text: the turbojet powerplant 
  be appreciated. 
  or adjusted 
  operates at less than the “trimmed” 
  the deficiency of 
  speed for maximum thrust, 
  thrust 
  for takeoff may cause a considerable 
  increase in takeoff distance. During approach, 
  an excessively low RPM may cause very low 
  thrust and produce a very steep glide path. 
  In addition, the low RPM range involves the 
  much greater engine acceleration time to pro- 
  duce thrust for a waveoff. Another compli- 
  cation exists when the thrust is proportional 
  to some large power of rotative speed, e.g., 
  Nb.O. The small changes in RPM produce 
  such large variations in thrust that instruments 
  other than the tachometer must be furnished 
  for accurate indication of thrust output. 
  The “specific fuel consumption, ci’ 
  
  If 
  
  is an 
  important factor for evaluating the perform- 
  ance and efficiency of operation of a turbojet 
  engine. The specific fuel consumption is the 
  proportion between the fuel flow (in lbs. per 
  hr.) and the thrust (in lbs.). For example, 
  an engine which has a fuel flow of 14,000 lbs. 
  per hr. and a thrust of 12,500 lbs. has a specific 
  fuel consumption of: 