The engines for the Concorde supersonic transport are being developed jointly by SNECMA and Bristol Siddeley Engines Ltd. The basic engine is derived from the Olympus engine and the responsibility for this part of the development will rest with Bristol Siddeley Engines Ltd., but the jet pipe, propelling nozzle, thrust reverser and noise suppressor will be the responsibility of SNECMA.

On 13th May 1915, the Minister of Education, speaking in the House of Commons, said, “Our successes over our enemy in aviation are largely due to the investigations made into automatic stability by a young man who went through an elementary school.”

That young man was Leonard Bairstow, who began his early education in the elementary and secondary schools of Halifax, Yorkshire, and obtained a scholarship at the Royal College of Science, London, in 1898.

H. E. Wimperis, who became President of the Society in 1937, was a student at the Royal College of Science at the same time as Bairstow and declared in later years, “I remember that, for several decades there, the most brilliant student that had been produced by the College was Professor Bairstow. He had an uncanny faculty of making himself acquainted with and making completely original suggestions on subjects which we did not think he knew anything about.”

Part II deals with the development, from a simple flight simulator used in tachistoscopic studies of attitude displays, to more advanced equipment used to study an instrument system for high-speed low-level flight. This involved the concept of information flow in parallel and visually-mediated control loops, for visual and instrument flight, requiring developments in the simulation of visual flight, by a tele-visual method, and in the assessment of tracking performance, by a method of mean modulus errors; these developments allowing observation of performance of concurrent visual tasks. Flight trials confirmed simulator studies of learning effects, information capacity and instrument to visual transition. The complete scheme of simulation included ground control and autopilot facilities.

The lecture discusses the extent to which the problems met in the fuel systems of subsonic aircraft are aggravated by flight at supersonic speeds and mentions some new problems of considerable severity. These arise from the relatively large fuel quantity required, its high rate of consumption and its heating by kinetic effects or by its use as a heat sink for the aircraft systems. The paper includes a discussion on fuel management and gauging and of the means used to transfer fuel to the engines—showing the relative merits of some of the available pumping techniques. A few comments only are made on the engine control system.

The problem of thermal degradation of the fuel in the tanks and in components leading to the engine is discussed, with particular attention being paid to the difficulty of establishing a valid test method for differing aircraft configurations.

Spontaneous ignition of flammable mixtures in contact with heated surfaces is a hazard that is likely to arise in a particularly acute form at a Mach number of about 3. The progress of research into this phenomenon is briefly outlined, and some of the measures which may be adopted to ensure safety are indicated. Associated with this is the necessity to develop instruments to detect hazardous conditions in various parts of an aircraft, on which some recommendations are made.

A choked nozzle with an appropriate wall contour has adischarge coefficient, CD, so close to unity that a theoretical calculation of (I—CD) would allow the nozzle to be used as an absolute meter for air flow. The high discharge coefficient results basically from the fact that ∂(ρv)∂p=0 at M=1.

Simplified calculations yield formulae for the boundary layer displacement thickness and for the flow reduction resulting from the variation in static pressure across the throat. The optimum profile for the wall at the throat of an absolute meter is suggested to be a circular arc of radius of curvature equal to about twice the throat diameter. For such a meter the theoretical discharge coefficient is found to be within ¼ per cent of 0·995 over a wide range of Reynolds numbers.

The uncertainty in the discharge coefficient for a steady flow at Reynolds numbers of 106 and over appears to be less than ±0·15 per cent, both when the boundary layer is known to be entirely turbulent and when it is known to be entirely laminar. When the state of the boundary layer is not known the corresponding figure appears to be ±0·25 per cent. Experimental information might therefore be helpful on transition—under the appropriate conditions of flow unsteadiness and rig vibration. Available experimental results with known boundary layers tend to confirm the theoretical discharge coefficients down to a Reynolds number of 0·4x106.

A pressure ratio of about 1·1/1 or less would probably be sufficient to establish fully supersonic flow if the nozzle were followed by a suitable diffuser.

The current interest in supersonic transport aircraft makes it appropriate to consider the problems of propulsion nozzle systems for high speed flight. The discussion will be confined mainly to this field of activity.

In the absence of external drag and weight factors, the ideal configuration to maintain optimum thrust at all flight speeds would employ a mechanically variable area ratio nozzle. By such means the jet flow could be fully and properly expanded at all times.

A practical design to accommodate such variations is inherently complex, and so an alternative solution using aerodynamic techniques has been sought. It is necessary to remember that the success of whatever method is eventually chosen must rest on its ability to combine a high performance at cruise with very small loss during other critical phases of the flight plan.

This paper describes some of the results of a nozzle research programme aimed primarily at solving the above problem, with an attempt to explain the philosophy behind the aerodynamic techniques tried. Some discussion is given of the experimental difficulties in establishing a sufficiently accurate standard of measurement for design point performance. In a few chosen configurations experimental results have been extensively backed by theoretical studies.

The need to demonstrate off-design behaviour in the presence of an external flow field is stressed, with special reference to the misleading results often obtained from static tests.

