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Is there a tutorial on setting up fuel tanks and pumps?

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I'm looking for a good tutorial on using the xml parameters for fuel tanks, pumps, selectors , transfer pumps, etc...Thanks,John

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Hi!Whats about Arne's XML Tuturial, where all Variables are included in text files? Or the SDK from Microsoft, there are also all Variables in the TokenVariables document.Best regards,Harry

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Hi,Fuelsystems are not quite easy to program.Use 2 Fuelselectors, one for each engine.Then you have to define the number of tanks in the aircraft.cfg.Best is to use the SET K-event:(>K:FUEL_SELECTOR_SET) for left engine and (>K:FUEL_SELECTOR_2_SET) for the rightSynthax: 1 (>K:FUEL_SELECTOR_SET) 6 (>K:FUEL_SELECTOR_2_SET) etc.0=Off, 1=All, 2=Left Main 3=Right Main etc.Make a string for control:R ENG: %((A:FUEL TANK SELECTOR 2,ENUM))%{case}%{:0}%CUT OFF%{:1}%ALL%{:2}%LEFT MAIN%{:3}%RIGHT MAIN%{:4}%LEFT AUX%{:5}%RIGHT AUX%{:6}%CENTER%{ : 7 }%CENTER2%{:14}%X FEED LR%{:15}%X FEED RL%{end}With these data it must be possible to create a good functioning system.Jan"Procul Negotiis"

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>I'm looking for a good tutorial on using the xml parameters>for fuel tanks, pumps, selectors , transfer pumps, etc...>Thanks,>John I want to figure out how to bypass the FS fuel system. It is too limited. I think one can fake fuel usage, pumping between tanks, etc. by monitoring the fuel in each tank and adding/subtracting fuel as required to result in the correct changes. If a turbine is burning 1000 lb/hr then one has to subtract 1000/3600 lb each second from the tank(s) it is connected to. Note one could set the left side engines to use the left tanks, and the right engines to the right side tanks. As is usually done in real AC. Further, one could set the tanks to be drained as one wished by coding fuel line switches. Note one should use the 'lbs per gallon' Parameter to convert between volumn and mass; then he can change fuel quantity by 'pounds' or by 'gallons' (liters and kg also). That means one has to know how much fuel the engines are using. But, not let FS take fuel from the tanks. I think that could be done by setting the 'fuel_flow_scalar' to 0.0 in aircraft.cfg, then basing fuel used by each turbine as "Thrust/SFC". That's how FS sets PPH; with the scalar set to 0.0 PPH will be 0. SFC varies from 0.55 to 0.85 or higher, depending on the turbine. Reciprocating engines need to include Mixture in fuel flow, so one can't independently calculate it as easily. However, it is feasible to calculate a more accurate GPH. One of the things I want to get to.Ron

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Ron,Thanks for your reply.Here is my problem....I have 4 tanks (aux, center, left main & right main) in my DC-9-41. The left engine is fed from the left main tank while the right engine is fed from the right main tank. I want the center tank to transfer fuel to the left and right main tanks to keep them topped. When the center tank gets to a certain minimum the aux. tank will transfer it's fuel to the center tank, which in turn will keep the left and right main tanks topped.How are the FUEL TRANSFER functions to be used?How do the FUEL SELECTOR functions work? someone suggested using 2 fuel selectors.What is this problem with the fuel crossfeed functions when using the left and right main tank? (..it was suggested to use external tanks 1 and 2 if you want crossfeed functionality)I have so many questions about the FS fuel system.Thanks,John

