Before I configure the FMC I start FSpassengers inputting how much cargo weight, loading passengers and selecting the amount of fuel I have calculated for the flight out. FSP automatically takes that amount of fuel in weight/gallons and spreads it our evenly out all 3 tanks ( example 40% full in Left, Right and center tanks). I can change this but not sure what I should put in which tank. Should I completely fill the wing tanks and whatever is left put in the center or should I just leave an equal amount in each tankI use the 737-900 aircraftThanksChris

I think the wings get filled before the center tank.

Hi,According to Tim Metzinger's tutorial, there should be a minimum of 150 gallons in the center tank (about 1000 lbs) and if there is more than that, the wing tanks must be full.Hope this helps,Bruno

Thanks, Yeah I saw that while going online. Found a download for a fuel planner for pmdg which said the same thing. All this time I was doing it wrong. Sad.Thanks for the replies guys

Thanks, Yeah I saw that while going online. Found a download for a fuel planner for pmdg which said the same thing. All this time I was doing it wrong. Sad.Thanks for the replies guys

Sorry, keep forgetting to add my name to my replies (last reply).Chris

Since the PMDG 737 NG is fairly old, you can base your fuel filling requirements on what used to be the case but is no more, since a modification which became available in mid 2004 for the real NG. The NG's fuel pumps are located in the tanks, whereas on earlier 737s they were in a dry area in the wing root, this means that older NGs had to maintain a minimum amount of fuel in the tank, and that had to be monitored manually. Running the tanks dry requires some maintenance to the pumps, since it will damage them, and is also an explosion risk unless the aircraft is fitted with a nitrogen inerting system. After mid-2004, new NGs were fitted with an automatic cut off device which shut off the fuel pumps when pressure below a certain level was detected, thus automating the decision. This modification was also made available for earlier NGs and Classic 737s too.The relevant airworthiness directive can be read here if you want to get really technical and there are guidelines on what you should do fuel-wise if realism is your thing:http://www.airweb.faa.gov/Regulatory_and_G...6E?OpenDocumentIf you really, really like realism, there are other considerations with fuel levels on real thing too: Since the systems on 737s is notorious for under-reading fuel contents, and contents can vary depending on temperature, and the levels and weights can vary depending on the climb angle on the 737 too, it generally pays to err on the over-filling side of things for the centre tank (since you can't be sure it really is under-reading), although that's more of an issue on Classics than it is on NGs.NGs have their own problems with fuel in the wings too which have to be considered (especially the 900 and 900ER). Because the NG has a beefed up landing gear which had to be strengthened for the 900 and 900ER, as well as made longer to allow the tail to maintain clearance during rotation, the fuel tanks were moved, and they sit closer to the wing's surface on an NG than they do on earlier 737s. This means they are more susceptible to environmental icing when on the ground in low temperatures, so there's another reason to top up the centre tank, although of course the weight of the fuel in the wings serves as a counterbalance to the bending the wings endure when in flight, so the decision on which tank to fill is not always totally clear cut.Al

Since the PMDG 737 NG is fairly old, you can base your fuel filling requirements on what used to be the case but is no more, since a modification which became available in mid 2004 for the real NG. The NG's fuel pumps are located in the tanks, whereas on earlier 737s they were in a dry area in the wing root, this means that older NGs had to maintain a minimum amount of fuel in the tank, and that had to be monitored manually. Running the tanks dry requires some maintenance to the pumps, since it will damage them, and is also an explosion risk unless the aircraft is fitted with a nitrogen inerting system. After mid-2004, new NGs were fitted with an automatic cut off device which shut off the fuel pumps when pressure below a certain level was detected, thus automating the decision. This modification was also made available for earlier NGs and Classic 737s too.The relevant airworthiness directive can be read here if you want to get really technical and there are guidelines on what you should do fuel-wise if realism is your thing:http://www.airweb.faa.gov/Regulatory_and_G...6E?OpenDocumentIf you really, really like realism, there are other considerations with fuel levels on real thing too: Since the systems on 737s is notorious for under-reading fuel contents, and contents can vary depending on temperature, and the levels and weights can vary depending on the climb angle on the 737 too, it generally pays to err on the over-filling side of things for the centre tank (since you can't be sure it really is under-reading), although that's more of an issue on Classics than it is on NGs.NGs have their own problems with fuel in the wings too which have to be considered (especially the 900 and 900ER). Because the NG has a beefed up landing gear which had to be strengthened for the 900 and 900ER, as well as made longer to allow the tail to maintain clearance during rotation, the fuel tanks were moved, and they sit closer to the wing's surface on an NG than they do on earlier 737s. This means they are more susceptible to environmental icing when on the ground in low temperatures, so there's another reason to top up the centre tank, although of course the weight of the fuel in the wings serves as a counterbalance to the bending the wings endure when in flight, so the decision on which tank to fill is not always totally clear cut.Al

This brings up another question then. Is it better to use the center tank of fuel first or use the wing tanks first?Mike

