The present time, when the prospect of high speed flight often seems to recede, not to approach, may well be a good occasion to review the ram-jet, an engine whose main use is at high flight speed. We owe the succinct name “ ram-jet” to the Americans and the original idea to the French. But despite the admirable efforts abroad this paper is most concerned with British ideas, especially and naturally with those conceived and prosecuted at the National Gas Turbine Establishment. At the outset it is appropriate to acknowledge all the separate personal contributions to the subject of this paper and the assistance of my colleagues in preparing some of the information presented.

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.

I Consider it a great honour to be invited to deliver the First Lanchester Memorial Lecture, which, according to the instruction received from the Secretary of the Royal Aeronautical Society, should deal with Lanchester's personality and achievements. It is also a great pleasure for me to recall my personal contacts with this great man. On the other hand, I am not quite sure whether the decision of the Council, choosing me as the first Lanchester Lecturer, was really a wise one, since I am not in the best position to present a full biographical sketch of Lanchester. Somebody more familiar with Lanchester's automobile work, as, for example, Sir Harry Ricardo, would be more able to present a full picture of Lanchester's achievements. I must, therefore, restrict myself essentially to the treatment of Lanchester's contributions to the sciences of Aerodynamics, Flight Mechanics and Operational Analysis.

This is the first meeting at which it has been possible to talk openly about transonic tunnels with ventilated working sections. Many already knew that a large number of tunnels, particularly in the U.S.A. and this country are being built or modified with slotted or perforated working sections. Up to quite recently, however, security considerations have shrouded this work but it is now possible to draw the curtain.

It is never satisfactory to design a structure piecemeal. The whole construction ought to be considered as one unit and designed from the outset to meet each of the several loading actions to which it may be subjected. Part structures designed for one principal loading system and later modified to accord with other part structures or to meet other loading requirements, will seldom prove efficient. Moreover a structure designed from the outset to meet alternative loading cases is necessarily better integrated than a structure designed primarily for one loading case and later modified to meet another.

Until the past few years inertia navigation has been a little known subject due to a cloak of security; but recently a number of informative reports and articles have been published, notably those by Adams, Schnerb, and Klass, all published during 1956. Moreover, many of the components of inertial systems have emerged from the early development stage, during which they were largely monitored by military agencies, and may now be purchased with a guaranteed performance specification.

Early in 1946, when work on guided weapons had only just begun in the United Kingdom, it became clear that there was a future need for a long Range, preferably over land, for the testing and development of guided weapons. Such a Range could not be located in the British Isles, and a survey throughout the British Commonwealth indicated that Australia was most likely to provide a suitable site. Therefore, a party of Ministry of Supply and Ministry of Aircraft Production personnel under the leadership of Lieut. General (now Sir John) Evetts carried out a preliminary survey in 1946, selected a site in South Australia which appeared most suitable and submitted a detailed report to the Ministry of Supply.

This paper contains nothing new to airline people. It is not an original contribution. For some time I had been under the impression that the ideas we use and the troubles we have in the airline business were clearly understood by technical people outside the airlines. Recently, however, I have been surprised to discover that this is not so and this fact is the excuse for the shape of this lecture. So I am not talking to airline people but for them. If, when you have heard me, you have heard nothing you did not know, I shall be happy.

Two simple examples of aeroelastic effect are given in which chordwise distortion is important. The first relates to static distortion of a solid wing at high temperature using non-linear relations derived by Mansfield. It is shown that the chordwise distortion is stabilising as regards divergence, but leads to considerable loss of lift. The second example shows that chordwise distortion can reduce the flutter speed of a flat plate.

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.

Thermal effects in aircraft may arise from kinetic heating, engine installations and auxiliary systems. The first source is potentially of greater importance, although problems in connection with the second source can be severe, especially with vertical take-off aircraft of the “flying bedstead” type. The difficulty encountered in a formal analysis of heat conduction problems when practical boundary conditions are to be satisfied frequently suggests a finite difference approach. This may take the form of direct numerical integration or the use of digital or analogue computers or network analysers in which electrical circuits are arranged to be analogous to the thermal system. Several examples illustrating the use of these finite difference methods are instanced, such as the growth of temperature in a thick plate, the transient distribution of temperature in a rib carrying a hot duct; the chordwise distribution of temperature and transient loss in torsional stiffness in a thin wing due to kinetic heating, and the distribution of temperature and spanwise thermal stress due to kinetic heating in a bay of an integrally stiffened panel. The importance of experimental methods is emphasised and a brief description and illustration of a model fuel tank for simulated kinetic heating tests is given. An urgent plea is made for correlated data on thermal contact resistance of typical aircraft joints, some examples of which are also illustrated. Data is given on some physical and mechanical properties of materials likely to be used for airframes where thermal effects are expected. These include thermal expansion, conductivity, diffusivity, creep, fatigue, specific strength and stiffness, and a parameter called here the “Thermal Stress Efficiency.”

