bluuebunny/crossref_metadata_2025 huggingface dataset:
Two Approaches to Reduction: A Case Study from Statistical Mechanics
Authors: Guo Bixin
Published: March 2023

I argue that there are two distinct approaches to understanding reduction: the ontology-first approach and the theory-first approach. They concern the relation between ontological reduction and inter-theoretic reduction. Further, I argue for the significance of this distinction by demonstrating that either one or the other approach has been taken as an implicit assumption in, and has in fact shaped, our understanding of what statistical mechanics is. More specifically, I argue that Boltzmannian statistical mechanics assumes and relies on the ontology-first approach, whereas Gibbsian statistical mechanics should assume the theory-first approach.
Calculation of Mach number from given turning angle in supersonic isentropic flow
Authors: Fraser S. M.
Published: March 2023

In many design procedures for calculating supersonic isentropic flow the problem arises of calculating the change in Mach number which will occur due to a specified change in flow direction, e.g. considering simple Prandtl-Meyer corner flow, it is required to calculate the final Mach number M to which the initial sonic stream will be accelerated by turning through a specified angle v.
Future flight deck design
Authors: Hillman R. E. , Wilson J. W.
Published: March 2023

The greatly increased cost of fuel has intensified the need for the manufacturer to increase operating efficiency in the aerodynamic, structural and propulsion fields. These aspects have already been highly refined and further improvements will be more and more difficult to realise. However, DOC is also equally affected by equipment and crew costs and this paper therefore attempts to examine the potential for improvements to the flight deck that will determine the most cost-effective combination of crew and equipment required for the safe operation of relatively large transport aircraft.

In the past, design effort has, very logically, been concentrated on those fields that could be shown to give an obvious economic return, and since investment in new instrumentation, flight deck workload analysis and system automation showed less tangible results than increases in speed, range, payload, etc, there was no great incentive to allocate money and effort to “human engineering”.
Mr. Billing's war baby
Authors: Jarrett Philip
Published: March 2023

Veneration can often bestow an undeserved degree of respectability upon stories which have come down to us from the past. Some of these stories even acquire the status of legends if they are repeated with sufficient regularity, and, like the “laws” which tend to limit the vision of the scientist, these legends can restrict the retrospection of the historian. Aviation has its share of such tales, and it is one of these which now needs to be re-examined in the light of several new pieces of evidence.

The central character of this story is that great eccentric Noel Pemberton Billing, and the aeroplane with which we are concerned is the P.B.9, a neat little biplane scout which appeared at the outbreak of the First World War.
Approval of flight simulator flying qualities
Authors: Davies D. P.
Published: March 2023

Flight Simulation has made good steady progress over the years, and is now being given significant credit for its ability to reproduce aircraft flying qualities in a device on the ground. However, the simulator world is tending to claim too much credit for its present level of achievement. This talk is an attempt to review the present state of the art against an accurate comparison with aircraft flying qualities, to highlight the deficiencies and to appeal to the users of simulators to consolidate their present gains before proceding further. This paper deals only with civil fixed-wing transport aircraft above 20 000 kg maximum weight.
Aeronautics and Cranfield—why, — what and whither? —
Authors: Keith-Lucas D.
Published: March 2023

It is a sign of greatness in a man that he leaves footprints like those of Good King Wenceslas to guide and invite others to follow. Sir Frederick left his boldly in the Aircraft Industry, SBAC, Cranfield, Royal Aeronautical Society, Air Registration Board and many other places. Not in every place but in all those I have named he has been my Good King Wenceslas and I his page.

In this lecture I could choose to follow any one of these tracks but they are not divergent but criss-cross and intertwine with the result that in starting along one I may well switch onto another. The track I shall start to follow is aeronautics at Cranfield.
The choked jet flowing into a stationary atmosphere
Authors: Gibbings J. C.
Published: March 2023

A previous discussion of the expanding flow of a choked axi-symmetric jet into a stationary atmosphere drew attention to the differences between various existing sets of observations and between observation and analysis. One reason advanced for these discrepancies was the influence of the mixing region at the edge of the jet while another was the degree of uniformity and steadiness of the flow at exit from the nozzle.
On the estimation of aerodynamic blocking in heat-transfer studies of char-forming ablators
Authors: Stolarik Eugene
Published: March 2023

Aerodynamic heating, which is generally recognised as one of the most important aspects of the re-entry technology, plays an important role in the design of re-entry vehicles. Vehicles entering the earth's atmosphere at high velocities are subjected to severe heating. A number of methods are available for protecting the interior of a re-entering vehicle. However, preliminary studies indicate that, in general, utilisation of a charring ablator is one of the most effective thermal protection systems.
The British Aircraft Corporation: the first twelve years
Authors: Smith Reginald Verdon
Published: March 2023

It is an honour which I greatly appreciate to be invited to give the 19th Barnwell Memorial Lecture and I value the invitation all the more after noting that all previous lecturers have been distinguished aeronautical engineers, or at the least specialists, very experienced in air transportation.