Finally, some attention is given to the question of base bleed, with its repercussions on the installation of the propulsion nozzle in an aircraft.

Since the mythical dawn of man's attempt to emulate birds and fly, and some believe this started with Icarus, man has been frustrated by his apparent inability to predict or prevent occasional disaster arising from failure of his mechanical aids to flight. From ancient Icarus with his ultimate and disastrous thermal structural failure, to the present and future aircraft the same problem although now in a more sophisticated and complex form, confronts the aircraft designer and engineer of today.

This paper is not intended to be a comprehensive treatise on Aircraft Accident Investigation as a whole because this is a subject of many facets and problems, but rather is it intended to draw attention in basic and elementary form to some types of mechanical failures or inadequate design criteria which have caused accidents to aircraft in the past, the methods used in their diagnosis and, what is perhaps more important, some lessons that have been learnt from them.

Sir Henry Tizard’s work and–above all–his part in our survival in 1940–have been the subject of many memoirs since his death in 1959. The biography written by Ronald Clark at the invitation of Professor J. P. M. Tizard, Sir Henry’s eldest son, will shortly appear. This first Memorial Lecture of the Royal Aeronautical Society thus occurs when a full record of Tizard’s life is about to be made available, and there is therefore little point in the plain re-iteration of a condensed biography. Future Memorial Lecturers, as they inevitably grow more remote from personal contact with Tizard, may well choose to describe the advances of the future in those fields to which Tizard himself so notably contributed: science, defence, education and government. My purpose in this first Memorial Lecture is, therefore, to build a bridge between biography and those future fields in which Tizard’s example, although unlikely to be excelled, will be emulated and extended.

The problem of maximising the range of a given unpowered, air-launched vehicle is formed as one of Mayer type in the calculus of variations. Eulers’ necessary conditions for the existence of an extremal are stated together with the natural end conditions. The problem reduces to finding the incidence programme which will give the greatest range.

The vehicle is assumed to be an air-to-ground, winged unpowered vehicle flying in an isothermal atmosphere above a flat earth. It is also assumed to be a point mass acted upon by the forces of lift, drag and weight. The acceleration due to gravity is assumed constant.

The fundamental constraints of the problem and the Euler-Lagrange equations are programmed for an automatic digital computer. By considering the Lagrange multipliers involved in the problem a method of search is devised based on finding flight paths with maximum range for specified final velocities. It is shown that this method leads to trajectories which are sufficiently close to the “best” trajectory for most practical purposes.

It is concluded that such a method is practical and is particularly useful in obtaining the optimum incidence programme during the initial portion of the flight path.

A considerable amount of material has been produced over the past few years on the subject of heliports and therefore it is proposed to make only brief reference to general heliport requirements and the national and international activity in this field. The application of these requirements to the proposed heliport at Penzance will then be discussed.

I felt very honoured when asked to give this lecture in memory of one of the leading figures of the period which saw the greatest British achievements in aeronautics. The contrast between the technical situation of those times, and the uncertainties of today, immediately sprang to mind, especially in regard to British achievement (or lack of it) in space.

So also, very naturally, did those occasions in the 1940's when I used to visit Mr. Chadwick to discuss the propeller problems of various Avro aircraft, both real and projected. During the course of these sessions, we often discussed future propulsion trends, including the relative merits of piston and turbine engines, propellers and jet propulsion, and so forth. I cannot honestly recall that the question of space flight ever came up, although it probably did, because propulsion is even more of a fundamental problem for flight in space than it is within the atmosphere, and even in those days I was what the Americans call “a space cadet.”

There is not a great need for the further reductions in flight time that can be afforded by the SST over the near-sonic jets. Furthermore, the time gain by the SST will be counteracted by reduced in-flight comfort and, on the average, by an increasing difference in airport distance between supersonic and competing subsonic services. Nevertheless, most businessmen in a great hurry and some tourists are likely to prefer the SST on conveniently scheduled flights and at equal fares.

However, for utilisation reasons only some of the SST flights can be conveniently scheduled and the SST's will—for 15 specified reasons—be so grossly uneconomical in competition with subsonic aircraft that the condition of equal fares cannot be complied with without exceedingly high subsidies to be covered by the taxpayers in all SST-operating countries. The subsidies must continuously increase mainly because of

—improvements of competing subsonic aircraft in operating cost—and ability to use more centrally located airports and

—increasingly adverse sonic-boom reactions (as the operation grows and the SST's, as is normal, become heavier and create higher boom intensities) by people on the ground, including potential SST passengers.

As the SST enterprise will thus be an economic failure, most of the aspects that are claimed to be advantageous in the event of an SST success, in particular prestige and improved national economy, will instead turn into pronounced disadvantages: loss in prestige and an economical burden.

Over and above this, supersonic aviation will

—most likely be much less safe than subsonic aviation,

—possibly subject passenger and crew members or their off-spring to harmful effects of cosmic radiation,

—seriously counteract, probably make impossible, the urgently needed improvement of flight safety in aviation,

—hamper the brilliant prospects now in sight for making aviation a really cheap and convenient means of mass transportation, and

—retard the expansion of civil aviation.

