text: The axis system of an 
  airplane defines a positive rolling, L, as a 
  moment about the longitudinal axis which 
  tends to rotate the right wing down. As in 
  is con- 
  other aerodynamic considerations, it 
  venient to consider rolling moments in the 
  coefficient form so that 
  lateral stability can 
  be evaluated independent of weight, altitude, 
  speeds, etc. The rolling moment, L, is defined 
  in the coeflicient form by the following equa- 
  tion : 
  
  L=C,qSb 
  
  or 
  *
  
  +I 
  0 
  where 
  
  L=rolling moment, ft.-lbs., positive  to 
  
  the right 
  
  4 = dynamic pressure, psf. 
  S=wing area, sq. ft. 
  b = wingspan, ft. 
  C,=rolling moment coeflicient, positive 
  
  to the right 
  
  The angle of sideslip, 8, has been defined 
  previously as the angle between the airplane 
  centerline and the relative wind and is positive 
  when the relative wind is to the right of the 
  centerline. 
  
  The static lateral stability of an airplane can 
  be illustrated by a graph of rolling moment 
  coefficient, Cl, versus sideslip angle, 8, such 
  as shown in figure 4.27. When the airplane 
  is subject to a positive sideslip angle, lateral 
  stability will be evident if a negative rolling 