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A350 Prototypes Production Thread Part 2  
User currently offlineNZ1 From New Zealand, joined May 2004, 2251 posts, RR: 25
Posted (2 years 6 months 3 weeks 6 days 21 hours ago) and read 71854 times:
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Due to the size of Part 1, it has been archived:

A350 Prototypes Production Thread Part 1 (by ferpe Oct 26 2011 in Civil Aviation)

Please continue discussion here.

NZ1
Forum Moderator

257 replies: All unread, showing first 25:
 
User currently online747400sp From United States of America, joined Aug 2003, 3509 posts, RR: 2
Reply 1, posted (2 years 6 months 3 weeks 6 days 20 hours ago) and read 71924 times:

The A350 could take Airbus to another level.

User currently offlinelightsaber From United States of America, joined Jan 2005, 12910 posts, RR: 100
Reply 2, posted (2 years 6 months 3 weeks 6 days 20 hours ago) and read 71854 times:
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Ferpe's post 236 in the last thread was excellent. A worthwhile read for anyone who missed it.

Lightsaber



Societies that achieve a critical mass of ideas achieve self sustaining growth; others stagnate.
User currently offlinedynamicsguy From Australia, joined Jul 2008, 868 posts, RR: 9
Reply 3, posted (2 years 6 months 3 weeks 6 days 18 hours ago) and read 71690 times:

Thanks for that post on the wings ferpe.

There are a few questions I have on the trailing edge and I wonder whether in your research you've found the answers.

The pictures of the "advanced" drooped hinge flap look pretty much exactly like the 787's flaps, or at least they are at the hinge supports. The slide describing the ADHF shows what I would guess to be the outboard hinge support of the inboard flap based on the simple configuration. Have you found anything which describes how they achieve the streamwise motion of the outboard flap?

Have you found anything which describes the auxiliary supports of the flaps? It looks like the configuration of main hinges and actuators is similar based on the location of the flap support fairings, but I can't tell whether any additional support is given to the flaps. The 787 has tracks and rollers at the ends of the outboard flap and the outboard end of the inboard flap, as well as at the middle of both flaps. This is pretty much there to ensure that the flap bends with the wings and to provide support in bending.

Also, on the flaperon you wrote

Quote:
B would counter with the less generated torsional twist of their flaperon when used as an aileron and that raising it in the start gives the engine thrust stream free way

This is not quite the reason for the flaperon to float at the start of the takeoff roll. This is a means to protect the flaperon structure and actuators from high sonic fatigue and thrust impingement loads. The flaperon isn't actively lifted out of the way - there is just no hydraulic pressure in the actuators holding the flaperon in place. This could be seen as a small advantage for the 777 and 787 flaps since the flaps themselves don't need to withstand this load, but for the 787 the inboard flap's outboard edge is inline with the engine centreline.


User currently offlineferpe From France, joined Nov 2010, 2800 posts, RR: 59
Reply 4, posted (2 years 6 months 3 weeks 6 days 12 hours ago) and read 71271 times:

Quoting dynamicsguy (Reply 3):
Have you found anything which describes how they achieve the streamwise motion of the outboard flap?

I was certainly looking for it but I found no info on it. What can be seen from the CAD and the Airbus Bremen Hycom test bed pictures I found was that there is:

INNER FLAP
An inner drooped hinge under the root fairing and one mid span (where I also got hold of the structure picture), both visible on the Hycom test bed picture.

OUTER FLAP
One hinge 1/4 span and another 3/4, neither is well visible on Hycom or CAD solid model pictures. The little I can glean from the pictures would be that the mechanism are simply aligned streamwise and that the hinge line would be applied as a skewed line passing these 2 supports. Can't figure out if you need any special bearings to take any geometrical displacements with such a design, for you in the know to comment   .

Anyway seems not to require anything complicated. I have seen no evidence of further support, does not mean there is none    .

Quoting Pihero (Reply 240):
If one disrupts the continuity of the trailing edge devices, one is in fact using different sets of "wings", the aspect ratios of which would be less than the continuous foil. That's the reason that allowed, up to the 777, Airbus wings to be more efficient though simpler than Boeings.

