For the past few years there has been some interest in aerofoils with blunt trailing edges but most work has been associated with the investigation of the base pressure and the pressure distribution on the aerofoil has received little attention. Nash proposed a method of calculating the pressure distribution on aerofoils with blunt trailing edges in the absence of a vortex street, that is with the vortex street suppressed by means of a splitter plate or base bleed. He assumed that the wake of the aerofoil could be taken into account in the calculation by specifying a pressure distribution along the wake and then applying thin aerofoil theory to the aerofoil and wake. This leads to a mixed boundary problem with the aerofoil shape and the wake pressure distribution specified and the calculation is laborious.

The refractory metals are usually referred to as metals which have melting points equal to, or higher than, chromium. A number of these metals, such as chromium, molybdenum, niobium, and tungsten are already being used quite extensively as alloying elements in both ferrous and non-ferrous alloys. Tungsten has been used in the lamp industry for many years, while molybdenum has been used for heating elements and niobium has been of interest in the atomic energy field.

The advancements in design and efficiency of aero engines has been associated with an increase in engine temperature. If this advancement is to continue, it will be necessary for a new family of alloys to be made available to the engineer. The current nickel-base high temperature alloys are now approaching their limit. It is difficult to be precise about these temperatures because the applications in terms of stress vary widely.

Various natural phenomena can result in sufficient difference of potential between an aircraft in flight and its very rapidly changing surroundings that, immediately adjacent to the aircraft extremities, there will exist potential gradients high enough to produce local atmospheric ionisation or “corona”.

Since there is no effective method known to prevent the development of these potential differences, aircraft are commonly fitted with a number of so-called “static dischargers” or “neutralisers” to control the nature and occurrence positions of the corona in such a way as to minimise the generation and radiation of RF noise, which would otherwise be quite capable of causing complete mis-function of navigational aid systems.

In spite of more active fungicides and improved methods of application, including the use of aircraft, the control of potato blight is not very much better than it was thirty years ago. The basic weakness appears to be the impossibility of achieving and maintaining anything like a complete fungicide cover on the foliage of a growing crop of potatoes. In every season in which the weather favours the parasite a time comes when the number of blight spores is so great that many of the gaps in the fungicide defence cover are bound to be penetrated. Once a number of infections have thus been established in a crop, the progress of the disease is only a matter of time and weather, for each of the new infections normally becomes an ineradicable centre for further spread. If this diagnosis is essentially correct, the chances of major improvements in blight control with our present methods are small. It is therefore desirable to examine the history of blight epidemics in detail, to see if there is any possibility of delaying the build-up of the spore inoculum. This would give the protective fungicides a better chance of holding off the attack until the crop had produced its full potential yield.

My Part of this discussion concerns development for reliability—the part after the original design and before production starts. But this stage cannot be divorced from the other two. All designs evolve from past experience of one sort or another or analogies. So new designs are evolved which use bricks or assemblies or mechanisms which have been used previously, even though perhaps in another way; these pieces have therefore been tested and there is practical experience of their behaviour. This applied to the original design. It is certain, however, that this will require modification, because in the confined space and with the extreme technical requirements demanded in the aircraft industry, any initial design will require modification—if not the scheme has been too pedestrian in concept and will be out-classed by competitive ideas evolved with more daring. Thus once again the designer needs development knowledge.

A summary of available information on the problem of body-wing interference in supersonic flow has shown, inter alia, that a large number of theoretical methods are available for the prediction of interference characteristics. Many of these methods are chiefly concerned with the estimation of overall characteristics, i.e. normal force and pitching moment. Several methods are available to determine the pressure distribution for restricted types of configurations, but these often involve lengthy computation.

It is the aim of this paper (Part I) to summarise a simple yet reasonably accurate method of estimating the pressure distribution and hence (in Part II) the overall characteristics of as general a body-wing configuration as possible. The method which applies essentially to a cropped-delta wing symmetrically mounted on a cylindrical body, achieves reasonable accuracy without considerable computational effort; it is based on certain theoretical results together with empirical modifications. The results for pressure are generally valid up to an angle of incidence, α=6° —8° and in some cases for higher values of α. The overall normal force and centre of pressure position should hold up to α= 10°.

