At this stage in the Symposium three papers have been presented on the subject of Supersonic Flight. They will have left untouched a field which is much too wide and extensive to cover in a single paper. In fact, any attempt to cover the major problems remaining would result in a superficial and valueless effort. However, the general problem of control, particularly that resulting from the elimination of the pilot, is clearly the next major consideration and this is basically the theme of this paper.

Other major problems may be described as those associated with Electrical and Mechanical Engineering; they include power supplies, services and, in particular, refrigeration. If one looks back some twenty years these problems were not considered of any great importance, although at some stage every designer must have decried their reliability. In fact “ electrics again ” seems to have been heard far too frequently when trouble occurred.