question concerning fuel calculations

[Guest bisinchi]

Hi,I wanted to fly from Paris to Rio de Janeiro, that is a 5042Nm flights, so I went through the fuel planning bit of the documentation my weight was 485,000 lbs, so I planned for 212000+10000 of fuel for the trip, on top of that I added 25000lbs of reserve and 10000 lbs in case. Well, in total I entered 259000 lbs of fuel.I entered the flight into the FMC and the fuel prediction when I activated the route gave me a remaining fuel of 17000 lbs, which I translated as 236000 lbs of fuel needed for the flight, which was much more than the predicted 222000 lbs originally planned, what would cause such a difference?I didn't enter any winds prior to the FMC giving me these figures.Regards,Fran

[michal 44]

Because of all the contingency fuel you added (which is OK) your planned landing weight will be much higher than the 475,000 lbs. The table you used for fuel planning (page 2-7) is only valid for landing weight of 475,000 - in your case you have to make correction (as descrobed on page 2-7) and you should be ok. Follow the description in the manual how you plan your landing weight but once you know this number you have to make final adjustments as described on page 2-7.Michael J.http://www.precisionmanuals.com/images/for...argo_hauler.gifhttp://sales.hifisim.com/pub-download/asv6-banner-beta.jpg

[Guest bisinchi]

Thanks for the answer, that might actually answer the question!!Cheers,Fran