Hi all,Nothing more to add except:1. Very beautiful panel John!2. Roman, the way you describe the Elec Fuel Pumps is exactly how i use them.3. I use fuel pressure, voltage and bleedair to restart an engine in case of an engine stall/flame out, wrong fuel management, all A:Var's.4. With both engines off i need an "emergency" descent to 12000 ft to get enough athmospheric pressure and oxygen to start the APU and thereafter the engines. When voltage is to low for a restart (long duration of the descent with to much elec equipment on), deploying the RAT corrects that.Perhaps not enterily real, but fun to do (and to code).Still busy with it.Jan"Procul Negotiis"

BTW,Here you have am lot of info about fuel systems:http://www.smartcockpit.com/Click Boeing 737 or 767 and look under systems for fuel and powerplants etc.Among other things these data made it possible to understand and construct my own fuel- and other systems in MSFSJan"Procul Negotiis"

Thats a good link !!! Too bad some of my work was for the 737,,, but I have become acustomed to what I see every day... CRJ 200 - 700 - 900.But still all in all a good one, thou shalt be bookmarked.Regards,RomanGREEN BAY PACKERS][/i :-ukliam :-beerchug

Hallo all,Also i advice you strongly to use "Pike&Arne's Fueldump Gauge"!!!You can dump or refuel to 0!!!, 10, 15, 45, 55, 75, 90 and 99%.Very, very usefull, and realistic (besides the time, it happens in one moment).Jan"Procul Negotiis"

Here are some changes that more specific to the DC-9. I have used the left engine in the example.If the left tank pumps are off ....having the fuel selector switch to the center would be impossible. Remember... In the real aircraft the fuel is drawn from the "left" tank. If it's pumps are off... you get no fuel. I think the following covers this. (I have not worked in x-feed yet.)*** variables used ***(other code sets these 2 ..STAT variables based on FWD or AFT pump switch status)FUEL_PUMP_LT_STAT ; 0=off 1=onFUEL_PUMP_CTR_STAT ; 0=off 1=onVALVE1 ; 0=off 1=on*** Left Engine Fuel Seletor Logic***(L:VALVE1, bool) 0 == if{ 0 (>K:FUEL_SELECTOR_SET) } els{ (L:FUEL_PUMP_LT_STAT, bool) 0 == if{ 0 (>K:FUEL_SELECTOR_SET) } els{ (L:FUEL_PUMP_CTR_STAT, bool) 0 == (L:FUEL TANK CENTER LEVEL, percent) 0.1 < & if{ (L:FUEL TANK LEFT MAIN LEVEL, percent) 0.1 > if{ 2 (>K:FUEL_SELECTOR_SET) } els{ 0 (>K:FUEL_SELECTOR_SET) } } els{ 6 (>K:FUEL_SELECTOR_SET) } } }Do others see what I'm trying to do here?Thanks,John

John,Can you describe what you want with the code?It is quite hard to read.Anyway, use for levels A: instead of L:(Also realize, when the engines are running they use there own inbuild fuel pumps to draw fuel from the tanks and give pressure for mixing with air before combustion.Selectors from which tanks.Valves shut the fuel lines off.Bleed air also gives pressure in the tanks.Tank pumps divide fuel over the fuel pipes and or tanks.X-feed valves enable the engines to take fuel from whatever tank.AC power is neccesary for the pump operation, except for the DC, by the battery, pump, in the left main for providing fuel to the apu.Gravity drains the wingtip tanks etc.And some things more...Still complicated neh?)Jan"Procul Negotiis"

>Hallo all,>>Also i advice you strongly to use "Pike&Arne's Fueldump>Gauge"!!!>You can dump or refuel to 0!!!, 10, 15, 45, 55, 75, 90 and>99%.>Jan Where is this gauge? Is it in XML or C? I see it can 'refuel'. If it were modified to automatically add a small amount of fuel to one tank equal to that removed from another once per second it would essentially pump fuel between tanks. Ron

Hi Ron,In the AVSIM Library:c4sst12.zipJan"Procul Negotiis"

