Engine failure - fuel management and FMC ENG OUT VNAV page, aileron trim

[VHOJT 177]

Hello all:

 

I was hoping some of you out there might be able to provide me with a little bit of knowledge that I haven't had much luck finding elsewhere!

 

Last night, Engine #3 randomly failed with the ENG 3 FAIL EICAS warning despite no failures being set - just a werid little hiccup I've never experienced before. My question is not so much as to why that happened, but:

 

1) Fuel - is there a procedure to follow with the engines failed as far as fuel management goes. I was in tank-to-engine configuration when the engine failed, and had to do a lot of switching pumps on and off when the engine failed to try and keep fuel even between the tanks. I know that British Airways crew a few years ago that flew over the Atlantic on three engines after losing an engine after take-off at LAX ended up with uneven fuel due to not knowing/poor training in the correct procedure. Unfortunately, I don't know what the correct one is either - I thought the procedure was to turn on/open all pumps and cross-feed valves? Maybe I'm mistaken? Do any of you chaps know the correct procedure, or is it a matter of simply fiddling from time to time to keep it even?

 

2) FMC ENG OUT CRZ page- I have done a bit of forum searching on the matter, but couldn't find much conclusive:

 

a) In your experiences (or if PMDG know that would be great!), is the ENG OUT function of the CRZ page accurate when it gives the MAX/OPT ALT? My aircraft was ~290,000kg and could definitely not maintain the ENG OUT OPT of FL340. In fact, it could only barely maintain FL300 with thrust set to CON. TAT/OAT seemed fine.

 

b ) I cannot seem to execute the ENG OUT page when I press on it - I believe the real-world FMC you execute it. Is this possible with this model?

 

c) When I switch to another FMC page and then back to the FMC CRZ page, it doesn't say ENG OUT anymore. The weird thing is that even although it makes no reference to being ENG OUT anymore, it still gives MAX/OPT altitudes lower than it would for a flight with four engines. If I press ENG OUT again, it gives an OPT ALT of about FL180. I imagine that would be if you were on two engines. So essentially, what I am asking is - does the FMC CRZ page automatically switch to three-engine figures once an engine has failed, and pressing the ENG OUT actually shows two-engine figures?

 

3) When would a 747-400 pilot use aileron trim? Would they normally use only rudder trim for an engine failure?

 

I realise some of these questions are fairly technical - hopefully someone at PMDG might be in the know, or some of you rather knowledgeable forum members! Thanks in advance for any help you could offer. It just goes to show - the sim is still capable of surprising and challenging me even after a few years.

 

Thanks in advance again.

 

Cheers,

Rudy

 

PS don't know if it makes any difference - but I have the FS9 PAX version of the 744. It has all the updates installed - which I believe brings it in-line with the FSX 744 and 744F in terms of updates etc.?

[PHXMD-11 86]

Hello all:

 

I was hoping some of you out there might be able to provide me with a little bit of knowledge that I haven't had much luck finding elsewhere!

 

Last night, Engine #3 randomly failed with the ENG 3 FAIL EICAS warning despite no failures being set - just a werid little hiccup I've never experienced before. My question is not so much as to why that happened, but:

 

1) Fuel - is there a procedure to follow with the engines failed as far as fuel management goes. I was in tank-to-engine configuration when the engine failed, and had to do a lot of switching pumps on and off when the engine failed to try and keep fuel even between the tanks. I know that British Airways crew a few years ago that flew over the Atlantic on three engines after losing an engine after take-off at LAX ended up with uneven fuel due to not knowing/poor training in the correct procedure. Unfortunately, I don't know what the correct one is either - I thought the procedure was to turn on/open all pumps and cross-feed valves? Maybe I'm mistaken? Do any of you chaps know the correct procedure, or is it a matter of simply fiddling from time to time to keep it even?

 

2) FMC ENG OUT CRZ page- I have done a bit of forum searching on the matter, but couldn't find much conclusive:

 

a) In your experiences (or if PMDG know that would be great!), is the ENG OUT function of the CRZ page accurate when it gives the MAX/OPT ALT? My aircraft was ~290,000kg and could definitely not maintain the ENG OUT OPT of FL340. In fact, it could only barely maintain FL300 with thrust set to CON. TAT/OAT seemed fine.