This is interesting, haven't heard it before. That a non dropped inboard aileron (no aileron droop like the 767 and flaperon like the 777, 787) would create a dip in the lift distribution in eg landing config is obvious, that it would create havoc with the aspect ratio is less intuitive    . Now the 787 flaperon would almost make the flap line continuous for landing as it has a drooped hinge line (less then the flap but still) and I assume the spoiler manages the slot when it goes down. So while it won't be 100% of the flap in efficiency the loss is not that high.

For start it floats as dynamics guy says so there is a dip but then your flap deployment is considerably less.

So how big an effect on L/D does this have at start? For landing you don't mind drag IMO as it requires more throttle (good for go around transitions) and makes your management of the float phase easier.

[Edited 2012-01-07 05:41:46]


Non French in France
User currently offlineRheinbote From Germany, joined May 2006, 1968 posts, RR: 52
Reply 5, posted (2 years 6 months 3 weeks 6 days 3 hours ago) and read 70238 times:

Quoting ferpe (Reply 4):
Quoting Pihero (Reply 240):
If one disrupts the continuity of the trailing edge devices, one is in fact using different sets of "wings", the aspect ratios of which would be less than the continuous foil. That's the reason that allowed, up to the 777, Airbus wings to be more efficient though simpler than Boeings.

This is interesting, haven't heard it before.

Me neither. I have never come across any serious reference that showed A wings being more 'efficient' than B wings. How could that be measured, anyway? And what does 'more efficient' mean? Aerodynamic efficiency in terms of Mach times lift upon drag? Bare wings or trimmed with the stabs thrown into the equation? Or overall aircraft? Wouldn't wing weight have to be factored into overall efficiency?

Quoting ferpe, reply 236 of previous thread:
"B has opted for a smaller wing then A with a higher wingloading (700-770kg/m2 for 788-789 vs 580-650 for the A358-35J) thus going for lower weight and lower wetted area vs lowest drag due to lift."

That was not a design choice, B ended up with this high wing loading due to the unplanned weight growth. When the weight growth became inevitable, a span increase was considered as a mitigation but proved unfeasible and/or unviable. The high wing loading is now partially compensated by load management utilizing the trailing edge variable camber system to shift lift loads inboards at high gross weights, to the detriment of take-off and climb performance (moving lift loads inboards basically adds induced drag)


User currently offlineEPA001 From Netherlands, joined Sep 2006, 4705 posts, RR: 38
Reply 6, posted (2 years 6 months 3 weeks 6 days 1 hour ago) and read 69492 times:
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Quoting Rheinbote (Reply 5):
That was not a design choice, B ended up with this high wing loading due to the unplanned weight growth. When the weight growth became inevitable, a span increase was considered as a mitigation but proved unfeasible and/or unviable. The high wing loading is now partially compensated by load management utilizing the trailing edge variable camber system to shift lift loads inboards at high gross weights, to the detriment of take-off and climb performance (moving lift loads inboards basically adds induced drag)

And I did not know the specific technical details you posted here. Thanks for the information. Again something learned here on A-net.  


User currently offlinetdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 7, posted (2 years 6 months 3 weeks 5 days 21 hours ago) and read 68289 times:

Quoting Rheinbote (Reply 5):
Quoting ferpe, reply 236 of previous thread:
"B has opted for a smaller wing then A with a higher wingloading (700-770kg/m2 for 788-789 vs 580-650 for the A358-35J) thus going for lower weight and lower wetted area vs lowest drag due to lift."

That was not a design choice, B ended up with this high wing loading due to the unplanned weight growth.

From 580-650 to 700-770 is a gain of 18-20%...the 787 weight didn't grow anywhere close to that much after the wing configuration was frozen. Therefore it absolutely was a design choice. The exact value that the 787 ended up with was partly influenced by the weight growth but that fact that it's larger than the A350 is very clearly a conscious design choice. The alternative is in direct disagreement with the facts.

Quoting Rheinbote (Reply 5):
The high wing loading is now partially compensated by load management utilizing the trailing edge variable camber system to shift lift loads inboards at high gross weights, to the detriment of take-off and climb performance

Trailing Edge Variable Camber doesn't do load shifts and isn't operative during take-off and climb. It has zero influence on take-off or climb performance.

