In recent years the need for high Reynolds number wind tunnel facilities has led to the development of the Cryo-genic Wind Tunnel. In this type of tunnel, the flow is cooled to extremely low temperatures, with the result that at constant Mach number the Reynolds number is greatly increased whilst the power required to drive the tunnel is reduced. The cryogenic tunnel incorporates a means of injecting liquid nitrogen into the free stream. The evaporation of this liquid cools the flow and some or all of the tunnel structure. Once the required low temperature has been reached a steady flow of liquid nitrogen into the tunnel and gaseous nitrogen out balances the heat input through the walls and from the fan and maintains constant pressure in the circuit. In addition to providing increased Reynolds numbers at reduced drive power, the cryogenic wind tunnel possesses numerous other advantages over its ambient temperature counterpart. For a detailed theory see Ref. 1.

It would be amazing if everybody agreed with all of the contents of the White Paper—with the possible exception of its author!

A first reading of ‘Airports Policy’ brought to my mind a stage show, very popular some years ago, called ‘1066 And All That’. With satiric comment, the show traced key dates in British history from the landing of the Conqueror until what was then the present day. With a proper sense of chauvinism, it placarded 1776 and American independence in the dismissive comment: ‘1776—End of American History’.

The Flight Simulation Facility at the Warton Division of British Aerospace provides support for the design and development of advanced military aircraft. In fulfilling this rôle, opportunities often arise for innovation in the required flight simulation equipment. The combat simulator which we will describe is a good example of such an opportunity.

The practice of using flight simulators for research and development is well established, and the range of problems which are solved by this means is continually growing. Computers, which are at the heart of all simulators, are being improved at a remarkable rate, and improvements in other areas—electronic, hydraulic and mechanical, all contribute to more effective simulators. At the same time, the demand for simulation increases because the cost saving trade-off improves as the cost of flight testing to the ever-more-stringent design goals increases.

Previous attempts to analyse clamped skew plates by Galerkin's variational procedure have resulted in discrepancy occurring for rhombic plates. Iyenger and Srinivasan employed along both of the skew axis of the plates the characteristic displacement functions for the normal modes of vibration of a clamped-clamped beam. Their results compared well with those of other investigators but not with Kennedy which differed significantly from the others for rhombic plates.

It was a great pleasure for me to accept the invitation to give this lecture on European Pioneer’s Day and at the same time a great honour to be able to revive the memory of Max Schuler, an ingenious engineer and scientist, whose work in a most remarkable way influenced the development of aerospace technology. For many decades Schuler (Fig. 1) was actively working in the fascinating field of gyros and their numerous applications, especially on problems of navigation, stabilisation and attitude control. Schuler’s name is closely associated with the gyro—which the British astronomer Sir John Herschel once described as ‘a philosophical instrument’. But it had a long way to go before it became a useful technical device. I will try to cover this development and say some words on what the method of ‘Schuler-tuning’ means and how it was detected.

I am sure you will remember those days and weeks, more than five years ago, when we anxiously waited to hear news of the different Apollo missions to the moon. We were astonished at the scarcely believable precision of these flights and in my opinion technical outsiders were in a much better situation than specialists, for they were under more stress because of their knowledge about the function of the subsystems in the extremely complicated Apollo spaceship.

In 1951, Tsien and Evans successfully solved the problem of finding the optimum flight path for a vertically ascending sounding rocket (Ref. 1). Hibbs, in 1952, solved the problem of finding the optimum burning program for horizontal flight of a winged, rocket-propelled vehicle (Ref. 2). Since then work on optimal flight paths within the atmosphere has stagnated, most work being done for constant thrust, programmed in angle, in vacuo.

The present work extends Tsien and Evans', and Hibbs' work, to flight paths off the vertical. Although the simpler paths produced analytical solutions in the time domain, the present solution is not analytic and is carried out numerically using distance or path length as the independent variable.

