Initially, supercharging of aero-engines was introduced with a view to restoring the pressure in the induction manifold at altitude to that corresponding to sea level. During recent years this has been changed, and supercharging is now employed not just to maintain sea level pressure in the induction manifold, but to boost engines at altitude, in order to develop high B.M.E.P.s and thereby obtain high power outputs at high power to weight ratios.

At this stage in the Symposium three papers have been presented on the subject of Supersonic Flight. They will have left untouched a field which is much too wide and extensive to cover in a single paper. In fact, any attempt to cover the major problems remaining would result in a superficial and valueless effort. However, the general problem of control, particularly that resulting from the elimination of the pilot, is clearly the next major consideration and this is basically the theme of this paper.

Other major problems may be described as those associated with Electrical and Mechanical Engineering; they include power supplies, services and, in particular, refrigeration. If one looks back some twenty years these problems were not considered of any great importance, although at some stage every designer must have decried their reliability. In fact “ electrics again ” seems to have been heard far too frequently when trouble occurred.

Simple Formulae are presented for the first three bending-type and the first torsion-type natural frequencies of any constant thickness cantilever triangular plate. The formulae are derived by a semi-empirical method. Comparison of calculated frequencies with test values indicates agreement within a few per cent. for a variety of plate plan forms.

In modern aircraft, the flying performance, design of the airframe, engines, armament, or the military purpose are the features of principal interest, while the efficiency of the undercarriage is usually known only to a limited number of specialists. Shock-absorber legs, wheels and brakes are now such highly developed structural components that they deserve special attention. In the following, modern types of wheels and bra kes are described in detail and following, modern types of wheels and brakes are described in de the theoretical basis for the calculation of the landing process discussed.

The following paper forms a continuation of a recent work by Prandtl (I) “On the Calculation of Boundary Layers.” It deals with the problem of developing in detail the method, proposed in that paper, for continuing a given velocity profile in a laminar boundary layer when the pressure distribution is given; the method is tried out in practice by numerical evaluation of an example.

Compressor stages are usually designed on the assumption that the gas velocity is nowhere affected by the friction at the walls. The only way in which viscosity is taken into account is in the assumed efficiency, and in a guessed “work-done factor,” which ensures that by aiming high the required work is actually attained.

It is known that the radial profile of the axial velocity component becomes more and more peaked through successive stages of a compressor, so that the assumptions just quoted become very inaccurate. It is possible that the efficiency of a stage could be raised considerably if the axial velocity profile were controlled; moreover up to 20 per cent. more work could be done if a “ work-done factor ” did not have to be applied.

The position to which aircraft construction has proceeded is due in a large measure to the intense metallurgical investigations of recent years. Amongst the materials that have arisen out of this are the light alloys of aluminium, and in particular, that known by the general name “duralumin.” This alloy plays the part of main structural material in many of our present-day aircraft. The object of this paper is to give a brief general account of duralumin with reference to aircraft construction.

The Aerodrome, as the point of contact between the aircraft and the world of reality, has to a large extent been taken for granted. The designer regards it as the base for prototype tests and the airline operator as his aerial railway station. It is my intention to show that aerodrome development is at a critical stage of evolution on this side of the Atlantic, that many of the related problems do concern the aircraft designer and operator, and that if these problems are not given consideration, difficulties will be encountered in civil operations.

To quote an example; the optimum aircraft type to serve a system of air routes can be worked out taking into consideration the range required, payload and speed, but if the aircraft ultimately ordered and produced cannot safely operate from the aerodromes to be served because of the runway length and approaches, then the operations will either have to be reorganised or continued without due regard for safety.