Development is the process by which a design conceived to meet a practical requirement is transformed from drawings, and perhaps a working prototype, to a piece of fully engineered hardware suitable for production which will meet the original requirement for performance (including reliability) and cost in a time-scale which makes it useful.

There are thus three main parameters in development: performance, cost and time, which are inextricably related to each other, and which must be constantly in mind during a development programme.

The technical aspect of development consists largely of optimising a basic design, making and proving individual parts of it, particularly where new technology is involved, and finally making and proving the complete equipment.

On receiving an invitation from your distinguished Association to come and speak to you about EUROCONTROL, I was most pleased and honoured. I am glad to be able to represent our Organisation and in the name of the Organisation I wish to thank you most warmly.

Before this gathering of legal experts I, as a technician, would fear to be presumptuous if I did not feel that nowadays no progress is conceivable without close collaboration between the legal and the technical. It is with this thought in mind that I shall lay before you some of the technical reasons which led to the setting-up of EUROCONTROL, the operation, the structure, the achievements and the future prospects of this new European Organisation for the safety of air navigation.

The question, as phrased, suggests there is an optimum method of using graduates; this in turn suggests that all graduates have untapped resources and are ready to learn all that can be put before them.

In my view, it can always be said of any industry that it does not make the best use of any specific grade of labour; good managements, of course, make much more effective use of their labour force than the bad ones.

Graduates vary tremendously in previous training, from say, a mathematics graduate straight from school and college, to a specialist aeronautical graduate with works experience in addition.

Events leading to the inception of the Air Registration Board are described, together with a survey of its make-up. The problem of airworthiness in general is dealt with in broad outline and a variety of problems which have been experienced are dealt with in more detail.

Aeronautical research in South Africa probably dates back to a project which is reputed to have culminated in the successful launching of a glider from a hill in Natal, some twenty years before Otto Lilienthal made his first successful flight in 1895. The glider was constructed by two brothers, Archer and Goodman Houshold, its design having been based on a study of bird flight and its design calculations having been verified by Dr. Colenso, at the time Bishop of Natal. Goodman Houshold was at the controls when the glider made its first and last flight from the hill down to a valley below. Further flights were forbidden by an anxious mother.

In the early 1930s, when the 14-passenger DC-2 made its appearance, it was regarded as too big for anything but transcontinental operations, both from the standpoint of capacity and airport requirements. When its follow-on, the 21-passenger DC-3, came along, it sparked a mammoth new Federal Airport Programme, and several regional air carriers in the United States almost choked on red ink. Others merged into systems big enough to absorb this monster.

Had someone suggested that within a short span of three decades a helicopter carrying 28 passengers would be hedge-hopping around Southern California, operating day and night from “micro” airports, which we call heliports, I am afraid he would have been given a silent stare.

In the past there has been some ambiguity—primarily in the spoken word—attached to the meaning of such terms as “thermal strain”. There is thus a need to standardise terminology. It is proposed that the following definitions be adopted generally. These are common to standard text books and have been adopted as a National Aerospace Standard in America and by the Royal Aircraft Establishment.

The definitions are not phrased for the mathematician, but for the engineer who deals with normal engineering materials. Materials which are not homogeneous or isotropic, for example, require more detailed mathematical definition.

The purpose of this note is to present formulae, derived by stationary energy considerations, for the deflection of an arbitrary length of sandwich structure subjected to the three-point bend test, for comparison with experimental results.

The purpose of this note is to draw a formal parallel between the fundamental hodograph flow equations in subsonic and supersonic regimes when expressed in terms of a generalised velocity parameter. This parameter can cover, by simple algebraic extension, hodograph flows in either regime; it has simple geometrical and dynamical interpretations and models of the combined hodograph plans in terms of this parameter are also suggested.

A similar, and perhaps familiar, velocity parameter appears to have been first used in the solution of certain subsonic flow problems by Tsien, following a suggestion of von Kármán, although a more general and basic form was not described.

A few years ago the United States Air Force became interested in developing a higher temperature version of its standard pitot-static tube capableA of accurate operation to Mach number 5 and 150 000 ft with angles of attack up to 14°. It soon became evident that the existing aerodynamic configuration was inadequate because (a) the sharp pitot pressure source could not be protected from high heat fluxes and temperatures, (b) the static pressure source geometry produced serious errors at Mach numbers above 3·0 for α> 5°, and (c) the static pressure source geometry could be responsible for unacceptably high lag above 100 000 ft altitude because it consists of two orifices of only 0·070 in diameter.

When fluid flows in a tube which rotates about an arbitrary axis, the presence of centripetal and Coriolis acceleration components modify the velocity and pressure fields which exist in the absence of rotation. Barua considered the case of an incompressible fluid flowing in laminar motion through a cylindrical tube which was rotating about an axis perpendicular to itself with uniform angular velocity. For distances well away from the tube entrance Barua illustrated that secondary flow in the r-θ plane occurred and that the axial velocity profile was distorted towards the leading edge of the tube. Since the pressure gradient along the tube is proportional to the gradient of the axial velocity profile at the tube wall the rotation thus has a consequential influence on the resistance to flow offered by the tube.