The 744 FMS at Cost Index = 0 gives you max range for the current altitude INCLUDING wind effects. Theoretically, you cannot find a more fuel-efficient cruise speed. If you are at optimum altitude, you theoretically cannot find a better fuel burn. Also, since tailwind corrections will generate cruise speeds less than no-wind cruise speeds, all the way down to max enduarance speed (minimum fuel flow), you may indeed be significantly "nose cocked Up" in these situations, but NEVER on the "back side of the power curve."
Note that the FMS does not take into account wind differences at different altitudes, so some other way to determine best altitude for the wind profile must be found.
If the company is PLANNING your fuel for CI=0, you will have NO extra fuel available, and will burn more than planned if you run into ANY adverse weather/winds.
Last edited by Intruder; 28th April 2006 at 12:14.