crossfeed and fuel transfer

[ulisses]

Hi,

In the controls list there are:

Cross_feed_off

Cross_feed_left_to_right

Cross_feed_right_to_left

Cross_feed_open

Cross_feed_toggle

Set_Fuel_tranfer_aft

Set_Fuel_tranfer_auto

Set_Fuel_tranfer_forward

Set_Fuel_tranfer_off

I'm simulating a boeing 737 and I can't make these controls to work, do I need a special panel ?

Fuel selectors (left, center, right) work fine.

Any tip in how to work with Fuel Transfers in FS ?

Thanks,

[Pete Dowson]

Sorry. I merely list the controls which are provided in CONTROLS.DLL, and (mostly) also listed in the Gauges SDK. Whether they work, and even what they do, I've had to give up discovering since FS2000 days. I was instrumental getting many of them added (for use in EPIC cockpits mostly) in FS98, thanks to friendly contacts in the FS team (Tim Gregson being my main one then), but as the FS team changed I think many of the controls got disconnected.

The fuel transfer forward/aft controls were probably peculiar to the Concorde when that was part of the official release -- there are Concorde Visor controls in there too, still. As for the crossfeed ones, I don't know why they are there. I think the fuel selector switches are the real controls in this area.

Experimentation is key.

Regards,

Pete

[ulisses]

Thanks Pete for the feedback, you are right, probably some controls aren't working anymore. Fuel Selector is fine !

[Guest Anonymous]

Thanks Pete for the feedback, you are right, probably some controls aren't working anymore. Fuel Selector is fine !

STOP STOP STOP:

Fuel selector commands DO all work.

I know the Crossfeed toggle one does work, but I don't know what it is used for.

Could you enlight me?

p.s.

I've only noticed it on the eric marciano a320-330 panels.

thanks

Luca

[Pete Dowson]

[quote name="Luca Zappala

I know the Crossfeed toggle one does work' date=' but I don't know what it is used for. Could you enlight me?

[/quote]

I think it may vary according to aircraft implementation, but if you look at the fuel selector switches on those cockpits with them showing, you'll see that crossfeed left-to-right will feed both engines from left tank, and vice versa. Usually left tank feeds left engine, right tank feeds right engine. I assume you'd use crossfeed to correct an imbalance, or to keep balance when one engine is out.

Regards,

Pete

[Guest Anonymous]

[quote name="

I know the Crossfeed toggle one does work' date=' but I don't know what it is used for. Could you enlight me?

[/quote]

I think it may vary according to aircraft implementation, but if you look at the fuel selector switches on those cockpits with them showing, you'll see that crossfeed left-to-right will feed both engines from left tank, and vice versa. Usually left tank feeds left engine, right tank feeds right engine. I assume you'd use crossfeed to correct an imbalance, or to keep balance when one engine is out.

Regards,

Pete

sorry I'm lost:

If I press FUEL_SELECTOR_RIGHT does it mean it's using the CROSSFEED function as well?

or is it possible to "CROSSFEED" without choosing any FUEL_SELECTOR_direction... or what?

I thought crossfeed was used to move fuel from and to different tanks meanwhile FUEL_SELECTOR_direction was used to choose the tanks (used to feed the engines).

I suppose I haven't got a clear knowledge of it , have I?

:-)

THanks for your support Pete

[ulisses]

Crossfeed Closed: isolates engine #1 and #2 fuel lines

Crossfeed Open: connects engine #1 and #2 fuel lines

I'm using fuel selectors to simulate it, so when I select ALL, all tanks feed all engines, LEFT, left tank feed all engines, RIGHT, right tank feed all engines.

FS is very limited simulating systems, so I guess it is the best we can get right now, but not sure too....

[Pete Dowson]

I suppose I haven't got a clear knowledge of it , have I?

Nor I, I'm afraid. You'd need to look at a specific aircraft, see what's being done. Sorry. The aircraft I'm more familiar with have either fuel selector switches OR a crossfeed switch. I have no idea what happens when you have both.

Regards,

Pete

[Guest Anonymous]

I suppose I haven't got a clear knowledge of it , have I?

