Strength of Riveted Joints
Authors: Bowen I.G.
Published: November 2014

A CONSIDERABLE volume of data on the strength of typical aircraft rivets in joints of Alclad (D.T.D. 390) sheet, has been published in the M.A.P.'s Scientific and Technical Memorandum series. The need for such an investigation arose from the use by the stress offices of different aircraft manufacturers, of strength figures which showed little unanimity even when identical riveted joints were compared. The result was that fixed conditions of manufacture; of the proportions of the joint; of methods of testing and finally of analysis led to a body of data which gives a fairly representative basis for practical design.
Undercarriage Retraction Mechanisms
Authors: Conway H.G.
Published: November 2014

THE subject of retractable undercarriages has already been dealt with before the Royal Aeronautical Society as well as in numerous technical articles. This article endeavours therefore to deal with some aspects of the matter which have not been discussed very widely in the past. Reference is made to the problem as it affects the aircraft designer rather than the specialist undercarriage or hydraulic engineer, and stress is laid on the geometrical and installational problems rather than the mechanical design aspects of the equipment itself.
Quality Control
Authors: Phillips H.S.
Published: November 2014

ONE of the things which led mo to develop the idea of “fixed period renewal”, was 12 months' experience of Quality Control with a famous aero‐engine firm. During that time I kept life‐charts and quality data in regard to numerous interesting variables relating to the failures and use‐characteristics of components within the power‐plant structure as a whole. Despite failure percentages of rarely more than 5 per cent, as a proportion of total production, I was absolutely amazed at the utter uncertainty as to failure probability, cither in terms of timing or quantity. It was equally appalling to realize what a low life‐expectation there is for all components. During the war the comparative lack of reliability in many minor components, within important assemblies, has led, in my personal and it is true restricted experience, to a terrible wastage of man‐power. Even though material weaknesses and shortages have to some extent excused this (with regard for example to the repair schemes) the result has not infrequently been to endanger or actually to end human life. When a component would be expected, Tor both safety and economic reasons to last χ hours, it has been found to last instead perhaps χ/3 or χ/4 hours.
Unsymmetrical Bending and Strut Design
Authors: Kinkead A.N.
Published: November 2014

IN dealing with beams, in which the trace of the plane containing the applied bending moment does not coincide with a principal axis of the beam section, the present design method is to draw the Momcntal Ellipse on the section in question and at the point where the trace of the plane containing the applied bending moment cuts the Momental Ellipse, a tangent is drawn. The line‐drawn through the centroid of the section parallel to this tangent is then the neutral axis under the conditions of loading, and the perpendicular distance between these two parallel lines is the radius of gyration of the section for this plane of loading. The fibre stress in the section is maximum at the point in the sectipn furthest away from the neutral axis under the component of the applied bending moment which is perpendicular to the neutral axis.
‘Carpets’ and ‘Lattices’
Authors: Yates A.H.
Published: November 2014

A NOVEL method of plotting a function of two independent variables has recently come into use in aeronautics and a description of it may be of interest to workers in this and other fields of experiment. The idea was originated by Mr. R. F. Sargent of the National Physical Laboratory and has since been extensively used in this country and in America. The idea can be extended to include plotting a function of three independent variables in the form of a ‘lattice’.
British Aircraft Gas Turbine Engine Progress
Authors: Roxbee Cox H.
Published: November 2014

The first gas turbine patent was granted in England to John Barber in 1791, and since then there have been numerous gas turbine inventions. These have been adequately described elsewhere, 1, 2 and I shall concern myself only with the developments which have led directly to recent British achievements.
Evolution of Energy for Jet and Rocket Propulsion
Authors: Bielkowicz P.
Published: November 2014

Specific Heat of Gases THE chemical reaction having been accomplished and the energy of fuel released, we can follow its further transformation. It can be assumed that in the first stage this energy is absorbed and stored in the surrounding gaseous medium composed mainly of combustion products. The mechanism of the absorption and preservation of energy by gases is given in their specific heat theory, and is based mainly on the assumption of the equipartition of energy among all degrees of freedom of gas molecules. Heat, being the equivalent of kinetic energy of these molecules, is stored in four different ways by the molecules, and assumes four different forms of energy, three of which are quantized without any doubt, i.e. the exchange of energy does not take place as a continuous flow, but by small packets of a definite size (quanta). The value of a quantum is equal to hp, where h is the Planck's constant and p is the frequency of radiation associated with the energy change.
The Stressing of Cabins Under Uniform Pressure
Authors: Thompson E.W.H.
Published: November 2014

AS an approach to the determination of the end loads, shears and bending moments induced by uniform pressure in a cabin former ring of any odd shape, it is instructive to observe how the end loads, shears and bending moments vary in a cabin ring according to changes in the space parameters of cabins of simple mathematical form. The condition of a cabin under uniform internal pressure only is dealt with.
The Evolution of Energy in Jet and Rocket Propulsion
Authors: Bielkowicz P.
Published: November 2014

WHEN the temperature of the gas reaches the high level, the molecules begin to break up into atoms or groups of atoms, which after recombination form new and smaller molecules of a simpler structure. For instance, tri‐atomic molecules after having been split form diatomic ones. This process is called the dissociation of gases. The newly‐formed molecules, when colliding, again form molecules of the original gas, so two processes are occurring simultaneously. However, the higher the temperature, the larger the percentage of dissociated molecules.
Alloys of the Heavy Metals
Authors: Fitzgerald‐Lee G.
Published: November 2014

THIS paper shows briefly the origins and development of a comparatively new and certainly important branch of engineering science. For many years the alloys of the light metals, particularly of aluminium and magnesium, have been developed, until the term “light alloys” has come to be generally accepted as indicating the alloys of the light metals or any metallic alloy having a density of less than about 3·8. Towards the other end of the density scale are now being developed alloys of the heavy metals, mainly tungsten and tantalum. The techniques of production and manufacture of these two groups are very different: whereas the light alloys are produced and manipulated mainly by melting, casting, annealing, and forging, the heavy alloys are produced by various processes of powder metallurgy, resulting in substances with densities of 15 or more.
Servicing the Derwent I Jet Engine
Authors: Cooper F/Lt. S.
Published: November 2014

SERVICING, at specified intervals, is essential to the safe and reliable running of all mechanical devices. This is, perhaps, even more important in the case of the jet engine than with other mechanisms. With this object in view, the following paragraphs outline the servicing requirements of the Derwent jet propulsion power unit.
Design and Production Technique
Authors: Schroeder A.J.
Published: November 2014

When shaping any press parts, attention must be paid as follows to the manufacturing cost of dies and their durability as well as to the flow of material and the deburring of workpieces:
The Evolution of Energy in Jet and Rocket Propulsion
Authors: Bielkowicz P.
Published: November 2014

THE transformation of energy stored in the fuel into heat energy of exhaust gases was followed in the previous parts. The molecular changes occurring in the working fluid were investigated, as well as the changes of its physical constants due to the high pressures and temperatures. It is known that the combustion of hydrocarbon fuel results for the most part in the formation of CO2 and H2O as combustion products and consequently special attention is given to the behaviour of these gases since they constitute the working fluid of a rocket engine. The general equation of hydrocarbon combustion has the following form: