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razorseal

insufficient fuel from FMC?

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I'm currently flying a route from KMIA to EDDF. keep getting the 'insufficient fuel' from the FMC. it shows @EDDF i'll be at 0.0I remember it did this on my last flights as well, and I ended up having many many pounds to spare upon landing. as a matter of fact, I compleletly filled all the tanks just to see what it will say and it still said ins. fuel @0.0 upon landing...Right now I havemain 1/4 - 24 eachmain 2/3 - 57 eachcenter - 43.7 res 2/3 - 2.7 eachI'm currently 470nm W of the COLOR int. to give you an idea of where I am (about 100 miles E of YQI on the 290R)let me also add that cost index is currently 120

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You will have that warning even if you have 100 tonnes left in the tanks at landing. The Insufficient Fuel warning comes on when the fuel estimated to remain at landing equals or is less than the Reserve you set in the PERF INT page. For example, if your fuel load is sufficient according to your flight planner, and said planner takes into account the wind at each waypoint, you should have enough fuel. But, if you are also going to be flying with mostly heavy tailwinds and you don't put in this information in the FMC, it will make an assumption that the winds are zero along your entire route. As a result, if you set a reserve of 12 tonnes, at takeoff, you will have the Insufficient Fuel message. Your FMC may even say that you will have 0.0 tonnes of fuel left. This is because you will save fuel because of the tailwind, but the FMC doesn't know about it yet. As far as it's concerned, you are going to have no help and no opposition. Therefore, as you fly, the estimation of fuel will gradually go up. Now when you come into land you should have about 15 to 17 tonnes at landing if there were no delays.Just as a note, you should fly with just enough fuel to get to your destination plus a 45 minute reserve plus taxi fuel plus your holding fuel. I personally usually have >17 tonnes at landing. If you carry too much fuel, believe it or not, it reduces your range.Hope this helps. And if it's complicating, tell me and I'll try to simplify it. Ryan GamurotLucky to live Hawai'ihttp://www.virtualpilots.org/signatures/vpa296.png

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"main 1/4 - 24 eachmain 2/3 - 57 eachcenter - 43.7res 2/3 - 2.7 each"If you have this amount of fuel in your tanks, you are not filling your tanks properly or managing your fuel pumps/crossfeeds properly.Your reserve tanks and main tanks should be completely full before you consider putting fuel in the center tank.If you have fuel in the center tank, you should burn all that fuel first.Let PMDG fill your tanks for you, using a total fuel value (use the PMDG menu). Then (suggested option for beginners), prior to takeoff, switch on ALL fuel pumps and open ALL crossfeed valves. The EICAS should then prompt you to take correct action. e.g. If tanks become empty, switch off the pumps for those tanks. If you get a TANK/ENG prompt, switch off your Override Jettison Pumps and close your 1&4 crossfeeds... and of course, read the manuals and tutorials ;)Cheers.Q>

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Another thing to check is your Progress page and see how far the FMC thinks you need to fly. I sometimes get a bit of a shock when I see the distance is way out in left field. You can then check to LEGS page and find the offending waypoint and remove it.

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yeah, I know something wasn't right hah!and I'll check that stuff out guys thx!I didn't know there was a fueling option in the PMDG menu, going to look at it now :(and I thought the wind info was automatically put in from the INS (or was it IRS since we got GPS :()

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"and I thought the wind info was automatically put in from the INS (or was it IRS since we got GPS :()"The FMC knows the current wind (from the IRS and ADC system), but it doesn't know what wind is further down the track (unless you tell it). The FMC computes times based on both current and expected winds.Cheers.Q>

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