It has always been a matter of regret to me that I never knew Frank Barnwell at work. When I went to Filton in October 1938 it was a few weeks after the flying accident in which he lost his life, so I cannot add from personal experience to the comprehensive account of his career compiled by Major Bulman for the first Barnwell Lecture in 1954, supplemented by the reminiscences of Captain Cyril Uwins and others.
A simplified approach to helicopter ground resonance
Authors: Done Q. T. S.
Published: March 2023

The theory of the self-excited oscillation of the hinged blades of a helicopter rotor has been treated by Coleman and Feingold and their paper, although written several years ago, remains a standard reference on the subject. Since then, the scope of theoretical studies and calculations has been broadened to include hingeless rotors, more degrees of freedom and blade aerodynamic forces. All this has led inevitably to a great complexity in the equations of motion, with the result that, although the dynamicist can perform adequate calculations, he loses the insight and physical appreciation that he needs, for example, to identify the important parameters in the system. In order to maintain these qualities a different mathematical model is required, one that retains only the most basic parameters and yet still exhibits the fundamental ground resonance instability.
On the velocity induced by a semi-infinite vortex cylinder: with extension to the short solenoid
Authors: Gibson Ivan S.
Published: March 2023

The mathematical analysis of the induced velocity components of a screw propeller has occupied the attention of fluid dynamicists for many years. Early approaches to the problem concentrated mainly on momentum and blade element theories, neither of which are capable of providing a detailed knowledge of the flow field, except at the propeller plane or the boundary of the fluid. The early vortex theories also suffered from equally significant, but less severe, limitations and such methods were found to be completely unsatisfactory for many applications. In particular, the development of the ducted propeller for the propulsion of supertankers and VTOL aircraft has demanded a highly detailed knowledge of the flow field, especially around the propeller tip.
Application of numerical techniques in fluid mechanics
Authors: Krause Egon
Published: March 2023

More than sixty years ago Theodore von Kármán showed in a paper entitled Über die Turbulenzreibung verschiedener Flüssigkeiten (On turbulent friction of various fluids) how the pressure drop of various fluid flows through pipes could be correlated in a single curve. The correlation parameter he used is now known as Reynolds number. It had been named after Osborne Reynolds only three years earlier in 1908 by A. Sommerfeld, shordy after he had left Aachen, in a note at the Internationaler Mathematiker Kongress in Rome. Sommerfeld had recognised the importance of Reynolds' similarity law and was deeply persuaded by his experimental and theoretical work.
Design and development of the Hawker Siddeley 748 prop-jet feeder liner
Authors: Troughton Alan J.
Published: March 2023

This paper describes the design and development of the HS. 748 short/medium range turboprop aircraft. At the RAeS Convention on “Economical Factors in Aviation” held on the 13th/14th May 1970, Mr. Knight of BAC stated, when analysing post-war British civil aircraft projects, that “there are really only three types that can be called true commercial aircraft successes. They are the Vickers Viscount, the HS.748 and the BAC One-Eleven”. This paper discusses the philosophy behind the original design of the aircraft, its development to date, its in-service history and also gives examples of the many different projects based on the HS.748 which have been and which are still being considered. The aircraft is described as the HS.748 throughout this lecture as this is its current designation. It should not be forgotten, however, that this aircraft was designed and flown as the Avro 748 for at least three years.
Use of helicopters in search and rescue — some possible further applications
Authors: Townshend B. W.
Published: March 2023

It was of great interest to learn, from their most comprehensive paper “Helicopters in the Royal Navy“*, of the authors’ views on the SAR role, and especially of their outlines of the most beneficial features for ideal SAR aircraft (pages 472-476). This note refers to some aspects of the latter that were not mentioned, on which it would be interesting to know the opinions of the authors and of other helicopter pilots.

Some six years ago, I learned from the US Coast Guard of a system they had adopted with considerable success, to minimise the above hazards- At that time, I drew this arrangement (illustrated in the accompanying sketches) to the attention of RN and RAF officers concerned with rescue, but the idea received little support, for which there may be two reasons.

