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Texas Hood

Md-11 -- Fmc Insuf. Fuel (but Not)

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When I load the program manager with my cargo and adjust fuel accordingly (best guess), at times the FMC will tell me I don't have enough fuel so I increase it in the Load Manager so that I won't get that message anymore. When I flew today from KOAK to PHNL I landed with about 33,000 lbs of fuel in each tank (started with 175,000 lbs total). I wish I had some afterburners so that I could at least use that fuel up for fun :( . 1. I am sure I am doing something wrong but I can't tell what it is, any assistance would be great thanks. 2. I am also not sure how to figure a better amount of fuel that I would need other than guessing, is there a freeware fuel calculator out there that somebody knows about? (of course the first question needs to be solved before this one).PMDDG I think I have said it before but I gotta say it again, Wonderful aircraft.OUTSTANDING!!! job guysRyan Gann

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Ryan,Most likely the FMS is calculating more reserve fuel than what it predicts you will arrive with. Do another flight and when you get the message post a screenshot of the FMS Weight Init 2/3 page

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If you were flying with real weather, than that would be your problem. You were flying westbound over the US. You had tailwind on the whole flight. Your actual vs. FMS flight time would also be off. Depending on how deep you wan't to go into realism, you can purchase FSBuild, and it will issue you flight plan using real wind conditions. I'm 80% finished with my version of the GE MD-11, there's still a small bit of tweaking to go. But as I'm flying now, after a 10 hour flight I'm within 1500 kilo's of Flightplan fuel. The correct procedure would be to then enter the average wind component of your whole flight in the INIT page. This will give you spot on the same trip fuel. The cumbersome way is to add all winds to the LEGS section, but why the hassle.Xander

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Don't forget the FMS system is not just looking at route fuel (fuel usage if everything goes to plan) but it wants sufficient Holding fuel, Alternate fuel (if selected), taxi fuel, reserve fuel then expects a positive extra fuel number, if extra fuel is calculated with a negative number it will display insufficent fuel.Also as said if the FMS calculated enought fuel at the start of the flight then got unexpected head winds which could push it out of it calculations, doesnt mean you are actually low but if you got diverted or had to hold for a extended period you could be caught out.Jay V

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If you were flying with real weather, than that would be your problem. You were flying westbound over the US. You had tailwind on the whole flight. Your actual vs. FMS flight time would also be off. Depending on how deep you wan't to go into realism, you can purchase FSBuild, and it will issue you flight plan using real wind conditions. I'm 80% finished with my version of the GE MD-11, there's still a small bit of tweaking to go. But as I'm flying now, after a 10 hour flight I'm within 1500 kilo's of Flightplan fuel. The correct procedure would be to then enter the average wind component of your whole flight in the INIT page. This will give you spot on the same trip fuel. The cumbersome way is to add all winds to the LEGS section, but why the hassle.Xander
I would offer the alternate viewpoint that waypoint winds are indeed worth all the hassle. The FMC is wonderfully attuned to aircraft performance at various weights, fuel being the largest variable through consumption. Should you enter average winds you would alternate INSUFFICIENT FUEL with enormous FUEL REM predictions and still end up with a less than stellar FUEL REM figure- entering the waypoint winds allow for more precise computations, and allow the FMC to calculate the appropriate est FUEL REM for each leg, thereby voiding the INSUFFICIENT FUEL messages in the MCDU. FSX weather has its own set of issues that are far from being resolved satisfactorily......FUEL REM targets obviously vary with the destination, Wx, ATC anticipated delays, ALT distance (esp. during island operations with distant alternates). Deciding to fly this platform correctly, inherently will require meticulous pre-flight planning.Arriving at a destination some 4000 miles away, through complex Wx patterns, over hostile terrain and with the destination Wx at minimums; with FUEL REM spot on is an entirely separate facet of this sim. The satsfaction achieved is immense, but the work involved is also representative of a $300,000,000 investment ;).Either way- you are flying something never seen/experienced in FS before- enjoy!

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Oh YES I do love this aircraft without a doubt so much so that the last couple of days I've been researching the internet about cockpit building (shhh don't tell the wife). my only concern is the fact that to get rid of the fuel message I have to put an extremely large amount of fuel (yes I know it's a long flight) and end up landing with what seems to be over half of what I left the airport with. I don't belive that real pilots do that and that is why it seems like I am doing something wrong but I just don't know what.I will post a couple of before shots and after shots in the next day or two because I have a nice 9:00 hour flight coming up.NOTE: on my fuel page I get total fuel and some letters next to it (see Example) what do they mean? I didn't see them there during the tutorial flight but I am a sound guy not a lighting guy.EXAMPLE: 170.0/FF+FQWhat does the FF and FQ mean?Thanks ya'llRyan

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Reference FMS.10.23: FF fuel flow sensor and fuel quantity sensor, used to calculate useable fuel on board.

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