text: NAVWEPS DGROT-50 
  STABBITY AND CONTROL 
  
  The contribution of sweepback to the lateral 
  dynamics of an airplane is significant. Since 
  the dihedral effect from sweepback is a function 
  of lift coefficient, the dynamic characteristics 
  may vary throughout 
  the flight speed range. 
  When the swept wing airplane is at low C,, the 
  dihedral effect is small and the spiral tendency 
  may be apparent. When the swept wing air- 
  plane is at high C,, the dihedral effect is in- 
  creased and the Dutch Roll oscillatory tendency 
  is increased. 
  
  spiral motion is so gradual that the pilot can 
  control the tendency without difficulty. 
  
  An additional oscillatory mode is possible 
  in the lateral dynamic effects with the rudder 
  free and the mode is termed a “snaking” oscil- 
  lation. 
  is greatly 
  affected by the aerodynamic balance of the 
  rudder and requires careful consideration in 
  design to prevent light or unstable damping 
  of the oscillation. 