Substantial cut-backs in the national defence budget over the past five years have forced upon the Defence Ministry and missile designers alike a growing awareness of the importance of weapon costs. As a result, the ideal technical solution to a particular defence problem sometimes has to give way to the realism of what the country can afford to develop and procure—and, most important, what it could afford to sustain, if need be, in anger. A further factor has been the growing importance of exports to the country's economic position, to which arms make an important contribution. Weapon designs, therefore, have to be such that overseas customers can afford not only to purchase them but can also maintain and use them. This is particularly important in the case of developing countries.

The Royal Aeronautical Society is now 102 years old, and astronautics has already existed as a technical discipline for some 70 of these years, even if one disregards its long pre-history of mythology, science-fiction, and vague speculation. Tsiolkovsky began to make his amazing and entirely serious scientific contributions just before the dawn of the twentieth century.

This suggestion that aeronautics and astronautics are much of an age would surprise many laymen, who are apt to accept literally the dating of the popular Press; this usually argues that the “Space Age” began with the launching of Sputnik I in 1957, disregarding even the first successful large rocket, the V2, which flew 15 years before Sputnik I. However, whether one argues that astronautics is already a septuagenarian, is in its vigorous and youthful twenties, or is not yet even a teenager, one must admit that its amazing development has occurred mostly in the last decade.

The twenty-first Louis Blériot Lecture was given in Paris on 5th April 1968 under the auspices of L’Association Françaises des Ingénieurs et Techniciens de L'Aéronautique et L'Espace. The lecture “Some Thoughts about the Future of European Aeronautics” by Handel Davies, CB, MSc, CEng, FRAeS, FAIAA, was read on his behalf in French by General Lecamus, FRAeS. The Lecture was attended by the President, Mr. M. B. Morgan, CB, MA, FRAeS, the Secretary of the Society, Dr. A. M. Ballantyne, OBE, TD, PhD, by several members of Council and a large and distinguished French audience.

The Chair was taken by Monsieur Robert Blum, President of AFITAE. Following the lecture a dinner was given by AFITAE.

Before I begin, may I say how much I appreciate the honour of being invited by the Derby Branch of the Royal Aeronautical Society to give this Lecture. It is now eleven years since Mr. Evernden gave us the story of Henry Royce himself and an account of the idealism and inspiration which laid the foundations of the great firm that bears his name. Mindful of this and of the accomplishments of my predecessors, I approach my task in a spirit of great humility.

This paper presents basic disciplines for effective management of costs for profitable operation in technologically orientated industries. The techniques outlined for strategic planning, implementation of the ensuing plan and for operational planning and control are not new, but available and proven by wide application in the USA and to a lesser extent in the UK.

The adoption of these or similar disciplines in the UK aerospace industry in co-operation with the Government in defining industry objectives and strategic plans, could represent a big step towards promoting a healthy and expanding industry for the future.

Application of these techniques will present difficulties in the aerospace industry, but by their very nature should yield an immense return in this environment. There would appear to be no insuperable difficulties in achieving successful application by both Government and Industry.

Since the 1967 Management Studies Group Symposium showed a strong demand for information on these techniques, and because no single source document can be recommended, the preparation of this survey has been undertaken.

In the design of compression structures, the effect of lateral loading is usually ignored. This assumption has been justified where the structure has represented the wing skin of a conventional aircraft, in which the compressive end load due to bending is high, but the lateral load due to aerodynamic pressure is comparatively low.

However, in some cases the approximation is too crude, such as where the effect of the aerodynamic pressure is added to by pressurised fuel tanks together with the possibility of the accelerated weight of fuel. Such situations arise in supersonic transport aircraft where a considerable weight of fuel is carried in the wing and aerodynamic heating causes high compressive stresses in the skin.

The Biot-Savart law gives the velocity associated with an elemental portion of line vortex, or the magnetic field associated with an elemental portion of line current. The following proof may appeal to students who approach fluid mechanics or electromagnetic-field theory from the engineering viewpoint. It will be stated in terms of fluid mechanics.

Consider a very small length δs of line vortex of circulation strength Γ. At P(x) the velocity δV associated with this portion depends on Γ δs and x.

Simple two-dimensional theory is extended to the case of a hovercraft having forward speed. It is shown that in general the effect of forward speed on lower surface lift is adverse but that the static pressure in the region of the rear jet has an important influence and if this pressure is low and hit is also low some reduction in lift power is achieved.

Howard suggested that the shear stiffness of a beam in bending could be more expeditiously determined by using the five point loading system.

Grayley reviewed the accuracy and speed of various methods of finding the shear stiffness of sandwich beams and showed that five point loading compared favourably on all counts with three point loading, four point loading, and with block shear tests.

The RAeS Data Unit gave a description of an experimental method of determining the shear and flexural stiffnesses of a sandwich material, based on Howard's work.