bluuebunny/crossref_metadata_2025 huggingface dataset:
Rotating Cylinder Flaps for V/S.T.O.L Aircraft
Authors: Alvarez Calderon Alberto
Published: February 2008

A SPANWISE rotating cylinder placed at a suitable location in an aerofoil with the cylinder's upper surface moving rearwards in the direction of the local air flow can serve to re‐energize the boundary layer on the aerofoil. For example, when placed between a flap and a wing with the cylinder protruding substantially into the air flow as shown schematically in no. 1, the moving surface of the cylinder destroys, by viscous shear action, the low‐energy boundary layer impinging on the cylinder from the wing and results in a new boundary layer on the flap's upper surface which has a higher energy level adequate to negotiate the adverse pressure gradients and flow conditions existing at the rear of a flap deflected through a large angle. The boundary layer re‐energizing function of the cylinder depends on its upward protrusion, on its peripheral speed, and on the local flap geometry. The beneficial effects of the rotating cylinder on the flow fields have been visualized in two dimensional smoke studies conducted by Alvarez Caldcrón and Arnold of Stanford University on a flap designed for deflected slipstream V/S.T.O.L. aircraft. Fig. 2 shows flow around the flap with the cylinder stationary. It exhibits complete flow separation at the flap which is also typical of a slotted flap deflected through a large angle. The large white disk is a cylinder end plate; the actual cylinder appears in the darker circular shade of small diameter. The photograph of FIG. 3 was taken with the cylinder rotating: it shows a radical flow change not only in the total elimination of flow separation on the flap but in the induction of strong upwash fields and low pressure regions toward the leading edge of wing itself which obviously greatly increases lift and decreases wing pitching moments.
Reliability and Performance of Aircraft Transparencies in Civil Airline Service
Authors: Barber E.G.
Published: February 2008

Broad statistics or the incidence and cost of windscreen panel failures are given. The implications of these statistics are discussed with particular regard to the inability to predict with any degree of certainty the time between installation and failure. Failures occur not only at random points in a time scale but also at any point on the airline's routes. If improvement in reliability is not economically attainable then compensation must be gained in ease and speed of replacement. The designer must make a realistic assessment of achievable reliability. The result of this assessment in dictating the need for ease of replacement may well be the controlling factor in the installation design.
Recent Developments in Vectored‐Thrust Turbofans
Authors: Barrett J.A.
Published: February 2008

A Description of the Development of the Bristol Siddeley Pegasus and Plenum Chamber Burning for the BS.100 and an Outline of the Performance of a V/S.T.O.L Subsonic Strike Fighter Utilizing a Vectored Thrust Engine with PCB as Compared with a Composite Power Plant Fighter and a Vectored Thrust Type without PCB. The Bristol Siddeley Pegasus vectored‐thrust turbo‐Tan has now been in operation for six years, and during that time has been developed to a fully operational stan‐dard in the Hawker Siddeley Kestrel V/S.T.O.L. sub‐sonic strike fighter. Initial development of a second‐generation V/ S.T.O.L. strike fighter for supersonic flight necessitated thrust augmentation by combustion in the normally cold by‐pass flow. This gave rise to the design and development of a suitable combustion system, now known as ‘Plenum Chamber Burning’, or ‘PCB’. This paper summarizes the satisfactory development of the Pegasus vectored‐thrust turbofan, gives some description of the PCB system development, and shows how the application of this system to a V/S.T.O.L. subsonic strike fighter vectored‐thrust power plant gives the latter considerable superiority when compared with an equivalent composite power plant configuration.
Really High Speed Propulsion by Scramjets
Authors: Curran E.T. , Swithenbank J.
Published: February 2008

A quiet revolution is currently taking place in the field of propulsion, as engineers begin to appreciate the remarkable capability of the scramjet. The scramjet, or supersonic combustion ramjet, is a very simple device consisting only of an intake, combustion chamber and nozzle. It differs from the ramjet in that, at hypersonic speeds, the air velocity is only decreased by a few per cent in the inlet and the combustion heat release occurs at supersonic velocity. Although its efficiency is small at low supersonic speeds, FIG. 1 shows that it can achieve high efficiency over a very wide velocity spectrum. Furthermore, for much of this range, a fixed geometry (Ref. 2) can be used with little loss in efficiency (as indicated by the dashed line on FIG. 1), thus presenting unparalleled capability for a simple engine unit.
Lift Jet Installational Experience
Authors: Coplin John F.
Published: February 2008

