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Capt. Windh

Engines 2 and 3 shutting down after landing

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Guest hlm65

Hi,it seems to be a fuel issue. Normally you should get a fuel tank/engine advisory when the main tanks 2 and 3 have approximately the same quantity left as the main tanks 1 and 4 . You should close the crossfeed valves and each engine will be fueled by its fuel tanks (check it in the EICAS fuel page: green solid lines from the tanks to the engines and x-feed valves closed). If your fuel planning is adequate, you should not have any flame out due to fuel.Hope this helps.

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Guest 744nut

I had the same experience: I left the aircraft alone for a few hours ....did not change "tank to engine".....and than 2 and 3 are empty first ;-)Ton

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Not to worry, you're not the only one that doesn't get the fuel system!!See the thread on the trained BA pilots that couldn't figure out how to set the crossfeeds when they had to shutdown #3 engine. They wound up having to declare a fuel emergency!Makes you wonder why Boeing wouldn't have added better automation to the fuel system... it is easily the most complex system on the plane!- Bill


- William Ruppel, CYTZ, VATSIM 816871

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Could you post some screenshots of your fuel synoptic and overhead panel when this happens again, please, Johan.Thanks.Q>

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Guest D17S

You might have noticed that I'm a big MD11 fan, so this is a bit painful for me. But I've got to say, I much prefer the way the 747-400 handles fuel management automation . . . because it has no automation. How come? The system basics of these big airplanes are really very simple. The inboard tanks are bigger than the outboard tanks (They're huge, actually. I was walking around in once once . . . and got lost!). If the total fuel load is heavier than the outboards X 4, then the inboards are going to have more fuel in them than the outboards. The basic idea is to burn the inboards down to where they're even with the outboards. Then go tank to engine so all 4 tanks remain even from there. If an operator keeps that in mind, it's easy. Heck, the airplane will even tell you when to reach up and push a button. But which buttons? Is this why we need automation on the -400. Nhaaa. Even that's too simple. Here's what's going on: The inboard (and center tank) jettison/override pumps make much more pressure than the boost pumps. They are not called 'override' pumps for nothin'. When they are on, they will over/back-pressure any operating boost pumps and effectively shut them off. For instance, if the inboard (jettison/) override pumps and the outboard boost pumps are on at the same time, the inboard (jettison/) override pumps will actually back-pressure the boost pumps. This reverse pressure will close check valves in the outboard boost pump's fuel lines. The boost pumps are running, but they just can't get any fuel out into the system. This is by design. This is how the system allows the inboard (jettison/) override pumps to feed all 4 engines. The (jettison/) override pumps will actually "override" the outboard boost pumps. But you have to have the manifold wide open so the pressures can work with/against each other. Notice that the cross feed valves are all wide open when you are feeding from the inboard or the center tanks. This is how the system is is set up to burn down quantity in the inboard or center tanks first. So the drill is to open all the cross feeds and turn on the (jettison/) override pumps from whatever tank you want to use. The boost pumps in any over-riden tanks are left on just in case the stronger pump should fail. They would provide an immediate backup source of fuel pressure. Once the tanks are equalized, shut off the jettison/override pump, swap to the boost pumps and close the cross feeds. This will force tank to engine ops. We need automation for this?! This used to be the Flight engineers Big Moment in the -1/200s. It was just about all he had to do! But there on the other hand, here's my argument for manual operation. It makes the crew pay attention. It forces the issue. It forces the crew to stay involved in fuel management. It forces (well, it should anyway) the crew to constantly be reminded of how the system works. Why should this matter? They need retraining every flight? They're pros, right?I'm around MD11s too. It's a big airplane trying to accomplish the same basic fuel management task. But this sequence is completely automated on the MD11. There is a single "Auto" light on a ridiculously complicated overhead fuel panel. As long as it's on, the crew is involved in absolutely nothing to do with fuel. We have had 2 instances where this AUTO light went out and the crew had problems. Right here, we just went through the 60 seconds of the basics of big airplane fuel system function. You could now handle a fuel panel for goodness sakes, but the MD11 crews had trouble. It's not about training. This was an emergency procedure. To them, it was all about following some line item'd procedure in an emergency procedures book that maybe had an ambiguity or two in it. They didn't crisply understand the real operations they were trying to achieve with all that button pushing. We are all human. We simmers . . . and even 20,000 hour pilots. I'm guessing we are seeing the effects of book based procedural applications here these real world MD11 fuel system, manual ops problems. Flying the -400s fuel panel will make us better pilots. Following procedures is critical. But understanding "why" can be a really, really big help! So, IMHO, the workload reduction the MD11's fuel system automation does not offset the positive effect of having the crew re-trained on fuel system basics every time they fly the airplane. The workload is absolutely incidental and the positive benefits are significant. Therefore, I like the manual method the -400 forces much better than the MD11s automation. I think it's a smarter way to go.

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The fuel system does have some automation to it. Have a look at the old 747-200 to see a nightmare of a fuel system! It was a work of art to get that system up to what it is now on the -400. The EICAS tells when you are required to change to the tank to engine configuration and the fuel synoptic is simple and straight forward to check on the various configurations.http://forums.avsim.net/user_files/146691.jpgCheersSteve


Cheers

Steve Hall

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Guest D17S

Ahh, that's my sweetheart. But after dealing with this panel for a while, it took just a moment to see how the 747-400 worked. This is because the 747-1/200 and the 747-400s fuel systems rely on very similar philosophies. Look carefully. The only difference is that the -400 has taken the #2/3 tank jettison/override pump switches from the dump panel and added then to the main fuel panel. It

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You forgot about the auto inboard crossfeed valves and also the addition of the stab tank, but yes essentially the same just automated slightly for 2 pilot ops.CheersSteve


Cheers

Steve Hall

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Guest hlm65

Check that you switch off the override pumps too, as per manual instruction at page 4-7...

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