text: The total drag of the airplane is the sum of 
  the parasite and induced drags: Parasite drag 
  is the sum of pressure and friction drag which 
  is due to the basic configuration and, as de- 
  Induced drag is 
  fined, is independent of lift. 
  the undesirable but unavoidable consequence 
  In the process of 
  of the development of lift. 
  creating lift by the deflection of an airstream, 
  the actuai iift is inclined and a coimponcn: of 
  lift is incurred parallel to the flight path direc- 
  tion. This component of lift combines with 
  any change in pressure and friction drag due 
  to form the induced drag. 
  to change in lift 
  While the parasite drag predominates at high 
  speed, induced drag predominates at low speed. 
  Figure 2.1 illustrates the variation with speed 
  of the induced, parasite, and total drag for a 
  specific airplane configuration in steady level 
  flight. 
  
  The power required for flight depends on the 
  thrust required and the flight velocity. By 
  definition, the propulsive horsepower required 
  is related to thrust required and flight velocity 
  by the following equation: 
  
  The total power required for flight can be 
  considered as the sum of induced and parasite 
  effects similar to the total drag of the airplane. 
  The induced power required is a function of the 
  induced drag and velocity. 