The American aircraft had, I believe, winch lines 200 ft long, whereas that on the Wessex was only 106 ft long. The Sea King (winch line 245 ft) had not then become operational. For their ideal SAR aircraft, the authors propose one 300 ft long. Thus, on the Wessex, the risk of fouling an obstruction would have been approximately doubled. As the longer lines now available and being proposed would go far to minimise this risk, perhaps the US system may in future be considered more favourably.
Some heat transfer measurements in compressible turbulent boundary layers
Authors: Hughes T.
Published: March 2023

This paper gives details of a method for measuring local heat transfer rates and shows that the results obtained are in fair agreement with the expected values.

The experiments were performed in the 8 in x 3·5 in supersonic intermittent wind tunnel at Queen Mary College (University of London). A maximum Mach number of 1·6 is obtainable at which the free stream Reynolds number in the working section is 4·92 x 106 per foot under normal conditions. The tunnel has a running time of approximately 20 seconds at a Mach number of 1·6.

The series of heat transfer measurements were restricted to flat plate conditions with non-constant wall temperatures.
The financing of essential communication, navigation and terminal aids
Authors: Johnston F. J. H.
Published: March 2023

To say that air transport is a complicated business is trite but nevertheless true. Only part of the job of providing service to the public is done by the airline itself. To operate efficiently in the complex environment of the world's airways, some clearly defined, some not, an airline requires a co-ordinated system of highly developed technical equipment, skilled personnel and competent management, largely financed by Government authorities who believe it is in their best interests to do so. In the beginning, the airlines were creatures of Government, either actually owned by them or supported and subsidised by them in one way or another. Then and now, the airlines are subject to close Governmental control both as regards their technical standards and performance and their commercial environment. The airline industry has now grown up and is big business. Many airlines are still owned by Governments wholly or in part but all are now expected to operate on a commercial basis.
Aircrew workload during the approach and landing
Authors: Nicholson A. N.
Published: March 2023

The approach and landing of a transport aircraft is a complex operation over which the pilot has only limited control. Although the efficiency of the crew and the serviceability of the aircraft and its systems are to a considerable extent within the command of the pilot, the standards of air traffic control, the availability of navigational aids and the runway length and lighting are beyond his immediate influence. Letdowns with imperfect air traffic control and limited precision aids, particularly if complicated by adverse meteorological conditions, lead to very high workloads which the pilot may find difficult to assimilate. Under these circumstances difficulties may arise during the approach and landing.
Effect of yaw on supersonic and hypersonic flow over delta wings
Authors: Hui W. H.
Published: March 2023

The problem of a delta wing in a high speed stream has been approached using linearised potential flow theory for low supersonic Mach number, and using thin shock layer theory for hypersonic Mach number. Recently the author has given a new theory of supersonic and hypersonic flows with attached shock wave over the compression surface of an unyawed delta wing. It has the advantage of being unified for both supersonic and hypersonic flows, and it gives almost identical results compared with exact numerical solutions. The purpose of this note is to extend the theory of Ref. 4 to include the effects of yaw.
The design aspects of heliports
Authors: Slocombe A. E.
Published: March 2023

This paper is intended to show what would be necessary for a heliport suitable for scheduled helicopter services should a vehicle become available which proves economically viable for inter-city services. BEA is considering the possibilty of scheduled services from Central London to near-European capitals and in this respect, some preliminary investigation of sites has been carried out. However, the views expressed in this paper are personal and do not necessarily reflect BEA policy.

In this context we are therefore concerned with a heliport which will meet the required standards of safety and regularity, and will provide passenger handling facilities, car parking and support services at least comparable with equivalent fixed wing operations. Other types of landing place for helicopters, such as helipads, helistops, and conventional airports are outside the scope of the paper although similar design criteria may apply to these facilities.
The use and usage of helicopters
Authors: Ford G. E.
Published: March 2023

It WOULD be foolish to pretend that helicopters do not have their competitors but some may be surprised to know that in recent years one of the main competitors to the executive passenger carrying helicopter in this country has not been another aircraft but the excellent inter-city service operated by British Rail.

It would equally be misleading to pretend that there are not occasions when enquiries are received to charter a helicopter but because of the particular circumstances, including perhaps the stage length of the journey, they have to be frankly and honestly advised that it would be better to travel by scheduled air service.

This, however, has applied to the past. We are now at a stage when a whole new breed of helicopter is becoming increasingly available with improved performance, they are faster, are equipped for day and night and all weather operation and hopefully as the result of this very symposium, will be provided with the facilities to enable them to land in or close to the centre of cities and towns throughout the UK.
The prevention of separation and flow reversal in the corners of compressor blade cascades
Authors: Stratford B. S.
Published: March 2023

From tests on tunnel cascades one of the sources of loss in axial compressors could be corner stall, i.e. local separation of the flow in and near the corners between the annulus walls and the convex surfaces of the blades.

