text: LATERAL DYNAMIC EFFECTS 
  
  Previous discussion has separated the lateral 
  and directional response of the airplane to 
  sideslip. This separation is convenient for 
  detailed study of each the airplane static 
  lateral stability and the airplane static direc- 
  tional stability. However, when the airplane 
  in free flight is placed in a sideslip, the lateral 
  and directional response will be coupled, i.e., 
  simultaneously the airplane produces rolling 
  moment due to sideslip and yawing moment 
  due to sideslip. Thus, the lateral dynamic 
  motion of the airplane in free flight must 
  consider the coupling or interaction of the 
  lateral and directional effects. 
  
  The principal effects which determine the 
  lateral dynamic characteristics of an airplane 
  are : 
  
  (1) Rolling moment due to sideslip or 
  
  dihedral effect (lateral stability). 