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-   -   B787 ENG FAIL L, R (https://www.pprune.org/tech-log/592391-b787-eng-fail-l-r.html)

flaretoland 18th Mar 2017 16:38

B787 ENG FAIL L, R
 
Is there an experienced 787 pilot that can answer this question?

Question: The ENG FAIL L,R QRH checklist towards the end, item 20, says "Do Not accomplish the following checklists" FUEL PUMP CTR L+R.
Why does it say that? What would happen if the Fuel Pump CTR L+R was infact done. cheers.

Roj approved 22nd Mar 2017 07:59

Hi Flare,

This will only be a problem if you have the CTR tank pumps on.

If you go back a few steps in the Cxlist it says start the APU.

Also, if you have a look in the FCOM under load shedding 6.20.12 it talks about auto loadshedding.

So, the CTR pumps will get loadshed when you shutdown the engine, taking 2 generators off line.

But, you have started the APU, and it takes a minute or 2 to come online. Once online, you are back to normal ops re Elec pwr, 4 gens. So the CTR pumps will come back online. This will inturn feed fuel from the CTR tank to the running engine as they have a higher output than the other pumps.

If you did the CTR pump cxlist, you have done 3 things:
1/ operated outside of the QRH/FCOM
2/ put yourself in situation where you will now get a FUEL IMMBALANCE cxlist before time.
3/ made that fuel unusable (until you dump or put the pumps back on)

You will have FUEL IN CENTRE on the EICAS, and that cxlist says........................turn on the pumps. So, best to stick to the cxlist.

I hope that helps


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