Engines #2 & #3 Shut off on landing!!!

[Guest flightgamer]

Ok, here is my issue.... whenever i land, about 1 minute after touchdown, my #2 & #3 Engines, either just plain shut off, or they spool down, to lets say 5%, then spool back up to where the other two engines are marked at.....Is this a Known problem, and was it fixed in the SP provided on the Downloads page, i haven't downloaded and installed it yet because im led to believe it was slowing my computer down..... is there anyways to fix this???/ thanksother than that, LOVE IT, KEEP IT UP PMDG :-badteeth

[Guest flightgamer]

See, please help :-zhelp

[Farlis 2,277]

I suspect you are not managing the fuel load correctly. Load the situation again and take a look at the fuel tanks. I bet that the inner tanks are empty because you did forget to configure the cross-feed valves correctly.Karsten

[rgamurot 1]

This isn't a known issue as far as I know therefore as far as I know, it isn't something fixed by the SP. I would say check the as the tanks may be empty but you said that sometimes they spool back up? How often does this happen? Ryan GamurotLucky to live Hawai'ihttp://www.virtualpilots.org/signatures/vpa296.png

[Subs 0]

I've also found this, but it's always been due to incorrect fuel loading - it happens when there is no fuel in MAIN 1&4, but there is fuel in MAIN 2&3.This can occur in the following situation:On a long haul, sometimes you are not available to go Tank-To-Engine config at the appropriate time. So at landing, STAB has drained, then CWT, then because the Overdrive pumps are on, MAIN2&3 drain to empty first. And with no fuel in MAIN2, APU is not available after landing.So sometimes early in the flight, after STAB and CWT are empty, I switch off the Overide pumps and allow all engines to feed from MAIN 1 & 2 & 3 & 4 using boost pumps only and with all crossfeed valves open. This should allow an 'even' draining of fuel as the flight progesses, but because MAIN2&3 has much more fuel then MAIN1&4 to being with, many unattended hours later, you'll find MAIN1&4 are empty first, and the remaining fuel is all in MAIN2&3....Now when you land in this situation engines 2 & 3 shut/spool down momentarily, just as you described. CON IGNITION does not make a difference.It just occured to me, it could also be influenced by the automatic closing of crossfeeds 1&4, as is with takeoff (does aircraft logic make this happen at landing as well??)A screenshot of your Lower EICAS Fuel Synop page would confirm my suspicions.And I know, know, this is not proper fuel handling, but without a automatic Tank-To-Engine in long hauls flights, this 'technique' ensures there is sufficient fuel in MAIN2 at landing to start the APU.Hope this helps,Subin.

[Subs 0]

>It just occured to me, it could also be influenced by the>automatic closing of crossfeeds 1&4, as is with takeoff (does>aircraft logic make this happen at landing as well??)Sorry I meant automatic closing of crossfeed 2&3.:-rollSubs.

[Qavion 19]

It just occured to me, it could also be influenced by the automatic closing of crossfeeds [3 & 4], as is with takeoff (does aircraft logic make this happen at landing as well??).Actually, it doesn't. The airplane logic assumes you wouldn't want to close these for landing, only takeoff.BTW, the correct logic is simulated in PMDG ;)Cheers.Q>

[Subs 0]

Thanks Q, I always enjoy your posts on this forum :-)What is the reasoning behind auto closing of the crossfeeds during takeoff? I always thought redundancy, but I would think it is just as important during landing as well in that case?Thanks,Subin

[Qavion 19]

I guess the fuel logic assumes you are normally landing with a tank-to-engine config anyway, so there is no need for additional isolation. The tank-to-engine phrase is a bit of a misnomer (the aircraft never really feeds individual engines with individual tanks). I don't quite understand the Boeing logic..... Perhaps it's a compromise which best guards against fuel starvation and fuel contamination... and provides the best weight distribution/balance in the process.Cheers.Ian R>

[rgamurot 1]

>The tank-to-engine phrase is a bit of a misnomer (the aircraft>never really feeds individual engines with individual tanks).It actually does in tank-to-engine configuration. You have cross feeds 1 and 4 closed. This means that tank 1 is isolated and can only feed engine 1. Same with tank and engine 4. With tanks 2 and 3, since you shut off the override pumps, each tank is now only pumping enough fuel to comfortably feed one engine each. So technically tank 2 is feeding engine 2 and tank 3 is feeding engine 3.Ryan GamurotLucky to live Hawai'ihttp://www.virtualpilots.org/signatures/vpa296.png

[Qavion 19]

"With tanks 2 and 3, since you shut off the override pumps, each tank is now only pumping enough fuel to comfortably feed one engine each."I'm not sure how you figure that, Ryan. Engines can gravity feed if need be. Two boost pumps are more than adequate to provide power to 2 engines (should both pumps on one side fail)... otherwise there would not be MEL's allowing one pump to power one engine.Cheers.Q>

[rgamurot 1]

>I'm not sure how you figure that, Ryan. Engines can gravity>feed if need be. Two boost pumps are more than adequate to>provide power to 2 engines (should both pumps on one side>fail)... otherwise there would not be MEL's allowing one pump>to power one engine.I stand corrected. I think it was full thrust I was thinking of.Ryan GamurotLucky to live Hawai'ihttp://www.virtualpilots.org/signatures/vpa296.png