Airbus banging noise

[MasterBates]

Every time I deadhead in an A-320, I wonder what on earth is going on in the wheel bay during taxy. There is this whining noise followed by a slam of somekind, over and over. Maybe they manage to lock somebody in the cargohold every time I travel. :}

MasterBates.

[GARDENER]

http://www.pprune.org/forums/showthread.php?s=&threadid=73257&highlight=a320
This is why I do not work on the Airbus! Me and computers.....cut and paste the link for previous post regarding donkeys in the hold!!
Oh it has worked now where is my application foy MYT

[square leg]

During taxi the noise would originate from the "Automatic Selector Valve". This normally is only heard shortly after you move for the first time. Thereafter the valve should stay in such a position, so that GREEN supplies the brakes. Once parking brake is set the valve moves across again, thus the noise and the park brake is then supplied by YELLOW.

[747FOCAL]

It's just the hydraulics powering up.

[MasterBates]

So, the bang is for the hydraulics powering the brakes etc.
I.e. if I don´t hear the bang there will be one even greater soon when the bus rams the tail of the one in front!
Thanks lads.
MB:ok:

[AVIACO]

I travel a lot on A300 and A330. I notice the same type of noise (especially on the A300) just after push back has been completed and before we start to move forward under our own steam. The noise is particularly loud if you sit over the wing area (I feel) and sounds like someone trying to put the plane into gear!

[RadarContact]

That would have been the PTU...