A review of some of the progress made in lift jet installations is presented in this paper. At the heart of it all is the low cost lightweight RB162 second generation lift jet which is simple and makes extensive use of glass reinforced plastics. Examples of plastic components are shown. The higher thrust/weight and thrust/volume ratio of a third generation lift jet are revealed. The weight of installed features is of comparable importance to the weight of the basic engine. Installed weight has been reduced over three lift jet generations, more than keeping pace with the improvements in basic engine thrust/weight ratio. Weight breakdowns are given for the V.T.O.L. equipment in a fighter‐type aircraft representative of all three generations. Progress on lift intake and exhaust jet deflectors is shown with reference to specific examples. Ground erosion is briefly discussed and shown to be greatly reduced by multiple nozzles and the rolling take‐off technique. Progress being made on some of the problems associated with installing eight lift jets in a V.T.O.L. strike aircraft is briefly discussed with reference to maintenance and instrumentation.
Effects of Airframe and Powerplant Configuration on V/S.T.O.L. Performance
Authors: Creasey R.F. , Boorer N.W. , Dickson R.
Published: February 2008

This paper discusses a large range of layouts that have been studied in relation to both strike and transport V/S.T.O.L. requirements. The performance of aircraft with different powerplant arrangements is considered, with the effects on structure and aerodynamics being based on extensive detail design work.
A Design Study of a Two‐seat Road‐going Air Cushion Vehicle
Authors: McGrath I.L.
Published: February 2008

A design study is carried out for an air cushion vehicle based on a specification giving it a performance comparable with cars of similar power and size, and compatible with current road conditions. Preliminary examination of requirements leads to the adoption of a plenum chamber lift system and ducted fan propulsion, powered by a single piston engine. Care is taken to provide the vehicle with the responsive and accurate control necessary on the road. Performance calculations are carried out, enabling it to be compared with wheeled road vehicles. It is found that its cruising speed and fuel economy are better than its wheeled counterpart, due to the low resistance to motion offered by the air cushion, while its turning performance is definitely inferior.
Development and Production Trials of Flomat Moulding Material
Authors: Williams R.
Published: February 2008

THERE are, within an aircraft, a very wide range of small non‐metallic detail parts which have to be produced in quantities that render economic production a constant problem. The quantities involved range from 200 to 10,000 off spread over a period of five years.
Survey of Aircraft Interiors
Authors: Spark Robert
Published: February 2008

The introduction of second generation jets on world air routes, and the progress being made with supersonic jet transport, have focused attention on developments in aircraft interiors. These developments also raise the question of the importance of interior design in the success of a modern airliner, and the extent to which the influence of soundly engineered and designed interiors in the British and American aircraft industries is reflected in the sales of civil aircraft over the last 10 years. If factual answers to these points are not easily obtainable, there is one thing that is quite certain: interior design is vital to the success of an aircraft, in both its purchase and its subsequent operation.
The Beagle B.206‐S
Authors: Greenhalgh A.J.
Published: February 2008

THE Beagle B.206‐S aircraft is a low‐wing monoplane of all‐metal stressed skin construction powered by two Continental Type GTSIO‐520C engines driving Hartzell constant‐speed, fully feathering propellers.
Structural Design
Authors: Larroucau G.C.J.
Published: February 2008

WHEN attempting to discuss the structural philosophy of the B.206, it is necessary to go back to the closing days of 1960, when it was decided that the newly formed Beagle Aircraft Company would produce a twin engined executive aircraft along the lines of the existing American products of the day. A very rigid time scale was fixed for the project since it was deemed essential to have a first aircraft flying not later than September, 1961. The urgency of this time scale precluded too deep an excursion into unconventional structural solutions since these would have had to be backed by a considerable amount of development tests, the facilities for such tests not being in existence at Beagle in those early days. However, whilst well tried conventional solutions were adopted, the dictates of weight control and structural efficiency were obeyed and a certain amount of fairly advanced structural solutions based on the use of Redux bonding were attempted.
Flight Control for Automatic Landing
Authors: Colwell A.R.
Published: February 2008

DURING the past eighteen years, Elliott‐Automation Ltd. has developed and proved a concept of high‐reliability design in aviation control systems, which is now finding increasingly wide application outside the limits of its original conception.
Flight Development of the VC10 toward Automatic Landing Capability
Authors: Dirs Peter
Published: February 2008

The automatic flight control system of the Standard and Super VC10 was designed to be capable of development to full blind landing. To meet this requirement the system had to be capable of failure survival and this includes associated services such as power supplies and flying controls. The method of autopilot failure survival chosen was to provide two monitored systems which are fail soft, i.e. there is negligible aircraft disturbance after a failure. Then auto changeover between the systems provides failure survival when it is necessary. The arguments for this type of system are expanded in the article on p. 49 by A. R. Colwell.
Power Units for Very High Speed Winged Vehicles
Authors: Jamison R.R.
Published: February 2008

THE term ‘Winged Vehicles’ is used here to describe various forms of aircraft, either manned or unmanned which fly through the atmosphere and have wings to provide lift. The lift of the wings may be used to sustain the weight of the aircraft and also to provide lateral forces required to manoeuvre it. It is flight within the atmosphere with which we are concerned here. In this setting we are looking at the problems of the propulsion of aircraft at high speeds. Manned aircraft are operating now at speeds up to Mach 3 and winged missiles at higher speeds, so for our present purpose we are concerned with propulsion in the atmosphere at speeds above Mach 3, about 1,700 knots.
Structural Prospects for Hypersonic Air Vehicles
Authors: Heldenfels R.R.
Published: February 2008

