Apprentice wrote:

Hello: As Caltech used to be carefully in his posts, I pay a check to Airbus A330’s “ Flight Deck and System briefing for pilots”, page 4.2. ““http://www.smartcockpit.com/docs/A330_Flight_Deck_and_Systems_Briefing_For_Pilots.pdf“ and, Airbus included and schematic with.. a PTU !!!. As A330 does not need PTU, I may suppose that Airbus included it to get $. And gave a false reason, “ in case of full hydraulic power lost, RAT will power Grren System , And PTU , using Green power, may pressurize Yellow System . Still difficult times but with less heavy FC.”

Rgds

I still get the feeling that was an error in the PDF, or perhaps an option that was never taken up.

Apprentice wrote:

Hi, Sorry again, reading same “FDASBFP” in “Abnormal Proccedures”, Airbus also consider this one:

“- in the event of engine 2 failure, the Yellow electrical pump runs automatically when flaps are not retracted”, thus pressurizing Yellow and Green System, using PTU. (See schematic no same page 4.2) .
Sorry Airbus, it looks that, beside Mx, there are cases when pump is needed....

Rgds

In that particular case, there's no need for the PTU to pressurise the yellow system because it would be done with the electric pump.

My point is that the PTU adds a bit of redundancy but is not really necessary.

Starlionblue wrote:

Sorry for being unclear. CALTECH showed a slide above showing a PTU on the A330, so I was talking about the A330 and the fact it does not need a PTU.

Indeed.

I have a couple thousand hours on the A330 and ours were earlier build machines. NONE had a PTU, so of course it would not be mentioned in the MEL.Our A330s are certified to ETOPS 180.

For the same reason, it is not mentioned in the Abnormal Procedures ... not there.

It sounds like it was a Customer option.

If you look into the original drawings for the 777, there is engineering data for a folding wing tip, however exactly ZERO customers ever felt the need for it. I do remember reading about the option in early Gen Fam training literature.

So it is possible there is outdated Bus training literature showing a PTU.

longhauler wrote:

Starlionblue wrote:

Sorry for being unclear. CALTECH showed a slide above showing a PTU on the A330, so I was talking about the A330 and the fact it does not need a PTU.

Indeed.

I have a couple thousand hours on the A330 and ours were earlier build machines. NONE had a PTU, so of course it would not be mentioned in the MEL.Our A330s are certified to ETOPS 180.

For the same reason, it is not mentioned in the Abnormal Procedures ... not there.

It sounds like it was a Customer option.

Thanks longhauler. Our older ones are mid-90s builds so not quite the oldest but close.

Starlionblue wrote:

CALTECH wrote:

Starlionblue wrote:

I don't know what you heard but it wasn't a PTU since the A330 does not have one. There are 3 hydraulic systems and no way to transfer power from one to another.

(Yes, Mr. Smith is wrong on that one.)

Are you sure ?

http://www.smartcockpit.com/docs/A330_F ... Pilots.pdf

Page 39 of 210

A330 hydraulic system
4.3
General
• Three fully independent systems : Green, Blue, Yellow
(nominal pressure at 3000 psi).
• Normal operation :
They are managed by the HSMU (Hydraulic System
Monitoring Unit) which ensures all autofunctions (electrical
pumps, RAT, monitoring, etc) ; manual override is
available on the overhead panel.
- one handpump on the Yellow system for cargo doors
operation when no electrical power is available.
• Abnormal operation :
ELEC
OVHT
GREEN
3000
LO AIR
PRESS
OVHT
1
ELEC
BLUE
3000
1
ELEC
YELLOW
3000
2
PTU
GREEN
2

Ah. I saw the link now. The picture of the ECAM HYD page does indeed show a PTU. However, the same page in the FCOM does not show anything in that location.

I get the feeling there's a misprint in that presentation. Either that or the Ghost PTU (GPTU) existed at some point during the design or in initial frames but was later deleted.

Think you are right.
Heard A-320, A-330 Hydraulics were very similar, but can not find anything else about it. Seems strange having a misprint in a Airbus document.

