text: The effect of altitude on climb performance 
  is illustrated by the composite graphs of figure 
  2.22. Generally, an increase in altitude will 
  increase the power required and decrease the 
  power available. Hence, the climb perform- 
  ance of an airplane is expected to be greatly 
  affected by altitude. The composite chart of 
  climb performance depicts the variation with 
  altitude of the speeds for maximum rate of 
  climb, maximum angle of climb, and maximum 
  and minimum level flight airspeeds. As alti- 
  tude is increased, these various speeds finally 
  converge at the absolute ceiling of the airplane. 
  At the absolute ceiling, there is no excess of 
  power or thrust and only one speed will allow 
  steady level flight. The variation of rate of 
  climb and maximum level flight’ speed’ with 
  altitude for the typical propeller powered air- 
  plane give evidence of the effect of supercharg- 
  ing. Distinct aberrations in these curves take 
  place at the supercharger critical altitudes and 
  ~blower shift points. 
  The curve of time to 
  climb is the result of summing.up the incre- 
  incre- 
  ments of time spent climbing 
  ments of altitude. Note that approach to the 
  absolute ceiling produces tremendous increase 
  in the time curve. 