THE purpose of this paper is to review the major structural design problems common to all hypersonic air vehicles and describe some of the current research results to indicate the structures and materials technology produced during the initial phase of a new era in aeronautics. To further limit the scope of the discussion and to focus it on a particular application, these structural problems will be discussed in relation to a hypersonic commercial air transport that might be ready for intercontinental airline service 15 to 20 years' hence.
The Medical Aspects of Skill
Authors: Barwood A.J.
Published: February 2008

AVIATION medicine is that branch of occupational medicine concerned with all the many tasks associated with the operation of aircraft. Inevitably the pilot of an aircraft is the crew member of greatest interest and the number of factors which may affect his well‐being all ultimately affect his skill as a pilot. The principal aim and purpose therefore, of aviation medicine, is to advise the designer and engineer of the particular physiological, psychological, and medical factors which exist and how best to eliminate or greatly reduce them, and so maintain the enrivonment and conditions of flight that the pilot can function to his best advantage at all times and so be able to exercise his acquired skill to ensure maximal safety at all times.
The Influence of Sheet Thickness on Crack Propagation
Authors: Broek D. , Schijve J.
Published: February 2008

THE influence of the sheet thickness on fatigue‐crack propagation was studied on specimens of 2024‐T3 alclad sheet of five thicknesses, viz. 0.6, 1, 2, 3 and 4 mm. It turned out that cracks grow faster in thicker sheets. The different states of stress at the crack tip probably cause the thickness effect.
Material Failures and their Relation to Component Design
Authors: Islip L.
Published: February 2008

THIS Note discusses the types of failure to be expected of some main engine components and the problems of avoiding such failure in new designs. Examples are given of the shortcomings of some design practices and in the current presentation of material property data. The need is stressed for more research in these areas to enable true safety factors to be predicted from a knowledge of the state of stress and the appropriate material property.
The Interaction between the Aero Engine Industry and the Growth of Air Transport
Authors: Eltis E.M.
Published: February 2008

COMMERCIAL air transport is a major growth industry. This growth, although fundamentally due to economic and political trends, has been greatly accelerated by the technological advance of aero engines and airframes.
An account of the design philosophy of the Lockheed SST project
Authors: Heppe R. Richard , Englebry Channing R.
Published: February 2008

Development of the Lockheed supersonic transport has followed the basic philosophy that an advance in air travel in terms of speed and economics should be accompanied by similar advances in aeroplane safety and flying qualities. To achieve these objectives, Lockheed's SST design work has been concentrated for many years on the development of a fixed‐wing design. The present configuration—called a double delta—provides a simple high lift system with low wing loading, excellent low speed stability and control, and large favourable ground effects in landing, with inherent advances in operational simplicity and safety.
The Evolution of the Engine Noise Problem
Authors: Greatrex F.B. , Bridge R.
Published: February 2008

DURING the 1950s noise around airports increased steadily with increasing traffic and size of aircraft. With the introduction of heavy jet transports the very different quality of noise (compared to piston engines) highlighted the problem and the upward trend had to be halted. This led to a considerable increase in effort to investigate the noise of turbojet engines.
The Influence of the Mean Stress on the Propagation of Fatigue Cracks in Light Alloy Sheet
Authors: Broek D. , Schijve J.
Published: February 2008

Clad 2024‐T3 and 7075‐T6 sheet specimens were loaded at three different load amplitudes and three different mean loads. It turned out that the mean stress had an important influence on the crack propagation rate. The crack growth rate in the 7075 specimens was three to four times as large as in the 2024 specimens.
The Effect of Metals and Alloys on the Thermal Stability of Avtur 50
Authors: Smith J.D.
Published: February 2008

The effects of a number of metals and alloys on the thermal stability of Avtur 50 have been evaluated from ASTM‐CRC and high temperature coker tests. The materials tested are used in current aircraft fuel systems or are possible alternatives for fuel systems of supersonic aircraft where they will be in contact with hot fuel. The alloys currently used in aircraft fuel systems have been classified and their probable effects on the stability of hot fuel listed. A number of the materials affected stability adversely, particularly alloys containing significant amounts of copper, and the use of these should be avoided. The pick‐up of copper by Avtur 50 at ambient temperature from alloys such as brass and gun‐metal has also been investigated. The results indicated that sufficient copper to affect thermal stability adversely is readily picked up from these alloys.
The Concorde Automatic Flight Control System
Authors: Wolfe B.S.
Published: February 2008

This paper represents a review of the status of the automatic flight control systems at present being developed by the consortium of Elliott, SFENA and Bendix. Elliotts were selected as prime contractor and have worked continuously with Sud‐Aviation and the British Aircraft Corporation. The present advanced development state of these systems is a tribute to the skill and determination of the combined Anglo‐French‐American project teams.
Air Cooling of Turbine Blades and Vanes
Authors: Halls G.A.
Published: February 2008

