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Guest islaymalt

Md-11 Fuel Freeze....

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Greetings:I hate to gush, but the PMDG MD-11 is simply the best money I have EVER spent on a Flight Simulation product, period. I have used it for about 3 weeks and I am amazed at how well it works and how much fun it is to fly this aircraft! Amazing value for money and I congratulate you on a job well done.I want to blame this on REX which I recently purchased and really, really enjoy but it still has lots of bugs. I fly real weather with updates, and over the past two days, the temperature at altitude (approx FL380) is circa -40 to -60 degrees C. So, my fuel freezes up, I get all the warnings, and eventually I start having engines shut down (seriously, how cool is that!) I get down to around 15,000 feet and can get the engines restarted and therefore avoid certain disaster. The first time it happened was on a long-haul flight from Barrow, Alaska to Osaka, Japan. OK arctic circle, so I figure this may be normal, but today it happened flying from Dulles to Dallas! I know it's cold, but it's not that cold.

So, are these temps way out of line?

Are there fuel heaters on the MD-11 like on many other aircraft to prevent the fuel lines from seizing up in sub -40C temps?

Thanks for any info you may have, and thanks again for a terrific product!!

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I hate to gush
Gushing is completely justified in this case :) I'm curious what will be in the (FSX version) update, because I honestly can't find much to fix.You can load a fuel type with a lower freezing point, such as Jet-A1. In the FMS on the FUEL INIT 3/3 page, enter A1 and line select 3R.It is discussed on page FMS10.25. There is a good article on Wikipedia about jet fuel.Tom

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The ge engines normally send the fuel through a oil heat exchanger to warm the fuel before going through the fuel controller. So it is in a sense a fuel heater. Most jets recommends avoiding flight through temp that are within 6 degrees of the fuels freezing point. In the dc10 we would transfer inboard gas outboard to keep the fuel from jelling if temps got close.

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Glad you brought the fuel freezing thingy up.I too suffered a fuel freeze last night half way to KJFK -from TNCM, and lost an engine. 1st time that has happened to me. After some panic, I did as the FMS recommended and dove for warmer altitudes then re-fired the engine and was good to go, albeit 10,000 feet lower than the "optimal" altitude....was all moot, however; FSX crashed just as I lined up for 31R. @#@%!Kenp.s. I was running REX, also.

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You can always change the fuel type you are using at the MD11 or the freezing tempOn teh Grounf if you go to the INIT page 3 if I remember correctly it has the Fuel type and Freezing temp. If you put A1 at the fuel type the freezing temp will change. Or you can just change the freezing temp to another value :)

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Don't know about GE but on a PW aircraft fuel heat is controlled by the FADEC (Full Authority Digital Engine Control) by scheduling fuel through the IDG and engine oil/fuel coolers.If it ain't working there's not much you can do about it except perhaps selecting FADEC alternate mode, I'll have a look at the checklist...Chris

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I prevented an engine-out on a NATS flight by crossfeed from a different tank, at the time only one tank was -41C. I then dropped 10k feet normalized the fuel feed when temp rose.

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Excellent Replies all, as it turns out my research indicates those temps at altitude are not that unusual. I really appreciate all the responses.BTW - I discovered in my trials that switching to manual fuel control, and then cross-feeding the the engines turned out to be critical. Only after the cross-feed was initiated and I had descended to a warmer altitude would my engines re-light. The warmer altitude alone would not do the trick.Again thanks for a terrific product.....Cheers

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I've run into this before... I alleviated the issue before engine power loss by stirring the fuel until well below freeze temp.

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Stirred, not shaken?
:(I like my drink how I like my fuel at FL390.... Stirred not shaken.

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