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Originally Posted by wheelsup  I'll be honest, I find it hard to believe climbing at 270 saves 500# of gas. Even on a 2 hour flight you're saying you increase fuel efficiency almost 10%? Hmmm I dunno. I agree with power off descents, I know UPS has been working with ATC to perfect them as much as possible. However it's not always possible to go from FL320 to 3 mile final without touching the thrust levers. Maybe in podunk AR but certainly not anywhere on the east or west coasts. Also just because you burn less gas at a higher altitude doesn't mean it's cost effective to go up there, one has to consider the additional burn to reach that higher altitude.
I start a trip tomorrow, I'll plug 270/.7 into the VNAV page to see what the FMS calculates fuel burn at on some legs and get back to you. I'm not trying to downplay your work, I applaud this sort of stuff, I am an efficiency connoisseur, however I remain skeptical of any "magic" profiles. |
Give it a shot but re-read the post. 500 lbs over a 2 hour flight with a combo of the climb, higher cruise alt, and a steeper decent. Not just a steep climb. I was getting between 300-500 lb differences on the long flight (1.5hours+ enroute). On the short stuff there is not much difference cause you don't go high or far.
In the Vnav you would want 270/.70, cruise at 290/.74 (default), decent at 320/.74 (to get an idle decent not a .77 acceleration) and the default planning to 4.0 degrees. I would be interested in seeing how it works out for others.