bluuebunny/crossref_metadata_2025 huggingface dataset:
Stability and Control Problems of Supersonic Aircraft
Authors: Michaelsen O.E.
Published: February 2008

This article deals with some of the stability, control and handling problems that have arisen as a result of drastic changes in aircraft configuration coupled with the advent of supersonic flight at high altitude. The article will be published in two parts. The present part contains a brief introduction to the subject of aircraft stability and control in addition to a description of the longitudinal characteristics of supersonic aircraft. The second part will be published in our next issue, and will deal with the lateral characteristics of supersonic aircraft. Some of the problems encountered in the design of the flying control system for this type of aircraft and an indication of the methods and techniques used for solving the various stability problems are also presented in the second part.
Guided Weapon Engineering
Authors: Clemow Brigadier J.
Published: February 2008

THE purpose of a guided weapon is to destroy the enemy. Therefore the success of a guided weapon design must be measured by the efficiency with which it achieves this aim. According to one's up‐bringing it is customary to regard the guided missile either as a small high‐speed aircraft without a pilot, or as an artillery shell provided with wings and some method of manoeuvre. From the engineering point of view the second is, I think, the better attitude to take. For in Service use the guided weapon as an engineered product must be much more akin to the artillery shell than to a fighter aircraft in matters of robustness, long‐storage life without deterioration or too frequent maintenance, case of handling and cheapness. As there is no pilot in a guided weapon, there is a considerable easement relative to orthodox aircraft design in matters relating to safety in flight, although there is, of course, a paramount need to ensure that the missile is safe during the launch period and on other occasions when it is near one's own troops or aircraft. Thus, because the guided weapon designer is not hazarding the life of a pilot, he is free to choose a missile design of less reliable performance but which is cheaper to make rather than a highly reliable design which is expensive to make, provided that the economic effort of firing more of the less reliable missiles is a significant saving on the firing of a fewer number of the more expensive reliable missiles. Reliability is the word most often heard in guided weapon engineering circles.
Design Notes for Glass Reinforced Plastics
Authors: Wright J.H. , Dowman R.D.
Published: February 2008

Reinforced Plastics have been widely used in the Aircraft Industry over the past ten years, but its application is still treated as something of a special field. The purpose of these notes is to introduce the subject to the Drawing Office and to set simply before the draughtsman another engineering material. The use of plastics is not recommended for primary structure at present, due to insufficiency of test results, but for secondary structure they may offer advantages in robustness and non‐corrodibilily over light alloy, with increase in weight, and sometimes with less weight. In complex shaped fairings, the ease of forming of reinforced plastics enables the component to be moulded as an integral structure, thus reducing fabrication and consequently costs. The reduction in the number of parts means less weight and the resulting structure is often intrinsically stronger. They also have many applications where their particular properties, such as electrical properties, non‐corrodibility, acid resistance or high specific tensile strength are desirable. Typical applications for the material are summarized in TABLE I together with reasons for their use.
The Annular Aerofoil with Central Body and Propeller
Authors: Pivko Svetopolk
Published: February 2008

CONSIDER an isolated circular fairing whose cross‐sections along in the flow direction are of aerofoil shape, inclined at small angle of attack a, FIG. 1. By applying the general concept of the aerofoil theory in two‐dimensional flow, it is assumed that the local velocity increment on the surface of annular aerofoil may be considered to be composed of three components v1 v2 and v3, depending on the section thickness and camber and on the angle of attack.
A Theoretical Analysis of the Airborne Path during Take‐off
Authors: Buckingham W.R.
Published: February 2008

The solution of the problem of estimating the take‐off distance to a height of 50 feet has to a certain extent been limited by the absence of a theoretical analysis of the airborne part of the take‐off manoeuvre. The three main physical quantities associated with the motion immediately after an aircraft leaves the ground are aircraft speed, the angle the flight path makes with the horizontal and the lift coefficient increment. This latter quantity is the lift coefficient in excess of that required for level flight at the unstick speed, and is produced when the pilot pulls the stick quickly back at take‐off. A linear theoretical analysis is obtained by assuming that variations of the physical quantities already mentioned are small enough for squares and higher powers of such variations to be neglected in comparison with the variations themselves. The results of the analysis depend on the solutions of a pair of ordinary simultaneous linear differential equations with constant coefficients. If the aircraft speed never falls below the unstick speed, the limiting values of the lift coefficient increment which define the safe range of take‐offs can be determined. By considering the mean value of the lift coefficient increment over the safe range of take‐offs it is possible to define a mean safe take‐off, and for such a take‐off, the mean safe airborne distance from the unstick point to a height of 50 feet can be estimated. The application of the theory as a means of estimating the take‐off performance of a bomber aircraft is given as an example at the end of this work.
Plastics for Leakproof Fuel Tanks
Authors: Spurgeon J.R.
Published: February 2008

