A319 noises in cabin
 

On a recent flight down the back of an A319, as the Captain was starting #2 engine, there was a loud and heavy cyclical thumping noise from the rear galley with a frequency of around 3 cycles per second which caused the trollies to shake vigorously and the cabin lights to flicker in sympathy.

The crew explained that there was a problem with the APU air bleed valve and the engine was started using ground equipment.

In all the sectors I have flown down the back of numerous a/c types, I had never heard a systems noise giving out so much energy as this before. Is this typical of the A319?

On a lighter note, what causes the noise which sounds like a load of dogs barking in the hold?

I believe what you are hearing is the hydraulics pressurizing. Always interesting to watch people's faces when that happens.

:D :cool:

Correctly identified prob with the APU bleed valve.

The "Barking Dog " noises come from the hydraulic PTU (power transfer unit) . Yellow system (Using a elec pump) is also powering the green system thru the PTU . Basically it is a back to back motor/pump assembly. As soon as L/h engine spools up the EDP (engine driven pump ) will take over and pressurize the green sys and the PTU will stop. :D