text: The modern high speed airplane configura- 
  tion is typified by low aspect ratio, swept wing 
  planforms with relatively large yaw and pitch 
  inertia. The aerodynamic characteristics of 
  such a configuration are shown in figure 4.32. 
  The lift curve (C, versus U) is quite shallow at 
  high angles of attack and maximum lift is not 
  clearly defined. When this type of airplane is 
  provided a rolling motion at high angles of 
  attack, relatively small changes in C, take 
  the 
  place. When this effect is combined with 
  relatively short span of this type airplane, it is 
  apparent that the wing autorotation contribu- 
  tion will be quite weak and will not be a pre- 
  dominating pro-spin moment. The relatively 
  large changes in drag coefficient with 
  rolling 
  motion imply .a predominance of yaw for the 
  spin of the high speed airplane configuration. 
  Actually, various other factors contribute 
  to the predominating yaw tendency for the 
  the modern airplane configuration. 
  spin of 
  The static directional stability deteriorates at 
  high angles of attack and may be so weak that 
  extemely large yaw displacements result. 
  In 
  certain instances, very high angles of attack 
  may bring such a decay in directional stability 
  that a “slice” 
  or extreme yaw displacement 
  takes place before a true spin is apparent. At 
  these high angles of attack, the adverse yaw 
  due to roll and aileron deflection can be very 
  strong and create large yaw displacements of 
  the airplane prior to realizing a stall. 