A320 Family 'Strange Noise'

[Greg F]

Hi All

I was just wondering if anybody here could enlighten me to the strange noise, almost sounds like a dog barking when an A320 (family) starts its engines...

here is an example
http://www.youtube.com/watch?v=grd5eJjJcL4

Cheers

Greg

[Gavin Otto]

Greg,

It is the Power Transfer Unit and the hydraulics.

http://en.wikipedia.org/wiki/Power_Transfer_Unit

[Greg F]

Cool thank you very much for your help...

It was one of those things every time i heard it I was like 'What is that?':D

[Craig Lindsay]

Maybe it was a dog

[Brendan Lawrence]

Maybe it was a dog

Well that's what I always tell the pax that it is - "just the dogs barking down in the hold"... SOME people will believe it for a second, and then I give them the truthful answer. :p

[Brad M]

battery's flat , needs a jump start :)

[Philip Argy]

How is the noise actually created in the PTU? Is it the sound of pressurised hydraulic fluid, or compressed air, or something else? I used to call it the 'slipping fan belt'! :)

[Greg F]

Maybe it was a dog

To my knowledge JQ don't carry dogs/cats etc..

[Mick F]

It's simply the hydraulic motor.

We have the same sound in my turbo-prop when the gear is raised/lowered or anytime when the hydraulics are re-pressurised.

Mick

[Brendan Lawrence]

To my knowledge JQ don't carry dogs/cats etc..

Correct, we don't. It's either because the holds are unpressurised or non-heated... can't remember which. Either way; non-inhabitable environment for pets.

[Andrew McLaughlin]

Correct, we don't. It's either because the holds are unpressurised or non-heated... can't remember which. Either way; non-inhabitable environment for pets.

It'd be not heated...they'd have to be pressurised as they're part of the tube.