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>Ron,>>Thanks for your reply.>>Here is my problem....>>I have 4 tanks (aux, center, left main & right main) in my>DC-9-41. The left engine is fed from the left main tank while>the right engine is fed from the right main tank. I want the>center tank to transfer fuel to the left and right main tanks>to keep them topped. When the center tank gets to a certain>minimum the aux. tank will transfer it's fuel to the center>tank, which in turn will keep the left and right main tanks>topped. We couldn't fully model the fuel system in the DF C310. It has two aux tanks and two tip tanks and the standard FS fuel system didn't allow a completly realistic model. As I'd said, real AC feed left engines from left wing tanks, and vica versa. Or, they can X-Feed left tanks to right engines and right to left engines. The FS X-Feed is unrealistic.>How are the FUEL TRANSFER functions to be used? I don't know the reason for one or two fuel tank switches. All I've ever done is set fuel tanks. ;) Possibly the XML code in this thread allows more than the basic default. Howver, I doubt it. Note some AC have a 'fuel dump' To dump fuel one has to reduce the fuel in the tanks being dumped. Though he doesn't have to worry about the exact rate it is dumped. Again, I think a new approach to the fuel system should be tried. Use the standard FS functions (token variables or XML parameters) to read the amount of fuel and then remove it at the appropriate rate from any combination of tanks you want. Or, add fuel to one tank and subtract the same amount from another to pump fuel. The Concorde fuel tank pump does that, but I expect only between #1 and #3. If that part gets worked out I'll work on programming my own "fuel flow" rate so I can improve the accuracy of the FS powerplant models. I don't think it would be too hard to code the reduction in tank fuel, even in XML. Just keep adding the amount of fuel burned per one or ten seconds and then subtract that quantity from the tank(s) involved less often. If somethign along this line were used, excessively cold jet fuel could be modeled to jell, and starve the engines. One could also set something other than 6.0 or 6.7 lb/gallon. MS messed up when it reduced the fuel densities to only two. WWII AC used gasoline of a different density. Some AC burn alcohol. >Thanks,>John Others may have more detailed ideas. Ron

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Ron,Thanks for your feedback.Do I need to be a "C" programmer to change tank quantity the way you mentioned? (...subtract from one tank and add to another.)If this can be done in XML, how would it be done? Are there FS variables that can be changed to effect fuel load for any given tank?I want to use the 4 tanks, but to simulate fuel being transfered from the aux. to the center to the mains, I would just point the engines to draw from a particular tank. for example...if the mains were topped off with pumps on and the center pumps were on (which would transfer fuel to the mains as fuel was fed to the engines)and the center had not depleted enough to start the aux transfer pump, I would just point the engines to draw fuel from the center tank. when the center reached it's minimum I would point the engines to draw from the aux. tank. Does this make sense? It's trickery ...but could it simulate the way the real aircraft fuel system works?I would prefer to use FS to actually transfer fuel from one tank to another as required and keep the engines set to draw fuel from the left and right main tanks.These are the only KEY events I can locate for transfering fuel...but I have no idea how to make them work.KEY_SET_FUEL_TRANSFER_FORWARDKEY_SET_FUEL_TRANSFER_AFTKEY_SET_FUEL_TRANSFER_AUTOKEY_SET_FUEL_TRANSFER_OFFI think these are for fuel cross feed.KEY_CROSS_FEED_OFFKEY_CROSS_FEED_LEFT_TO_RIGHTKEY_CROSS_FEED_RIGHT_TO_LEFTI'm assuming I can set a particular engine to draw from a specific tank with the following KEY events...Assuming this would be the left engineKEY_FUEL_SELECTOR_OFFKEY_FUEL_SELECTOR_ALLKEY_FUEL_SELECTOR_LEFTKEY_FUEL_SELECTOR_RIGHTKEY_FUEL_SELECTOR_LEFT_AUXKEY_FUEL_SELECTOR_RIGHT_AUXKEY_FUEL_SELECTOR_CENTERKEY_FUEL_SELECTOR_SETAssuming this would be the right engineKEY_FUEL_SELECTOR_2_OFFKEY_FUEL_SELECTOR_2_ALLKEY_FUEL_SELECTOR_2_LEFTKEY_FUEL_SELECTOR_2_RIGHTKEY_FUEL_SELECTOR_2_LEFT_AUXKEY_FUEL_SELECTOR_2_RIGHT_AUXKEY_FUEL_SELECTOR_2_CENTERKEY_FUEL_SELECTOR_2_SETagain, I would prefer to just be able to transfer fuel from tank to tank as needed.Any others want to share some insight into FS fuel management?Thanks,JohnThanks,John