Tests on a tunnel cascade at entry Mach numbers of 0·5 and 0·6 show that, at least in a tunnel, the stalling may be cured by boundary layer control. The present tests obtain control by suction through a corner slot. The tests show that removal through the slot of 1·3% of the flow decreases the total losses of the cascade by about 25%.

A more detailed examination of the losses in the tunnel cascade without suction suggests that about three-quarters of the end losses are due to the separation and reverse flow. Much of the remaining end loss appears to result from the fact that the low energy stream tubes in the entry boundary layer would experience a disproportionately large increase in cross-sectional area during diffusion, even in attached two-dimensional flow. The suction corner control can eliminate the greater part of the end losses, by eliminating the separation.
Man powered flight—the Jupiter project
Authors: Potter John
Published: March 2023

Successful man powered aircraft projects may be divided into three main stages:

(a) Design.

(b) Construction.

(c) Operation.

From a purely practical standpoint, this sequence represents the order of increasing difficulty. It is in the later stages of a project that the major problems of team management and of organisation arise. Indeed, many groups, having designed and built a machine, have encountered the utmost difficulty in flying with any regularity. As a result, relatively little has been recorded on the matters of operating methods or handling characteristics, although there has been much discussion on the theoretical aspects of flight under human muscle-power.
Man-powered flight: the oscillating wing machine
Authors: Upeimieks H.
Published: March 2023

The aim of this article is to describe a method of power utilisation in a man-powered oscillating wing machine and to suggest features of design, which it is hoped might be of practical value to the many man-powered flight enthusiasts wishing to engage in what might, perhaps, become a relatively cheap and exhilarating sport.

With considerable expenditure of time and resources, successful attempts at man-powered flight have been made in the not so distant past. These exercises, at or near the limits of man's physical endurance, have been rewarded with flights lasting but a short while. And it is believed that any improvement of results in the near future can be only marginal.
An oscillatory method for the flight calibration of sideslip and incidence sensors
Authors: Burns B. R. A.
Published: March 2023

The local flow angles measured by incidence and sideslip probes mounted on aircraft differ in general from the free stream or ‘true’ values due to the flow field of the aircraft and of the sensors themselves.

This note describes a method of determining the correction factors by means of measurements made in oscillatory motion. The longitudinal short period mode is used for incidence calibration, the dutch roll for sideslip.
A method to analyse the wall jet flow
Authors: Mura Hari V.
Published: March 2023

The wall jet is described as a jet of fluid which issues to a wall at an angle from 0 to 90 degrees and grows along the wall in a surrounding stationary or moving fluid of infinite extent. The plane turbulent wall jet issuing tangentially to a smooth wall surrounded by the same fluid of infinite extent at rest is known as the classical wall jet and is explained in Fig. 1.

Considering the importance of the phenomenon in explaining some of the practical hydraulic engineering problems like submerged flows from outlets and other problems like paper drying and rocket exhaust effects, it would be helpful to analyse the problem more rationally. The purpose of this note is to present a method to analyse the flow mechanism in a wall jet consistent with the physical situation of the problem.
Air transport and a sound economy
Authors: Berchtold W.
Published: March 2023

Air transport is a part of the overall transportation system and has no special mission of its own other than to serve the community by performing those functions for which it is best suited, technically and economically.

The impact of transportation on the development of world societies can hardly be overestimated. Before the advent of the steam engine, the horse on land and the sail at sea were the available tractive forces. Speed and capacity were low and transportation costs were high. Only high value goods could be hauled over extended distances. While ocean transport was often the prerogative of a national flag (remember the Navigation Laws under William Pitt—perhaps the forerunner of today's air traffic rights), local hauling activities were either performed by the users themselves or, if exercised as a trade, subject to the usual regulation of medieval guilds.
Piloting techniques and flying qualities of the next generation of aircraft
Authors: Wanner J-C. L.
Published: March 2023

The main objective of the first builders of flying machines was to fly; the question of handling qualities was not so important as the question of performance. But when the fight against weight began to be won, the pilots wanted to fly easily. This was a reasonable requirement but very difficult to comply with because everybody had their own opinion about the meaning of “easily”. The engineers added some confusion by introducing mathematics. After many years of discussion during which everybody talked about Cm, Cmq,stability and manoeuvrability, the engineers won the battle and prescribed the holy regulations that they wanted and that they hoped would be eternal. For instance the centre of gravity lost its freedom and was assigned a position always ahead of the neutral point.
The History of Metal Aircraft Construction
Authors: Langley Marcus
Published: March 2023