Tom.


User currently offlineferpe From France, joined Nov 2010, 2800 posts, RR: 59
Reply 8, posted (2 years 6 months 3 weeks 5 days 17 hours ago) and read 68107 times:

Quoting Rheinbote (Reply 5):
That was not a design choice, B ended up with this high wing loading due to the unplanned weight growth.

I had the same observation as you but B clearly had the choice to reduce the wingloading not only for the 788 (which ended up at 700kg/m2) but they decided to keep the wing planform unchanged for the 789 at a wingloading of 770kg/m2. B does pretty substantial changes for the 789 project, extending the wingtip as planned or increasing the TE areas as A does for the 35J would have been perfectly feasible changes but they were happy to stay put, it was a conscious choice as Tdscanuck writes.

IMO B learned a lot from the 777. The 777 project started with wingloadings in the same area as todays A350 (567 for the 777-200) but gradually grew this to 700 for the 777-300 and planned 780 for the 77W. For hike to 780kg/m2 B added the swept wingtip and LE vortex generators (to control the boundary-layer beaten by the schockwaves). The 77W/LR swept wingtips efficiency surprised B for the second time (first was 767-400), the landing speeds went lower then predicted and they could increase the max weights another 10t for the final configs (this extra 1.5 hours of flight is what takes the 77W from very good to excellent IMO).

To control the cruise situation they were happy to add vortex generators on the leading edge of the wing (see picture, click on it for a better magnification):

http://i298.photobucket.com/albums/mm262/ferpe_bucket/77Wwing.jpg

We learned from Oldaeroguy over at TechOps that they are not only there for the above 1G case like the 787-8 (manouver, gust, see 787-8 picture below) but at the 77W they are also improving the 1G cruise drag. The high winloading (800kg/m2) generates sufficiently strong schockwaves so that the generators are needed to stop significant bounduray layer separation. While they generate some parasitic drag the net effect is positive and B is happy with the balance of parasitic drag (pressure=form drag and wetted area drag), induced drag and the transonic drag.



So for the 787 B had enough experience to go for the higher wingloading, taking the positives (lower weight, lower wetted area) and controlling the negatives (tortured boundury layer  ).

I have not seen A using this philosophie, they seem to optimise their wings differently. As said it is intriguing how our 2 leading framers design their wings, very similarily superficially but then differently when one digs a bit   

[Edited 2012-01-08 01:28:22]


Non French in France
User currently offlineRheinbote From Germany, joined May 2006, 1968 posts, RR: 52
Reply 9, posted (2 years 6 months 3 weeks 5 days 11 hours ago) and read 67721 times:

Quoting ferpe (Reply 8):
B does pretty substantial changes for the 789 project, extending the wingtip as planned or increasing the TE areas as A does for the 35J would have been perfectly feasible changes but they were happy to stay put, it was a conscious choice as Tdscanuck writes.

Well, I don' recall whether it was Pat Shanahan or another Boeing exec ho said it, but the truth is that extending the wingtips would have added so much weight that the aerodynamic benefit would have been eaten up completely. That is indicative of a marginal design (which is not a bad thing if you aim for low weight) and/or indicative of the problems with the side of body join.
I also remember that Boeing PR at the time tried to make us believe that "there was no need for the span extension because the baseline design was found to be better than anticipated" or something like that.  

If it would have been feasible to extend the span, they would have done it, that's for sure.

Turns out that the side-of-body join is right now being "optimized" (Boeing marketing wording) for the 787-9. I would expext this 'optimization' to be aimed at getting rid of the SOB band-aid *and* aimed at restoring margin for a span extension, but so far Boeing has indicated they are going to stick with the current span and only slightly increase wing area by trailing edge extension and may be a little tweaking of the leading edge as well. That may change - it would make the 787-9 and especially the 787-10 significantly more competitive.

Quoting tdscanuck (Reply 7):
Trailing Edge Variable Camber doesn't do load shifts and isn't operative during take-off and climb.

If your statement is accurate then I have to wonder why the concept was dropped.

Quoting tdscanuck (Reply 7):
a gain of 18-20%...the 787 weight didn't grow anywhere close to that much after the wing configuration was frozen.

