text: REGION 0~ REVERSED COMMAND 
  
  The variation of power or thrust required 
  with velocity defines the power settings neces- 
  sary to maintain steady level flight at various 
  airspeeds. To simplify the situation, a gener- 
  ality could be,assumed that the airplane con- 
  figuration and. altitude define a variation of 
  thrust required or 
  power setting required (jet 
  This 
  prop power required) versus velocity. 
  general variation of required power setting 
  versus velocity is illustrated by’the first graph 
  of figure 6.2. This curve illustrates the fact 
  that at low speeds near the stall or minimum 
  control speed the power setting required for 
  steady level flight 
  is quite high. However, 
  at low speeds, ant increase in speed reduces the 
  required power setting until some minimum 
  value is reached.at the conditions for maximum 
  endurance. Increased speed beyond the con- 
  then 
  for maximum endurance will 
  ditions 
  in&ease the power setting required for steady 
  level flight. 
  
  REGIONS OF NORMAL AND REVERSED 
  This .typical variation of re- 
  COMMAND. 
  quired power setting with speed allows a 
  sort of terminology to be assigned to specific 
  regimes of velocity. Speeds greater than the 
  speed for maximum endurance require increas- 
  ingly greater power settings to achieve steady, 
  level flight. Since the normal command of 
  flight assumes a higher power setting will 
  achieve a greater speed, the regime of flight 
  speeds greater than the speed for minimum 
  required power setting is termed the “region 
  of normal command.” 
  Obviously, parasite 
  drag or parasite power predominates in this 
  regime to produce the increased power setting 
  increased velocity. Of course, 
  required with 
  the major items of airplane flight performance 
  take place in the region of normal command. 
  Flight speeds below the sperd for maximum 
  endurance produce required power settings 