> .............>Enclosed is my last FUEL TEST gauge ( got what I needed ). It>addresses all these and provides a workaround for the bogus>ELEC_FUEL_PUMP. Crossfeed now works with all 3 tanks>available. The auto levelling feature can be disabled in 1>section. And Autostart is fully implemented.( see .xml )>Regards,>Roman I put your last gauge in the Concorde I imported into FS9. I had to experiment to see what happened when I threw the switches. I did see Left to Right, Right to Left, and Center feed. Various turbines would stop as I toggled some of the other fuel switches on your panel. The four turbines appeared to draw fuel evenly from the wing tanks while leaving the two center tanks in reserve for longitudinal balance. The Concorde fore/aft pump still worked, though most all the fuel was pumped to the rear during my supersonic cruise. With only the original Concorde fuel system (X-Feed fixed by setting 737 X-Feed gauge in panel.cfg) I'd have to switch to Left for a while, then to right to keep from using fuel from the center tanks. Switch toggles on your panel moved the X-Feed switch on the Concorde's fuel panel, but the end effect was different. In fact, that X-Feed gauge could be removed and some of your code controlled with a new switch on the Fuel panel to make fuel management on the Concorde much easier. In fact, if two more wing tanks were added to enable extra fore/aft balance, and fuel draw set to use the more forward or aft wing tanks, fuel management for a complete flight could be automated. Once the two center tanks were down to about 60% of total capacity they could be turned off (but still pump fore/aft). Currently, one doesn't get enough longitudinal balance change from the two center tanks. That's why fore/aft wing tanks on each side are desirable. No pumping between these tanks, just the ability to burn fuel from the appropriate tanks to generate the most appropriate balance as a flight progressed. I read that Concorde trims roll by shifting fuel laterally, trim surfaces add too much drag. We know longititidinal CG is critical and I have been able to trim pitch by manually pumping fule fore/aft. MS did a good job on the for/aft pump gauge, it does move the CG correctly as a function of Mach number. Though, they didn't model the actual Mach Pitching moment well, I did. ;) I have worked on Concorde flight models for years and it appears some variation of your XML code will considerably enhance an MSFS Concorde. The real AC has 17 fuel tanks, but far fewer suffice to model the general system. Ron PS: A Voyager flight model I've hacked also requires better fuel management than what FS2K provided. I need 'wing tanks' fore and aft' that use fuel evenly, not from the 'tip' tanks before the main wing tanks. Since I set the two tanks on each side fore/aft along a 'nacelle', not actually in the fragile wing.

>Hi Ron,>>In the AVSIM Library:>c4sst12.zip>Jan Looking at it now. I had installed "C4SST" some time ago. Ron

Hi,Fuel system still groing strong!Well, what do you use as indicator for Fuel Temperature?Jan"Procul Negotiis"

> use for levels A: instead of L:Thanks for pointing out the switching of L: and A: ...at the time I wrote that msg I had not run the code yet. (that msg was sent from work and I did not have chance to test in FS.)> Can you describe what you want with the code?> .....> X-feed valves enable the engines to take fuel from whatever tank.Based on conversations with a DC-9 pilot, (real life functionality) the fuel only comes from the left and right tanks to each respective engine unless the x-feed valve is open. (than fuel can be drawn from left or right tanks only) The center tanks will keep the left & right main tanks full as long as it can, but does not send fuel "directly" to the engines. ...so, in the "logic" code sample in my msg, (FS2002 life functionality) I was tying to show that the FUEL_SELECTOR_SET commands should only point to the center tank if either the left or right main tank pumps were on.I hope I clarified this. I was looking for confirmation that my "logic" code was accurate.> when the engines are running they use their own inbuild fuel pumps > to draw fuel from the tanks and give pressure for mixing with air> before combustion.Are you saying that the tank fuel pumps are not needed once the engines are running? and it's only matter of fuel valves being open at that point? (icluding the x-feed valve?)> Still complicated...?Yep! (I'm momentarilly lost over here) But, your questions are making me think this through. There is no doubt about it.. fuel systems are complicated.Thanks,John

>Hi,>Fuel system still groing strong!>Well, what do you use as indicator for Fuel Temperature?>Jan Me? What AC FTT?Ron

Hi John,I am only sure about the 737 and 767 fuel system.Have a look here:http://www.smartcockpit.com/Lots of deeper insight.The fuel is drawn from the center until a specific level, after which fuel is taken from the mains, (center remnant drains via scavenge pump; wing tip tanks drain by gravity to the center).System logic regulate pumps and valves, override is possible.Indeed the tankpumps are not necessary for engine operation.The engines suck from the tanks by means of 2 engine driven pumps.Tankpumps help to give additional pressure to the fuel lines.For startup you need them.They don't transfer fuel to another tank; in some planes transfer is used for CG, Concorde.Valves (The Selectors!) in the fuelmanifold determine from which tank etc.Cutoff valves and firehandles on pedestal shut off all fuelpipes to the engines by a DC powered valve in the wingroots.In your code you can set the Selectors on the Center tank, while the left- and right main pumps work.But you don't need them..., because fuel is always taken from the center tank when Selector is set on center.Of course you can switch on the center pumps, but that is just a matter of taste, visually.In the 767 you set all fuel tank pumps on and system logic determines which tankvalve is opened and which pump operates.By overriding the system logic in case of an engine failure or electronic failure whatsoever or just for fun, pressing the fuelpumpswitches or turning them off will now operate the Fuelselectors.So first you have to construct a system logic and a way to override for operating the selectors yourself.etc.Jan"Procul Negotiis"

Ron,Boeing 767-300ER.I tried different A:Var's, but sometimes Fueltemperature is below freezing point, -37C (Gives Eng Failure etc.), not so real.So i use now (Ambient temperature - Altitude/1500)At N 80 minimum measured temp. was -26C.Btw. Perhaps Arne is willing to recode the FSUIPC Fuel Dump Gauge for a more realistic operation:Only dump possible for the center tank with 2500 lbs/min or so.Refill at own discretion.May be he reads this thread?!Jan"Procul Negotiis"