I want to begin by reminding you of the old friend of all of us, the late Captain J. Laurence Pritchard, who did more than anyone to record and analyse aeronautical history as it was happening. It was he who, in 1930, pointed my nose in the right direction and suggested that I should write a book on metal aircraft construction. The writing of that book showed me the gaps in my knowledge and I had to fill these in before the book was finished. I want to pass on to you–and particularly the younger members—some wise advice that JLP gave me then: “If you do not know a subject and want to learn, write or lecture about it. Then you will teach yourself”.
The Aims and Methods of Operational Research on Weapons
Authors: Stratton A.
Published: March 2023

In view of the very wide scope of Operational Research in both the civil and defence fields, it is instructive to recall that it originated in wartime, as a means of increasing the operational effectiveness of combat forces. In the Second World War in particular it had a major effect on the efficient functional uses of the new radar equipment and achieved many other notable successes in increasing the effectiveness of our forces. It rapidly spread to all Services and in particular it was introduced into the Army through the formation in 1941 of the Army Operational Research Group, which in 1961 became the Army Operational Research Establishment, which in turn became in 1965 the tri-Service Defence Operational Analysis Establishment. Operational Research in wartime, functions in direct contact with the operational environment and the analytical predictions which it makes leads to direct application to the real world of war, the outcome in many cases being checked against the predictions. Operational Research in the original sense of investigation of operational factors continues to play a major part in peacetime in increasing the potential effectiveness of the services.
Power Law for Turbulent Cylindrical Boundary Layers
Authors: Joseph M. C. , McCorquodale J. A. , Sridhar K.
Published: March 2023

Considerable research effort has been devoted to the experimental and theoretical study of turbulent boundary layers on flat plates. However, relatively little research has been done on turbulent boundary layers in the presence of transverse curvature. In this paper transverse curvature denotes curvature in a plane normal to the flow direction as shown in Fig. 1. In particular, flow along the outside of cylinders is considered.

In most of the experimental and theoretical investigations of the cylindrical boundary layers (see for example references 1 to 4) the effect of transverse curvature on the velocity profile, especially on the power law, was not considered. Exceptions to the above statement are Rao's inference on the velocity profile and Bonsignore's prediction of change in the index of the power law.
De-icing of Runways from the Air
Authors: Briscoe John
Published: March 2023

As there is apparently no expert in the world on “De-icing Runways from the Air”—and certainly not the author— the best start is to relate something of the difficulties of de-icing runways, the chemicals used and the rival methods of spreading them, and to leave it to the operators of agricultural aircraft to decide whether and how agricultural aviation can do a useful job in freeing runways from the menace of ice.

Clearly for the safety of landings and take-offs, runways should be kept clear of anything which reduces the coefficient of friction, whether this reduction is the result of plain wet, snow, ice or slush. It is the objective of the British Airports Authority in common with other airports, to remove precipitation so that one, to use the Canadian expression, “gets down to the black top”—even though one's runway is near-white concrete. When ice forms on an untreated runway, it is liable to key itself to the irregularities of the surface and become difficult to move. Therefore a good plan is to have deposited one's chemicals, when there is precipitation, before the temperature falls to freezing point or else early on in the fall before freezing is too firmly established. However, on occasions, precipitation, as everyone knows, occurs without being forecast or the temperature falls unexpectedly.
A European View
Authors: Mostyn F. E. , Martin P.
Published: March 2023

I am to argue in favour of strict liability as against the carrier and to oppose the limitation of damages, arguments which I advance with some satisfaction since I happen also to believe them.

Strict liability is a doctrine more usually associated with the law of tort than the law of contract but as an injury resulting from an air crash is both contractual and tortious (and it even seems at one time to have been decided in America that the Warsaw Convention had itself created a cause of action), even if it be inelegant from a lawyer's point of view, I shall make no distinction between them. There are enough distinctions to be made on this topic without insisting on the lawyer's habit of mind.
A United States View
Authors: Kennelly J. , Lapham G.
Published: March 2023

The Legal Committee of the International Civil Aviation Organization met recently in Montreal and decided to recommend a modification of the Montreal Interim Agreement to provide for a novel rule of liability. The rule would make the carrier absolutely liable, regardless of whether the carrier was at fault. The only exception to the rule would be where the passenger or person claiming damages had himself caused or contributed to the accident. The limit of the air carrier's liability would be raised to $100 000.

I will attempt to outline not only the current state of the law of aviation, but to critically dissect those provisions of the proposed treaty which I believe to be incompatible with fundamental concepts of justice and equality, and violative of constitutional safeguards of the Constitution of the United States. Recognisably, some of these comments may be controversial, but it is hoped that they will provide luminosity concerning a complex subject and reduce polarisation of views.
Operational Assessment of Air and Sea Launched Guided Weapons
Authors: Lightbody A.
Published: March 2023

My paper is concerned with Operational Assessment on Air-to-Air, Air-to-Ground and Naval Surface-to-Air Guided Weapons.

