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In this article solutions are set out for various types of external loading of a plate in the shape of an infinite wedge. All the problems considered are two‐dimensional in character and a state of generalized plane stress is assumed throughout. The general approach is that developed by A. C. Stevenson in terms of complex potentials, details of which have been published, but a summary of the results required in this article is included in §1. This method embodies also the use of stress combinations Θ and Φ which together with the complex potentials leads to a compactness of solution which compares very favourably with the Airy stress function method, particularly in respect of boundary conditions. Certain classical problems are presented in this light and used to obtain the approximate stress distribution when the beam is under the action of an elliptically distributed load. The effect of the weight of the beam is also indicated. Although not engaged in work on aircraft design, the writer is encouraged by work previously published on this subject to believe that the solutions contained in this article may have applications in that field.

AMONG the many problems of drag reduction engaging the critical attention of aircraft designers to‐day, that parasitic appendix known as the undercarriage stands out, in more ways than one, as probably the most serious single offender still challenging the ingenuity of the designing engineer in his unceasing quest for aerodynamic refinement. Not so many years ago, however, quite a number of designers were openly sceptical of the mechanical feasibility of retracting the undercarriage unit; at least, in such a manner as to make it economically worth while. One suspects that our devotion in this country to the thin‐wing biplane had something to do with that particular brand of aerodynamic astigmatism, because it was not until the cantilever low‐wing monoplane became an accepted type that the idea of wheel retraction became a fashionable formula.

Retracting mechanisms may be operated either manually or by power systems, according to the type and size of aircraft. Manual systems may be classified into two main groups, mechanical and hydraulic. The mechanical group may be further sub‐divided according to the form of mechanism; e.g., cable and pulley, screw and nut, worm and other gears, all of which have been used for retraction schemes at some time or another. Power systems are even more diverse, many of them being of recent birth and, therefore, still in the experimental stage. Some of the various ways in which power can be applied to drive the retracting mechanism are by: electric motor and mechanical coupling; electric motor and hydraulic pump; aero engine coupling to hydraulic pump; compressed air motor and hydraulic pump; and other pneumatic systems.

Squadron‐Leader A. Firth has been appointed General Service Manager of Blackburn & General Aircraft Limited, and will be responsible to the Managing Director, Mr Eric Turner, for the aircraft and engine post‐production services of the Company. This will include the supervision and control of the field service representatives, the circulation of technical maintenance information and spares provisioning and supply.

A Report on the Second Conference Organized by the Southern Section of the Institution of Production Engineers and Held at the University of Southampton on December 18 and 19, 1953

TODAY aviation is a most influential factor in our lives and Brooklyn a most influential factor in aviation. This was clear to all who attended the very successful conference on High Speed Aeronautics organized as a feature of the Centennial year by the Department of Aeronautical Engineering and Applied Mechanics of the Institute. Over 600 research workers and technicians assembled at the Engineering Societies Building, New York, to hear and to discuss papers by scientists and engineers from America, England, France, Germany, Italy and Sweden.

It was found possible to produce fatigue failure in the blades of a J‐47 jet engine compressor after a comparatively short running period. An analysis was then made to determine the most suitable characteristics for the blade material.

An aircraft or other vehicle in which a stream of air taken in from the surrounding atmosphere is passed through a duct to cool the cooling surfaces placed therein of the engine and in which stream a conversion of energy into pressure takes place before the cooling surfaces arc reached and a conversion of pressure into kinetic energy of the stream at its discharge is raised by transferring to the stream waste heat from the engine at a position behind the cooling surfaces and before further loss of pressure is sustained beyond that involved in passing the stream over the cooling surfaces. The above means are adapted to assist propulsion. In one form, an engine a is mounted in a wing b. Engine radiators bl, b2 are mounted in ducts b3, b1 the leading edges of which are in front or behind the leading edge of the wing. Exhaust manifolds c, c1 are provided with fins c0 and are mounted in the ducts to heat the stream. Hinged flaps c3 are provided at the rear of the ducts. In a modification the duct is situated beneath an engine disposed at the front end of the fuselage and a fan forces air through the duct. The invention may be applied to air‐cooled engines. Specification 447,283 is referred to.

In a retractable aircraft undercarriage in which an articulated radius rod 6, 8 has one of its lengths 8 pivoted about an axis 9 for retracting or extending the undercarriage, the length 8 is formed with an arm 10 connected by a link 12 or its equivalent to the moving part 16 of a fixedly aligned jack, the part 16 being guided in the fixed alignment. As shown, a landing wheel 2 is carried between cross braced shock‐absorber members 1 articulated at 3 to the aircraft wing structure. The radius‐rod 6, 8 is pivoted to the shock‐absorber at 5 and to the wing at 9. The part 16 is guided on a fixed stem 15, of a hydraulic jack 14, the stem is mounted between swing spars 17, 18. The wing is provided with a lined cavity 4n to receive the wheel when retracted. Locking and indicating means may be provided.

THERE has been a very marked tendency of late towards simplifying the control of aeroplanes. Those who have read M. MIGNET'S book on the reasons that led him to develop his Pou de Ciel, will remember that he decided to go back to the beginning, as he himself had found the complications of the normal triple control confusing and complicated. He has consequently gone back to a design which is in essentials strongly reminiscent of the early tandem monoplane evolved by S. P. Langley. This included a heavy dihedral angle with two main planes set in tandem at a fore‐and‐aft dihedral to each other. Lateral stability and control was dependent entirely upon the dihedral angle and the rudder, ailerons being absent.