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Hi. this topic is good one.. The Transfer FWD and RR are a hard one to get going as they also include an .air file section to make them work... ( works fine on Concorde ) try it on another bird.THE ONE MAJOR BUG.. You can always take away from any tank.. You can never put anything back..If MS would read that... Crossfeed and auto transfer ( kerosene burning ) would work fine.If they would build.... ( I would like to put something back. ) in any way shape or form we could do it.Fuel dump too would be a good one too. Regards,RomanGREEN BAY PACKERS][/i :-ukliam :-beerchug

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Hi,This is my system (767):Left Main, Right Main and Center Tank.2 Fuelselectors, Left and Right Engine.Commands:Off, All, Left Main, Right Main, Center, X-feed Left, X-Feed Right."Control"(see upstairs)4 Elec Fuelpumps (Nr 3 and 4 not necessary, but in my plane they are used for starting the APU), change airfile!Some Logic in a to switch automatically between tanks dependant of amount fuel left (amount of fuel in all tanks is of course monitored too).This logic steers control lights in the fuelpump switches and on the EICAS.In normal operation the center tank is emptied first, then the mains.You can switch on the main tanks only and the "" shows left engine takes fuel from the left and right engine from the right main tank; monitoring fuelburn shows that it works.Opening the crossfeed valves shows either both engines take fuel from the right- or the left main tank.Of course you can switch on All tanks or choose only to use the center one.The elec fuelpumps give a fuelpressure indication and dependant of a certain value the fuelselectors are switching off, so you have a dead engine, thus.. be careful!.Up until now it was not possible for me to FILL any tank from another.As Fueldump i use Arne's fueldump gauge(----> 10% fuel left).Also there are the Fuel-Cut-Valve-Handle's on the ECU.Finally there are some L:Var's and A:Var's making the system complete, using Elec power and Air pressure.All in all pretty realistic (i think).I used aux-, external-, tip- and extra center tanks and that works the same, but i don't need those extra's.You can rename the tanks in the aircraft.cfg file and leave them on the same spot.An important trick for me was using the selectors as a sort of pump. On the panel it looks like a pump, but works as a selector.There are only 2 elec fuel pumps, which i use for the left and right main together with the FUEL SET events 2 and 3.For the centerpumps i had to make dummy's working with the SET event 6Hope you can do somethin with it.Jan"Procul Negotiis"

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If you avoid using the mains, using external1 and 2 instead, crossfeeding (left engine draw fuel from right tank) works fine. The "draw from all" bug only occurs when mains are present.However, this is valid for FS2002, I haven't checked with FS9 yet.If Microsoft reads this: Some engines draw more fuel than is actually burnt, say from an aux tank. The unused fuel vapour is then returned not to where it came from, but to a userdefined tank (main in this case). In addition, if the fuel returns to an already full tank, the fuel exist (?!) through the fuel vent in the tank. Complex stuff :)The complex fuelmanagement required by some of the larger Cessnas cannot be reproduced convincingly by Fs2002, and I hesitate to believe it can be done in FS9. Sometime in the future we might be able to model the fuelsystem of a C310 or C421B (the C is easier to manage) with accuracy.

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To summarize some main points... (that I think I'm understanding)To get functionable crossfeeds, DO NOT use the left main and right main tanks in your system! Rather, substitute the mains with external 1 and external 2.Using 2 fuel selectors will give more control over which tank a particular engine draws from! Use the "...." command suggested by Jan for selecting the appropriate tank. (...use this approach when using fuel selector functions to simulate fuel pumps switches)Some things I'm still a little confused about...Roman - "...You can always take away from any tank.. You can never put anything back.." How can this be? Can someone clarify this?Roman - "...The Transfer FWD and RR are a hard one to get going as they also include an .air file section to make them work..." If I trigger the FUEL_TRANSFER FORWARD event... what exactly would happen in my configuration. (i.e. center, center2 (aux), external 1 (left main) and external 2 (right main) - see my earlier msg.)Jan - "...Up until now it was not possible for me to FILL any tank from another...." Please explain how you are doing this.Jan - "...There are only 2 elec fuel pumps, which i use for the left and right main together with the FUEL SET events 2 and 3.For the centerpumps i had to make dummy's working with the SET event 6" Please clarify this. Where can I download your airplane?Thanks everyone.John(Please continue supporting this topic so we can better understand the FS2002 fuel system.)