 

b ) I cannot seem to execute the ENG OUT page when I press on it - I believe the real-world FMC you execute it. Is this possible with this model?

 

c) When I switch to another FMC page and then back to the FMC CRZ page, it doesn't say ENG OUT anymore. The weird thing is that even although it makes no reference to being ENG OUT anymore, it still gives MAX/OPT altitudes lower than it would for a flight with four engines. If I press ENG OUT again, it gives an OPT ALT of about FL180. I imagine that would be if you were on two engines. So essentially, what I am asking is - does the FMC CRZ page automatically switch to three-engine figures once an engine has failed, and pressing the ENG OUT actually shows two-engine figures?

 

3) When would a 747-400 pilot use aileron trim? Would they normally use only rudder trim for an engine failure?

 

I realise some of these questions are fairly technical - hopefully someone at PMDG might be in the know, or some of you rather knowledgeable forum members! Thanks in advance for any help you could offer. It just goes to show - the sim is still capable of surprising and challenging me even after a few years.

 

Thanks in advance again.

 

Cheers,

Rudy

 

PS don't know if it makes any difference - but I have the FS9 PAX version of the 744. It has all the updates installed - which I believe brings it in-line with the FSX 744 and 744F in terms of updates etc.?

 

I have no clue about the 744 for FS9.

 

Have you tried restarting the engine?

 

1. I would run number 4 off tank 3 to get the fuel out of that tank. Then run engine 4 off tank 2 until both sides are even then run engine 4 off tank 4. That should keep fuel balanced on both sides.

 

2. a. The ENG OUT page should be right if you programmed it right. If you didn't then you're going to have problems.

b. I had to uninstall Windows so I don't have the 747 in front of me at the moment. Sorry.

c. I would think that a regular 3-engine cruise altitude would be around 260. I can't see a 744 making it from LAX to the UK on three engines at 18000. I would go with the VNAV Cruise page.

 

3. Rudder trim is for engine failures. I would say that aileron trim is for something such as a fuel imbalance or other issue making the wings unlevel.

[VHOJT 177]

Hi there Kenny, thanks for the reply.

 

Yes, the engine would not restart - that doesn't matter as much to me as the behaviour afterwards.

 

Yes, that's the point - the CRZ alt suggested by the FMC were too high.

 

Yes I didn't think I'd heard of aileron trim for engine failures - thought I would check.

 

Hopefully someone has had some experience with an engine-out cruise vs what the FMC is telling them?

 

Thanks again for the reply,

Rudy

[FSXReality 1]

Hello. I have answered your questions below

 

1) Fuel - is there a procedure to follow with the engines failed as far as fuel management goes. I was in tank-to-engine configuration when the engine failed, and had to do a lot of switching pumps on and off when the engine failed to try and keep fuel even between the tanks. I know that British Airways crew a few years ago that flew over the Atlantic on three engines after losing an engine after take-off at LAX ended up with uneven fuel due to not knowing/poor training in the correct procedure. Unfortunately, I don't know what the correct one is either - I thought the procedure was to turn on/open all pumps and cross-feed valves? Maybe I'm mistaken? Do any of you chaps know the correct procedure, or is it a matter of simply fiddling from time to time to keep it even?

The quick answer is 'No', you don't initially have to do anything. The 747-400 has an FQIS (fuel quantity indication system) which actually controls fuel flows automatically. An indication will be supplied to the EICAS when the aircraft is approaching a fuel-imbalance state, by when the crew must take action when time permits. Don't forget that, depending on the FTR (flight time remaining), the aircraft's lateral balance being disturbed is quite minimal for the first long while, and even after a good 2 hours or so, even only a little aileron trim would be required to keep level. It's not an 'emergency, land ASAP' situation. However, don't forget that trim increases drag (especially aileron trim), so the more used, the more fuel consumption, the greater the imbalance, the more trim... etc.. ad nausem. But that does occur over large time frames. Depending on the cause of the fuel imabalce (which may not be known, à la Air Transat A330 into the Azoes), you could simply allow the tank which is not supplying the fuel to its engine (you said each tank was feeding each engine, which means it was below 30K lbs in each tank), to stay higher by 5K lbs or so by letting the other 3 run, then switch off the opposite tank to that which is off (for example, 1 and 4, 2 and 3) and allow them to go down together, but alternating between the two, 5K pounds apart - see what I mean? Hope so.

