text: condition (I) applies some known condition 
  of velocity, thrust required, and specific 
  range for (&QCD),, 
  basic altitude. 
  
  at some original, 
  
  condition (2) applies to some new values of 
  velocity, 
  required, and specific 
  range for (fi/CD)mm at some different 
  altitude. 
  
  and 
  
  The combined effect of these three factors de- 
  fines altitude as the one most important item 
  affecting the specific range of the turbojet air- 
  Pl ane. As an example of this combined’effect, 
  the typical turbojet airplane obtains a specific 
  range at 40,ooO ft. which is approximately 150 
  percent greater than that obtained at sea leirel. 
  increased TAS accounts for approxi- 
  The 
  mately two-thirds of this benefit while 
  in- 
  creased engine performance (reduced cJ ,~ ‘ac- 
  counts for the other one-third of the benefit. 
  For example, at sea level the maximum spe- 
  cific range of a turbojet airplane may be 0.1 
  nmi/lb. but at 40,000 ft. the maximum specific 
  range would be approximately 0.25 nmi/lb. 