Depends on when the wing config was frozen. Apart form that, the 787-9 started with an MTOW of 219t, that was increased in 2004 to 230t based on the concept of a span increase. The 787-9 is at 251t right now without that span increase, that's 15% above 219t - close enough for me (not sure what assumptions are behind ferpe's wing loading figures)


User currently offlinetdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 10, posted (2 years 6 months 3 weeks 5 days 8 hours ago) and read 67442 times:

Quoting Rheinbote (Reply 9):
Well, I don' recall whether it was Pat Shanahan or another Boeing exec ho said it, but the truth is that extending the wingtips would have added so much weight that the aerodynamic benefit would have been eaten up completely.

That's not exactly what they said...they phrased it the other way (that the 787-8 wing could work on the 787-9 without excess compromise), not that the 787-9 would barely provide any benefit.

Quoting Rheinbote (Reply 9):
That is indicative of a marginal design (which is not a bad thing if you aim for low weight) and/or indicative of the problems with the side of body join.

The side of body problems are long gone...remember, they certified the thing to ultimate load. And by "marginal design" I think you mean "low margin" ("marginal" means "almost bad" in normal usage). As you say, that's a good thing.

Quoting Rheinbote (Reply 9):
Quoting tdscanuck (Reply 7):
Trailing Edge Variable Camber doesn't do load shifts and isn't operative during take-off and climb.

If your statement is accurate then I have to wonder why the concept was dropped.

The concept wasn't dropped...the 787 has trailing edge variable camber in cruise and, as far as I know, always has. You may be thinking of maneuver load alleviation, a totally different function (that doesn't involve the TEVC system), that's active all the time.

Quoting Rheinbote (Reply 9):
Turns out that the side-of-body join is right now being "optimized" (Boeing marketing wording) for the 787-9. I would expext this 'optimization' to be aimed at getting rid of the SOB band-aid *and* aimed at restoring margin for a span extension

What band-aid? The in-line production fix for side-of-body showed up quite some time ago. Given that they're now strapping the 787-8 wing to the 787-9 it's normal that they have to beef up some primary structure for the higher weights.

Quoting Rheinbote (Reply 9):
Quoting tdscanuck (Reply 7):
a gain of 18-20%...the 787 weight didn't grow anywhere close to that much after the wing configuration was frozen.

Depends on when the wing config was frozen. Apart form that, the 787-9 started with an MTOW of 219t, that was increased in 2004 to 230t based on the concept of a span increase.

They only selected the 787-8 wing for the 787-9 last year...about 7 years after the weight growth you're talking about.

Tom.


User currently offlineXT6Wagon From United States of America, joined Feb 2007, 3392 posts, RR: 4
Reply 11, posted (2 years 6 months 3 weeks 5 days 7 hours ago) and read 67317 times:

Quoting Rheinbote (Reply 9):
Turns out that the side-of-body join is right now being "optimized" (Boeing marketing wording) for the 787-9. I would expext this 'optimization' to be aimed at getting rid of the SOB band-aid *and* aimed at restoring margin for a span extension, but so far Boeing has indicated they are going to stick with the current span and only slightly increase wing area by trailing edge extension and may be a little tweaking of the leading edge as well.

Only problem was that it wasn't too little strength, it was too much strength. Extra material was making It too stiff, causing delamination under high wing deflection.

You are also missing that while the wingtip extentions did provide lower fuel burn. It simply wasn't worth the wieght, cost, and reduced gate access. Not every mission is 9,000nm. Infact there is a nice post up showing how rare 7K nm flights are. So why are you demanding planes be optimized for the rare cases?


User currently offlineferpe From France, joined Nov 2010, 2800 posts, RR: 59
Reply 12, posted (2 years 6 months 3 weeks 5 days 7 hours ago) and read 67265 times:

Quoting Rheinbote (Reply 9):
(not sure what assumptions are behind ferpe's wing loading figures)

I use 325m2 area and 228t and 251t for the 787. For the 350 8,9 443 and 35J 461m2 and their MTOWs 259, 268 and 308t.

Quoting tdscanuck (Reply 10):
the 787 has trailing edge variable camber in cruise

I am very surprised it does not use the variable camber to make the climb and cruise climbs more effective.



