text: From this relationship it is appreciated that 
  is a direct 
  the rate of climb in steady flight 
  function of the difference between power avail- 
  If a given airplane 
  able and power required. 
  configuration is in lift-equal-to-weight 
  flight 
  there 
  at some specific airspeed and altitude, 
  is a specific power required to maintain these 
  If the power available from the 
  conditions. 
  is adjusted LO equal the power 
  powerplant 
  required, the rate of cl&b 
  This is illustrated in figure 6.1 where the power 
  available is ser equal to the power required at 
  If rhe airplane were in steady 
  velocity (A). 
  level flight at velocity (A), an increase in 
  power available would create an excess of 
  power which will cause a rate of climb. Of 
  course, if the speed were allowed to increase 
  by a decreased angle of attack, the increased 
  power setting could simply maintain altitude 
  the 
  at some higher airspeed. However, 
  original aerodynamic conditions arc maintain- 
  ed, speed is maintained at (A) and an increased 
  power available results in a rate of climb. 
  Also, a decrease in power available at point (A) 
  will produce a deficiency in power and result 
  in a negative rate of climb (or a rate of descent). 
  is apparenr. that pomr 
  For 
  setting is the primary control of altitude in Jtcady 
  Bight. There is the direct correlation between 
  the excess power (Pa-P,>, and rhe airplane 
  rate of climb, RC. 