That is the infamous PTU (Power Transfer Unit) aka Airbus's 'Barking Dog'. Its basically transferring hydraulic power from one system to another as required, its usually heard after starting up one engine, as all 3 of the hydraulic buses come alive, I'm not 100% on these but to keep it brief, engine 1 has 2 hyd systems tied to it, so once its started up it can power those hydraulic systems entirely, but the 3rd system needs to have hydraulic fluid transferred to it via the PTU until the 2nd engine is started for example (again a very simple example just to give you an idea to what's happening and why)
@@lugash4 yes that is correct as the system is still trying to power other hydraulic items such as opening/closing the cargo doors, so the remaining hydraulic pressure from the accumulators can be used wherever needed, and you can also hear the electric hydraulic pump which is that high pitched whine sound, the system remains pressurised and ready to be used thanks to the electric pump pressurising the yellow hydraulic system, and then the PTU manually pressurising the green hyrdraulic system, as these would normally be pressurised by pump generators from each engine. Thus the aircraft has hydraulic systems available even when on ground with engines off. Eventually it is switched off automatically later on once the aircraft is secured
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5:57 engine start up
14:15 take off
3:16:09 landing
You the GOAT
Excellente 😍😍😍😍😍😴😴😴😴😴
5:57 engine start up😍👌🏻
1:01:44 - ECSTASY! (literally)
boarding is underrated
That video will make me sleep
nice mate
u miss 1sound
DeBoArDiNg SoUnD
Can anyone tell me what the noise is at the end that sounds like someone is sawing wood!!! Is it the trim being put into neutral?
That is the infamous PTU (Power Transfer Unit) aka Airbus's 'Barking Dog'. Its basically transferring hydraulic power from one system to another as required, its usually heard after starting up one engine, as all 3 of the hydraulic buses come alive, I'm not 100% on these but to keep it brief, engine 1 has 2 hyd systems tied to it, so once its started up it can power those hydraulic systems entirely, but the 3rd system needs to have hydraulic fluid transferred to it via the PTU until the 2nd engine is started for example (again a very simple example just to give you an idea to what's happening and why)
@@ThomasSpiteriBangalter Ok on start up but i hear it on the shut down as well???
@@lugash4 yes that is correct as the system is still trying to power other hydraulic items such as opening/closing the cargo doors, so the remaining hydraulic pressure from the accumulators can be used wherever needed, and you can also hear the electric hydraulic pump which is that high pitched whine sound, the system remains pressurised and ready to be used thanks to the electric pump pressurising the yellow hydraulic system, and then the PTU manually pressurising the green hyrdraulic system, as these would normally be pressurised by pump generators from each engine. Thus the aircraft has hydraulic systems available even when on ground with engines off. Eventually it is switched off automatically later on once the aircraft is secured
3:15:10
Kikikikikiki 0:12