Fuel Xfeed off for landing

[trommel]

I have often been told that, during S/E ops, prior to landing you should turn the fuel xfeed off and return the engines fuel feed to their primary tanks.

Is this because fuel systems are not certifiied for operations at Go around thrust/power with the xfeed operating or

Is it something that has always been best practice since the second world war.

I have been told this when carrying out OCA's in Jets and turboprops none of which specifically prohibit landing with the xfeed on during.

Does anyone know which one it is? as i have been told both.

Thanks

[rubik101]

X feed valves are either Open or Closed, not On or Off.
During single engine operation, once the fuel is within balanced limits, then the remainder of the flight can be flown with the X Feed Open and all Fuel pumps On.
A regular watch must be kept to insure that any further imbalance does not occur.
You have other things to worry about apart from fuel balancing.
Fix it once and leave it alone.
Don't make a major drama out of a minor crisis.

[Mach E Avelli]

Quote: " During single engine operation, once the fuel is within balanced limits, then the remainder of the flight can be flown with the X Feed Open and all Fuel pumps On".
T'aint necessarily so. This is a furphy put about in simulator exercises, because some older simulators typically will stay in balance when set as described above. In real aeroplanes, chances are that one boost pump will put out more pressure than the others. In some engine-out scenarios, one boost pump in one tank may also be de-powered, thus exacerbating an imbalance if X feed is left open.
Only exception to this with some types is in an excessively low fuel situation when the QRH may say to leave it open.
Bottom line - if the QRH says to close the X feed for landing, just DO it.

[kijangnim]

Greetings,
If after crossfeed you leave the crossfeed valve open, although all fuel pumps are switched ON, the engines will still get fuel from one side only, this is what I have noticed at least on the B767 :O

[Sepp]

Rubik: Don't know what type you fly, but on my type if you leave the Xfeed on you empty the opposite wing - or with all pumps on, you don't get Xfeed. Please don't assume that all a/c work the same way!

As MEA says, do what it says in the QRH/FM.

[Capn Bloggs]

X feed valves are either Open or Closed, not On or Off.

The valve may be closed, but the cockpit control on my aeroplane says ON or OFF.

Bottom line - if the QRH says to close the X feed for landing, just DO it.
I think the point of the original post is if the FCOM doesn't say anything. Pretty obviously, if it says " turn it off for landing" then you don't have an option. But in those types where the FCOM doesn't say anything? It would be OK to land with it ON, and in fact depending on the fuel balance at the start of the approach, may be a good idea.