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John,The only aircraft that I remember that transfered, (not Cross fed) was the concorde where it taketh then givith .. But Alas there are some new variables for 04. That is the meaning of "...You can always take away from any tank.. You can never put anything back.." except for the Concorde.04(>K:ADD_FUEL_QUANTITY) ---- Does it add globally ???(>K:FUEL_SELECTOR_3_ALL) (>K:FUEL_SELECTOR_3_CENTER) (>K:FUEL_SELECTOR_3_LEFT) (>K:FUEL_SELECTOR_3_LEFT_AUX) (>K:FUEL_SELECTOR_3_OFF) (>K:FUEL_SELECTOR_3_RIGHT) (>K:FUEL_SELECTOR_3_RIGHT_AUX) (>K:FUEL_SELECTOR_3_SET) (>K:FUEL_SELECTOR_4_ALL) (>K:FUEL_SELECTOR_4_CENTER) (>K:FUEL_SELECTOR_4_LEFT) (>K:FUEL_SELECTOR_4_LEFT_AUX) (>K:FUEL_SELECTOR_4_OFF) (>K:FUEL_SELECTOR_4_RIGHT) (>K:FUEL_SELECTOR_4_RIGHT_AUX) (>K:FUEL_SELECTOR_4_SET)These where the Concorde vars:(>K:SET_FUEL_TRANSFER_AFT) (>K:SET_FUEL_TRANSFER_AUTO) (>K:SET_FUEL_TRANSFER_FORWARD) (>K:SET_FUEL_TRANSFER_OFF)Taken from the upper threads..Use the following strings to monitor selectors:L ENG: %((A:FUEL TANK SELECTOR 1, ENUM))%{case}%{:0}%CUT OFF%{:1}%ALL%{:2}%LEFT MAIN%{:3}%RIGHT MAIN%{:4}%LEFT AUX%{:5}%RIGHT AUX%{:6}%CENTER%{ : 7 }%CENTER2%{:14}%X FEED LR%{:15}%X FEED RL%{end}R ENG: %((A:FUEL TANK SELECTOR 2, ENUM))%{case}%{:0}%CUT OFF%{:1}%ALL%{:2}%LEFT MAIN%{:3}%RIGHT MAIN%{:4}%LEFT AUX%{:5}%RIGHT AUX%{:6}%CENTER%{ : 7 }%CENTER2%{:14}%X FEED LR%{:15}%X FEED RL%{end}***** NOTE THERE WAS ALSO A CENTER 3 AVAILABLE IN THE A: VARS ALONG WITH EXTERNAL1, EXTERNAL2, RIGHT TIP, LEFT TIP.. Add tanks to the aircraft.cfg under the {FUEL}] section the centers should be ??? Center1 = XXXXX and Center2 = XXXXXX... If the aircraft.cfg entries donot work go the airfile route. Use sections 525 (Left Main) 526 (Right Main) 531 (Fuel Center 1 fwd) 532 (Fuel Center 2 aft) from the Concorde .air file. Use AIR ED to copy these entries and paste them into The DC-9 .air file. ( MAKE A BACK UP !!) and place the locations / quanitites / others as needed. Remove the (FUEL) entries ( for safe keeping ) from aircraft.cfg and let FS rewrite that section on next aircraft load.Use 2 Fuel selectors..Aircraft.cfg entry {FUEL}number_of_tank_selectors = 2 **** MANDATORY electric_pump=0 ***** COULD THIS CONTROL COCNCORDE TRANFER PUMP ??? TRY AT 1LEFT DRAWING FROM CENTER ( Simulates center transfer to mains as long as mains are full ) 6 (>K:FUEL_SELECTOR_SET) RIGHT DRAWING FROM CENTER ( Simulates center transfer to mains as long as mains are full ) 6 (>K:FUEL_SELECTOR_2_SET) LEFT DRAWING FROM MAIN LEFT ( Once center is depleted ) 2 (>K:FUEL_SELECTOR_SET)RIGHT DRAWING FROM MAIN RIGHT ( Once center is depleted ) 3 (>K:FUEL_SELECTOR_2_SET)LEFT DRAWING FROM MAIN RIGHT ( Simulated Cross feed ) 3 (>K:FUEL_SELECTOR_SET)RIGHT DRAWING FROM MAIN LEFT ( Simulated Cross feed ) 2 (>K:FUEL_SELECTOR_2_SET)If the Aux transfer is automatic then you could use:(***** AUTO START *****)(A:Fuel tank center quantity, gallons) ** Value of auto start of transfer ** < (A:Fuel tank center2 quantity, gallons) 0 > & if{ (>K:SET_FUEL_TRANSFER_FORWARD) }(***** AUTO STOP ******)(A:Fuel tank center quantity, gallons) ** Value of full tank or pump shutoff value ** == (A:Fuel tank center2 quantity, gallons) 0 == || if{ (>K:SET_FUEL_TRANSFER_OFF) }Otherwise use manuallly.(>K:SET_FUEL_TRANSFER_OFF)(>K:SET_FUEL_TRANSFER_FORWARD) You could also use the following VARS to monitor what's going on. (A:Turb eng1 tank selector, ) (A:Turb eng1 tanks used, )(A:Turb eng2 tank selector, ) (A:Turb eng2 tanks used, ) (A:Fuel selected transfer mode, ) What do the switches on the 9-41 look like ??? /Type? ( This is just one engine )OFF / ON / CROSSFEED ---- an automatic tansfer from center ? Would need a good logic code to make work.. OFF / ON / CROSSFEED / CENTER --- manaul select to center / automatic AUX to Centre ?OFF / ON / CROSSFEED / CENTER AUX -> CENTER switch too ? manaul select to center / manaul AUX to Centre Or any of the above instead w/ 1 separate crossfeed switch per engine? LOGIC WOULD BE MADE DEPENDING ON ABOVE TYPE.Or any of the above instead w/ 1 separate crossfeed switch for both engines? LOGIC WOULD BE MADE DEPENDING ON ABOVE TYPE.IS this for FS 02, 04 or both ?? There have been a few Fuel selecter variables A: & K: that changed or for 04 only. Regards,RomanGREEN BAY PACKERS][/i :-ukliam :-beerchug

