scandinavian13

>FUEL TANK/ENG

51 posts in this topic

You guys should make the manual pdf's pop up after the installation of the 747...but even then people wouldn't read it, I guess.  :P

Am I the only one who reads manuals before an addon aircraft is even released? No..? Ok... :rolleyes:

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Trick when fiddling with fuel pumps is not to inadvertently deprive an engine of fuel...

If memory serves, it is a long time ago! when Ralph Tofflemire created the Vmax "ready for pushback"747-200. (FS9!!)

IIRC, on te FE's fuel panel you would have al least one X-feed (was it called that?) switch OPEN, in order to feed the manifold. (No pushbuttons, but switches yoy could turn horizontally or vertically).

In those days you had to watch the gauges, no eicas messages!!

 

So, the essence of the fuel management on the 744 still has  similarities to its famous predecessor?

 

regards,

 

Wijnand Lindeauf (EHBK)

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Agreed, brother Gabriel, more hands on is great.

Which is why it would be so great to have a PMDG 742 with a 743 expansion to fill out the family tree.  Just imagine...

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Addendum: :smile:

 

So in the middle your flight you went to make a sandwich and cut your finger. After your return trip from the urgent care center, you discover not only that you have a  Fuel Tank/Eng caution message, but also that you now have a fuel imbalance. Oh, no! What do you do?

 

Easy. Just turn off your MAIN 2 and MAIN 3 OVRD pumps but leave the outer crossfeed valves open. Then turn off the MAIN 2 and MAIN 3 pumps off as well. Now the two engines on the left will be drawing fuel from tank 1 and the right engines will be fed by tank 4. Keep a close eye on your fuel levels on the fuel synoptic page. Once tanks 1 and 2 (and 3 and 4, respectively) have an equal amount of fuel, turn on the MAIN 2 (and 3) pumps (not the OVRD) and open the outer crossfeed(s).

 

The QRH says only "[c]onfigure the fuel pumps and crossfeed valves as needed to balance fuel," so I figured I'd show a way of doing this because, believe me, it will happen to you . . . more than once (unless of course you set up the plane to do this automatically).

 

Cheers!

 

 

Or the with non bleeding hand, use the mouse and go to the PMDG options pages, setting the TANK/ENG to be handled by the sim.  Terrible idea for the perfectly healthy to run the sim this way but in an emergency it does the job.

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Kyle, I wonder if you'd be willing to update your OP and specify that the numbers you gave are in pounds? The rest of the world aren't stuck in the past, you see, and we use sensible units  :wink:  =@

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Kyle, I wonder if you'd be willing to update your OP and specify that the numbers you gave are in pounds? The rest of the world aren't stuck in the past, you see, and we use sensible units  :wink:  =@

Agreed, migh as well give us weight in doughnuts... :P 

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The >FUEL TANK/ENG message pops up to notify you that you need to configure the tanks such that each TANK is fueling an ENGine (TANK per ENG, or TANK/ENG). If you look at the FUEL page, you will see that the only pumps running all four engines up to this point are the OVRD pumps in MAIN 2 and MAIN 3. These pumps are heaving fuel out of these tanks to keep all four engines running, and the reason you're running all of the engines off of these tanks is that they can hold a lot more fuel than the outboards (think of the profile of the wing here). Once the inboard and outboard tanks are all at the same level, though, there's no longer a reason to be heaving fuel out of the tanks, so you turn the OVRD pumps off, and then set the engines up in a way that they all draw from their own tank (this also ensures that if there's a leak in a line between one of the tanks and an engine, you're not going to affect more than one engine, in theory).

Thanks Kyle for this detailed explanation!

 

So just for my own understanding/clarification:

 

I am currently on a long-haul flight.  I have 25000 KG in center tank, 37,600 KG in two inner main tanks and 13,600 KG in outer main tanks. I start with all pumps on including override pumps (except for L & R Stab tank pumps as these tanks are empty).

 

The 747 will burn the center tank first; when it's near empty I shut off the center tank pumps.

 

The two inner main tanks have much more fuel to begin with than the outer ones, so the override pumps are on to force more fuel from these two tanks. 

 

When the two inner main tanks' quantities equal the two outer main tanks' quantities, I shut off the override pumps to have all the main tanks pumping at the same rate to keep fuel balanced. I also close the two outboard X-Feeds.

 

The reason to have the two outboard X-Feeds open until the two inner main tanks have the same amount as the outer two, is that otherwise engines 1 and 4 would draw fuel from the two outer main tanks only, making a balanced condition impossible to obtain. 

 

Thanks,

Mike

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did I miss the detail about the fuel systems in tutorial 1? I don't remember seeing it. Also, is there no FCTM for the 747?

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did I miss the detail about the fuel systems in tutorial 1? I don't remember seeing it. Also, is there no FCTM for the 747?

Technically, the tutorial says that a description of the fuel system would be covered elsewhere, but it didn't say where. In this case, elsewhere meant you'd have to look in the FCOM (so that answers your second question).

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It's definitely in the tutorial. It's not to this level of detail, but it definitely instructs you to close the crossfeeds.

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Thanks for the replies, I've been working through the FCOM so that's great. I just wanted to check I had not missed something.

 

Should we expect an FCTM for the new 747 or is it not available as part of the product?

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The 747 will burn the center tank first; when it's near empty I shut off the center tank pumps.

Don't shut the center tank pumps off until the message appears on the EICAS. Twice during Beta I shut the pumps off when the center tank level was at about 5000 lbs. of fuel left. About 15-20 seconds after that I got a message on the EICAS concerning the fuel pumps. The only way I could get rid of message was to turns the pumps back on. About 2-3 minutes later I got the message to shot them off. Haven't seen it happen in the RTM yet but I never saw it in the Beta change log either. Now that was on 2 out of maybe 80 flights. So the chances of it happening are remote but it's still a distraction you don't need.
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Don't shut the center tank pumps off until the message appears on the EICAS. Twice during Beta I shut the pumps off when the center tank level was at about 5000 lbs. of fuel left. About 15-20 seconds after that I got a message on the EICAS concerning the fuel pumps. The only way I could get rid of message was to turns the pumps back on. About 2-3 minutes later I got the message to shot them off. Haven't seen it happen in the RTM yet but I never saw it in the Beta change log either. Now that was on 2 out of maybe 80 flights. So the chances of it happening are remote but it's still a distraction you don't need.

 

 

 


Sounds right.

 

Thanks to both of you.

 

Interesting experience: During initial climb, fuel in center tank was very low (maybe @ 1000 KG) so EICAS message appeared, fuel low center.  So I shut off the two center tank pumps.  But after level off at cruise altitude, EICAS message something like "CTR L/R OVERRIDE PUMPS" so I turned the two center pumps back on.  Burned a little more fuel from center tanks, then fuel low message appeared again.   Looks like this is a simulation of fuel sloshing away from pumps during climb, then flowing back to pumps after level off.  Pretty cool!

 

Mike

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