I will start by describing the strategy and tactics for the use of these weapons to provide the military environment against which operational assessment is carried out. I will then say something of the methods we use of measuring the effectiveness of weapon systems by taking a number of examples and illustrating some of the different approaches we have used in the past.
Modulus of Sandwich Core Materials under Compression
Authors: Cox H. L.
Published: March 2023

The elastic modulus of a honeycomb sandwich core under transverse compression should be simply (ρE/ρ0), where ρ is the density of the honeycomb, ρ0 that of the material of the honeycomb and E the Young's modulus of the material. However when honeycomb sandwiches are tested under compression between flat platens it is common experience that the deformations recorded are markedly greater than those predicted from the theoretical modulus. In order to throw light on this discrepancy comparative tests have been made on three samples, two of normal thicknesses, namely in and in, and the third 8 in thick.
Local Avoidance of Sonic Boom from an Aircraft
Authors: Hilton W. F.
Published: March 2023

The sonic boom from an aircraft in level supersonic flight has been studied extensively. What is perhaps not so well known is the effect of a curved flight path in causing a local focus of shock-waves, and accentuated boom, and more particularly the production of a zone of silence, or rather “no boom” in other localities closer to the centre of curvature of the curved flight path than the M=1 radius. A steady shock wave pattern cannot rotate at a subsonic speed. It remains to be determined whether the necessary aircraft flight paths can be tolerated by both passengers and aircraft.

The subject is not new, and was theoretically predicted by Bryan and Lamb in 1921, and verified experimentally by the present author in 1938, for the case of propellers or airscrews. Figure 1 shows the effect of progressively tightening the radius of turn of the aircraft.
Analysis of Taxiing Induced Vibrations in Aircraft by the Power Spectral Density Method
Authors: Kirk C. L. , Perry P. J.
Published: March 2023

Taxiing induced vibrations in large aircraft due to runway unevenness have been recognised as a significant factor in causing metal fatigue damage and dynamic stressing in airframes, as well as crew and passenger discomfort. The purpose of this paper is to develop a method of analysing random vibrations of a flexible aircraft, taking account of non-linearities in the oleo-pneumatic undercarriage in the form of orifice damping and Coulomb friction. The analysis assumes that the random input to both main undercarriage legs is identical, therefore it only considers symmetrical wing modes in the general deformation of the airframe.
A Flight Test Establishment—its function and a suggested composition
Authors: Lewendon J. M.
Published: March 2023

To the majority of an aircraft manufacturer's technical staff the words “Flight Test” conjure up a vision of a ramshackle collection of seedy looking huts on the far side of the company's airfield, which itself may be 20 to 30 miles away from the main organisation. Within these huts dwell a small band of dedicated enthusiasts who apparently are willing to subjugate most of their waking hours and personal lives to performing their function in spite of the machinations of their two greatest enemies—aircraft unserviceability and the weather. While starting work at 08.30 hrs. (if not earlier) their working day always seems to reach its climax about one hour before sunset, irrespective of the time of year, and goes on for long after the last test aircraft has landed. However, they are a fortunate few, in that they have the privilege and responsibility of working with the company's end product in its functional form, an experience that today is denied to, or at least is remote from, the large majority of design and manufacturing staff.
Stability Augmentation in Aircraft Design
Authors: O'hara F.
Published: March 2023

A general review of the state-of-the-art in relation to stability augmentation in aircraft design, with an attempt to produce a co-ordinated view on the philosophy of its application, is something that I have long felt I should like to see done—but not by myself. My initial reaction on being asked to present such a paper was that this would better come from those concerned with the development of auto-control systems, but on second thoughts, there appeared to be some merit in considering the situation from the point of view of one concerned with the more basic aspects of aircraft handling and operation, putting the emphasis, therefore, on what is required or desirable in these respects, rather than on how it might be achieved. This, then, is my first aim; to consider various possible areas of application of stability augmentation, and advanced control techniques, to aircraft design; my survey will not attempt to be comprehensive but rather, selectively illustrative; it will, however, extend out beyond the confines of pure aircraft design, to externally guided aircraft flight, and in particular automatic landing.
The Progress and Economics of the Aero-Engine
Authors: Garnier M.
Published: March 2023

Since they were introduced at the end of the Second World War, aircraft turbojets, with which the name of Sir Frank Whittle must be associated, were in fact the object of considerable progress in terms of performance improvement, although this was achieved at the cost of an increased complexity.
The Far East Flight of the Southampton Flying Boats, 1927/28
Authors: Livock G. E.
Published: March 2023

While preparing this paper from old log books, diaries, photographs, etc, I was struck not so much by the advances aviation has made in the past half-century, but by the enormous gulf that divides “flying” in those days from the present day. It is laughable for instance to record that our average speed over the ground for the whole Far East Flight was 70 kt—80 mph, the greatest height we achieved 5500 ft and we had to land for fuel 27 times between England and Singapore. It may be more efficient to be dragged through the air in a tin box at ten times that speed and height, but it is not nearly so much fun.

