Sign in to follow this  
JSACKS

Help! Tank-to-Engine fuel tank imbalance

Recommended Posts

I am 2/3 of the way through a 5000nm flight in the 744.  For some time, I had a TANK/ENG illuminated on the upper EICAS and wasn't sure what to do.  After a long delay, I finally closed the X-feed for main 1 and main 4 and that seems to have put me in Tank/Eng mode.  However, here's the problem: I have a total of 85K fuel remaining.  Main 1 and 4 each have 29k of fuel while Main 2 and 3 have 14k each.  I cannot for the life of me figure out how to get fuel from main 1 and 4 transferred into main 2 and 3 so that the fuel load is balanced among all 4 tanks.  I thought I could X-feed the fuel from 1 and 4 easily, but the fuel synoptic doesn't show that this is possible.  Can anybody explain how to do this?  Thanks for any replies.

 

JS

:O :unsure:

Share this post


Link to post
Share on other sites
Help AVSIM continue to serve you!
Please donate today!

First, when you get the TANK/ENG illuminated you should close the crossfeeds and turn off the override pumps. If you do this in a timely fashion you will not get your problem.......anyhow.............

 

to correct the imbalance you now have, you do the following:

 

Open all four crossfeeds

Turn off tank 2+3 main pumps.

 

Tanks 1 and 4 will now supply fuel for all engines. When you have equalised tank quantities, you turn on 2+3 main pumps and close all crossfeeds.

Share this post


Link to post
Share on other sites

If you wait too long (e.g. with time compression) the tank-to-engine fuel imbalance will never resolve itself because you would've burnt too much fuel from the inner wing tanks. 

 

In that case you should go to the PMDG options menu - fuel - and apply the current total fuel figure to the aircraft. This will reset the fuel system and everything will be back in balance.

Share this post


Link to post
Share on other sites

One of the things I like about flying the 747 long haul is that you have to do a little bit of fuel management work en route. It gives you something to do in cruise. Not everyone's idea of fun of course.

Share this post


Link to post
Share on other sites

Peter,

 

Thanks for your informative and helpful post.  Greatly appreciated.  I shall try this when I re-run part of the saved flight. 

 

JS

B)

Share this post


Link to post
Share on other sites

To be more correct, once tanks 1-4 are the same quantity, you should turn on 2+3 main pumps and close crossfeeds 1 + 4. Crossfeeds 2+3 remain open (auto) so as to keep the crossfeed manifold pressurised. This is important if you were to encounter an emergency situation which required engines 3 and 4 for example to be fed from tanks 1 and 2.

Share this post


Link to post
Share on other sites

Thanks again, mate, very helpful indeed.  I'll be a cross feed expert by the time I've mastered this!

 

JS

Share this post


Link to post
Share on other sites

Thanks again, mate, very helpful indeed.  I'll be a cross feed expert by the time I've mastered this!

 

JS

 

Definitely check out the fuel status page on the EICAS...really helps you understand what is going on when you flip the switches!

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Sign in to follow this