text: CONTROL SURFACES. The design of con- 
  trol surfaces for transonic and supersonic flight 
  involves many important considerations. This 
  fact is illustrated by the typical transonic and 
  supersonic flow patterns of figure 3.19. Trail- 
  ing edge control surfaces can be affected ad- 
  versely by the shock waves formed in flight 
  above critical Mach number. 
  If the airflow 
  is separated by the shock wave the resulting 
  buffet of the control surface can be very objec- 
  tionable. 
  In addition to the buffet of the sur- 
  face, the change in the pressure distribution due 
  to separation and the shock wave location can  Therefore, for the wing in supersonic flow, 
  three- 
  no upwash exists ahead of the wing, 
  dimensional effects are confined to 
  the tip 
  cones, and no local induced velocities occur 
  along the span between the tip cones. The 
  
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