The dangers of using contaminated runways are a continuing concern in the aviation industry. A recent survey has reported on a total of 39 overrun and veer-off cases in the USA between 1962 and 1973 and in 26 of these cases the runway condition was cited as the major cause. The degradation of aircraft landing and take-off performance depends on the depth of water on the runway and thus an instrument is required that will give quick accurate remote estimates of runway water depth without hindering normal operational procedures. A suitable method, using a differential pressure transducer has undergone field tests and the instrument and preliminary results are discussed in this report.

Responses to Bermuda 2 in the United States range from cheers to castigation and from praise to predictions of doom. I have included in these remarks quotations from various public figures in my country which illustrate the diversity of views held with respect to that agreement.

In order to grasp fully the spectrum of reactions to Bermuda 2, one must first understand current changes and developments in American aviation policy.

In order to understand our new policies, however, one must have an appreciation of political influences as they impact on our international aviation programmes.

Frankly, as I do not understand either the policies or the politics, this should make for a very short speech. I have a story to tell you, however, that should contribute to your perception and comprehensive of the American scene.

I have been asked to describe the American attitude toward Bermuda 2 from a Pan American perspective. I will not burden you at length with an introspective analysis of how happy or unhappy we are with the results. We did not anticipate that the negotiations would be a tea party, and the event was certainly not as universally acclaimed on the US side as was the Boston Tea Party (an affair whose 204th anniversary will be celebrated in about two weeks).

As you know, a good deal of dissatisfaction with Bermuda 2 has been expressed in various quarters in the United States, some of it informed and quite sincere, some of it unrealistic and exaggerated. Pan American, which thought it had the most to lose in the negotiations, was confirmed in that expectation. However, we have not engaged in sterile recrimination. The United States side was ably and effectively represented.Had the responsi-bility been ours, we cannot say that we could have made a better overall bargain given the ability and tenacity of the opposition and the need felt on both sides to reach an accommadation.

As a total pressure sensor in laminar or turbulent flows, the conventional, circular, pitot-tube, with a sharp plane mouth and diameter ratio of about 0.6, has long been known to be insensitive to yaw within about ±10°, relative to the incident stream direction, and, apart from a few isolated attempts to design special pitot-probes having a flat yaw response of over ±45° or thereabouts, information on pitot-tube response at very large yaw angles (>45°, say) is virtually non-existent, even though such information might be sometimes useful.

In this brief note is presented some exploratory measurements of pitot-tube response in a uniform stream at two particular yaw angles, namely 90° and 180°. While the 90° angle was chosen largely out of pure curiosity, the choice of 180° yaw has been motivated by some questions raised in a study on pressure-probe interference in a vortex flow. Included is a brief discussion of the effects of shear on the pitot-tube response.

Many methods and computer programs, e.g. those listed in reference 1, give ‘exact’ initial buckling loads for prismatic structures which consist of thin, rectangular plates which are rigidly connected together along their longitudinal edges. The component plates can be flat or curved, isotropic or anisotropic and can carry any combination of longitudinally invariant in-plane stresses, i.e. longitudinal, transverse and shear stresses. The working which follows can be extended to cover all such plate assemblies, but for simplicity attention is confined to assemblies of uniformly longitudinally compressed, isotropic, flat plates with simply supported ends. The stiffened panel of Fig. 1 is typical of such assemblies, and hence is used to represent them below, because the extrapolation from this particular assembly to the general is obvious.

My contribution to these proceedings will be to comment on the strong and weak points in the Government's White Paper from the standpoint of the major airport operator concerned—the British Airports Authority. There cannot be many other businesses operated today which are subject to such a numerous and varied number of voices and influences telling the operator what to do, how to do it, when to do it and where to do it. If there are, I'm sorry for them!

The British Airports Authority is a profitable public enterprise set up 11 years ago (as the result of the last White Paper) to own and operate airports. We run seven airports, four in Scotland (Aberdeen, Prestwick, Edinburgh and Glasgow) and three in the South-East of England (Heathrow, Gatwick and Stansted). About 75% of the UK's passenger traffic and 85% of air cargo go through the BAA's airports.