THE demand of the aircraft designer has been, and presumably always will be, for his engines to operate better in three basic respects. To give more thrust, to have less weight, and to require less fuel.
Drag Development of the Belfast
Authors: McCluney B. , Marshall J.
Published: February 2008

THE Belfast was designed and built to a specification for a long range strategic aircraft suitable for carrying heavy and bulky items of freight. The ability to airdrop supplies, combined with structural advantages, led to the choice of rear access to the freight hold; utilisation of part of the freight door as a loading ramp leads to independence of ground based freight handling equipment. The rear fuselage was up‐swept in order to provide ample head‐room for cargo on the ramp. To minimise this upsweep and also to facilitate handling of heavy loads, a low angle of inclination of the ramp is necessary. This led to a low freight floor height in relation to the ground, and to flattening of the rear fuselage undersurface. These features are illustrated in FIG. 1 which depicts the unloading of an Abbott self propelled gun carrier.
Leaching of Chromates from Primers
Authors: Tuitt D.
Published: February 2008

SEVERE natural exposure and laboratory test, dry salt/humidity, have both shown the advantages of primers that leach chromate over similar primers that do not. This advantage, applicable to both primer only and primer plus finish schemes, is paticularly evident where there are breaks, in the paint film due to edges, damage or paint cracking round rivet heads Several other laboratories have used other tests and have reached the same general conclusions. Sufficient experimental work has been carried out to formulate primers with very different leach rate characteristics. Many of these have been produced and are now being corrosion tested When the results are available it is hoped that they will be sufficiently consistent to enable a leaching test to be included in some paint specifications instead of the present two year corrosion test. Until then it is suggested that this fairly simple test provides a useful means of screening new primers for the paint industry and, for the aircraft constructor, one possible way of chuosing between the several competitive schemes offered to him, without having to wait many years for the results of corrosion lasts.
Design Philosophy for Corrosion Protection of Civil Aircraft
Authors: Scott J.A.
Published: February 2008

A new corrosion protection system developed at B.A.C. Weybridge was first introduced on Vanguard aircraft and has remained in use almost unchanged up to the VC10 and B.A.C.1 11 aircraft which are being produced at this time. The system represented a complete change from previous ones, both in materials and methods of application and was the result of a very considerable amount of research into the limitations of the protective methods used up to that time. Through these investigations it became evident that insufficient emphasis had been placed on the importance of organic materials in corrosion protection and that the paints then in use failed to give satisfactory service due to lack of adequate‐fluid resistance and an inability to withstand repeated flexing and straining of the metal substrate without cracking of flaking. Hence the paint had to be resistant to all anticipated contaminants, including freight spillage, over the entire temperature envelope of the aircraft and had to be sufficiently adherent and flexible to withstand deformation of the substrate up to the point of metal failure. Long term protection from corrosion and compatibility with other forms of protection e.g. sealants, jointing compounds, etc. was also required, as well as an ability to withstand casual damage during service and maintenance. This lead to the decision (hat the Vanguard was to be an all‐painted aircraft and that the many and often conflicting requirements of the paint could only be met by a polyamide‐cured epoxy material. Having thus established the basic concept, consideration can now be given to the detailed requirements.
Elastomers and Airframes
Authors: Evans G.B.
Published: February 2008

FOR the purpose of this paper discussion is only centred around rubber mouldings for various purposes. Sealants, adhesives, tyres etc. are covered elsewhere in the symposium.
The Utilisation of Reinforced Plastics in the Wessex Helicopter to Prevent Corrosion
Authors: Bottrell N.L.
Published: February 2008

MAGNESIUM metal with its low density high strength and stiffness properties is a material which is used extensively in the Wessex helicopter for castings, forgings, and in sheet form in the skin stringer constructed fuselage. Extensive utilisation of these aircraft has shown that a corrosion hazard is present with this material in the fuselage application. Accidental damage, mis‐use and normal wear and tear removes the carefully applied organic protection permitting moisture to come into contact with the non‐protected metal, with the result that corrosive conditions are generated and it is found that in the non‐accessible areas, intensive corrosion damage occurs and it is not discovered in time for remedial action and the efficiency of the structure and airframe is impaired.
Dual Analysis of a Multiweb Sweptback Wing Model
Authors: Sander G.
Published: February 2008

THE idea of a dual analysis in finite elements of a given structure was put forward in Ref. 4. The first analysis should be of the displacement type, using conforming displacement models of the finite elements. This results in a continuous, piecewise differcntiable displacement field in the whole structure, for which linear elasticity theory predicts lower bounds to the local static influence coefficients. The second analysis should be based on equilibrium models of the finite elements. The stress field within the structure is then continuously transmitted across the interfaces and satisfies detailed equilibrium conditions in the interior of each element. This property furnishes upper bounds to the influence coefficients.
The Rolls‐Royce Three Shaft Turbofan Engine
Authors: Wilde G.L. , Pickerell D.J.
Published: February 2008