FOLLOWING the initial development of Convair's delta‐winged aircraft, a new concept of fuel tank design became imperative because it is necessary to use every available cubic inch of space for fuel storage in relatively thin wings.
The Shear Modulus of Foil Honeycomb Cores
Authors: Kelsey S. , Gellatly R.A. , Clark B.W.
Published: February 2008

Simple expressions for upper and lower limits to the shear modulus of honeycomb sandwich cores are obtained by application of the Unit Displacement and Unit Load methods in conjunction with simplifying assumptions as to the strain and stress systems respectively in the core. The theory is given for cores built up from foil ribbons to form cells of general honeycomb form. Test methods for the experimental determination of the shear modulus are also discussed. Of these, the three‐point bending test on sandwich beams is considered most satisfactory and results of such tests on steel and aluminium foil honeycombs show good agreement with the theory.
Natural Vibration Frequencies of Flexible Rotor Blades
Authors: Lockwood Taylor J.
Published: February 2008

HELICOPTER rotor blades, as is well known, are subjected to alternating bending stresses at various multiples of the rotor r.p.m. when the aircraft is flying forward. One of the factors determining the magnitude of the fluctuating stresses at the various frequencies is the approach to resonance between the harmonic components of the periodically varying aerodynamic loads and the natural blade frequencies. Most rotor blades are flexible enough to allow the frequencies of at any rate the lower modes, which are probably the most important, to be estimated by applying a correction for blade bending stiffness to the natural frequency of the blade if it were perfectly flexible, and subject only to inertia and centrifugal forces. It is on this latter aspect of the problem that the present article is concentrated.
Interference Fits
Authors: Thurgood D.A.
Published: February 2008

IN many instances of machine design it is expedient to retain a bush within a body by interference alone. Under certain circumstances the stresses may be excessively high, or conversely the initial shrinkage may be insufficient to restrain the bush in the body at high operating temperatures. It thus becomes necessary to investigate these effects from a design viewpoint, and it is the object of this article to present a relatively quick method for solving the equations involved. In addition it is often necessary to determine deflexions of the bore of the inserted bush, and occasionally the growth of the outside of the body. Expressions are also developed in the following analysis for the determination of these.
Aerodynamic Influence Coefficients for Delta Wings in Steady Supersonic Flow
Authors: Lees D.E.
Published: February 2008

A routine numerical method of solving integral equations arising in steady supersonic flow past flexible delta wings, with supersonic and subsonic leading edges, is presented. The wing is subdivided into diamond shaped panels, by a network of equi‐spaced Mach lines, and the effect of placing unit downwash at each panel in turn is calculated. The resulting influence function, which has been tabulated, is then formed into the required matrix of influence coefficients. Within the limitations of linearized theory the results are valid for all Mach numbers and mode shapes, including chordwise bending. Although applied here to delta wings the method is equally suited to wings of arbitrary plan form. An aeroelastic efficiency calculation, for a sonic leading edge 45 deg. delta wing of representative torsional stiffness, is included for comparison with strip theory.
The Analysis of Fuselages of Arbitrary Cross‐section and Taper
Authors: Argyris J.H. , Kelsey S.
Published: February 2008

A DSIR Sponsored Research Programme on the Development and Application of the Matrix Force Method and the Digital Computer. This work presents a rational method for the structural analysis of stressed skin fuselages for application in conjunction with the digital computer. The theory is a development of the matrix force method which permits a close integration of the analysis and the programming for a computer operating with a matrix interpretive scheme. The structural geometry covered by the analysis is sufficiently arbitrary to include most cases encountered in practice, and allows for non‐conical taper, double‐cell cross‐sections and doubly connected rings. An attempt has been made to produce a highly standardized procedure requiring as input information only the simplest geometrical and elastic data. An essential feature is the use of the elimination and modification technique subsequent to the main analysis of the regularized structure in which all cutouts have been filled in. Current Summary A critical historical appraisal of previous work in the Western World on fuselage analysis is given in the present issue together with an outline of the ideas underlying the new theory.
Electrical Analogue to a Celled Tube Subjected to Flexure and Torsion
Authors: Zaid Melvin , Ryder Frederick L.
Published: February 2008

A new analogue approach is presented for the solution to the multi‐celled, multi‐stringer tube subjected to flexural and torsional loads. This approach is based upon the condition of current continuity and an equivalent to Castigliano's theorem which holds for certain types of electrical networks. The associated equations lend themselves to creating an analogue with a high degree of pictorial similarity, so that the network can be constructed without formulating the structural equations. The analogue of a simple two‐celled structure is devised and the results obtained by electrical circuit analysis are checked against the structure.
The Analysis of Fuselages of Arbitrary Cross‐section and Taper
Authors: Argyris J.H. , Kelsey S.
Published: February 2008