Non French in France
User currently offlineRheinbote From Germany, joined May 2006, 1968 posts, RR: 52
Reply 13, posted (2 years 6 months 3 weeks 5 days 7 hours ago) and read 67221 times:

Quoting tdscanuck (Reply 10):
side of body problems are long gone...remember, they certified the thing to ultimate load.

I do not believe that 787-8 static testing went up to 787-9 MTOW of 251t.

Quoting tdscanuck (Reply 10):
by "marginal design" I think you mean "low margin"

Yes, you are correct, apologies.

Quoting tdscanuck (Reply 10):
You may be thinking of maneuver load alleviation

Yes, in that case the aileron would be used to un-load the wingtips for reduced wing root bending moment. That would still incur an induced drag penalty and have a detrimental impact on takeoof and climb performance. The need for this active loads management would be obviated in case the weights come sufficiently down and/or the wing root design is improved. Not sure whether the FAA would like that, anyway.

Quoting tdscanuck (Reply 10):
What band-aid? The in-line production fix for side-of-body showed up quite some time ago.

Which as far as I know still involves the titanium fittings inserted into the stringer profiles, fitted during wing production rather than added in the FAL.

Quoting tdscanuck (Reply 10):
They only selected the 787-8 wing for the 787-9 last year...about 7 years after the weight growth you're talking about.

I'd wager they rather had to 'make do with' that -8 wing, for lack of alternatives? In the meantime, the -9 schedule has moved to the right and there's talk about an 'optimized side of body join'.


User currently offlineferpe From France, joined Nov 2010, 2800 posts, RR: 59
Reply 14, posted (2 years 6 months 3 weeks 5 days 6 hours ago) and read 67134 times:

Quoting dynamicsguy (Reply 3):
Have you found anything which describes how they achieve the streamwise motion of the outboard flap?


Just to show what I have found, these mechanism has been labeled as 350 flap mechanisms by SABCA and they seem to be mounted at an angle to the rear spar, in such case the left should be the outer final one and the right hand the inner (which still have the torque axle going through it).

Weather they are the real deal or early concepts is more unsure however    :

http://i298.photobucket.com/albums/mm262/ferpe_bucket/Outerflapstreamwisemechanisms.jpg

Here where these mechanisms would fit and I could glean a 3rd support holding the outer tip in line as well:



[Edited 2012-01-08 11:44:29]


Non French in France
User currently onlineStitch From United States of America, joined Jul 2005, 30654 posts, RR: 84
Reply 15, posted (2 years 6 months 3 weeks 5 days 4 hours ago) and read 66922 times:
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Quoting Rheinbote (Reply 13):
I do not believe that 787-8 static testing went up to 787-9 MTOW of 251t.

It's not necessary. Boeing proved their calculations were accurate with the original test so that equation is valid for higher TOWs (up until the solution shows that you exceeded the load limit).

Hence why OEMs don't need to perform a new wing break test when they up the TOW. And why the A380-800 wing was certified even though it didn't survive to the full load limit - Airbus was able to prove their calculation was accurate enough that when they factored in the additional strengthening production wings would have, they'd survive the load.


User currently offlineRheinbote From Germany, joined May 2006, 1968 posts, RR: 52
Reply 16, posted (2 years 6 months 3 weeks 5 days 4 hours ago) and read 66800 times:

Quoting Stitch (Reply 15):
Boeing proved their calculations were accurate with the original test so that equation is valid for higher TOWs

I do not dispute that the ultimate load test may have proven the structural model valid (guess it has) so that Boeing may use the model to prove an up-gauged design for a higher MTOW w/o another hardware test.

But you cannot infer from this that "the side of body problems are long gone...remember, they certified the thing to ultimate load". The SOB fix is certified to ultimate load at 227t, but not yet to 251t. That the equation is proven right doesn't mean that it works up to any weight or that the SOB fix works up to any weight.


User currently onlineStitch From United States of America, joined Jul 2005, 30654 posts, RR: 84
Reply 17, posted (2 years 6 months 3 weeks 5 days 3 hours ago) and read 66750 times:
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Quoting Rheinbote (Reply 16):
The SOB fix is certified to ultimate load at 227t, but not yet to 251t. That the equation is proven right doesn't mean that it works up to any weight or that the SOB fix works up to any weight.

