text: When the airplane has a supersonic cruise for 
  maximum range, the optimum flight path is 
  generally one of a constant Mach number. 
  The optimum flight path is generally-but not 
  necessarily-a climbing cruise. 
  In this case of 
  subsonic. or supersonic cruise, a Machmeter is 
  of principal importance in cruise control of the 
  jet airplane. 
  
  An important comparison can be made between 
  the constant altitude cruise and the cruise- 
  climb with respect to the variation of specific 
  range. From 
  the previous relationships, a 
  2 percent reduction in gross weight durmg 
  
  The @ct of wind on nznge is of considerable 
  importance in flying operations. Of course, 
  a headwind will always reduce range and a 
  increase range. The 
  tailwind will always 
  the most 
  selection of a cruise altitude with 
  favorable (or least unfa:vorable) winds is a rel- 
  atively simple matter for 
  the 
  propeller powered airplane. Since the range of 
  the.propeller powered airplane is relatively un- 
  affected by altitude, the altitude with the most 
  favorable winds is selected for range. However, 
  the range of the turbojet airplane is greatly 
  affected by altitude so the selection of an op- 
  timum altitude will 
  involve considering the 
  wind profile ‘with the variation of range with 
  altitude. Since the turbojet range increases 