 

2) FMC ENG OUT CRZ page- I have done a bit of forum searching on the matter, but couldn't find much conclusive:

 

a) In your experiences (or if PMDG know that would be great!), is the ENG OUT function of the CRZ page accurate when it gives the MAX/OPT ALT? Yes. My aircraft was ~290,000kg and could definitely not maintain the ENG OUT OPT of FL340. I think you're missing something or misunderstanding something. The FMC would never show that as an E/O opt. altitude with that weight. That's more like 4 engine opt alt. In fact, it could only barely maintain FL300 with thrust set to CON. TAT/OAT seemed fine. There are many reasons why it may not give a good altitude, but maybe you are confuzzled by something: Max. possible altitude displayed does not mean target flown altitude. You would realistically request a lower altitude 'range' and ATC would ask if FLXXX is suitable; if below your max E/O, then accept. Then drift down slowly (around 3/400fpm unless urgent) and level off. One reason for slow descent rate is relaxed workload/no rushing. A second is that levelling off will not require large thrust increases which, with one engine out, will cause a flight path asymetry on level off which is neither comfortable nor helpful for aircraft balance/control. A/P may even disconnect if control goes outside it's controllable envelope.

 

b ) I cannot seem to execute the ENG OUT page when I press on it - I believe the real-world FMC you execute it. Is this possible with this model?

There are stages to this and the first depends on your altitude. If you're already above E/O max altitude, pressing Engine Out on the VNAV cruise page will bring up the E/O driftdown data (to the max e/o altitude). Once at E/O cruise level, it will change to E/O cruise. Logically then, if you're already at an altitude which the remaining three engines can maintain (maybe FL270 for ex.), then the FMC 'E/O cruise page' will display rather than the 'normal' 4 engine cruise page (i.e, the same just with e/o displayed), including a revised speed, if required.

 

c) When I switch to another FMC page and then back to the FMC CRZ page, it doesn't say ENG OUT anymore. That's because both it and you know that it's operating in engine out mode, most likely. The weird thing is that even although it makes no reference to being ENG OUT anymore, it still gives MAX/OPT altitudes lower than it would for a flight with four engines. Because it's in engine out mode as you told it to be! If I press ENG OUT again, it gives an OPT ALT of about FL180. I imagine that would be if you were on two engines. No, as I say below and will say now (on proof reading), E/O data is one and 2 engines inop. So essentially, what I am asking is - does the FMC CRZ page automatically switch to three-engine figures once an engine has failed (Not at all, crew must do it), and pressing the ENG OUT actually shows two-engine figures? No. As abve, E/O data represents one or two engines inoperative. Important to realise that. Only shows on crew selection.

 

3) When would a 747-400 pilot use aileron trim? Would they normally use only rudder trim for an engine failure?

I answered that already without realising you asked here. Yes, especialy for manual flying. In cruise with well-managed fuel control against an imbalance, the A/P will do good enough a job.

 

Maybe I'll create a little video and add it to my YT channel with detailed procedures.

 

I hope I helped! Ask again if you want more clarification. Screenshots can also help.

 

Best,

Dan

[VHOJT 177]

Hi there Dan,

 

I think you could be right about the fuel management.

 

You're right that theFMC ENG OUT page should need selection and EXECution. Before that's done, it already displays data that looks about right for three engines. I just did some more searching - apparently I'm forgetful and have posted before about the same issue. There seems to be agreement this page/feature, and the performance with three engine cruise is not quite right for one reason or another (could be an FS limitation?)

 

Also, in this thread, a 744 pilot that used to hang around on this forum (cowpatz, or Steve), has said that it doesn't behave correctly.

http://forum.avsim.net/topic/115936-fmc-engine-out-page/

 

Also, this PDF that appears to be a Cathay Pacific training powerpoint explains how the page should work:

cxpilot.info/B744/operational/nonNormals/B744EngineFailCruise.pdf

 

I guess the page is not modelled perfectly - it's just the manual seems to suggest it is.

 

There doesn't seem to be much official word from PMDG in the past on this - one designer said that it should work correctly/numbers are right etc. but it certainly doesn't seem that way. It doesn't really matter, I'm not having a dig, it'd just be interesting to know?

 

Cheers,

Rudy