The flexibility matrices for the unassembled structural elements are discussed and a more concise form developed appropriate to the fuselage structure. A general method is given for obtaining self‐equilibrating flange load and shear flow systems in a single‐cell fuselage, the primary redundancies being defined by a simple transformation matrix. The particular matrix based on the orthogonal stress systems for a circular section is especially convenient. A slight extension of the equations leads also to alternative statically equivalent stress systems in the cover.
The Analysis of Fuselages of Arbitrary Cross‐section and Taper
Authors: Argyris J.H. , Kelsey S.
Published: February 2008

The derived data matrices established for the basic system in the previous issues are assembled to give the compatibility equations from whose solution the redundancies are obtained. The assembly is presented in detail to show the necessary submatrix operations required in the computer. The general solution of the compatibility equations leads to the complete stress distribution and deformation of the regularized fuselage due to external loads, wing or tail interaction redundancies and to thermal strains. From these wc obtain, by use of the cut‐out and modification technique, the corresponding results for the actual fuselage as an independent structure. The interaction redundancies at the wing and tail unit attachments are determined on the assumption that these components are also analysed by the Force Method. Hence the final stress distribution is obtained for the fuselage as an integral part of the complete aircraft structure.
Machine Tool Automation
Authors: Peck L.S.
Published: February 2008

THE advent of the digital computer enables engineering designers to replace manual calculation by accurate high speed computation. The combination of the digital computer and a machine tool‐control system offers the possibility of reduced costs, improved accuracy and the reduction of the time interval between the conception of a design and the production of the finished part.
Reduction of Bending Moment at the Root of a Rotor Blade
Authors: van Leeuwen H.P.
Published: February 2008

It is shown that a reduction of the bending moments in a helicopter rotor blade may be achieved by replacing an elastic beam‐type flapping hinge by a stack of leaf‐springs having the same overall bending stiffness but no shear stiffness. This reduction becomes more pronounced when the tensile load on the flapping hinge is increased.
Estimation of Take‐off and Landing Airborne Paths
Authors: Rogerson G.E.
Published: February 2008

Two types of manoeuvre, in one of which lift coefficient and excess thrust are constant, and in the other of which speed is constant, are analysed. The analysis leads to simple methods of estimating take‐off and landing airborne paths, and may be useful in the study of some other flight manoeuvres.
Vibration of Missiles
Authors: Cox H.L.
Published: February 2008

The free and harmonically forced flexural vibrations of missiles accelerating along initial trajectories are considered. A general matric formulation is given for the problem whereby the effects of variable inertial axial loads along the missile length, variable stiffness and material properties, variable mass, variable mass moment of inertia, variable shear stiffness, and variably distributed forcing functions are treated. The matric formulation of the problem is in standard eigenvalue form and no special coding will be required for organizations that currently are solving eigenvalue problems on electronic digital computers. The time required for an engineer to fill in the matrices of the basic matric equation governing the vibrations of a missile structure is quite small since only fundamental data are needed and almost all calculations are performed within the computer.
Temperature Control by Means of the Peltier Effect
Authors: Armi E.L. , Kirkpatrick C.G.
Published: February 2008

A major potential application of the Peltier effect is the thermostating of electronic equipment, modules and individual components. Limitations of size and weight rule out mechanical refrigeration for small cooling units. However, Peltier cooling devices are size‐independent in their efficiency and in miniaturized form may be. incorporated into heat‐generating circuit components. Peltier units can remove heat directly from the source rather than from an external surface, and in addition, these thermodynamically reversible devices permit both heating and cooling. Electronics may thus be thermostated at or below ambient temperature to provide increased reliability and stability. The authors discuss specific applications of Peltier thermostating under development.
Emergency Arresting System
Authors: Bedford R.A.E.
Published: February 2008

THE purpose of this arresting system, which was demonstrated with the aid of a Supermarine Scimitar equipped with conventional naval deck‐landing hook at this year's Farnborough Air Show, is to prevent accidental over‐run of aircraft. Design and development has been carried out by the Royal Aircraft Establishment at Bedford, while the energy absorption units for the installation have been designed and supplied by the Aviation Division of the Dunlop Rubber Company, working in close collaboration with the Establishment.
The Routh and Routh‐Hurwitz Stability Criteria
Authors: Morris J.
Published: February 2008

THE classic Routh stability criteria1 are applicable only to polynomial characteristic equations with real coefficients. The writer recently came across co‐related criteria in a Russian treatise2 on the stability of rotating shafts which criteria are applicable to polynomial equations with complex coefficients. These criteria were apparently devised by Hurwitz as extensions of the Routh criteria and are thus known as Routh‐Hurwitz stability criteria. They are, however, not well known to British students of stability analysis nor are they readily accessible in British publications.
Lubricants for Engines for Supersonic Aircraft
Authors: Hunter N.J.
Published: February 2008

