A320 Eng Dual Flameout
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A320 Eng Dual Flameout
Hello
I have a small question regarding dual flameout in FCOM 3. It says on the first page at the bottom:FAC1 OFF then ON. Aircraft is out of trim due to right aileron up float <---What does this mean, and why is this happening? FAC is not controling the ailerons and we still have B-hyd from RAT?
I have a small question regarding dual flameout in FCOM 3. It says on the first page at the bottom:FAC1 OFF then ON. Aircraft is out of trim due to right aileron up float <---What does this mean, and why is this happening? FAC is not controling the ailerons and we still have B-hyd from RAT?
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re from captain87
Hi Cristianwold,
Here is the FCOM Sequence:
FAC1 - OFF then ON
" Aircraft is out of trim due to right aileron up float ... Resetting FAC 1 permits to recover rudder trim even if no indications is available "
Upfloat of control surfaces will happen every time there is the total loss of hydraulic power for that surface. Having said this, I think the situation above might be interpreted as "damping mode" of ailerons that are being powered by Blue Hyd Sys only through the RAT ...
As FAC also provide Turn Coordination, it directly influences ailerons which cause FAC to give a computer error in guiding them to the desired position, so FAC should be reset in order to restore the rudder trim ...
That's what I think ... but probably I'm getting wrong !
Best Regards,
captain87
Here is the FCOM Sequence:
FAC1 - OFF then ON
" Aircraft is out of trim due to right aileron up float ... Resetting FAC 1 permits to recover rudder trim even if no indications is available "
Upfloat of control surfaces will happen every time there is the total loss of hydraulic power for that surface. Having said this, I think the situation above might be interpreted as "damping mode" of ailerons that are being powered by Blue Hyd Sys only through the RAT ...
As FAC also provide Turn Coordination, it directly influences ailerons which cause FAC to give a computer error in guiding them to the desired position, so FAC should be reset in order to restore the rudder trim ...
That's what I think ... but probably I'm getting wrong !
Best Regards,captain87
Last edited by captain87; 4th Jun 2008 at 19:30.
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Here's what I think..
Dual engine failure leads to flight on Batteries until RAT is deployed and AC power supplied. FAC 1 is not powered by batteries and therefore needs resetting to make it work again. (Re-boot!)
Resetting FAC 1 does not affect the aileron upfloat - the FAC does not control the ailerons - but it does regain rudder trim.
As you are in Alternate Law (roll direct) it is important to use the rudder trim if the a/c has a tendency to roll with stick neutral - there is no "normal" roll stability to keep the bank angle constant and no bank angle protection.
As to why the right aileron upfloats - don't know! The Green servojack will be in damping mode, the Blue in active mode, but the position of the aileron is still controlled by ELAC 1.
TP
Dual engine failure leads to flight on Batteries until RAT is deployed and AC power supplied. FAC 1 is not powered by batteries and therefore needs resetting to make it work again. (Re-boot!)
Resetting FAC 1 does not affect the aileron upfloat - the FAC does not control the ailerons - but it does regain rudder trim.
As you are in Alternate Law (roll direct) it is important to use the rudder trim if the a/c has a tendency to roll with stick neutral - there is no "normal" roll stability to keep the bank angle constant and no bank angle protection.
As to why the right aileron upfloats - don't know! The Green servojack will be in damping mode, the Blue in active mode, but the position of the aileron is still controlled by ELAC 1.
TP
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Hi everyone,
Can anyone explain to me why Airbus recommends to use the ENG DUAL FAILURE - NO FUEL REMAINING paper checklist from the QRH, when u lose both engines even though you have sufficient fuel in the tanks.
Atleast thats what we were taught in toulouse. Any logical explanations ??
Can anyone explain to me why Airbus recommends to use the ENG DUAL FAILURE - NO FUEL REMAINING paper checklist from the QRH, when u lose both engines even though you have sufficient fuel in the tanks.
Atleast thats what we were taught in toulouse. Any logical explanations ??
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Not a definitive answer, but what reasons might there be for simultaneous (or almost) loss of both engines that are not to do with fuel? Volcanic Ash? Massive rain ingestion? Suicidal flight-deck colleague? The list must be pretty short and in each case the cause is probably quite easy to spot.
My suggestion is that if you are not absolutely certain as to the reason for the dual failure, then a fairly likely suspect is fuel contamination/freezing or similar (BA38?). In those cases there may be little point in doing the checklist which is mostly concerned with trying to restart an engine, since you may be wasting time and need to re-prioritise.
The fact that the FOB isn't zero may not the whole story - you need to select the most appropriate checklist for the situation.
My suggestion is that if you are not absolutely certain as to the reason for the dual failure, then a fairly likely suspect is fuel contamination/freezing or similar (BA38?). In those cases there may be little point in doing the checklist which is mostly concerned with trying to restart an engine, since you may be wasting time and need to re-prioritise.
The fact that the FOB isn't zero may not the whole story - you need to select the most appropriate checklist for the situation.
