NO. 5 STABILITY OF AEROPLANES HUNSAKER AND OTHERS 



present state of our knowledge, the calculation of the stability of 

 circling flight appears impracticable. 



o' 



s- 



^S" 



Fig. 20. — Curves of normal force, longitudinal force, and pitching moment as 

 angle of yaw changes. 



For flight in a straight line, we may reasonably conclude that if the 

 lateral motion be stable it will not compromise the stability of the 

 longitudinal motion, and vice versa. Such a machine should, in still 



