text: The climb performance of an airplane is 
  affected by many various factors. The con- 
  ditions of maximum climb angle or climb rate 
  occur at specific speeds and variations in speed 
  will produce variations in climb performance. 
  Generally, there is sufficient latitude that small 
  variations in speed from the optimum do not 
  produce large changes in climb performance 
  and certain operational 
  items may require 
  speeds slightly different from the optimum. 
  Of course, climb performance would be most 
  critical at high weight, high altitude, or dur- 
  ing malfunction of a powerplant. Then, opti- 
  mum climb speeds are necessary. A change 
  in airplane weight produces a twofold effect 
  on climb performance. First, the weight, W, 
  appears directly in denominator of the equa- 
  tions for ,both climb angle and climb rate. 
  In addition, a change in weight will alter the 
  drag and power required. Generally, an in- 
  crease in weight will reduce the maximum rate 
  
  Specific reference points are established by 
  these composite curves of climb performance. 
  Of course, the absolute ceiling of the airplane 
  produces zero rate of climb. The service ceiling 
  is specified as the altitude which produces a 
  rate of climb of 100 fpm. The altitude which 
  produces a rate of climb of 500 fpm is termed 
  the combat ceiling. Usually, these specific refer- 
  ence points are provided for the airplane at 
  the combat configuration or a specific design 
  configuration. 
  
  The composite curves of climb performance 
  for the typical turbojet airplane are shown in 
  figure 2.22. One particular point to note is 
  the more rapid decay of climb performance 