text: center of gravity aft of the main wheels a bal- 
  ancing load on the tail wheel must be produced 
  toward 
  the center of turn. When the tail 
  wheel is free to swivel, the equilibrium of the 
  turn requires a control force opposite to the 
  direction of turn-i.e.. 
  force insta- 
  bility. 
  The inherent stability problem exists 
  because the center of gravity is aft of the point 
  where the main side forces are developed. This 
  is analogous to the case of static 
  condition 
  longitudinal 
  the center of 
  gravity aft of the neutral point. 
  
  control 
  
  stability with 