Another thing I realised was how the map of the world has altered in 43 years. Except for a few comparatively small gaps the whole of our flight was over British Empire territory or land dependent on it. Many of the countries we visited in 1927 would slam the door in our faces if we tried to go there in 1970.
Fluidic Cabin Pressure Control Systems for Military and Civil Aircraft
Authors: Furlong O. D.
Published: March 2023

In common with other pneumatic and electronic cabin pressure control installations the two new pneumatic systems discussed in this paper have been designed to control cabin pressure automatically by throttling the out-flow of the cabin conditioning air. For those unfamiliar with the subject Fig. 1 shows diagrammatically a typical modern military aircraft installation. Both the systems discussed should however be of particular technical interest warranting general description, as for the first time with this type of equipment low cost and robust integrated fluidic circuits have been extensively used in their design. Patents covering these have now been granted in the United Kingdom, the United States and other countries.
Operational Experience with the SRN4
Authors: Jones S.
Published: March 2023

Seaspeed was established as a wholly owned subsidiary of British Railways to operate high-speed non-conventional marine craft, concentrating initially on the SRN4 hovercraft. As a first preliminary it was decided to establish an SRN6 route across the Solent to gain operating experience. Since those early days, with two SRN6s, two HM2s and two SRNs the company has ferried 1 026 595 fare-paying passengers a total approaching ten million passenger miles.

The Solent was chosen for a number of reasons. It was the birthplace of the hovercraft and manufacturers were all readily at hand. The weather conditions in relation to the size of the N6 were judged to be representative of the weather conditions facing the N4 on the Channel. Further, as we saw that successful hovercraft would have to operate in crowded terminal conditions, operating in and out of Cowes would give us valuable experience that we could transfer to N4 operating. Our first N6 route was, therefore, selected as Southampton/Cowes.
Some Experiments on Two-Stream Propelling Nozzles for Supersonic Aircraft
Authors: Lewis W. G. E. , Armstrong F. W.
Published: March 2023

The achievement of high propelling nozzle performance in supersonic flight is vital to the success of any aircraft designed to cruise supersonically for prolonged periods. For such projects, the payload fraction is small compared with subsonic aircraft, and the ratio of gross to net thrust is high. As a result, the penalty in range/payload performance for a shortfall in nozzle gross thrust efficiency is inevitably severe.
The Insurer's View
Authors: Dann David
Published: March 2023

“Earlier today a wide-bodied jet crashed into the Atlantic with the loss of all 200 passengers.”

I am not attempting either to scare you into leaving early or alternatively attempting to copy Orson Welles and his Martian invasion by making this statement— because nothing of tht kind actually happened. What we can be sure of, however, is that in the course of the next decade a similar statement will be issued by the news media of the world. It may not be into the Atlantic, it may be a mid-air explosion or break-up, it may be an incident of landing or take-off. All we can be painfully certain of, is that it will happen, and we in this room today will be more vitally involved than most.
The Evaluation of Local Skin Friction in Compressible Flow
Authors: Sivasegaram S.
Published: March 2023

In a recent note, Allen has investigated the use of Preston tubes and Clauser charts for determining the skin friction in supersonic, boundary-layer flows. He concluded that the Preston tube was best used in conjunction with the law of the wall of Fenter and Stalmach but that the Baronti and Libby wall law was most suitable for determining local skin friction from velocity profiles; both methods are complex and do not permit the direct use of Clauser charts. The present note presents a simple transformation which permits incompressible Clauser charts to be used for the evaluation of skin friction in supersonic flows; the method is applicable to both adiabatic and nonadiabatic situations. Some conclusions, based on experimental experience, are drawn regarding the determination of skin friction by sub-layer methods.
The Effect of Titanium on Equipment Design
Authors: Harben D. A. J.
Published: March 2023

In the paper by Messrs. Wood and Hammond it has been shown that titanium is likely to save weight compared with steel, where complexity together with the cost of manufacture make it necessary to have some material which is “structurally inert”. The presentation also showed that at high complexity factors, changing from aluminium to titanium would add weight. If the presentation could have included the effect of increasing the operating temperature it would have shown a narrowing gap until at temperatures above about 250 °C, aluminium is no longer viable.
The Application of “Fast-Time” Simulation Techniques to the Study of ATC Systems
Authors: Burford R. J.
Published: March 2023

Planning for the development of a future air traffic control system, or for the improvement of an existing system, requires a substantiated appreciation of the capacity and performance of the present system and of the projected future system.