“Built like a—battleship”. I always remember this cryptic remark from one of the deck crew of the Courageous after the first deck landing on this Carrier of the Blackburn Skua well over twenty-five years ago. I still don't know whether this was a compliment or not, but it aptly fitted the rugged aircraft required for the very arduous Naval duties. The Skua was in fact the first monoplane specifically designed for the Navy, and it followed a long string of biplanes starting with the Dart, a torpedo carrying aircraft designed at Brough as a “private venture” immediately after the First World War.

None of these machines were particularly attractive in appearance, restricted as they were in span, length, height and so on, and handicapped with folding wing requirements, and the provision of an alternative float seaplane undercarriage that in most cases determined a large proportion of the main structure of the aircraft.

The strength of a composite material will depend sensitively on that of the fibre chosen for reinforcement. Metallic and non-metallic whiskers can be very strong and other less strong, but more practical, fibres such as carbon, silica and boron are now available in experimental quantities. Some of the non-metallic whiskers, and the last three fibres mentioned, will no doubt eventually be made on a production scale.

The strongest drawn wires yet available have tensile strengths of more than 0.5 X 106 psi which is still only one-third of that of iron or sapphire whiskers, and compares with boron in filament form, although the specific strength of the steel wire would only be one-third of the latter. On the basis of specific strength drawn beryllium wire would be only slightly better than the steel, but would have about 6 times its elastic modulus (E) which is comparable to that of boron.

In the past, the Society did much for Lighter-than-Air, through its lectures, most of which I was able to attend. I well remember that anti-airship man, E. F. Spanner, who used to face a basically hostile audience, and the fighting speeches from that great protagonist for airships, the late Captain Boothby.

The first, I think, to give lectures on airships was the late Colonel Waterlow in 1912 and 1913, but I was at Wellington then, and so was not present. Nobody fought harder than he did for airships, and he was very helpful to me when I used to visit the airship station at Wormwood Scrubbs.

Captain Frank Barnwell is to be remembered as one of the pioneers of practical aviation. His love of flying inspired him and eventually killed him, for it was in an aircraft of his own design and construction that he eventually met his end; but his record of service to aeronautical design shows that he was much more than a brave and gifted amateur aviator. He was a professional engineer, a realist who foresaw the practical application of aeronautics to useful purpose. In an age when many considered aviation an interesting hobby of little practical importance, Barnwell set himself the task of designing aircraft for practical purposes.

The Holzer method is widely used in the solution of the modes and frequencies of lumped parameter torsional systems. Basically the method consists of assuming an approximate value of the required frequency and, starting from one end of the system, determining the amplitudes of vibration station by station. Since the assumed frequency is an approximate one there will be a residual (torque or displacement) at the last station. The true frequency to be determined is that for which the residual is zero. Among the special advantages of the method are that any natural frequency may be obtained directly without a knowledge of the lower modes and, with the use of transfer matrices, the method may be readily adapted for the solution of complex vibration problems using a computer.

The Centenary Year of the Society was launched by the Honorary President, His Royal Highness The Prince Philip, Duke of Edinburgh, by his Foreword in the Centenary Journal. “The hundred years of the Royal Aeronautical Society spans the whole romantic, even fantastic, story of Man's adventure into the air and into space.”

The Annual Reports and the Journal throughout these hundred years have chronicled the story. This Annual Report —the hundred and first—records the contrasting interests of this past year: the advent of the Centenary has resulted in the somewhat nostalgic writings on the past, and considerations on the future have been caused by the Plowden Report.

When Airship No. 1, which had been built at Barrow, was finally abandoned in 1912, her officers were sent to Farnborough as “The Naval Wing” to gain experience of the military airships and of the Royal Aircraft Factory where they were built. A German Parsival Airship, No. 4, and a French Astra Airship, No. 3, were bought by the Admiralty for the Naval Wing.

In 1913 I succeeded in getting transferred to the Naval Wing and I found in the Naval Mess a most inspiring community. Lieut. Commander N. F. Usborne was the dominant spirit.

We want structural materials to be as strong as possible, as light as possible and as stiff as possible. For all practical applications they must be tough or resilient. We might also want them to be of use at high temperatures, to have hard surfaces, to be resistant to corrosion and to be cheap and easy to fabricate.

With all orthodox structural metals strength and stiffness are roughly in proportion to the density of the material. There is therefore not a great deal of difference between them on the basis of specific strength and specific stiffness. This is illustrated in Table I.

There are a number of ceramic substances such as silicon carbide, aluminium oxide, beryllium oxide, boron and carbon which have very high elastic modulus values coupled with low densities and high melting points.