People in general are prepared to put up with a certain amount of noise—in confined areas and mainly during the working hours of the weekdays—if it is an inevitable by-product of a necessary, an important, or a profitable activity. But supersonic aviation, which will cause serious noise disturbances day and night, 365 days of the year, in unprecedently vast areas, is neither necessary, nor very important, nor profitable. Thus, the introduction of supersonic flight would mean that hundreds of millions of people would not only be seriously disturbed by the sonic booms, often to an extent detrimental to health, but also have to pay out their own money to keep the noise-creating activity alive, and in addition, have to accept a much less safe and cheap civil aviation than would otherwise be possible to achieve.

Therefore, the consequences are such that, once the supersonic era has begun, the general public will always strenuously oppose it. There will be an unprecedented tension between aviation and the public. Intense efforts will certainly be made to switch back to all-subsonic aviation. The cost of such a reversion will be fantastic and rapidly grow the longer the supersonic era prevails.

Obviously, it lies in the best interest also of civil aviation to prevent introduction of supersonic flight in its presently suggested form.

The activity at Woomera leading to the first flight trial of Blue Streak had two distinct phases. First, the activation of the Blue Streak site and second the preparation, static firing and launching of Blue Streak F1. These events are described in two parts, Part I dealing with the site preparation and Part II with the F1 trial.

During the past ten years the author has been collecting test data on the collapse of pressure loaded spherical shells in order to establish good design curves. The presence of initial imperforations causes wide variance in strength values from one investigator to another. An effort is undertaken to attempt to analyse all available data on some rational basis. Certain diagrams have been presented in the past.

The development of a special model aeroplane technique is reviewed which renders possible easy and illustrative experimenting In the Reynolds number regime from 1 to 5000. The models are built in extremely light-weight construction; with wing span from 0·1 to 1 metre and all-up weights from 0·01 to 2 grammes, flight velocities between 0·1 and 1 m/ sec are reached. The requirement of extremely low wing loading, together with the special air flow characteristics in this region, leads to rather unconventional construction principles with the materials balsa wood, nichrome wire and cellulose film. These principles are reviewed briefly. The problem of optimum propulsion for such model aeroplanes is treated analytically. Some results are given for flight performance optimisation. By combining theory and experiment there has been evolved, e.g. the Schwebeleistungs method (power required for horizontal flight) for optimising the duration of indoor model aeroplanes without exact knowledge of their aerodynamic characteristics. Flight characteristics with some elasticity of the structure present formidable problems and are reviewed in some examples. Finally, some problems of hangar meteorology are mentioned.

Rocket motors designed for operation in ground launched vehicles generally have nozzle expansion ratios giving optimum thrust at low altitude (about 20 000ft). At higher altitudes the jets are under-expanded and the thrust is less than the maximum available with nozzles of higher expansion ratio. Some of this lost thrust may be regained by suitable design of the propulsion bay geometry, without the low altitude disadvantages of high expansion ratio nozzles. In addition, where the vehicle is propelled by clustered motors, interaction between the jet effluxes at high altitudes can be used to develop an extra thrust acting on the base of the vehicle. The flow changes, from low to high altitude, leading to these effects are described.

The results of the first firings of Black Knight drew attention in this country to these effects. Model tests in both the U.K. and America have confirmed them and indicated various means by which the thrust of clustered rockets may be augmented; these are described and consideration is also given to the side effects of thrust augmentation on vehicle control and propulsion bay heating. A full scale experiment, planned for the end of 1962 is outlined and possible future applications are considered.

Because two world wars have exerted such a profound influence on military aviation I have chosen to treat the subject under the following headings:

• The Beginning

• The First World War.

• The Inter-War Years.

• The Second World War.

• From 1945 to the present.

• The Future.

Under each heading I will endeavour to outline the developments and changes in technology and rôle which have taken place, and to indicate the effects these were to have upon each succeeding period.

Aerial crop spraying necessitates the lowest feasible application rates to minimise costs. The low volumes now being used in the Tropics and in this country often require very high concentrations of active ingredient. Most agricultural sprays are formulated for use in 10-100 gallons per acre. When the same weight of chemical is applied in one gallon or less per acre any one of hitherto disregarded factors, such as surface tension, rate of evaporation, density, viscosity, dynamic catch, and so on, may unexpectedly reach a critical value. An understanding of the limits of these factors is essential for the diagnosis or prevention of faulty biological performance.

It is just three years since the Anglo-French proposals for a European Space Vehicle Launcher Development programme were put before a Conference of Government representatives from 11 countries in the Council of Europe Headquarters, Strasbourg, and slightly more since the Conference of 11 countries at Meyrin in Switzerland where the idea of a European Space Research Organisation was formally introduced. This seems an opportune moment to take stock of the situation in this new field of international co-operation and look ahead to the prospects in the immediate future. At the same time it may be useful to mention briefly the increasing scope of European interests in all aspects of Space and to survey the growth of national space programmes.