text: SR2 
  -= 
  SRI 
  
  where 
  
  condition (1) applies to some! known condi- 
  thrust required, and 
  at some 
  
  tion of velocity, 
  specific range for (&/CD)- 
  basic weight, Wi 
  
  condition (2) applies to some new values of 
  required, and specific 
  at some different 
  
  velocity, 
  range for (&/CD)- 
  weight, W, 
  
  The maximum range is obtained at the aero- 
  dynamic condition which produces a maximum 
  proportion between the square root of the 
  lift coefficient (CJ and the drag coe&cient 
  (CD), or (&/CD)-. 
  In subsonic perform- 
  ance, (G/C > D - 
  occurs at a particular value 
  angle of attack and lift coefficient and is un- 
  affected by weight or altitude (within com- 
  pressibility 
  At this specific aerody- 
  namic condition, 
  induced drag is approxi- 
  mately 25 percent of the total drag so the 
  turbojet airplane designed for long range does 
  not have the strong preference for high aspect 
  the propeller airplane. 
  ratio planform 
  
  and 
  
  V= velocity, knots 
  W=gross weight, lbs. 
  Tr= thrust required, lbs. 
  .SR= specific range, nmi/lb. 
  
  a 5 percent increase in velocity 
  a 10 percent increase in thrust required 
  a 5 percent decrease in specific range 
  when flight is maintained at the optimum con- 
  Since most jet airplanes 
  ditions of (&/CD)-.  like 