It would seem that Mr. Heughan (Journal, March 1954) has missed the basic design criterion of drag exerted for a given weight (and bulk) penalty. No mention is made of this fundamental point in the choice of a device for the reduction of the landing run of an aircraft. The choice of comparison of the “Wake brake” with a 7 ft. brake parachute has therefore been made somewhat arbitrarily. Brown does not state that “the usual size of a parachute used for braking an aeroplane is 7 ft.”; on page 271 of the reference concerned (“Parachutes,” Sir Isaac Pitman, 1951), a case for “a particular aircraft” was quoted as “ using a 7 ft. parachute.”

The paper outlines the existing procedures employed in the field of defence procurement and mentions some new ones which may be used in the near future. It will serve as a reminder of the way in which major aircraft and weapon and equipment projects are conducted and will lay the foundations for what is hoped will be a fruitful discussion.

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 preparatory work of the preceding technical note is followed up by deriving the elastic stiffness and the initial load vector of an arbitrary TRIAX 6 element subject to an axisymmetric state of stress or strain.

A simple model is presented for an aerofoil with a recirculating Prandtl-Batchelor region behind a spoiler. Using thin aerofoil theory the model is posed as a pair of coupled nonlinear singular integrodifferential equations for the shape of the separating streamline and the distribution of vorticity along the aerofoil. These equations are solved numerically and results are presented. In particular, some conclusions are drawn regarding the lift on such aerofoils.

The paper discusses the application of wind tunnels to aircraft design and consideration is given to the potentialities and limitations of types designed specifically for industrial use. Arguments affecting the choice of type, size and speed are stated and a detailed description is given of a particular tunnel which has very steady and even flow with a reasonable turbulence level. This description covers the aerodynamic and engineering design, the electrical driving arrangements and the six-component automatic balance.

A description is also given of a new type of high speed tunnel which has recently been put into operation. This is of the simple straight-through type and is driven by a jet engine acting as an ejector pump; the exhaust heat is used to control humidity and prevent condensation in the working section. This tunnel reaches a Mach No. of 0.9 when empty, and over 0.85 with a model in place. The Reynolds No. is 1.6 x 106 for a three-dimensional half model and 5 x 106 for two-dimensional wings.

No one who has the honour to serve on the Council of this Society, and can therefore be tackled in person once in every month, can long avoid the additional but more alarming honour of being called upon to lecture. When I in my turn was brought to bay, I cast about for a suitable subject, but could not satisfy myself that any of the work in which I happen personally to be engaged had a sufficiently general appeal. I therefore decided to take advantage of my association with the Aerodynamics Department of the National Physical Laboratory, and to base my lecture on the work of other men. I want to make this clear at the outset, because I may omit in some instances to attribute credit where credit is due, and at all events it must be understood that the credit does not belong to me.

In some recent tests we have successfully used the smoke from smouldering paper to indicate the flow of air in the vortices above slender wings at speeds in the region of 200 f.p.s. Smokes of this kind are particularly suitable for the production of the large volume flows required because in certain conditions they do not lose density by condensation in long supply tubes.

Ladies and Gentlemen, I feel that an introduction to our lecturer this afternoon is hardly necessary, as I am sure he is well known to most of you, but perhaps one or two may not be so well acquainted either with his background, or his work in rotating wing aircraft

Mr Pullin is the Managing Director and Chief Designer of the Cierva Autogiro Co Ltd, a Founder Memb2r of our Association, a Fellow of the Royal Aeronautical Society, and a Member of the Institute of Mechanical Engineers He has been actively engaged in the research and development of rotary wing aircraft since 1932, but his interest in aviation goes back to pre-1914 when he learnt to fly at Brooklands in the good old days He has been engaged in engineering for about 30 years, covering in this time, several of its different branches

The terms “cost-effectiveness” and to a lesser degree “cost-benefit” analysis have become familiar words in the technical and national press, the former usually in relation to defence projects—the latter in relation to social projects, such as transport, power generation and building. Indeed, at the time of the last General Election the political correspondent of a national newspaper wrote, “Mr. Heath and Mr. Callaghan, Chancellor of the Exchequer, vied with each other in stressing the importance of cost-effectiveness, which used to be known as getting value for money”.

The apparently simple concept of “value for money” raises three important issues:

(i) how is “value” of defence and social projects quantified?

(ii) what is the “money” involved, i.e. what are all the relevant costs? and

(iii) what are the information and decision processes that are used in attempting to obtain “value for money“?

The object of this talk is to give you a situation report on the Concorde flight test programme and to indicate the progress made to date.

Two aircraft have been engaged on the programme so far, the prototypes 001 and 002 (Fig. 1). The French base for Concorde flight test operations is at Toulouse and the British flight test base is at Fairford in Gloucestershire. The two prototypes will be joined in the flight test programme next year by the two pre-production aircraft, 01 and 02.

As is well-known, Concorde is a slender delta wing aircraft and it may be appropriate at this stage to state some of the considerations that led to the choice of this configuration. By virtue of a large root chord, the delta wing can overcome all the disadvantages of lack of structural stiffness and lack of wing volume associated with thin highly swept wings and yet remain aerodynamically thin.

Stability criteria for systems governed by linear differential equations with constant coefficients are discussed in a general way. Detailed treatment of the sextic equation includes a simple and expeditious scheme for computing the test functions.

This is a story of trouble and action—of an industry's trouble—of a company's, and in particular a division's actions, to ensure that there would be, in fact, a path to the future. The future, it turns out, probably will never be quite the same as the past—and I will cover some of that too. I have titled the three parts of the story Reduction in Cost, Increase in Sales, and Results and Comments.

Part of the material contained in this paper was originally written in early 1972 when I was Vice-President and General Manager of Boeing's largest commercial division, the one with which the paper is primarily concerned. The material was written for presentation to the management of another company in serious trouble. The story is that of a traumatic series of years in the life of one of the world's major companies. It is viewed of necessity from my position at that time as head of the company's largest division and does not constitute an official history of that period of life of The Boeing Company, even though some of the charts apply to the company as a whole rather than to just the division involved.