If you are referring to Airbus or Boeing training documents probably not a miss print. Training documents by their nature are uncontrolled data and are not the final authority of an aircraft's configuration. The flight manual and the maintenance documents are controlled and revised and are the final word on an aircrafts config.

On the first page of the linked document, there is a statement explaining this.

Hi, Good Morning. (Sorry, I have to learn how to attach images)

In a Flight Crew Operation Manual, 1.29. 10.. p3, On schematic of Hydraulic Power, on the top to the Right, PTU displayed, and on 1.29.20, PTU operation description.
Rgds

What carrier and what is the revision date of the document?

stratclub wrote:

What carrier and what is the revision date of the document?

And what aircraft type?

As this keeps moving back and forth between the A330 (I have never seen a PTU on an A330) and the A320 where it is an integral part of the hydraulic architecture.

Hi: Revision 33, but I find it back to at least, Rev 25
Plane, refer to lead title: “A-320ceo Dog Barking question”. (Located on top, left, on white letters)

Rgds

Good Evening: Let’s play to faults case scenarios.
Suppose You lost one engine, You have less electric power, including APU that You May no use in the whole flight’s envelope.
You also had one engine driven hydraulic pump gone, In that case, an Hyd electric pump will solve not to much, and a PTU that don’t use almost electric power, besides valves and don’t need an engine’mechanical power, is very useful
Rgds

I

The demand ACMP hydraulic pump would power on for the dead engine's hydraulic system and the electrical system would automatically shed a non essential electrical load if required such as galleys and or IFE.

A PTU would use system volume from the supplying system which could cause the demand pump for that system to kick on so generally the PTU might not be an advantage in an engine out situation. Also, some aircraft have ADP's to run the demand pumps that would use bleed air instead of electricity.

I'm not exactly sure about the A320ceo hydraulic system and would have to study the schematic.

Apprentice wrote:

Good Evening: Let’s play to faults case scenarios.
Suppose You lost one engine, You have less electric power, including APU that You May no use in the whole flight’s envelope.
You also had one engine driven hydraulic pump gone, In that case, an Hyd electric pump will solve not to much, and a PTU that don’t use almost electric power, besides valves and don’t need an engine’mechanical power, is very useful
Rgds

I

A330 case to be clear. You lose an engine:
- Hydraulics: You lose either the Blue or the Yellow hydraulic system. You still have two systems, Blue+Green or Green+Yellow since the Green system has one pump in each engine. (The APU cannot drive any hydraulics.)
- Electrics: You lose one of the two engine generators. You still have the one on the running engine, quite enough to amply supply all the essentials. You can also turn on the APU to get a second generator online. The APU produces electrical power throughout the flight envelope.

Not really dire straits, and I don't see how a PTU would add much redundancy.

Apprentice wrote:

Hi, Good Morning. (Sorry, I have to learn how to attach images)

In a Flight Crew Operation Manual, 1.29. 10.. p3, On schematic of Hydraulic Power, on the top to the Right, PTU displayed, and on 1.29.20, PTU operation description.
Rgds

As mentioned above, what type and what revision of this document would be great to know...

stratclub wrote:

The demand ACMP hydraulic pump would power on for the dead engine's hydraulic system and the electrical system would automatically shed a non essential electrical load if required such as galleys and or IFE.

A PTU would use system volume from the supplying system which could cause the demand pump for that system to kick on so generally the PTU might not be an advantage in an engine out situation. Also, some aircraft have ADP's to run the demand pumps that would use bleed air instead of electricity.

I'm not exactly sure about the A320ceo hydraulic system and would have to study the schematic.

Indeed.

Hello: As I said, FCOM rev 33, Do You have last revision available?
Long time since. Does any body please let me know How Much Electrical Power need an ACMP? And how much Power is available with one generator on.?
Rgds

Amusingly, I never thought of this noise as a barking dog. Now, I will never be able to not think of a barking dog.

Hi: Been a mechanical device, PTU make more noise as they get older. (Wich is not necessary related to a/c age, since item may be replaced at any moment for different reasons).
And, again, PTU is considered an emergency item (Full Hydraulic Press Loss is a no-no for Airbus), so this is an imprescindible item, wich is not possible to differ.

Rgds