The Sixteenth Louis Bleriot Lecture, “The Aeronautical Industry in the Europe of Tomorrow,” was given in London in the Society's Lecture Theatre by Captain R. M. Bloch, F.N., F.R.Ae.S., A.F.A.I.A.A. Mr. B. S. Shenstone, M.A.Sc, F.R.Ae.S., F.A.I.A.A., F.C.A.S.I., President of the Society, was in the chair.

Introducing the Lecturer, the President reminded the audience that the Bleriot Lectures were given alternately in Paris and London. This year was London's turn and their lecturer was a Frenchman, Captain Rene Bloch. Captain Bloch had many duties: he was Assistant Director of Aeronautics for International Affairs in the French Ministry of Defence, he was the French Representative of the NATO Maritime Patrol Aircraft Steering Committee and Permanent Chairman of the Technical Sub-Committee. He was also French Co-Chairman of the Anglo-French Naval Aviation Committee. Captain Bloch had a number of degrees, including the diploma of the Ecole Polytechnique and he was an M.A. of Harvard. He was a Chevalier de la Legion d'Honneur, a Combatant Volontaire de la Resistance and he held the Medaille de la France Libre and the Medialle de l'Aeronautique. He was a member of A.F.I.T.A.E., an Associate Fellow of the American Institute of Aeronautics and Astronautics, a member of the Institute of Radio Engineers, New York and he had recently been elected a Fellow of the Royal Aeronautical Society. They would appreciate that Captain Bloch's background and experience was certainly wide enough for him to speak with authority on his subject—“The Aeronautical Industry in the Europe of Tomorrow.”

The Nonweiler method of designing delta wings (caret wings) to have plane shocks on the lower surface is extended to the design of upper surfaces. Cambered and shock-free surfaces are also deduced, and methods of design for complete configurations suggested.

An important point is that all surfaces are of single curvature.

Boundary layer measurements have been made at four positions on a slender gothic wing of aspect ratio 0·75. Test's were made over a range of incidence at M=1·42 and 1·82. With transition fixed by roughness near the leading edge the boundary layer thickness varied little with small positive or negative incidence but was reduced at larger incidences, this being most marked at positive incidence for positions nearest the leading edge due to the influence of the wing vortex. With the exception of positions in the vicinity of the vortex, a good estimate of the boundary layer thickness was given by the theory for incompressible flow over a flat plate and an excellent estimate of the variation of local static pressure and Mach number with incidence was given by not-so-slender wing theory.

The second lecture to be given before the Air Law Group of the Society "Legal Liabilities Arising out of Aircraft Design and Manufacture" was given on 19th December in the Lecture Theatre, 4 Hamilton Place, London, W.l. The Lecture was in two parts, Major K. M. Beaumont, C.B.E., D.S.O., M.A., A.F.R.Ae.S., F.R.S.A., F.R.P.S.L., speaking from the legal point of view and Mr. C. B. White, M.A., Hawker Siddeley Aviation Ltd., sneaking from the manufacturer's point of view. The Chair was taken by Mr. Walter Tye, O.B.E., B.Sc., F.R.Ae.S., Chief Technical Officer, Air Registration Board. The report of the Discussion was prepared by Mr. B. J. Davenport, B.A.

My Task is to express the manufacturer's point of view and his problems in this field. I can only speak of my own experiences in one Group, and that experience has been chiefly in the civil field. The observations which follow are therefore related mainly to civil aircraft.

In a previous life as a recently qualified solicitor I had the task of presenting to the head of a company, on behalf of my client, a cheque for more than £lm. This payment was made partly because my client's product had run into trouble and partly because there was uncertainty about the legal liability. My experiences in the Aircraft Industry have, therefore, been coloured by a considerable respect for any manufacturer's responsibilities for his product.

Finite bodies supporting two-dimensional under surface flows behind “contained” plane shock waves of the type discussed by Professor Nonweiler in a recent paper are currently receiving attention from both theoretical and experimental workers. The experimental work already undertaken by the RAE has given hopeful indications that such bodies, characterised by a re-entrant lower surface in cross section, compete closely with more familiar convex bodies in terms of lift/drag ratio, and furthermore preserve the two-dimensional character of the flow away from the design incidence.

The purpose of this note is to point out that:

(a) Delta wings with inverted V or W cross sections are geometrically simple examples of a more general family of possible shapes supporting two-dimensional flow behind a plane shock.

(b) The concept may be extended to bodies supporting two-dimensional flows with multiple shocks (leading to isentropic compression in the limit) or shock-expansion systems.

In the past few years pilots landing in very heavy rain, or just after it, have found their wheel-brakes ineffective due to the layer of water, and this has been called aquaplaning; the word is preferable to “hydroplaning” which already has a well-established meaning in a deep-water context. The nature of this phenomenon has been speculated upon by NASA since 1959 and by Mr. Gadd of the NPL in 1961 (see R.Ae.S. Journal, March 1963). The latter gives the impression that in Britain we are still speculating, but in fact we know quite a lot about it now; much has been described in an RAE Technical Note last November and this was added to at a Take-off and Landing Symposium at Farnborough in December 1962. These sources are being drawn upon here.

The free flexural vibrations of rectangular plates with various boundary conditions have been considered by Warburton. The natural frequencies were calculated by the Rayleigh method, the mode assumed being the product of the characteristic beam functions for the given boundary conditions. Comparison with experimental results shows that the method gives reasonably good approximations. The present note describes a method of obtaining the approximately equivalent characteristic beam functions to enable Warburton's method to be extended to plates having one or more stiffeners parallel to an edge. As a numerical example expressions for the frequencies are derived for a plate, simply supported along two opposite edges, and having a central stiffener parallel to the other two free edges. The results are compared with those given in a recent note by Kirk, who solved the same problem by the Rayleigh-Ritz method, using a mode with one arbitrary parameter. In the case of the fundamental frequency of the unstiffened plate, the characteristic beam function in a direction perpendicular to the free edges is simply a constant, and the solution is less accurate than that given by the Rayleigh-Ritz method. However, numerical analysis of a square plate shows that above a certain stiffener depth the characteristic beam function method is more accurate than the Rayleigh-Ritz method. The two methods are also compared for the 2/2 mode.

In previous notes approximate values of the elastic critical loads of continuous and composite struts were obtained. In the case of continuous struts a semi-graphical technique was employed, while for composite struts values were derived from approximate solutions of the transcendental equations governing the behaviour of the struts. In the present note, the approximate elastic critical loads of coupled struts are investigated by a third method, using approximate expressions for the stiffness and carry-over factors entering into the equations expressing the critical conditions of the struts.