IT is nearly fifteen years since the introduction into civil operations of the Dart turboprop in the Vickers Viscount and the Ghost turbojet in the dc Havilland Comet. For many years it was thought that the turboprop would remain dominant in the short and medium haul classes, but the continued demand for higher cruising speeds and the passenger appeal of the jet have been largely responsible for the turboprop aircraft being superseded by the new generation of turbofan aircraft.
Test Equipment for Rapid Automatic Check‐out and Evaluation
Authors: Doig A.
Published: February 2008

ELECTRICAL and electronic equipment in the field has always needed some form of test rig (itself usually electrical) to demonstrate correct operation, or, alternatively, to show where a failure has occurred and to indicate what part to replace or repair. This is fundamental; the effective operation of electrical or electronic systems cannot be measured in terms of visible wear, as in the case of mechanical devices. Early test rigs matched the unsophisticated equipment they were required to test — a dry battery was the earliest stimulus and a small filament lamp the earliest measuring device. From then on the increasing complexity of the tests necessary to validate systems and components required an increasing number of more sophisticated stimuli and measuring devices.
Aerodynamic Design Features of the C‐5A
Authors: Paterson J.H.
Published: February 2008

The C‐5A is designed to provide the capability to transport heavy logistics payloads and outsize military equipment over long ranges for the lowest possible system and operating costs. It provides airport performance and traffic speeds equal to or better than current transports and is capable of operation into and out of short unprepared fields. A general arrangement drawing is shown in Fig. 1. The overall length is 246 ft., the wing span is 222 ft., and the overall height is 65 ft. Of the many missions which the C‐5A must perform, those critical to the design are shown in Tables I and II. The first of these largely defines the high lift system requirements for take‐off and climb performance, the second and third missions dictate the maximum take‐off gross weight for a limit load factor of 2.5 g, and the fourth mission defines the maximum take‐off gross weight for a limit load factor of .25 g. The support area landing distance requirement furnishes an additional constraint on the design of the high lift system. The C‐5A is designed to provide flotation characteristics that will permit 130 take‐offs and 130 landings using short unprepared fields having a California Bearing Ratio of 9. To achieve this flotation a total of 28 wheels, 24 of which form the main landing gear, are used. Stowage provisions for the landing gear constituted a substantial challenge to the aerodynamicist to devise fairings which minimized the penalty which conventional design would accrue. The C‐5A provides the capability of both nose and tail straight in loading at truck bed height in order to achieve a turnaround time of 15 minutes. In addition, it is capable of air dropping both cargo and personnel. These capabilities dictated the use of an upswept aft fuselage which provides clearance for straight in loading. The static ground clearance angle of 10 deg. comfortably exceeds the 7.75 deg. used for lift‐off: the ground clearance angle available with the gear kneeled to place the cargo floor at truck bed height is 7.4 deg. while the maximum ground clearance angle with the gear fully extended is 11.75 deg. The upsweep, or inverse camber, of the aft fuselage introduced the possibility for excessive drag due to the loss of pressure recovery or flow separation in this area. The development of the fuselage configuration to avoid this problem will be discussed in later paragraphs.
The Library Shelf
Authors: J.M.G.  , M.F.
Published: February 2008

Among the events marking the Golden Jubilee of the R.A.F. one of the most welcome is the publication of the 4th edition of this outstanding book. Previous editions have been described, rightly, as encyclopaedic, and since 1962 when the 3rd edition appeared there have been further revisions and additions. The book is now so far up‐to‐date that it covers all the new types on order for the R.A.F., including Jaguar, Harrier, Nimrod, Phantom and, optimistically, the F.111K.
The Sonic Boom Problem
Authors: Parker M.A.
Published: February 2008

THE nature of the sonic boom problem is briefly reviewed, and the experimental evidence relating to the Whitham‐Walkden theory presented. Although many atmospheric effects cannot be fully accounted for, the theory is used to predict ground overpressures directly beneath the proposed Concorde flight track. Using the work of Rao, over‐pressure values up to 2·0 lbf/ft2 are predicted for the initial climb and acceleration, as opposed to 1·6–1·3 lbf/ft2 for the cruise. Structural damage is thus unlikely, but until people are accustomed to the booms, they will cause annoyance, especially in the region 130 to 320 miles from take‐off. The minimum sonic boom for an aircraft of given length, volume and total lift is also discussed. Since the Concorde configuration is fairly close to the optimum, it seems that any significant reduction in sonic boom will mean an increase in the supersonic flight altitude or a decrease in aircraft weight.
The Development of Balsa Wood Laminates
Authors: Ancient Bernard J.
Published: February 2008

TODAY, wood makes as important a contribution to the aircraft industry as before. In the United Kingdom and abroad leading designers and aircraft manufacturers have turned to wood laminates for particular applications in aircraft, hovercraft and helicopter manufacture. Earlier this year it was stated by the British Aircraft Corporation, co‐designers with Sud‐Aviation of the Concorde SST, that the flooring would be manufactured in a balsa wood laminate.
Developments in Explosive Welding
Authors: Crossland B. , Williams J.D. , Shribman V.
Published: February 2008

