This paper gives an account of some of the practical display problems met in day to day airline operation by BEA and the application of this experience to the improved displays specified for the Trident.

The main contribution of psychology to the design of displays up to the present time has been in advising on detailed points of design. It is suggested that there are three areas in which psychology can make a useful contribution; these are

(a) in stating the basic characteristics of the human operator, particularly the working of the perceptual mechanism,

(b) in stating the effect of environmental conditions on performance, and

(c) in assessing the information required and in advising on man's rôle in the system.

Recent work on the Head-Up Display (HUD) has shown properties of continuous transition, easy learning and accurate use, when certain design principles are followed. Use of HUD in manual landing has suggested application as a monitor for automatic landing and another use is for the directed take-off.

Developments in display techniques have led to a proposal for an electronic flight instrument display (EFID), suitable for head-down, as well as head-up presentation. Economy in presentation area may result from compressing a number of displays into a single format, and from using the same area for a number of displays presented in sequence.

Similar flexible techniques applied to the topographical map display suggest a general-purpose plan position display, complementing the “front elevation” display of flight instruments. These ideas are combined in a proposal for an advanced cockpit layout.

To write a paper on the work of the Royal Aircraft Establishment is a formidable task. To summarise the programme of work of the Establishment would either provide material for a series of lectures or, if compressed to a single lecture, would lead to a cursory and superficial treatment. I make no apologies, therefore, for not attempting any sort of complete survey. Within the scope of this lecture all I intend to do is to give a brief description of the RAE, what it is, what it does and how it is organised and then to consider a few items drawn from three of the RAE's research programmes, which have been selected to show some of the characteristics of the RAE and the kind of work which goes on there.

The first series of items to be presented fall in the field of the slender wing. The great potentiality of the slender wing for a wide range of applications was apparent from the time the concept was first considered. What I want to stress is the enormous range of detailed researches which are required before such a concept can be used in practical designs.

THE SST project is the largest, most expensive and most dubious project ever undertaken in the development of civil aircraft. It is dubious because of the concern about the side effects of supersonic flying on a regular basis, the main one being the sonic boom. Apparently the more one learns about the sonic boom, the more intractable it appears.

The project is unique in that in Europe it was instigated by, and financed by, the Governments for airlines and not by airlines. A similar, although not exactly the same, pattern is followed in the USA.

Another main characteristic of the SST is that no airline has ever asked for it, but the project existing has tempted a few airlines to put in tentative orders, which has encouraged other airlines out of fear to put in other orders.

The general run of technical unknowns is pretty well-known, one of them being how to get rid of the heat caused by the friction of the air at the high speeds involved. However, probably the greatest doubt lies in the improbability that the SST will be able to be profitable in operation. I agree that it is possible to make any given number of calculations on this matter, all with reasonable degrees of honesty, and half of them will show that airlines will make money and the other half will show the opposite. This is merely a measure of our lack of knowledge of these aircraft.

We have heard that the SST project is the largest and most expensive project ever undertaken. It is fairly large and it is expensive. When making comparisons, however, it is important to remember that major developments in aviation have rarely been cheap. For some civil projects the subsidy has been indirect. For example, the present generation of successful American long range air liners, notably the Boeing 707, has succeeded to a large family of military progenitors and thereby enjoyed its massive inheritance. Even so, funds spent on the 707 development must have been substantial, for many hundreds of aircraft needed to be sold before the break-even point was reached. Those firms in the USA, lacking the advantage of a military ancestor, must have seen the prospect of profitability in the civil field, in straight competition with those better placed, as an illusive difference between two very large sums—launching expenditure and prospective income.

Now, and in the future, all civil projects everywhere must fight for existence without benefit of feed-back from a related defence project.

The question is whether to fight at all in this remorseless arena. Presumably nearly all at a meeting of the Royal Aeronautical Society would not agree that this country should reject the challenge.

This paper is in effect an illustrative case study based in part on an actual study but including also a large amount of subsequent work.

In the previous paper the cost structure of an air transport system was considered and some models appropriate to capital investment and procurement programmes were discussed. The importance of obtaining optimal utilisation of this capital equipment was stressed, and delays, especially during turn-round of aircraft at airports, were mentioned as one group of factors which reduce utilisation both of aircraft and airports and which therefore merit attention by the OR scientist.

Instead of proceeding immediately with the broad survey of models referred to in the second article, the opportunity is taken at this point to consider intensively one particular set of investigations focused on this problem area. It is based on field work done some years ago on the apron of an airport by A. M. Lee and the author, and is concerned with the human controller of turn-round operations.

It is of special interest in that it demonstrates the increasing ability of science to tackle problems previously considered intractable to any rigorous scientific method.

A decade has elapsed since triangular elements under constant strain and stress were independently introduced within the matrix Displacement Method by the Turner group at Boeing and the Aeronautical Structures Department at Imperial College. They proved a considerable success in the practical analysis of complex membrane shapes as occur in modern aircraft wings. However, the original formulation based on a local cartesian system of axes and the classical concept of stress and strain inevitably leads to an unsymmetrical and aesthetically (as well as computationally) unfavourable expression for the stiffness matrix k. Moreover, the method was restricted to isotropic media. The necessity of extending the theory to finite displacements ultimately showed the inadequacy of the past approach and guided the writer to the creation of new concepts, e.g. the natural stiffness of an element. This natural stiffness, which ignores the rigid body motions and is hence of dimensions (3 X 3) for a triangle with three nodal points, relates in a concise manner the nodal force components parallel to the sides and the elongations of the sides themselves. A powerful tool in its derivation and further development was a new definition of stress and strain vectors which excludes shearing contributions and only works with direct components parallel to the sides. The idea has also been extended to tetrahedra and many standard elements which are incorporated as a basic feature in the structural language ASKA (Automatic System for Kinematic Analysis) developed at ISD by the Applied Programming Group under Dr. H. Kamel. These fundamental ideas were emphasised in the author's recent lecture to the Society.

The Navier-Stokes equations are solved iteratively on a small digital computer for the class of flows generated within a rectangular “cavity” by a surface passing over its open end. Solutions are presented for depth/breadth ratios ƛ=0.5 (shallow), 10 (square), 20 (deep) and Reynolds number 100. Flow photographs ore obtained which largely confirm the predicted flows. The theoretical velocity profiles and pressure distributions through the centre of the vortex in the square cavity are calculated.

In an appendix an improved finite difference formula is given for the vorticity generated at a moving boundary.

Since Thorn began his pioneering work some thirty-five years ago the number of numerical solutions which have been obtained for the equations of incompressible viscous fluid motion remains small (see bibliographies of Thom and Apelt, Fromm). The known solutions are principally for steady streaming flows, although two methods have now been used with success for non-steady flows (Payne jets and Fromm flow past obstacles). By contrast this paper is concerned with the class of closed flows generated in a rectangular region of varying depth/breadth ratio by a surface passing over an open end. This problem has been considered for a number of reasons.