Well clearly it won't work for any weight - hence my comment that eventually you'll plug in a value for the weight that generates a solution that shows the wing would break when subjected to ultimate load at that weight.

As for the SoB fix, the same should apply. Otherwise Boeing would have to perform a test for the 787-9 and they have not indicated such a test will be necessary. That infers that the FAA, EASA and any other relevant agency has accepted Boeing's fix to be valid up to at least ~250t, which is said to be the limit of the current undercarriage geometry.

I mean let's turn this argument around and assume the SoB join had not been too strong and therefore no delamination had occurred during the test at the 787-8's weights. Would anyone be arguing Boeing needs to run new tests or generate new equations to take into account the 787-9's weights? No. So why should they have to do it now that they have proven the new SoB join works?

[Edited 2012-01-08 14:18:24]

User currently offlinetdscanuck From Canada, joined Jan 2006, 12709 posts, RR: 80
Reply 18, posted (2 years 6 months 3 weeks 5 days 2 hours ago) and read 66614 times:

Quoting ferpe (Reply 12):
Quoting tdscanuck (Reply 10):
the 787 has trailing edge variable camber in cruise

I am very surprised it does not use the variable camber to make the climb and cruise climbs more effective.

Climb is so far off the design speed of the wing that you're probably not going to get much mileage out of variable camber. It should be active during cruise climb.

Quoting Rheinbote (Reply 13):
Quoting tdscanuck (Reply 10):
side of body problems are long gone...remember, they certified the thing to ultimate load.

I do not believe that 787-8 static testing went up to 787-9 MTOW of 251t.

I would strongly assume it did not.

Quoting Rheinbote (Reply 13):
Quoting tdscanuck (Reply 10):
You may be thinking of maneuver load alleviation

Yes, in that case the aileron would be used to un-load the wingtips for reduced wing root bending moment.

Ailerons, flaperons, and spoilers.

Quoting Rheinbote (Reply 13):
That would still incur an induced drag penalty and have a detrimental impact on takeoof and climb performance. The need for this active loads management would be obviated in case the weights come sufficiently down and/or the wing root design is improved.

No, it wouldn't. Maneuver load alleviation only kicks in at high loading (more than 1g at MTOW)...it doesn't cause anything to happen during normal takeoff/climb.

Quoting Rheinbote (Reply 13):
Quoting tdscanuck (Reply 10):
What band-aid? The in-line production fix for side-of-body showed up quite some time ago.

Which as far as I know still involves the titanium fittings inserted into the stringer profiles, fitted during wing production rather than added in the FAL.

If the titanium fittings are the final fix then it's not a band-aid, it's just the final design. However, I believe Boeing said they would switch over to a beefed up fitting at some point...I thought that had already happened but perhaps not.

Quoting Rheinbote (Reply 16):
But you cannot infer from this that "the side of body problems are long gone...remember, they certified the thing to ultimate load".

Yes, you can. If there was a problem, it wouldn't have passed. They have a fix that works, is in production, is certified and, according to you, is the final design and will remain that way. That's not the definition of "band-aid."

Quoting Rheinbote (Reply 16):
The SOB fix is certified to ultimate load at 227t, but not yet to 251t.

Right, which is why they're upgauging parts of the wing. It's normal to increase gauge on structure during a stretch. You're presenting the totally normal design process for a larger derivative as if it's some kind of anomaly or failing.

Tom.


User currently offlineferpe From France, joined Nov 2010, 2800 posts, RR: 59
Reply 19, posted (2 years 6 months 3 weeks 4 days 10 hours ago) and read 66148 times:

Spirit has now rolled the first section 15 over to the Airbus PreFAL at Saint Nazaire, France:



I would assume this is for the static test frame (MSN5000) and therefore the mating and equipping time with section 21 (wingbox, MLG well and keel beam already waiting at Airbus, see post 148 ) will not take to long. We should then see it take to the Atlantic on a barge and then going up the Garonne river up to TLS soon   .

