text: The component of speed parallel to the lead- 
  ing edge could be visualized as moving across 
  constant sections and; in doing so, does not 
  contribute to the pressure distribution on the 
  swept wing. Hence, sweep of a surface pro- 
  duces a beneficial e&ct ‘in high speed flight 
  since higher flight speeds may be obtained be- 
  fore components of speed perpendicular to the 
  leading edge produce critical conditions on the 
  wing. This is one of the most important ad- 
  vantage of sweep since there is an increase in 
  critical Mach number, force divergence Mach 
  number, and the Mach number at which 
  the 
  drag rise will peak. In other words, sweep will 
  delay the onset of compressibility effects. 
  
  the effect of wing sweep will 
  apply to either sweep back or sweep forward. 
  While the swept forward wing has been used 
  1 in rare instances, the aeroelastic instability of 
  such a wing creates such a problem that sweep 
  back is more practical for ordinary applica- 
  tions. 
  
  Generally, 
  
  226 
  
  Revised Jaanuar~ 1965 