As the treatment of the different subjects must be brief and general this paper can only deal with the complex subject of aircraft fatigue in very broad terms, attempting to trace the development of the subject over the past ten years or so, to present some of the problems and the methods being adopted to solve them and to emphasise the very wide extent to which fatigue affects aircraft design today.

The fatigue of metals was recognised as a separate form of failure as long ago as 1854 and is now the subject of a very extensive literature. Mechanical engineers have long been familiar with fatigue as a criterion of design and are apt to be critical and even amused at the aeronautical engineer's recently found interest.