737 Classics. Single engine landing with crossfeed open.
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737 Classics. Single engine landing with crossfeed open.
When conducting a B737 Classic single engine approach with fuel imbalance procedures still applied (crossfeed selector open and two main tank fuel pumps off), is there any FCOM or FCTM requirement that normal fuel feed procedures (crossfeed selector off, all main tank pumps switches on) must be re-instated before landing? If so, in what Boeing document is this stated?
No – or not that I know of!
The FCTM has a section discussing fuel balancing at pages 8.18-19. Amongst it is written:
This suggests to me to return all the fuel pumps and crossfeed back to their normal position for landing (and possible go-around). I use the one engine inop landing checklist as my trigger point to do this.
S&L
The FCTM has a section discussing fuel balancing at pages 8.18-19. Amongst it is written:
“Fuel Balancing Considerations
…
during critical phases of flight, fuel balancing should be delayed until workload permits. This reduces the possibility crew errors and allows crew attention to be focused on flight path control”
…
during critical phases of flight, fuel balancing should be delayed until workload permits. This reduces the possibility crew errors and allows crew attention to be focused on flight path control”
S&L
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Fuel Balancing Considerations
…
during critical phases of flight, fuel balancing should be delayed until workload permits. This reduces the possibility crew errors and allows crew attention to be focused on flight path control”
…
during critical phases of flight, fuel balancing should be delayed until workload permits. This reduces the possibility crew errors and allows crew attention to be focused on flight path control”
Some regulators require risk assessment considerations to be addressed before ops departments direct operational changes from manufacturer's FCOM recommendations. That being so, perhaps fingers could be pointed by flight ops inspectors who might say there is no pressing reason before landing to configure back to crossfeed off and all pumps on as normal?
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Strange,
My FCOM states Fuel crossfeed valve must be closed before TO and LDG in the limitations section.
I wonder if there is a difference in this with different companies?
Greetings
My FCOM states Fuel crossfeed valve must be closed before TO and LDG in the limitations section.
I wonder if there is a difference in this with different companies?
Greetings
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flyburg....
that should read "crossfeed valve should be closed for takeoff and landing except during NNC's"
That's what I understood when I last flew that thing some decades ago...
that should read "crossfeed valve should be closed for takeoff and landing except during NNC's"
That's what I understood when I last flew that thing some decades ago...
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Hi,
My recollection was that the 707, 737-200 & L1011 had a note in the Limitations Section of the Flying Manual, that the fuel cross feed must be closed for Approach and Landing. I think the classic B747 had the same limitation.
The B747-400, 737-NG and A320 series don't have such a limitation i.e. they may have the fuel cross feed open for approach and landing.
So it depends on which variant you are flying and what the Limitations section of the FCOM says.
It's a mystery to me why it was a restriction in the first place. I can only guess it was originally due to something with VMCA demonstration flight on the GA and flying with up to 5 degs bank into the live engine(s) and fuel transfer from the high wing to the engine(s) on the low through the open cross feed and fuel imbalance could go out of limits.
It looks like the problem has been designed out in modern aircraft.
My recollection was that the 707, 737-200 & L1011 had a note in the Limitations Section of the Flying Manual, that the fuel cross feed must be closed for Approach and Landing. I think the classic B747 had the same limitation.
The B747-400, 737-NG and A320 series don't have such a limitation i.e. they may have the fuel cross feed open for approach and landing.
So it depends on which variant you are flying and what the Limitations section of the FCOM says.
It's a mystery to me why it was a restriction in the first place. I can only guess it was originally due to something with VMCA demonstration flight on the GA and flying with up to 5 degs bank into the live engine(s) and fuel transfer from the high wing to the engine(s) on the low through the open cross feed and fuel imbalance could go out of limits.
It looks like the problem has been designed out in modern aircraft.
Last edited by rudderrudderrat; 2nd Apr 2010 at 10:12. Reason: typo
In my copies of the B747 and B744 limitations both types require at least one cross feed valve open for T/O and landing.
Think about the number of tanks and it makes sense to have a "hot spare" available in the event of pump failure but still avoid the possibility of all engines feeding off the one set of boost pumps.
Think about the number of tanks and it makes sense to have a "hot spare" available in the event of pump failure but still avoid the possibility of all engines feeding off the one set of boost pumps.
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737-400 FCOM dated 4 Dec 2009 makes no mention of cross-feed valve being required to be closed on approach.
in the hick town where i'm from, we crossfeed till the difference reaches max (453 kgs), then crossfeed to the other side till max again. that way, we actually manipulate the valve only every 900kgs or so, approach phase or otherwise.
in the hick town where i'm from, we crossfeed till the difference reaches max (453 kgs), then crossfeed to the other side till max again. that way, we actually manipulate the valve only every 900kgs or so, approach phase or otherwise.