The idea of using engine power directly to provide the lift required to sustain flight has recurred frequently throughout the history of aviation. Most of these proposals have concerned some form of helicopter, but in a few cases methods of changing the line of action of the normal propulsive thrust to assist the landing and take-off manoeuvres have been suggested. Few, if any, of these schemes were ever successfully put into practice, one of the main difficulties being the excessive weight and bulk of the power plant, but with the development of the jet engine with its compactness and low specific weight this objection largely disappeared and the idea was brought nearer the realm of practical realisation.

Although the Guided Flight Section of the Society was only established last year, there have already been a number of valuable lectures and discussions and we can rely on the Section to provide a series of authoritative papers on various aspects of design and development. It might, therefore, be timely and appropriate for the Society to consider these new weapons in a somewhat wider context; and I propose to discuss the impact of guided weapons on our concept of air power and on the field of aeronautics as a whole. I must make it quite clear that I am expressing my own views; I am not describing official policy.

In December 1905 Wilbur Wright wrote to Octave Chanute, “ We were indeed very much gratified at the commendation of Mr. Wenham, whom we regard as one of the ablest and most useful men who have laboured in the cause of human flight.”

Wenham had written to Chanute expressing his delight at the success of the two brothers and adding, “It removes me from the list of cranks who always stated I was advocating an impossibility.”

There is very little information on the stress concentration which is caused by a notch on one side of a plate in tension and the authors are not aware of any published data based on experiment. The theoretical solutions due to Neuber are for notches of hyperbolic or elliptic form and only give an approximate result for U-notches of varying depth.

In recent years, due to the high cost of continuous supersonic wind tunnels, much attention has been focused on the simpler intermittent “blow-down” tunnel.

Considerable data has been published on most aspects of the design of this type of equipment and quite a number of large installations have recently been brought into operation in the United States, with even larger numbers currently building both in this country and in the United States.

An Adoption of matrix techniques is proposed as a method for the solution of torsional natural frequencies in a branch or geared shaft system. Both fundamental and higher mode shapes and frequencies are produced by a comparatively rapid and straightforward technique. The method is illustrated by a numerical example of a coupled turbine and reciprocating engine system driving a common propeller.

The Calculation of the roots of an algebraic or transcendental equation in a single unknown is a problem of frequent occurrence. For a real root the usual procedure is to obtain a first approximation to the required quantity, graphically or otherwise, and to improve this approximation by successive applications of the Newton-Raphson process. The extension of this process to the improvement of an approximate solution of a set of non-linear simultaneous equations in n unknowns is fairly obvious, but it does not seem to have received much attention in text books, although the case of two unknowns is dealt with in Ref. 2.