Since the PMDG 737 NG is fairly old, you can base your fuel filling requirements on what used to be the case but is no more, since a modification which became available in mid 2004 for the real NG. The NG's fuel pumps are located in the tanks, whereas on earlier 737s they were in a dry area in the wing root, this means that older NGs had to maintain a minimum amount of fuel in the tank, and that had to be monitored manually. Running the tanks dry requires some maintenance to the pumps, since it will damage them, and is also an explosion risk unless the aircraft is fitted with a nitrogen inerting system. After mid-2004, new NGs were fitted with an automatic cut off device which shut off the fuel pumps when pressure below a certain level was detected, thus automating the decision. This modification was also made available for earlier NGs and Classic 737s too.The relevant airworthiness directive can be read here if you want to get really technical and there are guidelines on what you should do fuel-wise if realism is your thing:http://www.airweb.faa.gov/Regulatory_and_G...6E?OpenDocumentIf you really, really like realism, there are other considerations with fuel levels on real thing too: Since the systems on 737s is notorious for under-reading fuel contents, and contents can vary depending on temperature, and the levels and weights can vary depending on the climb angle on the 737 too, it generally pays to err on the over-filling side of things for the centre tank (since you can't be sure it really is under-reading), although that's more of an issue on Classics than it is on NGs.NGs have their own problems with fuel in the wings too which have to be considered (especially the 900 and 900ER). Because the NG has a beefed up landing gear which had to be strengthened for the 900 and 900ER, as well as made longer to allow the tail to maintain clearance during rotation, the fuel tanks were moved, and they sit closer to the wing's surface on an NG than they do on earlier 737s. This means they are more susceptible to environmental icing when on the ground in low temperatures, so there's another reason to top up the centre tank, although of course the weight of the fuel in the wings serves as a counterbalance to the bending the wings endure when in flight, so the decision on which tank to fill is not always totally clear cut.Al

Thanks for the information and that attached document. I prefer to have things as realistic as possible (which my wife hates as it takes me a considerable amount of time to prep a flight let alone fly the flight) and document provides some help with that. Chris

This brings up another question then. Is it better to use the center tank of fuel first or use the wing tanks first?Mike

With all four tank pumps on, she will draw from the center first. Turn off center pumps when time to go to wings. RTFM: Normal Procedures 5-11

With all four tank pumps on, she will draw from the center first. Turn off center pumps when time to go to wings. RTFM: Normal Procedures 5-11

Just keep in mind, as stated by the attached document:"The center tank fuel pumps must be OFF for takeoff if center tank fuel is less than 5,000 pounds (2,300 kilograms) with the airplane readied for initial taxi". "Both center tank fuel pump switches must be selected OFF when center tank fuel quantity reaches approximately 1,000 pounds (500 kilograms) during climb and cruise or 3,000 pounds (1,400 kilograms) during descent and landing. The fuel pumps must be positioned OFF at the first indication of fuel pump low pressure".Note: "In a low fuel situation, both center tank pumps may be selected ON and all center tank fuel may be used. If the main tanks are not full, the zero fuel gross weight of the airplane plus the weight of center tank fuel may exceed the maximum zero fuel gross weight by up to 5,000 pounds (2,300 kilograms) for takeoff, climb and cruise and up to 3,000 pounds (1,400 kilograms) for descent and landing, provided that the effects of balance (CG) have been considered".Chris

With all four tank pumps on, she will draw from the center first. Turn off center pumps when time to go to wings. RTFM: Normal Procedures 5-11

Hi Dan,This is confusing. There are 6 pumps : 2 for the center tank and two each for the main - or wing - tanks.But the sequence you describe (ie turn off center pumps when time to go to wings) looks right to me.Rgds,BrunoPS : I just took a look at Chris Brady's "The Boeing 737 Technical Guide", (mine is Version 11, dated Aug 2006 - www.b737.org.uk) and it still mentions the same limitations about the center tank ie : - Main tank to be full if centre contains over 453 kg (1,000 lbs)- Centre tank pumps must be switched OFF when both LP lights illuminate- Centre tank pumps should not be allowed to run dry or be left running unsupervised- ....And the technical document quoted by Al doesn't say otherwise

This is confusing. There are 6 pumps : 2 for the center tank and two each for the main - or wing - tanks

With my memory, I am doing good to remember there are two wings.

:(Best regards,Robin.

With all four tank pumps on, she will draw from the center first. Turn off center pumps when time to go to wings. RTFM: Normal Procedures 5-11

I am doing good to be able to fly with the FMC. It took me quite some time to figure it out originally and had to "relearn" it after a couple of years break due to work and lack of a decent gaming PC that could run FS9. I am slowly learning the systems. One day I hope to be able to do a flight from cold and dark. I will have to read up some more when I return home again. I sure wish I had a NATOPS style manual for the 737NG to read. PMDG doesn't have the printed manuals on the website anymore and FedEx/Kinko's is expensive.Mike