THE possibility of explosive cladding was first recognised in 1957, when it was noted in explosive forming that if a metal die was employed and an excessive charge was used then the metal sheet which was being formed became welded to the die. Since that time numerous papers have been published, for instance Davenport and Duvall (Ref. 1), Pearson (Ref. 2), Holtzman and Ruderhausen (Ref. 3), Boes (Ref. 4), and Bahrani and Crossland (Ref. 5) to mention but a few. All the early work was devoted to the application of cladding, and it is only during the last two or three years that the applicability of the process to tube welding, lap welding, welding of tees has been mentioned. At the present time the main potential fields of application are to the cladding of dissimilar metals over large areas and the welding of tubes to tube plates.
Future Developments in Plasma Arc Welding
Authors: Burke M.H.
Published: February 2008

SINCE the introduction of plasma are welding, in its simplest form, the process and technology has made extremely rapid strides. It is the object of this paper to explain, in simple terms, the various types of plasma systems, equipments and applications for which they can be used.
Quality Control of Welding Techniques
Authors: Cook W.G.
Published: February 2008

THE effective use of new materials and new manufacturing techniques has always played a key role in the design philosophies of the aerospace industry. Expensive though this is, it is part of the price which must be paid if we are to maintain our place in the forefront of technological achievement. The range of activities is extremely wide and covers casting techniques, new metals and alloys, composite materials, new methods of forming and processing materials, new methods of joining both by bonding and welding and new methods of evaluating the resultant products.
The Use of Fibre Optics
Authors: Allen W.
Published: February 2008

ONE of the reasons why the aircraft industry has made prodigious achievements during the last years is because it has always been quick to realise the potential of a new design concept or production technique.
Vibration and Strain Analysis by Means of Holography
Authors: Hockley B.S. , Hill R.J.
Published: February 2008

CURRENT methods for the analysis of stress and mode of vibration of blades, discs and small components are briefly reviewed. Alternative methods using holography are described and compared with conventional methods in terms of yield of information and ease of operation. Finally apparatus is described which will take holograms of objects up to two feet in diameter and may be operated by non‐specialist staff.
Application of Power Spectral Methods to Aircraft Gust Clearance
Authors: Payne B.W. , Cox R.A.
Published: February 2008

POWER spectral methods for computing loads on aircraft due to atmospheric turbulence have been developed over the past dozen years or so. Such calculations are carried out on all new aircraft, and to date the results have been used to amplify fatigue and environmental data. The United States Federal Aviation Agency (FAA) is proposing the introduction of power spectral gust design procedures for and computing design limit loads on commercial aircraft. A parallel programme for the development of taxi load criteria is also being considered. The FAA have sponsored/research on the development of such power spectral gust methods and currently two approaches are being examined by industry. These are a design envelope approach and a mission analysis approach. A similar British investigation is now under way to establish the validity of the American proposals.
The Eleventh Anglo‐American Aeronautical Conference
Authors: Smith J.P.
Published: February 2008

THE requirement for a ‘big twin’ had been recognised at an early stage in Europe, and in the interests of securing a suitable home market on which to launch the project, a consortium comprising manufacturers from Germany, France and the U.K. was established at the initiative of the three governments to develop and produce such an aircraft. The formation of this group brought together considerable resources and experience, particularly relevant experience being found in the Caravelle and Trident.
Tooling for the Buccaneer
Authors: Byrne M.G.K.
Published: February 2008

THIS year the Hawker Siddeley Buccaneer low level strike and reconnaissance aircraft goes into service with the Royal Air Force. Already well established with the Royal Navy and built to fly at high subsonic speed at low level, its manufacture posed unusual problems. The central load‐bearing framework is literally carved out of blocks of steel. This demanded special machinery and none was immediately available on the market. Hawker Siddeley Aviation, Brough, met the problem by designing its own.
The German Aerospace Industry
Authors: Peters Klaus
Published: February 2008

THE German aerospace industry faces the new decade with optimism. Even the budget restrictions announced recently which affect most parts of the industry cannot lessen that impression. Some of the money not granted has only been frozen to avoid further overheating of the economy. In comparison with the aerospace industries of Great Britain — employing 240,000 people — and France — employing 100,000 people — the German aerospace industry with its 52,000 employees seems to be of less importance. This figure, however, is remarkable with regard to the fact that in 1956 this industry had to start from nothing. The airframe industry employs about 32,500, the space industry some 2,600, the engine industry about 6,200, the material and accessory industry 3,000 employees, and in the equipment industry another 7,200 people are working directly for the aerospace industry.
Forty Years of the Aircraft Gas Turbine
Authors: Fulton Kenneth
Published: February 2008

THE aircraft gas turbine is intriguing in that there were early attempts at its development not only by the established aero engine companies and research establishments in many countries, but also by manufacturers of marine and industrial turbines and — most successfully — by individuals. The aero engine companies failed because in virtually every instance they attempted to produce a power unit of comparable or lower specific fuel consumption to the traditional piston engine. This led to unduly complex designs involving unattainably high component efficiencies and turbine temperatures at far too early a stage in the development of the new prime mover.
Shock Pulse Measurement of Bearings
Authors: Arne Boto Per , Fernlund Ingemar
Published: February 2008

