text: (2) Yawing moment due to sideslip or 
  
  static directional stability. 
  
  (3) Yawing moment due to rolling veloc- 
  
  ity or the adverse (or proverse) yaw. 
  
  (4) Rolling moment due to yawing ve- 
  locity-a 
  If the 
  cross effect similar to (3). 
  aircraft has a yawing motion to the right, 
  the left wing will move forward faster and 
  the 
  momentarily develop more lift 
  right and cause a rolling moment to the 
  right. 
  
  (3) Aerodynamic side force due to side- 
  
  slip. 
  
  (6) Rolling moment due to rolling ve- 
  
  locity or damping in roll. 
  
  With certain exceptions during the condi- 
  the dihedral 
  tions of landing and takeoff, 
  effect or lateral stability should be positive 
  but light. The problems created by excessive 
  dihedral effect are considerable and difficult 
  to contend with. 
  Lateral stability will be 
  evident to a pilot by stick forces and displace- 
  ments required to maintain sideslip. Positive 
  stick force stability will be evident by stick 
  forces required in the direction of the controlled 
  sideslip. 
  
  (7) Yawing moment due yawing velocity 
  
  or damping in yaw. 
  
  (8) The moments of inertia of the air- 
  
  plane about the roll and yaw axes. 
  
  The complex interaction of these effects pro- 
  duces three possible types of motion of the 
  airplane: (a) a directional divergence, (b) 
  a spiral divergence, and (c) an oscillatory 
  mode termed Dutch roll. 