text: is the principal effect of the wing planform. 
  The relationship for induced drag coefIicient 
  emphasizes the need of a high aspect ratio 
  for 
  continually 
  In other 
  operated at high 
  words, airplane configurations designed to 
  operate at high 
  the 
  major portion of their flight (sailplanes, cargo, 
  transport; patrol, and antisubmarine types) 
  demand a high aspect ratio wing to minimize 
  the 
  the high aspect 
  ratio wing will minimize induced drag, long, 
  thin wings increase structural weight and have 
  relatively poor stiffness characteristics. This 
  fact will temper the preference for a very high 
  aspect ratio. Airplane configurations which 
  are developed for very high speed flight 
  (es- 
  specially supersonic flight) operate at relatively 
  lift coefficients and demand great aero- 
  low 
  dynamic cleanness. These configurations of 
  airplanes do not have the same preference for 
  high aspect ratio as the airplanes which op- 
  coefficients. 
  erate continually at high 
  This usually results in the development of low 
  aspect ratio planforms for these airplane con- 
  figurations. 
  
  the airplane which  is 
  
  lift coefficients. 
  
  efhcient. Decreasing aspect ratio increases the 
  wing drag coefficient at any lift coefficient since 
  the induced drag coefficient varies inversely 
  with aspect ratio. When the aspect ratio is 
  very low, the induced drag varies greatly with 
  lift and at high lift coefficients, the induced 
  drag is very high and increases very rapidly 
  with lift coefficient. 