The purpose of this paper is to outline briefly the aerodynamics of high-lift devices in the most general possible way to provide the background against which the more detailed advances in calculation methods to be described by the RAE may be viewed. At the same time it is intended to discuss the factors affecting maximum lift coefficient in which the methods described in the RAE paper may be used to obtain improved performance.

The object of this paper is to illustrate the high-lift research programme at the RAE. It is not intended to be a complete survey of all aspects of this programme, but rather to highlight areas which will stimulate discussion of the programme. Again, it was not intended to consider only completed research work, but rather to illustrate the problems that are being investigated, and the ways in which solutions to these problems are being sought.

Throughout this paper I shall be using the term Guided Weapon to describe a weapon which receives corrections to its direction of flight after leaving the launching device, the corrections being related in some way to the measured relative positions and behaviour of the target and weapon. With this definition some rocket weapons are guided, others are not; most of the so-called ballistic missiles are not. I must also emphasise that the opinions expressed are my own, although I gratefully acknowledge the permission of the Ministry of Defence, Navy Department, to publish the paper. I have drawn on UK Naval experience, in much of which I have been personally involved, but at various stages the evolution of Naval guided weapons has been mixed inextricably with that of the other Services’ weapons. For this reason I chose a more general title for the paper.