Airbus sound question

[kf4amu]

If its a pump, why does it turn on and off so quickly? I'd expect those conditions for PTU operation to be pretty static and unchanging from second to second.

 

[Cardinal]

It's not so much a pump as two hydraulic motors bolted to each other. And like everything else is electronically controlled. When it senses a differential of 500 psi between systems it will "run" (allow one hydraulic motor to turn the other) in order to bring the low side up to 3000psi, then stop until the system bleeds down and the differential agains reaches the 500 psi threshold for activation.

The system will also run during periods of high demand when one system's pressure is pulled down, i.e., gear retraction. Why build each hydraulic system to be up to it's task? Better to do it the socialist way, a team effort, with each system helping out when times get tough. I am the green system, and I am my brother's keeper.

 

[CA1900]

The system will also run during periods of high demand when one system's pressure is pulled down, i.e., gear retraction. Why build each hydraulic system to be up to it's task? Better to do it the socialist way, a team effort, with each system helping out when times get tough. I am the green system, and I am my brother's keeper.

:laugh:

Well-done.

 

[Vingus]

Jetblue SOP is to turn on the yellow pump during single engine ops to keep it quiet. We used to have a SOP that shut the PTU off on engine shutdown which would keep it quiet at the gate. That SOP went away when too many guys forgot to turn it back on when the left the cockpit. It was a good idea, but as usual, a few dummies ruined it for everyone.

 

[lowtimedriver]

It's a fly-by-wire baggage handler.

 

[BLUE BAYOU]

I still turn the PTU off at shutdown until at least a cargo door is opened (which actuates the yellow hydraulic pump). This usually resolves the barking dog issue which is at its worst at engine shutdown at the gate.

 

[ACL65PILOT]

Most big jets have them. That is why on the 767/757 we start the left engine first. That way it will not go on.

 

[Ralph Cramden]

Fifi plays both ways. It's a French tradition! PTU can be powered by yellow or green (that's L & R to the non french speaking), and powers the lower pressure side. Blue (center to non french speaking) is lonely, only plays with itself (the rat is it's backup).

 

[PreContact]

Just say the words RED RUM, that's what it sounds like to me!~

 

[Guppiedriver]

If you turn on the yellow electric pump you never have that noise..

The high pitched whine of the yellow electric pump is just as annoying as the PTU.

 

[RUhiring?]

If you turn on the yellow electric pump you never have that noise..

Yellow electric pump on or not, single engine ops with the #2 engine running will cause the PTU to operate.
(unless the parking break is set)

 

[Cardinal]

Yellow electric pump on or not, single engine ops with the #2 engine running will cause the PTU to operate.
(unless the parking break is set)

One more way Airbus Factory SOPs suck.

 

[slackass]

I still turn the PTU off at shutdown until at least a cargo door is opened (which actuates the yellow hydraulic pump). This usually resolves the barking dog issue which is at its worst at engine shutdown at the gate.

This leads to the problem of a pilot developing his own procedures. A FO sees this, passes it on to another Captain, who thinks it's a good idea and now we have a training notice on how not to turn off the PTU. Submitting this to the training dept. may be a better option. Then again some might just call it a technique.

 

[Hair-on-Fire]

I still turn the PTU off at shutdown until at least a cargo door is opened (which actuates the yellow hydraulic pump). This usually resolves the barking dog issue which is at its worst at engine shutdown at the gate.

Great job not following SOP

 

[Blue Dude]

Great job not following SOP

SOP doesn't say you can't turn it off. It's just no longer SOP that you must turn it off. That puts it firmly back in technique territory. Relax.

 

[Cardinal]

Technique. And a welcome one. Most annoying thing about flying the Airbus is folks that are afraid of pissing off HAL, and thusly disengage their brains and fly like an automaton.

 

[JetMonkey]

At US Airways, we also run the yellow electric pump during single eng taxi. However, before turning eng #2, we actually turn the yellow pump off so we can test the PTU. I know it's annoying for the pax, but at least we know it works if we need it.

 

[Bringupthebird]

Technique. And a welcome one. Most annoying thing about flying the Airbus is folks that are afraid of pissing off HAL, and thusly disengage their brains and fly like an automaton.

No. Many pilots have such a superficial understanding of how the airplane works that they screw things up when they begin to make up their own procedures.

Take Alpha Floor demonstrations during low passes at euopean airshows for instance...

 

[Cardinal]

Where's the procedure for turning on the chart holder light? Can't find it in my manual, I guess I won't touch that switch either.

 

[Blue Dude]

No. Many pilots have such a superficial understanding of how the airplane works that they screw things up when they begin to make up their own procedures.

Take Alpha Floor demonstrations during low passes at euopean airshows for instance...

I'd like to see you draw a more rational comparison than turning off a backup pump when shutting down the airplane at the destination and intentionally flying a plane at the trees waiting for the plane to save itself. Are you friggin' serious?