Oldpilot, I assume you mean "Revert" and not "Reset", as I can't find a "Reset" on the screen or under the "Options" button. What he wants is to eliminate the winds from the calculation. Your method reverts to the previous altitude, but continues to calculate the winds at that altitude into the flight time, fuel burn, etc. When you close the "Altitude Planning..." screen, the "Flight Planning screen will tell you in the lower left corner whether or not the winds are included in the calculations.