The electrical power consumed by an Earth-orbiting satellite is usually generated by panels of solar cells. On a vehicle such as the ESA Orbital Test Satellite the panels are attached, in cantilever fashion, to a relatively rigid centre body upon which are positioned the communication systems, attitude sensors and control equipment. The pay-load limitations of the launch vehicle imply that the relatively large solar panels must be of a lightweight construction and they are very flexible structures as a consequence. Currently-operating satellites do not appear to be troubled by the flexure of their solar panels. However, it is likely that attitude control problems will arise in the next generation of vehicles which will be equipped with considerably larger panels of solar cells.

The issue that I have been asked to deal with is the contribution that could be made to improving motivation and productivity in British industry by developing the quality and effectiveness of supervision. This seems to require four things: a general discussion of the ‘problem’ of supervision; an examination of the main characteristics of supervisory systems in British manufacturing; a review of some recent attempts to develop the supervisory function and a set of conclusions pointing out alternative policies which seem to be required.

The idea that supervision is ineffective and conservative was argued by Frederick Taylor and others some 70 years ago and has been repeated by management specialists ever since. His remedy in Shop Management was to propose greater specialisation of control functions at shop floor level and the abolition of ‘general foreman’ positions. Such an approach was built on the argument that supervision was too weak and could not cope with the number and range of problems encountered in running a workshop or production system. His ideas led to the development of specialist functional departments, particularly for planning, industrial engineering and quality control; they did not lead to the abolition of the foreman role, although the scope of responsibilities within that role was greatly reduced.

The problem of determining the attitude of a satellite, spinning in space, with its angular velocity being an arbitrarily specified time function, although of significant interest, has long remained analytically intractable in view of the complexity of the non linear coupling in the system of equations governing the Eulerian angles that prescribe the attitude of the satellite. Even the relatively simpler case of a satellite spinning with constant angular velocity poses significant analytical complexity, but has been solved recently. Although, numerical solutions to specific cases are not hard to obtain, the closed form solution, which brings out the inherent properties, is still of interest to the analyst. Accordingly, this study is aimed at an analytical method of solution to the governing equations. It is shown that the three, coupled, non linear, non-autonomous, first order, differential equations can be reduced to a single, equivalent, linear, uncoupled, autonomous equation of second order, through a differential transformation technique. The solution of this equivalent linear equation, is easily obtained and can be mapped onto the original space to derive the Eulerian angles. This backward transformation, using the transformation relations that established the equivalence of the non linear and linear systems of equations, is shown to be feasible as long as certain integrability conditions are satisfied by the input angular velocity time function. The earlier study is easily observed to be a particular case of this generalised analysis.

When one sits down and considers the title of this paper and its implications, I have no doubt that for most people and certainly for me, the word responsibility must conjure up a host of meanings largely depending on what sort of person one is, and what one's experience of life has been.

There is not any point in my talking about the ‘permission’ I would have thought, except to say for anyone in this audience who is unaware, that each operating Ag company negotiates with the CAA, in my view in a somewhat tedious way, for the issuance of this document; in it is set down the way the operator intends to run his show, and in effect it constitutes the rule book. Anyone here who is interested can obtain from the Cheltenham Stationery Office a copy of the guide to the Permission. Hitherto the permission has been free, but for this season it will cost £500 plus £300 for each aircraft on the register, no less, in line with the CAA's campaign to cover its costs.

From the two ‘approximate’ theories of bending—Elementary Theory and Winkler available to designers for the determination of bending stresses in beams having initial curvature, the Winkler approximate solution is the one closer to the exact solution development by Golovin.

Timoshenko and Goodier show a comparison of stresses resulting from the three theories for a beam having rectangular cross-section. It is shown here that the values of bending stresses given by Winkler theory are very close to Golovin's exact results. The difference between the two theories lies in the range of 0·1–3·1 % increasing with the ratio, c/a, of the outer to inner radius of curvature of the beam. The above close relationship between the two theories for a beam of rectangular cross-section is also reported by Ford.