MOST of the aircraft engines of the 1900 era were little more than adaptations of the existing reciprocating internal combustion engines used in motor cars, but progressive design improvements eventually led to the very efficient power plants of high horsepower which had by the 1940's enabled piston‐engined bomber aircraft to reach cruising speeds of 300 m.p.h. and piston‐engined fighter aircraft to attain level‐flight speeds in excess of 400 m.p.h. At this stage, piston engines had almost reached their peak performance and aircraft speeds could be significantly increased only by the adoption of some radically different type of engine. The development of the gas turbine resulted in this new power plant and aero gas turbines are now in the final stages of replacing piston engines as propulsive units for medium and large aircraft.
The Ultrasonic Testing of B.66 Compressor Blades
Authors: Harris‐Maddox B.
Published: February 2008

A Description of the Technique and Equipment used successfully to carry out Ultrasonic Inspection of Compressor Rotor Blades of the Allison J.7I Turbojet following the loss of a number of Douglas B.66 Bomber Aircraft of the United States Air Force in Europe due to Engine failure
Developments in Adhesive Bonding
Authors: Denney M.A.
Published: February 2008

BEFORE any designer can utilize adhesive bonding in critical structural components he must be able to assure himself of the reliability of the process. This is often'a very difficult procedure since the usual method of testing a joint is to destroy it.
Transparencies for Supersonic and Hypersonic Flight
Authors: Underwood G.W.
Published: February 2008

SUMMARY The main overall problems associated with transparencies for manned supersonic and hypersonic aircraft are considered. Civil and military concepts are compared in relation to aircraft performance requirements and the reasons for the continuing need for optical transparencies are enumerated. Aircraft performance requirements and typical flight plans show the necessity for designing the transparencies to withstand a considerable range of environmental conditions in addition to the aerodynamic dictates in relation to size, position and shape. These conditions are listed and design feature considerations are discussed in some detail with particular accent on the thermal problems. Reference is made to certain organic and inorganic materials for the basic glazings and the problems associated with the ‘marrying’ of these materials with retaining frame members are discussed. Detail proposals are made for typical windscreen and canopy assemblies. Brief reference is made to the poor reliability shown by many transparencies in present‐day modern aircraft which indicates the need for revision of certain existing test requirements. The proposed new requirements will result in the development of new testing techniques although test factors might well be reduced. The paper concludes with a statement on the importance which is being given to the subject matter by the various bodies in the U.K. and the emphasis which should be placed on the need for the continuation of research and development work in this field.
Grinding the Refractory Metals
Authors: Richards T.Z.
Published: February 2008

A BRIGHT future has been predicted for the refractory metals for aerospace applications. Typical uses include; solid propellent rocket motor nozzles, re‐entry surfaces for gliders and nuclear space power systems (liquid metal containers). Refractory metals are already employed on ram jet engines, hot structure sections capable of supporting aerodynamic and thermal stresses, or as heat shields protecting low temperature structural members.
Materials Research for the Hypersonic Air Breathing Engine
Authors: Hemming N.R.
Published: February 2008

The temperatures which will typically be encountered by various parts of a hypersonic air breathing engine at different Mach numbers are indicated in FIG. 1. A limited gain can be expected from the employment of cooling systems but in general the need for materials possessing heat resisting properties which are markedly superior to those conventionally used, such as the Nimonic range, is apparent at approximately Mach 4. Combustor flame stabilizing equipment for example must survive as an item of structure at temperatures around 1,300 deg. C. for Mach 4 and 1,500 deg. C. for Mach 5. Intake leading edges and ducts containing intake air are two further areas requiring the use of new high temperature metals once Mach 5 has been significantly exceeded. The combustor gas temperatures shown in FIG. 1, even allowing for limited cooling, require the use of a material capable of operating with a hot face temperature of 2,000 deg. C. or above. In this instance the material might be used as a non‐structural lining designed to lean on the cooler load‐carrying structure. In each of these instances the material is subjected to the effects of a high velocity oxidizing atmosphere.
Project Evaluation as a Design Function
Authors: Harvey R.A.
Published: February 2008

THIS paper relates to activities within an aircraft project office; the extent to which similar techniques are applicable, or are being applied in the design areas of other industries could well form a subject for discussion.
Fluidics—A New Technology
Authors: Wheatley D.E.
Published: February 2008

FLUIDICS is a term coined recently defining a rapidly emerging technology which involves the use of gaseous or liquid fluids in motion to perform functions such as amplification, sensing, switching, logic or computation. The accelerating interest in fluidics is no doubt due to the increasing awareness that fluid energy can be manipulated in much the same way as electricity and without moving parts. Also, since fluidic control components are highly reliable under extreme environmental conditions and are impervious to radiation — magnetic or nuclear—they offer many advantages for use in aerospace or nuclear engineering. These particular advantages and others, coupled with the probable low ultimate economic costs of fluidic components, are further stimulating active interest in many commercial and industrial applications.
A Rain Erosion Resistant Coating for High Speed Flight
Authors: Alle W.G.
Published: February 2008

