text: HIGH LIFT DEVICES 
  
  There are many different types of high lift 
  devices used to increase the maximum lift co- 
  efficient for low speed flight. The high 
  lift 
  devices applied to the trailing edge of a section 
  consist of a flap which is usually 15 to 25 per- 
  cent of the chord. The deflection of a flap 
  produces the effect of a large amount of camber 
  added well aft on the chord. The principal 
  types of flaps are shown applied to a basic sec- 
  tion of airfoil. 
  The effect of a 30’ deflection of 
  a 25 percent chord flap is shown on the lift 
  and drag curves of figure 1.17. 