Things start to move    . (PS Watch the guys on the side of the rolling jig for scale DS)

[Edited 2012-01-09 07:30:45]


Non French in France
User currently offlineBoeingVista From Australia, joined Jan 2009, 1563 posts, RR: 3
Reply 20, posted (2 years 6 months 3 weeks 4 days 10 hours ago) and read 66066 times:

Quoting Stitch (Reply 17):
As for the SoB fix, the same should apply. Otherwise Boeing would have to perform a test for the 787-9 and they have not indicated such a test will be necessary. That infers that the FAA, EASA and any other relevant agency has accepted Boeing's fix to be valid up to at least ~250t, which is said to be the limit of the current undercarriage geometry.

Boeing is like a Trappist monk when it comes to the 787-9, I don't think that we can infer that there are no issues from their silence actually, as this has not proved to be the case from past experience, also I think that you trying to forget that Boeings original calculations and models were way off hence the need for the SOB fix in the first place.



BV
User currently onlineStitch From United States of America, joined Jul 2005, 30654 posts, RR: 84
Reply 21, posted (2 years 6 months 3 weeks 4 days 7 hours ago) and read 65784 times:
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Quoting BoeingVista (Reply 20):
also I think that you trying to forget that Boeings original calculations and models were way off hence the need for the SOB fix in the first place.

If Boeing's revised calculations were still off, they would have failed the test. But they didn't. So it does not strike me as unreasonable to infer that they took the new data, plugged it in, developed a new, accurate calculation, and ran the test, which was successful, which at least implies the new calculations were correct.

Again, I keep going back to if the test had worked the first time without issue (because Boeing's original calculations of the transfer loads would have been accurate and they would have properly engineered the parts for those loads), we would not be having this conversation.


User currently offlineBoeingVista From Australia, joined Jan 2009, 1563 posts, RR: 3
Reply 22, posted (2 years 6 months 3 weeks 4 days 3 hours ago) and read 65453 times:

Quoting Stitch (Reply 21):
If Boeing's revised calculations were still off, they would have failed the test. But they didn't. So it does not strike me as unreasonable to infer that they took the new data, plugged it in, developed a new, accurate calculation, and ran the test, which was successful, which at least implies the new calculations were correct.

But that does not mean that the results will scale to higher loads and weights, it is entirely possible that the SOB fix has an upper load limit that is below that required to make the 787-9 work hence the rumblings about "optimising" the SOB fix.

Quoting Stitch (Reply 21):
Again, I keep going back to if the test had worked the first time without issue (because Boeing's original calculations of the transfer loads would have been accurate and they would have properly engineered the parts for those loads), we would not be having this conversation.

You would have us all ignore an inconvenient truth?



BV
User currently offlinePITingres From United States of America, joined Dec 2007, 1124 posts, RR: 13
Reply 23, posted (2 years 6 months 3 weeks 4 days 2 hours ago) and read 65364 times:

Quoting BoeingVista (Reply 22):
But that does not mean that the results will scale to higher loads and weights, it is entirely possible that the SOB fix has an upper load limit that is below that required to make the 787-9 work hence the rumblings about "optimising" the SOB fix.

ALL of the models used in aircraft design have some sort of limit of applicability. Knowing those limits is part of the model, and is just as important as the details of the model itself in its zone of applicability. If you're trying to argue that the modeling used for the SOB joint might zoom off into la-la land somewhere between -8 loads and -9 loads, AND that Boeing is ignorant of that situation ... I think that's completely unrealistic.

I expect that the "optimizing" of the SOB joint for the -9 is just that ... optimizing it, now that some more actual data points exist to refine the model.

In any case, I seem to recall at least one statement made when the SOB problem was revealed, to the effect that the model DID actually show a problem, although perhaps not as serious a problem as it should have. Which would imply that the model was just a bit off, augmented by human error in not following up. I'm too lazy to go back and try to dig up that reference; if anyone knows one way or the other I'd be curious.

I'd suggest that further discussion along these lines belongs in a 787 thread, not an A350 one.



Fly, you fools! Fly!
User currently onlineStitch From United States of America, joined Jul 2005, 30654 posts, RR: 84
Reply 24, posted (2 years 6 months 3 weeks 4 days 2 hours ago) and read 65364 times:
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Quoting BoeingVista (Reply 22):
But that does not mean that the results will scale to higher loads and weights, it is entirely possible that the SOB fix has an upper load limit that is below that required to make the 787-9 work hence the rumblings about "optimizing" the SOB fix.