WHEN a rolling bearing is damaged as a result of fatigue, spalling occurs cither on the ring tracks or on the surface of rolling elements. As a roller or a ball rolls over these spalls, which are depressions in the surfaces of the rings also known as flaking, impacts occur.
Design and Construction of Sprite
Authors: Jenkinson L. , Sharman P.
Published: February 2008

DURING the spring of 1968, Pilot magazine initiated the design of a homebuilt aircraft. The intention was to follow through the design in a series of articles highlighting the problems, difficulties and, hopefully, successes of the project. The initial design was undertaken by the staff of the magazine defining the basic specification of the aircraft as a two‐place, all‐metal tourer/sports plane of modern style, capable of 5 hours' endurance, and arriving at the aircraft shown in Fig. 1. It is a sensibly small aircraft of 24ft. wing span and 20 ft. overall length with a constant 4 ft. wing chord to give a gross wing area of 96 sq. ft. The cockpit area, covered with a one‐piece sliding canopy, is a generous 48 in. wide with ample leg room forward and luggage space aft.
Secondary Surveillance Radar in ATC Systems
Authors: Shipley R.
Published: February 2008

NORMALLY, the SSR interrogator is used in conjunction with a primary radar, the two systems being complementary. Primary Radar depends on the reflection of radio signals. These signals have to be strong enough to survive the two‐way path, therefore the emitted signals must be of relatively high power. Signals reflected from hills, trees, buildings and precipitation will also be received and displayed on the PPI, thus causing clutter on the display and confusing the picture.
The Repair of Glass Fibre Reinforced Plastic Radomes
Authors: Himsley D. , Hoare R.G.
Published: February 2008

IT is surprising to find, in the modern aircraft industry, a technical service that has developed in a short time from informal experiments with materials and techniques, carried out by a few individuals.
Environmental Testing of Concorde Components
Authors: MacMaster K.J.C.
Published: February 2008

THE advent of the aviation gas turbine created a demand for test equipment to reproduce operating conditions within the confines of the laboratory and test house. The importance of such testing is patently obvious and has been an accepted policy to ensure that engine component and airframe test experience is always well in advance of service life.
Prediction of wing group weight for preliminary design
Authors: TORENBEEK E.
Published: February 2008

A semi‐empirical relationship is derived for the structural weight of wings, applicable to a wide range of subsonic aircraft. The method is based on a generalized expression for the material required to resist the root bending moment due to wing lift in a specified flight condition. Appropriate factors make the result applicable to cantilever and braced wings, for passenger and general aviation aircraft and for freighters. An assessment of the accuracy, based on actual wing weights of 46 aircraft, indicates that a standard deviation of 9·64 per cent is achieved. The weight formula presented allows for the effects of variations in the main wing dimensions and operational limits of the airplane and is therefore suited to parametric design studies.
Optimum number of blades for maximum efficiency of centrifugal blowers
Authors: REDDY Y.R. , KONNUR M.S.
Published: February 2008

A BLOWER is a rotodynamic machine converting the mechanical energy into fluid energy. Its performance represents the combination of performance of all the components. In the present study the number of blades has been chosen as a variable, keeping the rest of the system same. Earlier work done by Kearton showed that 16 bladed impeller out of the 4 impellers studied by him gave good overall performance. Theoretical considerations of Stodola, Busemann and Pfleiderer indicated that the blade exit angle and the number of blades controlled the unit's performance. Recently Bommes carried out extensive experiments on blowers by varying both the blade exit angle and the number of blades. When Pfleiderer's method was used to predict the number of blades, the predictions were not in agreement with the experiments. In this a theoretical equation has been developed which agrees well with the experimental results.
Externally blown flaps, aerodynamic feasibility study of a STOL‐transporter
Authors: KUEHL Dipl‐lng P. , WELTE Dipl‐lng D.
Published: February 2008

TYPICAL STOL CHARACTERISTICS can be achieved for medium and heavy jet transport aircraft by means of externally blown flaps. As part of a project study conducted by Dornier AG., concerning a 40t STOL transport aircraft, the aerodynamic and flight mechanical feasibility is demonstrated. The basic data was supplied by wind tunnel tests with the model of a transport aircraft. With a view to V/STOL capability, the engine jet deflection was optimised by means of a novel slot flap design on a simple rectangular wing.
Modular automatic test equipment for commercial airlines
Authors: GUSTAFSON ROBERT
Published: February 2008