LIKE many other people, Hawker Siddeley Dynamics have also been interested in resin‐systems which have, or claim to have, a higher heat resistance, and tests on these as they became available were part of our normal evaluation programme at Whitley. It was during one of these programmes, when physical and mechanical properties of filled resins were being evaluated that the question of their suitability as protective coatings against rain was raised. The subject was a challenging one, and we decided to take it up.
Heating Element Design Features
Authors: Smith A.R.J.
Published: February 2008

THE ultimate performance of aircraft electrical ice protection systems is dependent to a large degree upon the design of effective healing elements. After considerable research Dunlop developed their ‘sheared foil’ element which has proved itself superior in most respects to other elements and is used in 90 per cent of Dunlop heater applications; this type of element has proved that it is capable of operating for many thousands of aircraft flying hours without any change to the design characteristics.
Vibration Monitoring on Jet Engines
Authors: Hatschek R.
Published: February 2008

MALFUNCTIONS of turboprop, turbojet and turbofan engines can be divided into two groups as follows:
Potential Technology Improvements for the CF6 Turbofan
Authors: Payzer R.J.
Published: February 2008

THE CF6 engine is a dual rotor, high bypass ratio turbofan engine designed for airline operation. It incorporates a variable stator, high pressure ratio compressor, an annular combustor, an air‐cooled core engine turbine and a co‐axial front fan driven by a five‐stage low pressure turbine (Fig. 1). The core engine has an exhaust thrust spoiler which operates in conjunction with the fan cascade reverser during landing roll.
The Characteristics and Problems Associated with V/S.T.O.L. Operations
Authors: Boorer N.W. , Davey B.J.
Published: February 2008

A study of the main parameters to be resolved for civil V/S.T.O.L. aircraft, the necessity for all weather operation, the airport requirements and the competition from other forms of transport. FROM a choice of a wide range of V/S.T.O.L. applications, this paper is concerned with the civil aircraft aspects. It deals with the main parameters to be studied in resolving V.T.O.L. and S.T.O.L. aircraft characteristics, the weighting of these toward favourable performance and to meeting the proposed certification rules for this form of transport. The part to be played by electronics in all weather operations is also discussed. Competition from surface transport, and V/S.T.O.L. airport requirements are referred to, and some general characteristics of the many different aircraft configurations are discussed. Some conclusions are reached suggesting the direction and weighting of future work.
The Eleventh Anglo‐American Aeronautical Conference
Authors: Hannan William M.
Published: February 2008

LOWER operating costs of the L‐1011 and the increased revenues generated by the aircraft's greater attention to cabin comfort and passenger appeal combine to permit airlines to achieve substantially higher profit than possible with today's jets.
Evaluation of Advances in Engine Noise Technology
Authors: McPike A.L.
Published: February 2008

ADVANCES in engine technology are evaluated herein, and, for the purposes of improving future noise evaluation of commercial jet aircraft, adjustments to current evaluation techniques are suggested.
Maintenance of an Electronic Powerplant Control System
Authors: Armitage D.I.
Published: February 2008

AS in every section of industry the costs of international airline operations continue to rise at an alarming rate. With the introduction of the wide‐body jet transports and SST during the 1970s it will be essential for the operators to reduce the aircraft turnaround to an absolute minimum. Rolls‐Royce and Ultra Electronics Ltd. recognised this need earlier in the electronic system development programme for the Concorde's Olympus 593 powerplant. The engineers concerned with the programme accepted that rapid servicing facilities coupled with maximum ‘go’ capability, were essential requirements if the airlines were to be able to maintain tight operating schedules which will be necessary if Concorde is to be a commercially viable aircraft and not just an expensive prestige flag carrier. Accordingly the design and layout of both the air intake and engine control systems is based on a definite set of maintenance rules which may be summarised as follows:
Avionics and Instrumentation in the Seventies
Authors: Coombs L.F.E.
Published: February 2008

FORWARD looking technical activities within the Aviation Division of Smiths Industries Ltd. will represent a major part of their research expenditure over the next few years. Current and forward projects include: the application of digital techniques to flight and engine control systems; electronic head up and head down displays and instrumentation; the development of radiation pyrometry for gas turbines; investigation into new methods of fuel measurement including nuclear radiation; the development of new types of instrumentation such as numeric indicators, electronic clocks and fuel management clocks.
Economics of Propulsion Systems for Air Transport
Authors: Huddie David
Published: February 2008

