text: An unbelievable feature of gliding perform- 
  ance is the effect of airplane gross weight. 
  Since the maximum lift-drag ratio of a given 
  airplane is an intrinsic property of the aero- 
  dynamic configuration, gross weight will not 
  affect the gliding performance. 
  If a typical 
  jet trainer has an (L/@- 
  can obtain a maximum of 15 miles horizontal 
  distance for each mile of altitude. This would 
  be true of this particular airplane at any gross 
  
  Type airplane: 
  
  (L/D) emz 
  25-40 
  12-20 
  2~25 
  1~15 
  14-16 
  lo-13 
  4-9 (subsonic)  High performance sailplane. 
  Typical patrol or transport.. 
  High Performance bomber. 
  Propeller powered trainer.. 
  J et trainer.. 
  Transonic fighter or attack.. 
  Supersonic fighter or attack. 
  
  of 15, the aircraft 1 
  
  32 
  
  Revised Januay 1965 