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Here are some screenshots of my fuel gauges in my panel.http://forums.avsim.net/user_files/28625.jpghttp://forums.avsim.net/user_files/28626.jpgCouple of questionsHow do I set the "from" and "to" tanks for the SET_FUEL_TRANSFER_FORWARD command?If I can do this between the aux. (center2) tank and the center tank (center1), why not from the center tank to the left or right main tanks?Also, this command seems to imply that fuel will actually be taken from 1 tank and put into another, something that contradicts an earlier statement that fuel can be taken out but not put in. Please clarify this for me.Does using the TANK SELECTOR command override the need to set FUEL_PUMPS to on? You made a note to set the electric pumps to 0 ...is this the transfer pump?You have good info ...it's really making me think differently about this.Thanks,John

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>How do I set the "from" and "to" tanks for the>SET_FUEL_TRANSFER_FORWARD command?THe Concorde was the only arcfarft to have the capability of taking fuel from 1 and actually placeing it in another. And that system only used CENTER1 fwd and CENTER2 aft. That command is only good for those tanks.>>If I can do this between the aux. (center2) tank and the>center tank (center1), why not from the center tank to the>left or right main tanks?Microsoft has left us all in the woods... :-(>>Also, this command seems to imply that fuel will actually be>taken from 1 tank and put into another, something that>contradicts an earlier statement that fuel can be taken out>but not put in. Please clarify this for me.Concorde setup only.. Center1 , Center2 >>Does using the TANK SELECTOR command override the need to set>FUEL_PUMPS to on? You made a note to set the electric pumps>to 0 ...is this the transfer pump?Unkwnow, but maybe.... Its a new 04 entry. >>You have good info ...it's really making me think differently>about this.I would like to help as I have an interest in this setup also..Tommorow take a real good peak at it.Regards,RomanGREEN BAY PACKERS][/i :-ukliam :-beerchug

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