With the growing volume of air traffic and the advancement of modern technology, ATC planners are concerned with making decisions relating to the organisation, development and control of an increasingly complex and sophisticated dynamic system. In many instances it is no longer possible to decide solely on the traditional basis of experience, intuition and “rule of thumb”, especially when the decision involves the selection of the best of several alternatives, involves the employment of very large sums in capital investment and affects the safety and security of large numbers of human lives. Under these circumstances it has become essential to turn to the Operational Research techniques which have been developed and which are now readily available to derive data on which sound decisions may be based.
Biaxial Yield Criteria
Authors: Mansfield E. H.
Published: March 2023

The von Mises yield criterion for sheet material under conditions of plane stress is given by

where σ1, σ2 are the principal stresses in the plane of the sheet and σy is the yield stress under uniaxial tension. If equation (1) is expressed in terms of elastic strains by virtue of the relations:

where v=Poisson's ratio and E=Young's modulus, it is
found that when

the term in ∊1∊2 vanishes and the criterion for the onset of yield simplifies to

Now v* is very close to that of most materials of structural interest.
Recent advances in thrust vector control for tactical missiles
Authors: Burgess B.
Published: March 2023

In recent years much attention has been given to developing new methods of steering tactical missiles. One method of particular importance is known as thrust vector control (TVC) which allows the missile to be steered by vectoring the efflux from the propulsion engine. In the case of engines powered by liquid fuel the normal TVC technique is to swivel the complete combustion chamber. This method is, however, unsuitable for solid propellant motors and so different techniques have been developed. This present paper makes a comparison of different systems of recent origin developed within the UK which are now available for project application.
Presidential Address 1974
Authors: Hislop G. S.
Published: March 2023

It is a very great honour to be the 41st person elected as President of the oldest aeronautical society in the world. I am very grateful to those who have thus shown their confidence in me for this elevated position and to my company, Westland Aircraft Ltd, for its full support in so many ways to the Society, and in particular to me during this Presidential year.

Our Society's view of Presidential Addresses is a thoroughly democratic one in that they are not a fixed custom, as in many other professional institutions in the UK. Whether to have one or not is entirely up to the President of the day.
Ancestral Kinship and the Origins of Ideology
Authors: Fasching Neil , Lelkes Yphtach
Published: March 2023

Families are not only the first institution ever created, they are also, for most people, the first institution ever encountered. The preindustrial family structure, which was a function of local ecology and cooperation needs, instilled family members with different values, such as trust in strangers and respect for elders. These values passed through generations and, as we show in three studies, impact today's political attitudes and policies. First, using surveys of second-generation immigrants representing roughly 180 ethnicities living in 32 European countries, we show that the tighter kinship structure of a person's ancestors predicts right-wing cultural attitudes. Among those who are less engaged in politics, tighter ancestral kinship structure also predicts left-wing economic attitudes. In a second study, we control for country-level differences by comparing ethnic groups within countries and find that ancestral kinship strength predicts right-wing cultural attitudes but not left-wing economic attitudes. Finally, in a third study, we examine the policy implications of ancestral kinship. We show that stronger country-level ancestral kinship strength also increases anti-LGBT policies and welfare spending. Finally, we examine whether value systems link preindustrial kinship with modern political attitudes. In total, this work indicates that our political beliefs are rooted in the value systems and familial institutions created by our forebears.
Local-scale panmixia in the lichenized fungus Xanthoria parietina contrasts with substantial genetic structure in its Trebouxia photobionts
Authors: Wyczanska Maja , Wacker Karoline , Dyer Paul S. , Werth Silke
Published: March 2023

Microsatellite markers can provide valuable information about gene flow and population history. We developed and tested new microsatellites for the nitrophilic lichenized fungus Xanthoria parietina and studied its genetic diversity and structure within the urban area of Munich, Bavaria. We compared its local genetic pattern with that of its photobiont partner Trebouxia decolorans, for which existing microsatellites were applied. For comparison, a reference site with clean air was included in the sampling. We found support for three genetic clusters in the fungus X. parietina, which occurred intermingled in collecting sites. There was a high degree of admixture within fungal populations and individuals, and analysis of molecular variance revealed a lack of population structure in the mycobiont. The Trebouxia photobiont, in contrast, exhibited structured populations which grouped into two to five genetic clusters, and individuals showed less admixture than in the mycobiont. This indicates that the two lichen partners differ in their ability to move around in the landscape. The microsatellite markers we report are polymorphic and are suitable for population genetic studies.