The B58 was developed and produced for the United States Air Force by the General Dynamics Corporation, Fort Worth Division, Texas. Until recently the organisation was known as CONVAIR, Fort Worth Division.

The B58 provided an abrupt advance in the technology of military aviation. In one step the speed performance of the strategic bomber was more than doubled over that of its predecessors.

The development and manufacture of the B58 was accomplished under the Weapons System Management Concept. Development of the aircraft began in 1951 with the origination of design studies. Detail design and manufacturing efforts were started in 1954. Initial flight of the prototype occurred in November of 1956. An exhaustive flight test evaluation programme then ensued in parallel with production of the aircraft. The flight test programme utilised a substantial fleet of B58's, and the combined efforts of the manufacturer and the U.S.A.F.

I am very happy to give this lecture and since it is in the nature of an historical review I make no apologies for requoting something I wrote on another occasion: —

I will, later in this lecture, show a film on the turbojet engine, which is a good example of this modern method of putting across educational and instructional matter on products and processes.

If we look at contemporary space vehicles which start their journeys from the surface of this planet, there is no doubt that the propulsion plant is the dominant feature. Physically it represents a major proportion of the total vehicle weight while the technical effort in attaining the necessary standards of performance and reliability has been of commensurate magnitude. It is clear also that the rocket motor has, at present, an unchallenged position as the chosen form of power unit. The question may well be asked in these circumstances what place there could be for an air-breathing power unit in such vehicles specifically intended to travel for most of their journey through the empty regions of space. Clearly the answer must be that such air-breathing units must function during the boost phase of space missions when there is air for them to breath so that the engines can add their quota of energy (kinetic plus potential) which is to be given to the vehicle in fulfilment of its task.

Many things have been said in the past year or two about the value of using Blue Streak to launch satellites and probes into space. Practical sense has at last triumphed and we have recently learned, with a great feeling of relief, that the European Space Launcher Organisation (ESLO) is now to be convened and there is now little doubt that a multi-stage satellite launcher rocket will be developed based on Blue Streak.

Unfortunately, there has been much misconception and loose thinking surrounding the Blue Streak concept and much unreal speculation on its life expectancy, performance limitations and general capability—mostly under-estimates. I would like therefore to try to summarise the present situation regarding the rocket, its ground facilities and its space applications.

In 1961 I assisted Mr. G. M. Lilley in writing a survey of the design and performance of man powered aircraft. Our conclusions were that man powered flight is just possible if the aircraft is carefully designed to give excellent aerodynamic characteristics, with a stiff, light structure and flown by a pilot whose power output is comparable with that of a National Amateur Cycling Champion. Such a machine would not fly more than fifteen to twenty feet above the ground and could operate only in still air conditions. The type of aircraft which emerged from the calculations was similar in general principles to those being developed currently at Hatfield and Southampton.

In this lecture I propose to investigate some of the basic relationships which are involved in the hope that possible ways of obtaining further improvements may emerge. Since the conclusion of our survey was that flight was marginally possible, slight improvements might well go a long way towards making man powered flight possible.

We are at the moment at what is probably the most interesting phase of the battle between man and gravity. This battle has been waged since the days of the ancient Greeks when men dreamed of emulating the birds, and using various “stick and string” devices tried without success to fly under their own power.

In the present day we have much more sophisticated machines into which a great deal of careful thought and design work has gone. Much publicity and speculation is at present centred around the Southampton and Hatfield fixed-wing machines which are enjoying a certain amount of initial success. Whether either machine will ultimately be successful remains to be seen and I am sure that all of us are following their progress with interest and wish them all the best in their endeavours. These are not by any means the only two projects being pursued at present, although there is a definite preference for a fixed-wing machine.

In the first Cierva Memorial Lecture, Professor Bennett dealt with the life and work of Juan de la Cierva. He was priviledged to know Cierva personally and to work with him. He described in vivid detail the qualities of Cierva as a man and the many aspects of his work which contributed to the successful evolution of rotating-wing aircraft. The lecture was aptly titled “The Era of the Autogiro.” At the time of Cierva's death in 1936, the autogyro had been well established and the helicopter, which was to supersede the autogyro, was only beginning to show promise as a satisfactory flight vehicle. By the time I first became directly associated with rotating-wing aircraft, some eight years later, Cierva had already become one of the legendary figures of aeronautics.

Although in recent years aircraft structures have tended to become rather complex, it is still possible in many cases to approximate the structure to a single cell tube with four corner booms during the initial design stages. Since extreme accuracy in computation is neither possible nor desirable in the early stages of design, the analysis has been restricted to structures with bulkheads which may be considered to be rigid in their own plane, although the effect of bulkhead flexibility can readily be included if thought to be of importance.

This note is concerned with the solution of the warping constraint problem for such structures without the necessity of solving a large number of linear simultaneous equations. The method is very similar to the Moment Distribution Method for continuous beams.

In a note by Goodey on the combined use of the WKB solution and Rayleigh's principle to estimate the lowest eigenvalue of a second-order linear differential equation, a numerical error concealed an interesting aspect of the result. The exact value λ = 2·062 corresponds to 0·6564π; and not 0·654π as stated. The approximate value 0·6559π is therefore lower than the exact value.

The possibility of approximate evaluation of the integral in a variational expression affecting the direction of approach to the exact value was pointed out by the author in a recent paper on the application of quadrature by differentiation. The application of the method described there to the example considered by Goodey may be of some interest as it gives the eigenvalue to within 1/2 per cent by the solution of a quadratic equation.

The stability of a uniform cantilever beam subjected to an articulated tip load has been analysed as an equilibrium problem of static elastic stability. It was found there that the articulation of the connecting rod applying the tip load introduced additional component forces during the process of beam deformation.

In a previous Note the elastic critical loads of continuous struts were investigated and approximate formulae were derived by employing a semi-graphical technique. In the analysis which follows, approximate formulae are derived for the elastic critical loads of composite struts, each consisting of two prismatic parts, and having various combinations of end conditions. These formulae are obtained as approximate solutions of the transcendental equations governing the behaviour of the struts. The derivation of the transcendental equations is standard, and is not given.