744 Fuel/Hydraulic question.

[CCA]

Failure of which hydraulic system 1,2 or 3 (choices given) may cause a fuel auto management deficiency ?(744)

Now I'm assuming SYS 1 thus Main Tank 1 due to relationship with the fuel temp bulb, the EICAS Fuel Temp message would come on and not be indicative of all tanks due to loss of heat generated from the hydraulic heat exchanger in that tank but is this deficient, I would assume a failure of SYS 2,3 or 4 would be deficient as you would know that tank temp to be lower but not by how much. I'm stuffed if I can find anything in writing so any help would be much appreciated, cheers.

[This message has been edited by CCA (edited 06 April 2000).]

[Cornish Jack]

Might one, perhaps, check the pedigree of the question?

Have, similarly, checked all my written info and there is nothing which provides any sort of tie-in. I take your point of the #1 tank temp and heat exchanger relationship, but Boeing obviously don't see any problem there since lack of a Fuel Temp display is acceptable for dispatch as long as there is an accurate SAT/TAT available.

There's nothing in our MMs which indicate any sort of cross coupling between hyds and fuel - other than the tank 'spaghetti'.

If the question source is reliable, and you get an answer (and the reasoning !) would appreciate a posting of same. http://www.pprune.org/ubb/NonCGI/confused.gif http://www.pprune.org/ubb/NonCGI/confused.gif

[CCA]

It was from a 744 tech quiz, it's possible it's in error ie from another A/C type any Airbus's have a system that fit's the question ?

[Cornish Jack]

Thanks CCA

Always open to correction, of course, but lacking any other input, I'd go with your other a/c theory....not unknown !!! :)

Our 'bus people are all away at the moment but will have a word when they return.

[Cornish Jack]

Our 'bus guru has just returned and is equally puzzled since the 'bus dry bolics are colour referenced - yellow, green, blue?
The only other fuel/hyd combination which we can come up with is the use of fuel as the hydraulic medium for i.g.v operation. That wouldn't have any sort of limitation to one system tho'.
Exits left, deeply puzzled http://www.pprune.org/ubb/NonCGI/confused.gif http://www.pprune.org/ubb/NonCGI/confused.gif

[moremj2]

Heard of similar message on 76 during gear functionals but cant help on 744