Nor I, I'm afraid. You'd need to look at a specific aircraft, see what's being done. Sorry. The aircraft I'm more familiar with have either fuel selector switches OR a crossfeed switch. I have no idea what happens when you have both.

Regards,

Pete

ok thanks anyway

[ulisses]

Hi,

Reading a real 737 manual, if you use crossfeed open, both engines will be receiving fuel from all tanks and after some minutes probably you'll get a fuel imbalance, if crossfeed is closed, engine 1 will receive fuel from tank 1/center and engine 2 from tank 2/center.

Using tank selector to ALL in FS will do almost the same thing as crossfeed open, but no fuel imbalance. Now in real 737 if you turn fuel pump off for a tank (usually 2 fuel pumps for tank) you won't get fuel from that tank. In FS selecting LEFT tank is like turning fuel pump OFF for center and right tanks.

I guess fuel pumps in FS doesn't work in this way, because even it off the engines continues ON.

In FS I can select center tank alone, but I'd like to have a way to select left and right tanks together (not center), but I guess it isn't possible.

[Pete Dowson]

I guess fuel pumps in FS doesn't work in this way, because even it off the engines continues ON.

Yes, it seems like the pumps are only boosters -- for low wing GA aircraft and for aerobatics. The fuel pressure should increase with them on.

Regards,

Pete

[Guest Anonymous]

Thanks, now it's much clearer to me.

crossfeed is used to feed all the engines from all the tanks.

Fuel_selector picks the tank(s) we want to feed all the engines with.

do you know if these commands are still working in fs9?

CROSS_FEED_LEFT_TO_RIGHT

CROSS_FEED_RIGHT_TO_LEFT

I looks to me they aren't working at all.

cheers

Luca

[Pete Dowson]

do you know if these commands are still working in fs9?

CROSS_FEED_LEFT_TO_RIGHT

CROSS_FEED_RIGHT_TO_LEFT

I looks to me they aren't working at all.

Not sure they ever worked really. Maybe with some aircraft models where there are separate fuel selector switches and cross-feed valves, if such is possible to implement in FS.

You will find, however, that on the default 737, for example, the FUEL_SELECTOR_LEFT control selects crossfeed left-to-right, and so on. The X-Feed switch graphic is ambiguous, and I find it misleading, as it shows the destination of the fuel, not the source, so LEFT to RIGHT shows as "Right" on the switch.

Regards,

Pete

[ulisses]

Luca,

If you are looking for transfering fuel from one tank to another in FS, I couldn't find a way to do that and I guess crossfeed isn't used for that.

[Pete Dowson]

If you are looking for transfering fuel from one tank to another in FS, I couldn't find a way to do that and I guess crossfeed isn't used for that.

There was the facility for moving fuel fore to aft or vice versa in the Concorde, to maintain the CofG in the correct range. I suppose that still works in FS2004, but certainly I know of no way to move fuel between left/right/centre tanks. I doubt if that feature exists on many if any real aircraft, does it?

Regards,

Pete

[ulisses]

Hi,

In real world (737), if you have fuel imbalance (lets say less fuel in left tank), the procedure is:

Crossfeed OPEN

make sure fuel pumps in right tank are ON

turn OFF fuel pumps in left tank

so right tank will fill all fuel system and correct the imbalance...

I'm interested in know how cockpit builders simulate overhead panel if FS doesn't support many functions needed (hydraulics, crossfeed, APU, etc)

[Guest Anonymous]

yeah...

by the way how do you manage the fuel/crossfeed when you use fs2004?

[ulisses]

As I told before, the only way I found to simulate crossfeed without complex aircrafts with overheads panel (DF, 767PIC, PMDG, etc) is using the fuel selector...

Command -> what is simulating

Select ALL TANKS -> fuel pumps all on / crossfeed OFF

Select CENTER TANK -> center fuel pump ON, left/right fuel pumps OFF / crossfeed OFF

Select LEFT TANK -> left fuel pump ON, center/right fuel pump OFF / crossfeed ON

Select RIGHT TANK -> right fuel pump ON, center/left fuel pump OFF / crossfeed ON