Airbus A320's "Barking Dog"

[HJ1an]

If you've sat in A320s then you'd have heard the 'barking dog' prior to take-off and after landing and stopping. Apparently it is a self-test of the hydraulics or something, I read about it somewhere, didn't bother to check for writing this here..

Anyways, upon landing at Singapore, the "poor loose barking dog in the cargo" became a bit repetitive... so much so that it went from woofing a few times to sounding almost like someone is down there sawing the wings in half. It was hilarious.

Went on for at least 2-3 minutes, I sat there grinning like a 5 year old child while the rest of the passengers can't wait to unbuckle their seat belts and run off the plane in case someone is really down there sawing the wings off like crazy

[legoboyvdlp]

It's the PTU -- I believe it is like a crossfeed or something for hydraulics

[jwocky]

Gosh, it would drive me nutz!

[KL-666]

The loudest and longest noises i know are from the gear and the screw jacks of the flaps. Next time try to keep an eye on the flaps when you hear the dog barking.

Kind regards, Vincent

[jwocky]

Yeah, but gear and flaps, I recognize ... barking dogs or coughing mechanics on the other hand, thing, I can't connect with normal operation, those are the things that make me VERY nervous.

[legoboyvdlp]

Barking dog is normal -- the A320 usually starts first left then right, and the 'woof' is equalizing hydraulic pressure.

[HJ1an]

It is indeed normal to hear it, what is different about it is how long it the woofing took and its frequency.. I was unconcerned because the plane was on the ground already, but it went from barking to sounding almost exactly like somone using a wood saw.

Looking back at it now, makes me think if the hydraulics were low to produce such an extended pumping?

Interesting bit about the flaps, i didnt notice much noise during the flap operation, only increased wind noise and buffering. I believe the B737 had noisy flaps though.

[KL-666]

Wait a minute. Plane barking on the ground? A normal plane would not do that. So for me it is another reason to avoid buses.

Kind regards, Vincent

[HJ1an]

Yeah, Airbuses do that (or at least the A320 does), they bark before taking off and bark again after landing. But usually just bark a three to four times, not 100,000 times.

It’s common to hear a loud, repetitive whirring sound emanating from the floorboards of Airbus planes. Sometimes it’s a high-pitched whine; other times it’s a stilted WOOF, WOOF, WOOF, like the noise a very agitated dog might make.

http://www.askthepilot.com/questionanswers/the-barking-dog-airbus-noises/

[HJ1an]

That's how it usually sounds like, but on my particular flight increase the video speed by 10x. ( youtube only allows speed up to 2x though.. just think of a guy frantically sawing a block of wood to get out of trouble, that's how it sounded)}


(Start this video at 0:30) to hear a similar sound