Some of the uses of ground based flight simulation as a research tool to aid the design of new aircraft and their equipment are described. The function of the simulator is to provide a method for investigating humon flying tasks in the laboratory, so that the relationship between the pilot's capabilities and the equipment's characteristics can be systematically studied. The paper is presented in two parts describing recent work on two research simulators at the RAE.

Part I deals with the use of simulation for studying aircraft stability and control characteristics. The equipment used at RAE for this work is described, with particular emphasis on methods of presenting to the pilot a simulated view of the outside world, and for reproducing some of the motion cues which he experiences in flight. Experimental evidence of the importance of these simulation cues when making aircraft control assessments is also presented. Several examples of simulation studies into the control of conventional and VTOL aircraft are given, to illustrate the type of research problems in this field which may be tackled and the techniques involved in solving them.

Part II deals with the development, from a simple flight simulator used in tachistoscopic studies of attitude displays, to more advanced equipment used to study an instrument system for high-speed low-level flight. This involved the concept of information flow in parallel and visually-mediated control loops, for visual and instrument flight, requiring developments in the simulation of visual flight, by a tele-visual method, and in the assessment of tracking performance, by a method of mean modulus errors; these developments allowing observation of performance of concurrent visual tasks. Flight trials confirmed simulator studies of learning effects, information capacity and instrument to visual transition. The complete scheme of simulation included ground control and autopilot facilities.

The activity at Woomera leading to the first flight trial of Blue Streak had two distinct phases. First, the activation of the Blue Streak site and second the preparation, static firing and launching of Blue Streak F1. These events are described in two parts, Part I dealing with the site preparation and Part II with the F1 trial.

Measurements of oscillatory derivatives made in various tunnels at the NPL over the past few years have indicated that slotted walls, as used in high-speed tunnels, may give rise to large interference effects on damping derivatives. Other workers in this field, notably in America, have also observed interference effects both with solid and with slotted walls. This paper presents the available evidence, so that those making similar measurements may be aware of the effects.

Five years have now elapsed since the last report on helicopter development in France was given by Francois Legrand, then Chief of the Rotary Wing Section at the “Service Téchnique de l'AéYonautique”. At that time, Sud-Aviation had been in existence for two years and the production of helicopters was at an early stage, with almost only French operators. In 1963, Mr. Legrand became Sud-Aviation helicopter chief designer; since 1959, the position of France in the helicopter production world has asserted itself considerably.

Any vehicle that is required to travel at high speed over the surface of the earth (either land or water) should have

• (a) Low drag and

• (b) Some form of spring suspension.

Anyone who doubts the need for the second of these, for travel over water, should consider the accelerations involved in following the surface of the sea at high speed and observe the behaviour of a high-speed motor boat on rough water.

The Vast amount of knowledge on the operation of long-haul jet aircraft will inevitably pass on to the short-haul jet; but it is felt that, in the take-off régime, further study must be done. A short-haul jet will probably average 8 to 12 take-offs a day—considerably more than a long-haul jet— and many of these take-offs will involve relatively minor airfields with short runways. In addition, on a world-wide basis, there is an increasing awareness of obstacles under the flight path. Roberts of North Central Airlines and Cooke of United Airlines have emphasised this aspect from the operator's point of view. As an example, calculation of a single point involving an obstacle limited take-off weight would take a pilot at least an hour. For efficient short-haul operation, this wastage of time is prohibitive.

It is of interest to investigate the design of a damped vibration absorber as a problem in feedback control. The method can then be compared with the vector solution presented in reference 2.

The auxiliary system M2, K2, c is regarded as a feedback element modifying the response of the main system. The method leads to the use of approximations to construct the response curve and for optimising the design of the damper.

In using resistance wire thermometers for measuring transient gas temperatures, such as internal combustion engine exhausts, errors occur due to the thermal inertia of the wire and conduction along it and the supports.

Benson and Brundrett analysed the situation by solving the heat transfer equation for a particular case where the gas temperature was assumed to vary sinusoidally with time. An estimate of the maximum error for particular sizes of wire could be obtained. Conduction in the supports was neglected.

Recent studies of the performance of high-speed aircraft have emphasised the importance of engine-airframe integration. For example, Probert and Mallinson, and Bragg have pointed out the advantages of jet deflection in producing extra lift with little penalty in decreased thrust. Townend has drawn attention to producing thrust or lift on high-speed aircraft by external heat addition, and has calculated the effects on the range of the aircraft.

Nadai and Bassali have discussed problems concerning plates supported at several points. Timoshenko and Woinowsky-Krieger have studied circular plates supported at several points along the boundary. In the present note the author has obtained an analytical solution for the problem of circular plates with bending moments applied at several points along the boundary. Some particular cases are also considered.

Let Г be a closed curve in the z-plane with p-axis of symmetry. The mapping function

maps in general the interior of the unit circle |ξ| < 1 on to the interior of Г such that ξ=0 is transformed into z=0.