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-   -   B777 single engine and fuel crossfeed (https://www.pprune.org/tech-log/609585-b777-single-engine-fuel-crossfeed.html)

Flyoveriraq 2nd Jun 2018 09:10

B777 single engine and fuel crossfeed
 
good day everyone
i was wondering if it is possible to land (or g/a) with the fuel crossfed open on B777.
After you get the fuel imbalance eicas message and decided that it is not a fuel leak, but it’s due to an engine shutdown, you might be landing after few minutes, therefore your inability to finish the checklist as the fuel is not balanced yet.....

any suggestion will be appreciated with reference to any boeing material....as i heard opposite answers to this question...

thanks,
FOI

wiggy 2nd Jun 2018 12:59


Originally Posted by Flyoveriraq (Post 10163108)
good day everyone
i was wondering if it is possible to land (or g/a) with the fuel crossfed open on B777.



Yes you can (it’s obviously physically possible, I guess you are asking if it is permissible).

If you want an example in Boeing documentation for an example of where you would actually deliberately set up to land with either of the cross feeds open look at the 777 fuel quantity low checklist....





















BAengineer 2nd Jun 2018 14:13

The crossfeed valves are hard wired to the switches on P5 so you can select the valves open/closed at any time. MM 28-22-00

Flyoveriraq 3rd Jun 2018 10:27

Thanks for you reply.
i believe a low fuel situation is very different from a fuel balancing....
As far as I remember it is not allowed to open the crossfeed valves for take off, if this is true than it is also not recommended on a go around...
FOI

wiggy 3rd Jun 2018 13:42


Originally Posted by Flyoveriraq (Post 10163821)
Thanks for you reply.
i believe a low fuel situation is very different from a fuel balancing....
As far as I remember it is not allowed to open the crossfeed valves for take off, if this is true than it is also not recommended on a go around...
FOI

:=

I answered your original question, which was: “ I was wondering if it is possible to land (or g/a) with the fuel crossfed open on B777.”..

The answer was, and still is, yes, and by way of an example I offered up the fuel quantity low checklist of an example of when you would do so, in a round about way hoping to make the point that there is no blanket ban or limitation on having crossfeeds open for a landing or go-around.

If you now want to “move the goal posts” , or at least make them narrower, and restrict the question about crossfeeds simply to the context of fuel balancing then the answer can be found in your 777 FCOM:


Fuel balancing is accomplished by opening either crossfeed valve and turning off the fuel pump switches for the fuel tank that has the lowest quantity. Fuel balancing may be done in any phase of flight.
Both landing and go-around are phases of flight, so certainly according to Boeing you can land or go-around with a crossfeed open.

Hope that helps.

(Belated Edit to add: is there any chance some confusion is arising because of Boeing’s warning (in the 777/787 FCTM) about not automatically opening a crossfeed in the event of an engine failure.....)?



















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