1. The dynamics of aeroplane motion is a comparatively new subject, and one that arouses interest in all students of mechanics. Although a full study of aeronautics involves the use of complicated analysis, yet some really useful information about aeroplane motion can be obtained with quite simple mathematics. It is the object of this paper to draw attention to such methods and results. It will be seen that some of the investigations can be understood by mere beginners in mechanics; others are more suitable for such students as have had considerable experience of mechanics.