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RKOines

Fuel temperature, can we start with warmer fuel?

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Today I departed PAFA (Fairbanks, AK) where the outside temperature was -38 F.  When I loaded on the fuel the fuel temperature was -38 F.  Needless to say, this is not good for taking off or any other time for that matter.  Realistically, I don't think fuel delivered to an aircraft from an underground system would be that low, even in Fairbanks.

 

Just another nit I know, but it would be nice if in the low temperatures the fuel wasn't quite that cold, say -10 F or something higher that -38 F.

 

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What happens if you go to Florida and fuel up there and then move your aircraft to Alaska with the Florida fuel already in it?

Did it warm up after engine starts (fuel/oil heat exchange?)

The Fuel temp indication is from the fuel tanks.

 

So before it goes through the heat exchangers.

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Realistically, I don't think fuel delivered to an aircraft from an underground system would be that low, even in Fairbanks.

 

Fuel could be that cold if it was delivered by a tanker truck. 

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Another scenario I always wondered about, you land in Florida after a long flight out of the cold north, you fully refuel and your fuel temp is still -27c.

 

Eric W

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Gents-

 

ORIGINAL POSTER:  Sign your posts in this forum please- else we will delete them.

 

We had a bug in the release version that would cause the fuel temp coming into the airplane to be the same as the temp of fuel already in the airplane.

 

With SP1, fuel coming in the airplane will be at Standard Temperature and mix appropriately with the volume of fuel already in the airplane...

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I am sorry sir, but I guess I don't know how to  sign in.  The name I used for this post is my real name.  What other information is required?

 

Thank you very much for your responses.  I am glad to hear that the problem has been addressed.

 

Even at this low temperature, I managed to take off and the TAT slowly but surely raised the fuel temp until it was -25 F when I landed in Vancouver.  The low fuel temp did cause me to fly at a lower altitude than I would have with warmer fuel. (FL330 vs FL390)

 

Ron Oines

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Apparently US jet fuel freezes at -37C whilst European jet fuel freezes at around -46C and Japanese fuel freezes at -50C so suggest you fill up at Narita !!!

 

 

Sent from my iPad using Tapatalk

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Or file a faster speed on your flightplan. Remember Total Air Temperature. 

 

In the Q400 the ambient tank temperature was measured in the left main tank, and we also could see the fuel entering the HP nozzles aft of the fuel/oil heat exchanger, which of course was the one that mattered. 

 

Boeing is similar. 

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Standard temp!?

 

That means what....15C?

I have no idea what the fueltemp is in Alaska, never been there (nor anywhere similar).

 

But I think the fact that Ron had to fly at FL330 in stead of FL390 due to low uplift fueltemp is actually pretty cool.

He had to think and plan and solve a problem.

 

Isn't that much more fullfilling than just pumping in 15C warm fuel everywhere on the planet?

 

Again, I dont know what standard means, maybe it does not mean 15C at all.

Maybe it does not mean the uplifted fuel will be the same temp everywhere at all.

 

Would appriciate it if someone can clarify!

 

Thx.

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Good news that this is being addressed in the next service pack.

I think it is 15C - wonder if PMDG would consider allowing us to enter a value with the required fuel? Or even set our own default temperature.

No biggie anyway - just thinking out loud  :smile:

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What happens if you go to Florida and fuel up there and then move your aircraft to Alaska with the Florida fuel already in it?

The Fuel temp indication is from the fuel tanks.

 

So before it goes through the heat exchangers.

The engine-oil/fuel heat exchanger is indeed outside the fuel tanks, but there is also an hydraulic-oil/fuel heat exchanger. This one is inside the fuel tank(s). But after start up the hydraulic system won't deliver that much heat to heat up the fuel. Especially when you've got tons of fuel in your tanks to heat up.

 

Richy

(sorry for my English, feel free to correct me)

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Indeed, but I just wanted to clarify that there are 2 types of oil/fuel heat exchangers to avoid confusion ;-)

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Jet A fuel has a regular freeze point of -40 whilst Jet A1 freezes at -47. Jet A is used in the USA whilst the majority of the world uses Jet A1.

 

What you might try doing is turning on all your fuel pumps on the ground whilst your at the gate boarding etc and watch the Fuel EICAS page in real life on the A330/340 you will observe the fuel temperature rising! I don't presently fly the 777 so I am not sure if the same will happen but it should since the fuel pumps are located in the fuel tanks!

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I am sorry sir, but I guess I don't know how to  sign in.  The name I used for this post is my real name.  What other information is required?

 

Thank you very much for your responses.  I am glad to hear that the problem has been addressed.

 

Even at this low temperature, I managed to take off and the TAT slowly but surely raised the fuel temp until it was -25 F when I landed in Vancouver.  The low fuel temp did cause me to fly at a lower altitude than I would have with warmer fuel. (FL330 vs FL390)

 

Ron Oines

 

Ron-

 

Ah- a fellow who knows how to deal with cold gas.  I like it.  B)

 

On the name thing:  We require posts to be signed without regard to the username.  (My username for example, does not exempt me either!)

 

We do this to keep it consistent and simple.

 

We are about to ramp up a pretty harsh cleanup campaign in which a bunch of folks will have their posts deleted because they are unsigned.  We do this because we have found after 16 years of experience in forum moderating that folks who have to admit who they are tend to be more civilized to one another than folks who can hide behind a user nickname...

 

Sorry if you thought I was roughing you up- I wasn't!

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