Question about A320 shuttle aircraft...

Dec 21, 2002
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had the opportunity SAT to fly an A320 shuttle aircraft into Dc and noticed while taxiing in and out of gate and for the entire stretch of pre take off and post landing there were bumping grinding shiffling clunking noises coming from beneath..it didn''t occur in conjunction with braking and it didn''t appear to be tires hitting cracks in the pavement.Customer next to me looked perplexed, I said nothing,,, but a few HAIL MARYS..lol..apparently the crew seemed oblivious therefore I toned down my concern..also the wing flaps made a lot of screeching noise as well during deployment which I was unaccustomed to..so what was I hearing???It was 60 degrees F at take off and 35 F at landing...in case wx had something to do with it.
Thanks for any ideas or input.
 
Sounds like the PTU operating for some reason but mid cabin, you are sitting right on top of all the guts of the hydralic systems. Hard to say what it was.

A320 Driver
 
[P]
[BLOCKQUOTE][BR]----------------[BR]On 1/26/2003 1:41:48 PM Severed-N-Happy wrote:
[P]I was sitting in row 17 out of 25..I had never on any a/c I have flown on heard so much noise, and was baffled. Thx for the input.[/P]----------------[/BLOCKQUOTE]
[P][/P]you ever fly on a BAE 146?..you wanna talk about noise.
 
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On 1/26/2003 1:50:07 PM willnotworkforfree wrote:



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On 1/26/2003 1:41:48 PM Severed-N-Happy wrote:


I was sitting in row 17 out of 25..I had never on any a/c I have flown on heard so much noise, and was baffled. Thx for the input.[/P]----------------[/BLOCKQUOTE]


[/P]you ever fly on a BAE 146?..you wanna talk about noise.
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Amen.
 
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On 1/26/2003 12:23:23 PM A320 Driver wrote:

Sounds like the PTU operating for some reason but mid cabin, you are sitting right on top of all the guts of the hydralic systems. Hard to say what it was.

A320 Driver
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[/blockquote]


That's what I was going to say, A320 Driver. It's been a while since I've flown the bus, but as I recall, if you taxi single engine, the PTU makes a ton of noise unless you close the green/yellow system crossover valve ... correct me if I'm wrong, A320 Driver (I'm pretty rusty on my systems knowledge).
Whenever I've heard the PTU from the back of the plane, it kinda reminds me of a barking dog.
 
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On 1/26/2003 11:42:03 AM Severed-N-Happy wrote:

had the opportunity SAT to fly an A320 shuttle aircraft into Dc and noticed while taxiing in and out of gate and for the entire stretch of pre take off and post landing there were bumping grinding shiffling clunking noises coming from beneath..it didn't occur in conjunction with braking and it didn't appear to be tires hitting cracks in the pavement.Customer next to me looked perplexed, I said nothing,,, but a few HAIL MARYS..lol..apparently the crew seemed oblivious therefore I toned down my "concern"..also the wing flaps made a lot of screeching noise as well during deployment which I was unaccustomed to..so what was I hearing???It was 60 degrees F at take off and 35 F at landing...in case wx had something to do with it.
Thanks for any ideas or input.
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[/blockquote]
Since we are talking about things that go bump in airplanes....why is some of the worst turbulence seem to be in clear weather and why are there wrinkles on the sides of the B-52 Buffs?
 
A barking dog is a good analogy of the sound the PTU makes. What has me puzzled is why it would be running at all. We single engine taxi with the Yellow hydraulic electric pump ON to pressurize the yellow system. No real reason for the PTU to operate if the system is already pressurized but who the heck knows. This I do know...the Airbus has a huge data bus complex with inputs from everything you can think of being monitored by the Flight Warning Computer. All that junk being said, not much can get by the FWC without the crew knowing it so I wouldn't fret about the noise. I flew Boeings and the Fokkers but the "Bus" is my personal fav. It's a truly great Aircraft IMHO.

That brings up another question. Can pilots really have a humble opinion???

A320 Driver
 
If you are pushing 50, you probably have a few wrinkles yourself...LOL.

Clear Air Turbulence can probably be best described as flying into an area of conflicting winds (different directions and velocities). Help me out here some of you meteorological type dudes! Can't see it but you can sure feel it.

A320 Driver
 
I too have heard the same nosies. It sounds like drilling, and I was sitting in the rear emergency exit row. At first I thought it might have something to do with the baggage loading, but it kept doing it after they closed the hold. The aircraft had been totally shut down during a thunderstorm in CLT and we were headed back to PHL at around 3:30am.
 
flew back on a320 non shuttle configured today.,,sat in row 17 again but the clunking noises came from further up this time..Today first time ever I heard the "drilling" sound someone mentioned up above after we landed today just after everybody stood up to leave the a/c and while deplaning..amazing after flying on all kinds of planes I am just now noticing stuff like this ..lol...
I have to disagree on the clear air turbulence opinion..I find it much less rattling than overcast turbulence.I hate flying thru certain types of cloud decks especially in summer.
 
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On 1/27/2003 8:23:34 PM A320 Driver wrote:

A barking dog is a good analogy of the sound the PTU makes. What has me puzzled is why it would be running at all. We single engine taxi with the Yellow hydraulic electric pump ON to pressurize the yellow system. No real reason for the PTU to operate if the system is already pressurized but who the heck knows. This I do know...the Airbus has a huge data bus complex with inputs from everything you can think of being monitored by the Flight Warning Computer. All that junk being said, not much can get by the FWC without the crew knowing it so I wouldn't fret about the noise. I flew Boeings and the Fokkers but the "Bus" is my personal fav. It's a truly great Aircraft IMHO.

That brings up another question. Can pilots really have a humble opinion???

A320 Driver

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OK, I'm starting to dust off some cobwebs. IF you forget to turn on the yellow electric pump while taxiing single engine, the PTU will run to maintain equal pressure between the green & yellow systems. I forgot to turn on the yellow electric pump once during single engine taxi, and there was a comment or two from the back about the noise.
Isn't there also something about when the cargo doors are open, the yellow electric pump has to be manually turned on by the baggage handlers? Again, lotsa cobwebs.
 
A320 Driver:

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On 1/27/2003 8:23:34 PM A320 Driver wrote:

A barking dog is a good analogy of the sound the PTU makes. What has me puzzled is why it would be running at all. We single engine taxi with the Yellow hydraulic electric pump ON to pressurize the yellow system. No real reason for the PTU to operate if the system is already pressurized but who the heck knows. This I do know...the Airbus has a huge data bus complex with inputs from everything you can think of being monitored by the Flight Warning Computer. All that junk being said, not much can get by the FWC without the crew knowing it so I wouldn't fret about the noise. I flew Boeings and the Fokkers but the "Bus" is my personal fav. It's a truly great Aircraft IMHO.

That brings up another question. Can pilots really have a humble opinion???

A320 Driver

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Seems to me that with the yellow electric pump running and the right engine running the yellow system is being pressurized by two differents sources (ie electric pump and right engine pump). Hence the ptu must pressurized the green system. With left engine running and yellow electric pump selected should inhibit the ptu. Dont forget the ptu is by-directional. It would pressurize either yellow or green depending on the source.

B4 (CLT Line mtc)
 
The yellow electric pump turns on automatically when the cargo doors are operated. Also the PTU is inhibited during cargo door operation to keep the Green system from pressurizing.

A320 Driver
 
B4,
Good point, but we only single engine taxi with the # 1 engine. That gives us a normal Green system for brakes and nosewheel steering. The electric pump is used to pressurize the Yellow system. Also, there are so many limitations on single engine taxi that it is rarely used or needed.

Thanks,
A320 Driver