THE DC‐10 era is effecting subtle changes in the maintenance procedures. The basic objectives of maintaining safe equipment at a reasonable cost have not changed. The means of achieving the objectives are changing. Digital equipment, which has so much to offer in terms of reliability, capability, and cost, will require a new degree of sophistication on the part of maintenance people and equipment. Digital circuits operate on the basis of information transfer at a high cyclic rate. The control of this data transfer is the function of special purpose digital computers. Although the computer has cither serial or parallel arithmetic organisation, the output information is in a serial digital format at a reasonably high output rate. These system characteristics have resulted in maintenance people requiring a new type of electronics knowledge — the ability to work with digital logic diagrams, computer organisation and computer programs. The performance data cannot be readily evaluated by voltage measurements or analog traces on an XY recorder as has been accomplished in the past. At the same time that the equipment is becoming more difficult to understand and test, manual testing is becoming more lengthy and, in some respects, tedious because of the digital mechanisation of the functions. Airlines will not be able to afford to use their skilled maintenance technicians for routine tasks. They will be better utilised for troubleshooting problems. As a result, the relatively unsophisticated test benches of the past are becoming obsolete and are being replaced by either sophisticated manual test equipment or sophisticated automatic test equipment.
Fuel tight fastening by automatic machine
Authors: SPELLER T.H. , RANDOLPH J.A.
Published: February 2008

CONTROLLED EXPANSION has an important implication in the mechanical fastening of high performance structures. The technique provides that a cylindrical fastener expands plastically during installation to a slightly hour glass shaped cross section. Expansion is one to two per cent of the hole diameter at the shear plane, and three to five per cent at the surfaces. The result is a joint with remarkable integrity and attractive in cost saving potential. The advantages of controlled expansion are being incorporated into the fastening of the A300B wing structure after a critically thorough study of the systems described herein, in comparison with all proven and potential alternatives.
Quick estimation of wing structural weight for preliminary aircraft design
Authors: TORENBEEK E.
Published: February 2008

A COMPILATION of formulae and data from the article on the same subject in the July 1971 issue of AIRCRAFT ENGINEERING is presented to enable weight engineers to make a quick estimation of wing structural weight for preliminary aircraft design. Application of the method to 46 samples of aircraft in a wide range of sizes demonstrates a standard deviation of 9·64 per cent, satisfactory for point designs and parametric studies.
Creation and dissemination by computer of electrical interface information in avionics systems
Authors: GARRETT D.C.J. , BOLTON R.A.
Published: February 2008

THE DESIGN and development of modern electronic systems, whether they are for military or industrial or commercial applications, is often exceedingly complex.
Decision diagram approach to “on condition” philosophies
Authors: NOWLAN F.S.
Published: February 2008

Very often it is not possible to recognise deterioration of failure resistance in complex devices while they are installed on the aircraft and out on the airline. In such cases operational failures may occur. The failures do not all occur at the same age, however, because the resistance to failure and the environmental stress of two pieces of nominally identical equipment are not the same.
Integrity of flight control system design
Authors: MANT I.S.
Published: February 2008

This is the first in a series of articles covering the various aspects of aviation safety. FLIGHT CONTROL SYSTEMS have now reached the stage where predictions can indicate that they reach the level of safety required by certificating authorities. This stage has been achieved by a combination of experience and techniques which regocnise that the majority of the components of which systems are composed may fail.
Use of chromoplastic models for the study of the behaviour of rectangular plates after buckling
Authors: POPESCU‐CASTELLIN NICOLAE D.
Published: February 2008

EXPERIMENT SHOWS that plane compressed plates can resist, in certain cases, loads greater in value than the critical load of buckling. Hence the plates can be used after the phenomenon of buckling, a fact which is of considerable importance especially when reduction in weight of the supporting structures is required.
Manufactured‐in‐house or subcontracted? finding the economic balance
Authors: LESSWARE D.A.
Published: February 2008

THERE ARE technical, financial and other advantages to be gained by an aircraft manufacturer's management from making fewer detail components in house and from placing the majority of such components with the supplier industries. These advantages can also benefit the aircraft manufacturer's employees and customers, the passengers and the public. The example of a mechanical flight control strut is used to illustrate the arguments. A range of factors of interest to management are considered such as structural efficiency, reliability and safety; the costs of design, development, tooling and production; the administrative aspects, the cash flow aspects, working capital usage trends and the problems associated with fluctuating capital and manpower requirements of the industry. The article is in several sections; the debate, the advantages, the technical benefits, the direct cost benefits, the indirect cost benefits and the three balance sheets for each section of the industry.
Interactive 3D shape design — Multipatch and Multiobject
Authors: ARMIT A.P.
Published: February 2008

MULTIPATCH AND MULTIOBJECT have been used for a variety of design tasks. As interactive systems they aim to relieve the user of repetitive calculations, picture drawing, etc. and to present an environment for creative thought, design and realisation of the design. So the systems do riot aim at automating design but rather at increasing the designer's involvement and control by relieving him of (usually) straight forward yet tiresome work.
Electronic safety test replaces radioactive test source
Authors: GUERIN D.W.
Published: February 2008

WHEN THE PROGRAMME for the development of Concorde was put in hand 10 years ago, it was appreciated that there were potential problems associated with the radiation levels at high altitude which needed to be investigated.