An Address by the President, Sir George Edwards, C.B.E., B.Sc, F.R.Ae.S., was given before a large and distinguished audience of members and their guests at Church House, Westminster, London, S.W.1, on 26th February 1958. Lord Hives, C.H., M.B.E., B.Sc, LL.D., Honorary Fellow, presided. At the end of the Address the second part of the Shell Petroleum Company’s film “High Speed Flight—Part II. Transonic” was shown for the first time.

Following the Presidential Address a Reception was held by the President and Lady Edwards at the offices of the Society, 4 Hamilton Place, W.1, which was attended by over 500 members and their guests.

During my five years from July 1929 at Weybridge the amount that was done was amazing, although the technical and design staffs were microscopic by present-day standards. The types included Vimy, Virginia, Victoria, B.19/27 Night Bomber—all of these were twin-engined—Type 163, 4-engined Night Bomber, a P.V. with tandem engines; Vespa, Vildebeeste Torpedo Bomber and other roles, C.O.W. Gun Fighter, G.4/31 Reconnaissance Bomber (2 versions)—all of these were single engined military machines; Viastra, passenger carrier, Vellore and Vellox Freighters—twin-engined civil aircraft, although Viastra first flew with three engines. All were biplanes with the exception of the C.O.W. Gun Fighter, the Viastra and the second prototype G.4/31 which were monoplanes. Incidentally, the G.4/31 was the first example of geodetic construction, the fuselage being so constructed. My recollection is that Mr. Wallis was responsible for the structural design of this aircraft which had an unusually large aspect ratio. It became the Wellesley, had a most honourable career in the R.A.F. and of course held the world's long distance record for many years.

From time to time, both military and civil aircraft have had a change of power plant to meet special circumstances but in all cases considerable redesign has been necessary and I know of no instance where it has been done in the field by means of a “ modification kit.” It has become quite commonplace to do so for test purposes, that is to make the aeroplane a flying test bed. Douglas DC-3 aircraft have been fitted with Darts and Mambas, Varsity with Elands, Canberras with Olympus and many others.

The past ten years have seen a wide variety of axial gas turbine aero-engines pass through their development phase into military service. A new phase began when the first axial gas turbine engines to operate to a civil schedule entered service in 1956-7, powering the Britannia and Tu.104 aircraft. The coming years will see an ever-increasing percentage of the world’s air traffic being carried by axial gas turbine engines and it may be confidently predicted that in another ten years they will be the rule rather than the exception.

The enormous importance of reliability in civil operation is well known. Possibly less well known is the incredibly rapid build-up of running hours which occurs when an engine is introduced into civil operation. In six months of civil operation these may exceed the cumulative hours in the whole life of a military type, and will outstrip the total manufacturers’ bench experience in an even shorter time. With all the achievements in bench development and military service in the past ten years, the axial gas turbine engine is still in the “ kindergarten ” in relation to civil operation.

Terms used in the description and analysis of the external drag of a body (with or without internal flow) are considered, and definitions suggested for the various components of the drag. Care has been taken to ensure that the proposed terms are consistent with those used in the Panel's report on thrust.

Semi-empirical methods are described for obtaining the normal forces and centre of pressure positions of isolated cone-cylinders and ogive cylinders with and without boat tails at supersonic speeds. The data for normal force slope and centre of pressure at zero incidence is, in general, accurate to better than 10 per cent and half calibre respectively. The data for high incidence must be considered speculative although reasonable agreement has been found with the very limited experimental data available.

Rapid developments in the use of the helicopter were made in the Korean War. These were taking place at the time when there was considerable urge to introduce the gas turbine engine into the civil aircraft market. It was also a time when much effort was being expended on various forms of reaction propulsion, mostly for missiles. A number of new helicopter projects were started, taking advantage of the new knowledge in propulsion engineering; some utilised new gas turbine designs and others various forms of tip jet reaction. Liquid fuel rockets, ram-jets, pulse-jets and air pressure jets were tried. However, the main line of development continued to be the gradual improvement of direct mechanical drive.

Since Korea the natural trend has been first to convert existing helicopters to turbine engines. When new helicopters were designed wisdom dictated mechanical drive pending the gathering of sufficient experience with other forms of rotor power, and so far the accumulated knowledge of the mechanical drive has proved of greater value to helicopter progress than the potential advantages offered by the alternative engine forms.

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.”