The industrialised nations of the free world are generally committed to the preservation of the right of self-determination for the developing nations, the principle of free trade, and the maintenance of peace. In addition, the source of much of the world's raw materials exists within the national boundaries of the developing nations. As these nations seek independence, both economic and political, it is anticipated that many confrontations will occur, some of which will be military, aided and abetted by the Soviet Union and communist-aligned countries. In enlightened self-interest, it is expected that more and more of the free world industrialised nations will participate in assisting these non-aligned nations in the self-determination process by providing supplies or military equipment in a timely fashion as required. If these are reasonable assumptions, it follows that, during the eighties, there will be a need by many nations for airlift capability for which there is no precedent. Today’s airlift systems are not optimised for these conditions.

Helicopter flight simulators have now been in use in the Royal Navy for fifteen years. The aim of this paper is to discuss the development of the helicopter within naval aviation, and in turn the development of the helicopter simulator alongside its actual aircraft counterpart. The uses to which the Royal Navy puts its simulators will be detailed, with particular reference to its most used simulator, the Sea King Flight and Mission Simulator. The expanding use of helicopters will be discussed, with a look at the Royal Navy’s present day aircraft, the Lynx, and its simulator. The assured future for flight simulation within the Fleet Air Arm will be explained.

Helicopters have been used by the Royal Navy since 1944, when four R4s were purchased from Sikorsky’s, and the change over of the Fleet Air Arm from an all fixed wing force to an almost totally helicopter force can be seen to be due to both operational considerations and political events.

In recent years digital computer technology has been employed to produce visual images for use in the training of aircraft pilots by simulation. The technology employed is that of computer graphics which has been in use since the 1950s in a variety of man-machine systems. The rudiments of a basic computer graphics system are represented schematically in Fig. 1. They are a graphics computer and a human operator. The interaction proceeds as follows:

• (i) the computer produces a visual image;

• (ii) the operator sees the image;

• (iii) the operator generates a response which he sends to the computer;

• (iv) the computer in turn causes some change in the visual image.

The use of this closed loop communication may vary greatly from application-to-application but the principles are universal.

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.

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.

A stiffened shear web, consisting of a thin plate (referred to simply as the web) attached to longitudinal members (or flanges) and supported by a series of transverse stiffeners, buckles in a mode involving both the web and stiffeners, at a shear stress which also depends on the restraint between the web and flanges. With increasing stiffener size changes in the mode of buckling occur until, at a certain critical value of the flexural stiffness of the stiffener, buckling is largely confined to the web between stiffeners, and the buckling coefficient is then practically constant. The buckling coefficient reduces to that of an unstiffened flat plate with decreasing stiffener size.

Engineering Sciences Data Item 02.03.02 plots buckling coefficients for long shear webs with uniform, equally-spaced stiffeners. The curves are based on work by Stein and Fralich, for stiffeners of zero torsional rigidity and simply-supported longitudinal edges, and on a more recent series of papers by Cook and Rockey (listed in the Data Item) which extend the analysis to clamped, as well as simply-supported, webs and also include the torsional rigidity of the stiffeners.