This paper develops the theory of turning flight in a
moving air mass to explain some of the problems
encountered in making downwind turns, particularly
in light aircraft. Although the basic mechanics of
flight and aerodynamics of the aircraft are well
understood, the methods used by the pilot to control
the aircraft in turning flight are less well
established and can be critical in maintaining a
safe flight path. In this paper the effect of the
control strategy likely to be employed by a pilot
flying close to the ground is used to show how the
energy loss during a turn can lead to an unsafe
flight path.