COMPARED with most other industries a distinguishing feature of the air transport business throughout its history has been the rapid development and replacement of its flying equipment. Aircraft have evolved to meet the needs of expanding traffic and each generation has been succeeded by different, newer and better versions. The thirties saw the appearance of the all metal monoplane with piston engines and propellers. As we all know this was developed to a high degree during the World War II years and afterwards culminating by the early fifties in such aircraft as the DC‐6, DC‐7 and Constellation series among many. During the fifties the turboprop emerged in successful aircraft such as the Viscount, Vanguard, Electra and Britannia but at the end of that decade the turbojets entered the picture — first at long ranges and then progressively over shorter stages during the sixties. Speed (Fig. I) and size (Fig. 2) have all increased with time, of course, and, no less important, what might be considered less obvious factors such as operating cost, reliability and maintainability have all improved as well. In parallel with and indeed essential to this process there has been a perhaps even more remarkable development in propulsion systems as illustrated in Figs. 3 and 4 and there is no need to elaborate on these at this point.
Thermal Insulation for the Concorde Engine Bays
Authors: Collins J.O. , Yerry B.R. , McGuire K.J.
Published: February 2008

A combination of a highly efficient thermal insulation, stainless steel foil, and PTFE film resulted in an insulation system which would protect the underside of the wing of the British/French Concorde SST from the heat of its engines. Noise level, engine fire conditions, and penetration by globules of molten titanium were factors which had to be considered in this application.
Flight Testing the Islander
Authors: Coombe A.J.
Published: February 2008

THE design team knew that the Islander was a winner from the very first moment it leapt into the air on June 13, 1965. The reliability was phenomenal; from that first flight on June 13 to the evening of Wednesday, June 16, the aircraft completed twelve flights totalling 7 hours 25 minutes over a wide range of e.g. positions and flight regimes in order to acquire the Special Category Certificate of Airworthiness that was required for attendance at the Paris Air Show.
A Reliable High Temperature Transducer for Engine Vibration Measurement
Authors: Hatschek R. , Schofield G.
Published: February 2008

EARLY in 1963, a project was initiated in co‐operation with an European airline with a purpose of starting development work for a new transducer for engine vibration monitoring. The low reliability of former pickups motivated this development work. In the course of the development, modern engine design requirements raised the need for the high temperature stability of these transducers. The development work was, therefore, based on the necessity to produce a vibration transducer with extreme high reliability, good interchangeability tolerance and useable up to approximately 600 deg. C. in practical flight operation. With regard to these requirements, a suitable technical approach seemed to be the use of the piezoelectric transducer technique, because seismic acceleration pickups working on the piezoelectric principle do not use moving parts, whereas displacement and velocity pickups, used so far, have at least one moving part, i.e. the inertial mass. Also the requirement for high temperature stability could be met by using modern crystal technology. The following chapters will expound some mechanical and crystallographic considerations in connection with such transducers, and furthermore describe some devices which are now being used in practical flight operation. Today, the concept of a piezoelectric, high temperature accelerometer with 2‐pole signal output has been commonly adopted in industrial production of transducers for airborne vibration monitoring.
Analysis of Bearing Vibration
Authors: Yhland Erland , Johansson Leif
Published: February 2008

THE breakdown of any kind of machinery always causes additional expense, not only because repairs are costly, but also because of the loss of operating time and production. Bearings are a particularly critical component and their serviceability is usually essential for the operation of any machine into which they are fitted. Thus it is important that bearing damage should be detected early enough to replace the bearing during a scheduled servicing period, and that unscheduled servicing of the machine should be prevented. This is particularly so where safety is a factor, as in aircraft engines, and certain parts of the process industries.
Progress in Safety with Industry
Authors: Holden Paul
Published: February 2008

IN industry, we understand and appreciate the pressures of the problems to which air traffic controllers are subjected. It is our task to provide the tools to alleviate the pressures and resolve the problems. And because of the time‐scale that is implicit in the design, development, proving, production and operational installation of the necessarily more complex devices that will assist ATC in its work, we must look further and further into the future to define precisely what the task is to be.
Recent Developments in ATC Systems
Authors: Choules C.W.
Published: February 2008

THE considerable interest in aircraft safety, or more precisely in the safety of people who travel in civil aircraft, which was aroused during the past year can be attributed to speculation in the popular press and other news media on the possibility of a 747 disaster, or on the exploits of the criminal organisations who have chosen to practise anarchism against civil aircraft and their innocent cargoes.
Developments in Electrochemical Marking of Components
Authors: Ayers R.
Published: February 2008

IN aircraft manufacture, it is essential that the identity of the individual detail components are known at all stages ensuring they can be correctly assembled. Loss of identity can cause considerable excess and delays to production schedules through the necessity to re‐identify.
The Challenge of the Supersonic Era
Authors: Foxworthy Capt. Thomas G.
Published: February 2008

