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BESTGLIDESPEED
6th Feb 2017, 23:12
Hello

Flying long winter flights on the A332 get some you a lot of "Lo Fuel Temp" ECAM advises.

Does anybody know why is the procedure recommending for ANY type of fuel to either descend or to accelerate, but ONLY for JET A to do the easiest and cheapest proc. of XFRing. OUTR TK fuel to the inners ?

The usual used fuel for us is JET A1 as I presume is for most of you.

The FCOM doesn't give any different hints either

KingAir1978
7th Feb 2017, 04:53
The machine doesn't know what kind of fuel you've put in the tanks. Airbus has designed the machine to go for the safest option and give you an alert at < -40C (outer or trim tank). Which is the highest fuel limit temperature (Jet A).

IcePack
7th Feb 2017, 08:46
Jet A, does not have an anti freeze (waxing) additive. A1 does. Jet A is normal fuel in the USA in say Florida.

BESTGLIDESPEED
7th Feb 2017, 19:31
Thx for the feedback guys

Just realized that the ECAM proc. has a typical Airbus brackets right after the condition I was asking about before. The one that stopped me from "using" this proc. IF my fuel WAS NOT JET A.

Literally, each statement leading to a XFR pops-up " IF JET A fuel loaded, starting FROM -40c. And right after that, u can read : " ( not displayed at -47c )"

Meaning, that JET A WILL NOT SHOW if we give it a chance for the Temp. To lower a bit further than that ( til -47c ), in which case we are now ( literally again ) entitled to do the so long desired XFR for our type of fuel ( normally not JET A but JET A1 )

waffler
8th Feb 2017, 15:03
Freezing Point : Because it is a mixture of many hundreds of individual hydrocarbons, each with its own freezing point, jet fuel does not become solid at one temperature the way water does. As the fuel is cooled, the hydrocarbon components with the highest freezing points solidify first, forming wax crystals. Further cooling causes hydrocarbons with lower freezing points to solidify. Thus, the fuel changes from a homogenous liquid, to a liquid containing a few hydrocarbon (wax) crystals, to a slush of fuel and hydrocarbon crystals, and, finally, to a near-solid block of hydro- carbons. The freezing point of jet fuel is defined as the temperature at which the last wax crystal melts, when warming a fuel that has previously been cooled until wax crystals form . Thus the freezing point of fuel is well above the temperature at which it completely solidifies.

The freezing point of jet A1 is -47C
The freezing point of jet A. Is -40C
So if you have a mixture of both, if you have refuelled is the USA, it is wise to use the jet A figures.

rigpiggy
13th Feb 2017, 05:04
I read about a DC10 over Russia that had a low fuel warning. Due to language problems they were unable to descend, or speed up. The FO had the brilliant idea to use the wing anti ice. It brought up the fuel temps enough to continue.

PyroPet
15th Feb 2017, 15:42
Say, if you fuel in USA (JET A), how many refuellings must you do afterwards with JET-A1 before you can consider it to be in your tanks (with regards to freezing point)?

JammedStab
16th Feb 2017, 01:09
Say, if you fuel in USA (JET A), how many refuellings must you do afterwards with JET-A1 before you can consider it to be in your tanks (with regards to freezing point)?
Three refills