On 3rd December 1903, with the wind gusting up to 25 mph (11·2 m/s), Orville Wright staggered into the air in a flimsy aeroplane powered by a four-cylinder piston engine, and, with that event, the Wright Brothers had added a new dimension to man's ability to travel (Fig. 1).

Their success was not just a piece of luck, but the result of years of study and experimentation, coupled with great personal effort in the design and manufacture of their aircraft. Like all pioneers, they were faced with important gaps in the availability of suitable equipment, particularly an engine of sufficient power and light enough in weight, and a propeller of high enough efficiency. These they had to develop for themselves.

The first question that a prospective lecturer of the august series in honour of Frederick William Lanchester should ask himself is the possible reason why he has been selected. I confess that for a considerable time I have been at a loss to understand this signal honour bestowed upon me. My mind ventilated a number of possible explanations starting from the evident but rather tenuous reasoning that both the eminent Mr. Lanchester and myself can show a connection with the leading Technological Institute of Britain, the Imperial College. But is this sufficient as a justification? I doubt it. Another path I tried to explore ventured along the intriguing intentional verbal slips and monumental sayings of Lanchester. Is it possible—I asked myself—that the wise Council of the Royal Aeronautical Society selected me on account of my undeserved reputation to have been in my Golden Youth an angry young man, an enfant terrible, and an early exponent of the anti-establishment criticism.

The modern aero engine is one of the most sophisticated machines currently produced by man. Its design, manufacture and repair necessitate the use of the latest knowledge and techniques, and development in one form or another continues throughout its service life.

Despite this high technical content, the fundamental requirement of the industry is to run on a sound economic basis. Often, however, this objective is lost in the equally demanding requirements of flight safety, or meeting over optimistic dates and of keeping up with competition in a multiplicity of other ways.

Much has been written about the initial development of engines up to type approval. This paper proposes to go beyond that and to describe some of the problems which arise during manufacture and operation, to emphasise the frustration and fury of an operator who has to unload 100 passengers and find them hotel accommodation—at his expense—in some outlandish part of the world because of a leaking oil pipe, and to highlight the need for repair techniques which are economical and simple.

A procedure has been developed by Moon for the determination of the total solar irradiance within the earth's atmosphere. The present note illustrates how transmission factors derived by Moon for the constituents of the atmosphere can be used with recent curves of spectral irradiance outside the earth's atmosphere to determine the solar heating at a point on or above the earth's surface at any given time. Special consideration is given to the variation in atmospheric water vapour content with altitude, season, and position on the globe since this is a parameter of some importance. The method described forms the basis of Engineering Sciences Data Item 69015.

There are many approximate methods for solving the laminar boundary-layer equations. They vary greatly in complexity and ingenuity but are similar in that most of them use the momentum integral equation together with data culled from Cohen and Reshotko's valuable catalogue of similarity solutions. Further details may be found, for example, in the book by Curle.

Perhaps one of the simplest approximate methods to use is that due to Luxton and Young. More recently Luxton has extended the method so that heat transfer rate distributions also can be obtained. He is careful to point out that, since his method depends on correlations obtained from similar solutions, it cannot be claimed a priori that the method gives an accurate result. Until recently there have been few “exact” calculations against which approximate methods may be tested. Indeed when Morduchow made his review of boundary-layer calculations in 1965 he quoted only two exact results for non-zero Mach number (by NPL) and cast doubt on one of those. Fitzhugh has now computed a number of solutions of the laminar boundary-layer equations using the finite-difference program of Sells. Further solutions have recently been obtained by F. Smith.

In several recent papers the bursting pressures of shock tube diaphragms of various sizes and materials have been presented either as discrete values or curves of bursting pressure against thickness. The lack of a unifying dimensionless presentation, however, restricts the general applicability of such results and it is the object of this work to present a suitable dimensionless strength parameter, and to outline a procedure which enables predictions to be made of the bursting pressure of ductile metal diaphragms in square-section shock tubes of any cross-sectional size, without performing bursting tests.

In a vibrating system with a non-linear restoring force the effect of gravity, if it influences the equilibrium of motion, is not completely balanced by the static deflection force. This produces in most cases an increase of the magnitude of non-linearity because of the displacement of the static equilibrium point on the restoring force characteristic. The static deflection parameter thus offers a more complete definition of this effect and is consequently used in the vibration equation in preference to the force of gravity. Previous investigation of the free vibration indicates that the existence of a static deflection must result in considerable changes of the forced vibration response.

The subject of management techniques needs to cover a wider field than the rather narrow interpretation given in much current discussion of its tools. To cover the relevant area, it is intended to use the managerial concepts pioneered by the Frenchman—Henri Fayol. Fayol suggested management activity is made up of five parts:

• Planning

• Organising

• Commanding

• Co-ordinating

• Controlling

The machinery used for the management of the development of the Sea Dart missile will be reviewed under those five parts.

The Rapier project began to emerge shortly after the publication of the report of the committee which sat under Sir Solly Zuckerman to consider the management and control of Research and Development. The “Zuckerman” formula was applied to Rapier and feasibility studies were followed by a project study, a holding contract, and eventually full development.

Meanwhile another committee under Mr. W. G. Downey had been considering the management of large development projects, and some of the techniques advocated by them have already been applied to Rapier.

Rapier, therefore, can be said to span the Zuckerman-Downey period, a period which has seen modern management techniques applied in more and more depth throughout the aerospace industry.

Although this paper forms part of a symposium dealing with management techniques used in guided weapon development, it is concerned with the organisation of management rather than with the techniques used. Techniques used on different guided weapon systems may well be the same in principle, although differing in detail. Martel differs from the other weapon systems considered in this symposium, however, in that it is a project in which the development was carried out by organisations in two different countries working in collaboration. The lessons which may be drawn from Martel, which cannot be drawn from other guided weapon projects, are concerned with international collaboration, and not with the detailed techniques used to manage the project. It seems, therefore, that it is desirable to concentrate on the management arrangements associated with this project and not on the detailed techniques used. It is an inevitable consequence of this concentration on international organisation that this paper is concerned mainly with the Government agencies and the main contractors.