IN the coming age of supersonic transportation, factors of economic success and indeed public acceptance will depend directly upon how well the pilot performs his tasks. As the ultimate operator, the airline pilot views the advent of the SST with optimism. Indeed, to control the airliners of tomorrow, shaped like smooth slim rapiers, yet carrying within them machinery representing the limits of man's technical knowledge—to guide these magnificent creations at over twice the speed of sound, to look out from over thirteen miles above the earth, to be a part of their contribution to commerce and men's affairs—this would boggle even the imagination of Tennyson! But it won't be all poetry and glamour. The airline pilot has many definite concerns, high among these being his working environment and the instrumentation and systems at his disposal for the efficient and safe management of his craft.
The Formidable Ingenuity of the European Aerospace Industry
Authors: Ford T.E.
Published: February 2008

IN recent years, the European aerospace industry has become characterised by two forms of activity which, in the major industrial countries anyway, have become largely inter‐dependent. One of these is the increasing participation in international collaborative programmes and the other is a need to maintain what may be called a ‘domestic’ capability in aerospace technology that is not directly associated with any other country. The second form is becoming of less importance in many areas as Western Europe moves more and more towards common requirements and the shared production of complex equipment. An example of this type of agreement is the Panavia multi‐national company set up for production of the multi‐role combat aircraft (MRCA). The existence of NATO has been for many years a powerful factor in the realisation of such programmes.
A common design approach to STOL and Y/STOL transport aircraft
Authors: SZLENKIER T.K.
Published: February 2008

HAWKER SIDDELEY'S studies on future advanced aircraft embrace the complete spectrum of field length from CTOL down to VTOL. However, this review is concerned solely with the results and conclusions obtained from past studies undertaken in 1969–1971 of STOL and V/STOL aircraft to meet requirements in the longer term.
High light transmission and electrically conducting film for windscreens
Authors: KING R.D.
Published: February 2008

FOR MANY YEARS now it has been standard practise to heat aircraft windscreens with electroconducting films for de‐icing and demisting. Previously the transparent electro‐conducting films have fallen into two general categories; each of which had advantages and disadvantages.
USSR electric impulse de‐icing system design
Authors: LEVIN I.A.
Published: February 2008

THREE MAIN DE‐ICING METHODS have for long been in use: thermal, mechanical and chemical. Systems incorporating any of these methods are in use on most aircraft throughout the world.
Powder coating technology
Authors: KOURY ANTHONY J. , CONTE JR ALFEO A. , DEVINE MARTIN J.
Published: February 2008

POWDER coating technology has provided a means of applying resin coatings to substrates via processing techniques which have two distinct advantages over conventional coating procedures. The first and probably most significant advantage from an ecological standpoint is the elimination of solvent carriers. The absence of solvents eliminates the emission of fumes and vapours thereby providing an environment that is virtually free of pollutants. Safety standards are also improved because the hazard of fire is substantially reduced.
Reducing the smoke hazard in small transformer failures
Authors: RAMSAY BELL J.
Published: February 2008

ELECTRONIC COMPONENTS over the last 25 years have shown a remarkable extension in their average working life and much laudable development work has been carried out by manufacturers to continuously improve reliability. The small highly specialised transformer, used widely in aircraft systems, is a typical example.
Turbine blade radiation pyrometer system
Authors: CURWEN K.R.
Published: February 2008

EVER SINCE the invention of the gas turbine engine accurate measurement and indication of the working temperature of the turbine has been a prime requirement, in order to limit the environmental stresses of the very hot components in that area. It is now recognised by most authorities that a radiation pyrometer viewing the rotor blades offers considerable potential advantages as an engine temperature sensor over the use of a thermocouple array in the exhaust gas.
Optimising the shape
Authors: SARTRE PIERRE
Published: February 2008

THE ECONOMIC and operational efficiency of any supersonic airliner depends on the successful reconciliation of two conflicting aerodynamic requirements: good control and handling characteristics at subsonic and transonic speeds and low trim drag at supersonic speeds. Years of aerodynamic research have established the slender delta wing as the optimum shape for mach two cruise. In the Concorde design, the basic slender delta was modified by cambering the profile and tapering the forward part of it, refining the wingtips and leading edges to give improved low speed controllability without detriment to supersonic performance. Thousands of hours in different wind tunnels have enabled optimisation of the shape of the aircraft. Some results which were not available in time for incorporation on the prototypes have already been embodied on the pre‐production and production planes. Even though some of these modifications, such as elongation, redesigned nose vizor and tail shape were not applied for aerodynamic improvements, they have nevertheless affected aerodynamics.
Hardware integration and improved operation of the flight control system
Authors: CLEWS D.G.
Published: February 2008

THE SYSTEM is a joint design and manufacturing responsibility of Marconi‐Elliott Avionic Systems Ltd, a GEC‐Marconi Electronics company, and SFENA (Société Française d'Equipements pour la Navigation Aérienne).
Airport handling of Concorde
Authors: TAN ROBERT
Published: February 2008

THE INVITATION to handle Concorde was accepted by Singapore Airlines in May 1972, following which advance arrangements were made in order that it would be handled not only smoothly and to the satisfaction of BAC, but also that it should be given priority to fulfil its programme of intense activity during its short stay in Singapore.
The use of single crystal blades
Authors: PETROV D.A. , TUMANOV A.T.
Published: February 2008

THE USE OF SINGLE‐CRYSTAL BLADES in gas‐turbine engines have considerable advantages over conventionally cast blades since they do not possess grain boundaries which in conventional castings are weak points along which premature damage can occur. Because grain boundary voids and vacancies are almost entirely eliminated, single‐crystal blades exhibit more uniform property characteristics, higher thermal fatigue resistance (even at temperatures close to the melting point) and hence superior reliability. At extremely high temperatures they can operate for about four times as long as conventionally cast blades whilst at intermediate temperatures (800° to 900°C) they can operate for eight to ten times as long.
Lufthansa and German aircraft production
Authors: Abraham Reinhardt
Published: February 2008

UNQUESTIONABLY the highly successful German aircraft industries made notable contributions to technological developments in aviation before the war. Lufthansa was always their principal customer. During the past decades the question, therefore, periodically arose as to whether this tradition might not be linked to present and future demands of Lufthansa and other European airlines.
Single engined aircraft for multi‐engined flying training
Authors: Clark K.W.
Published: February 2008

RISING FUEL, service and maintenance prices have highlighted the need for strict cost monitoring of basic flying training, both in the military and commercial spheres. This requirement has become particularly acute in the multi‐engined aircraft primary training context. The use of conventional twin‐engined aircraft for this purpose is expensive, both in terms of first cost and in operation. Moreover, the simulation of the “engine out” condition can, on occasions, prove hazardous.
Ceramics take to the Air
Authors: Danks E.R.
Published: February 2008

THE aircraft industry, in common with other engineering industries, is constantly searching for new materials. As developments take place and technology advances, materials with unique properties are required to satisfy new needs. In the aeronautical field this leads to the consideration of lightweight alloys and material with resistance to creep and fatigue stresses. Where then do ceramics slot into this chain of thought?
Digital Avionics — An Established Technology
Authors: Moulton Malcolm
Published: February 2008

IT IS nowadays recognised that modern flight operations depend on avionics, the airborne electronic systems through which commercial and military aircraft carry out their missions. As flight operations become more complex, avionic systems have been called upon to perform an increasing number of tasks. This has been possible through advances in technology and, in particular, the use of digital processing in avionics.
Education & Training of Maintenance Technicians
Authors: Stockham R.C.
Published: February 2008

EDUCATION and training of maintenance technicians begins with selection of potentially suitable students. Selection where possible should be based on personal interview in respect of the advertised course entry qualifications — Certificate of Secondary Education or G.C.E. in Mathematics, English and a Science subject — and an assessment of the applicant in terms of interest, enthusiasm and integrity, career ambitions and prospects.
Modern Bearing Technology in the ‘Hawk’
Authors: Vawser Eric
Published: February 2008

PLAIN, slide‐surface bearings were used right at the start of engineering practice, in the form of simple bushes. Whereas there is nowadays a very wide selection of bearings of more sophisticated types, it is a fact that sliding surface bearings are still employed extensively in many modern and exacting applications. The forms have, however, changed drastically over the years, and no longer is the sliding‐surface bearing limited in application to supporting properly aligned shafts under conditions where lubricant can be directed in copious amounts to the friction surfaces. The modern counterpart of the simple bush can be of spherical‐seating type if required, for accommodating shaft misalignment, and may be manufactured from so‐called ‘self‐lubricating’ materials.
The Development of Non‐destructive Testing for Aircraft
Authors: Clifton G.
Published: February 2008

Non‐destructive testing (NDT) makes use of the controlled application of physical phenomena to materials so that interpretation of signals derived from the materials indicates their fitness, or otherwise, to perform a design function. The purpose of NDT is to ensure that mainly load carrying components and structures are free from defects. Established non‐destructive testing has become of primary importance in aircraft maintenance and manufacture both as a positive indication for safety and as a method of saving costs. This article written for aircraft engineers is a broad review of the development of NDT in their industry and a brief indication of the status of its various components today.
The Control of Aircraft Noise
Authors: Large J.B.
Published: February 2008

1. Aircraft Noise—Its effect on people OF all the environmental noise sources, aircraft noise has received the most notoriety over the longest period of time. Aircraft noise is generally assumed to be a product of the jet age, but in 1939 in the United Kingdom, the Gorrell Committee on Control of Flying gave noise control the highest priority. However, it was not until post‐World War II that the public became disturbed by the continued high level of military aircraft operations, and this disturbance was aggravated by the rapid introduction of jet‐powered aircraft. Civil aviation developed rapidly and, as airports increased in size, and as aircraft movements doubled every five years, the surrounding communities expanded to the airport boundaries. These conditions of growth provided the ingredients for the aircraft noise problem. In the United Kingdom, all the major airports grew from military installations where little regard had been given to the environmental impact of these sites on the surrounding communities.