Then it's not a fix, is it?

Quoting BoeingVista (Reply 22):
You would have us all ignore an inconvenient truth?


I think the "inconvenient" truth is that the 787 did end up passing the wing-flex/SoB test. But hey, people love to whiz on Boeing and the 787 as payback for all the baloney thrown at Airbus and the A380.

The 777 wing and SoB survived a test at ~153% of load, but histories of the program I have read certainly infer that Boeing didn't plan at the time they performed that test for those wings to be able to support TOWs ~100 tons higher (the difference between a 777-200 and 777-200LR). And yet Boeing (and the FAA, and EASA, and others) were confident enough in those calculations that they felt that, with the proper reinforcement, those wings would survive with a 100t higher TOW.

I don't recall the final percentage that Boeing pushed the fixed 787's wings and SoB to, but it was at least 150%, which proves that their engineering was sound. So if the 777 passes the test, and the 787 passes the test, then why are the 787's results "suspect"?

And the dictionary definition of "optimized" is "to make as effective, perfect, or useful as possible". So that Boeing wants to optimize the 787-9's SoB is just that - make it better...

...not make it functional.


Any way, we should move this conversation to a new thread in TechOps, as we're dragging this thread off-topic.

[Edited 2012-01-09 15:29:59]

[Edited 2012-01-09 16:15:27]

25 Post contains links abba : Is this - as it is claimed - actually the front section of the A350 entering FAL? http://a350.a380production.com
26 Stitch : Yes, but it is for the static test frame. Do they have to add any more parts to it, or is this like a "fit test"?
27 Post contains links abba : The first flying frame will only begin its assembly in May or June according to this: http://www.aviationweek.com/aw/gener...aily&id=news/avd/201
28 zeke : That is correct, the picture was taken on December 23, 2011, it is MSN 5000, a ground test airframe. The first flight test airframe front fuselage be
29 Post contains links and images ferpe : A good article on the production flow for the A350 prototypes is done by Jon Ostrower today: http://www.flightglobal.com/blogs/fl...-correction-clarif
30 Post contains images r2rho : It really is a pleasure to see Airbus being so open about sharing information on the A350 assembly process, and a welcome change from the highly opaqu
31 Post contains images Stitch : I remember plenty of information flowing out of both the A380 and 787 programs as their first production frames were being built. Pictures. Articles.
32 Post contains images ferpe : A is the first of the 2 to have the benefit of doing a program after these 2 classical marketing programs turning a bit south . They both focused on
33 Post contains links and images ferpe : Staying with the wings for a while (they are not yet in TLS ) I discovered this nice story (and the next) at the informed french forum "ACTUALITE Aér
34 Post contains links and images ferpe : This story is about how the development continues unabated to improve (=lower the weight) for such things as the frames for the later coming A350-1000
35 Post contains images EPA001 : Again very interesting posts Ferpe. This shows that Airbus is still stretching or pushing the design of the A350-1000 to the maximum, to create as mu
36 abba : Good stuff indeed, Ferpe! It makes us even feel important! Not to mention all those who are working hard to become suppliers to the ones that that end
37 Post contains images r2rho : Indeed, I am surprised that the upper wing cover is manufactured in Stade, Germany, given that all the technology for it comes from Spain. Wouldn't i
38 Post contains links imiakhtar : That concurs with what Airbus said at the conference yesterday. MSN5000 assembly at the FAL due around March and MSN001 FAL June-July. http://www.air
39 Post contains links and images ferpe : So with this and other information lets try to conclude for the static test frame (ES or MSN5000) and first flying prototype (MSN001) where the diffe
40 Post contains links and images ferpe : Aspire Aviation is covering the status of the A350 as part of it's reporting of the Airbus New Year conference in Hamburg: http://www.aspireaviation.c
41 Post contains links and images ferpe : There is a news item at Flightglobal today on how a tier 2 or 3 subsupplier is lowering weight for the drainage piping for the A350. http://www.flight
42 Post contains images EPA001 : As always very interesting information ferpe. Thanks again for keeping all of us up to date. Still a lot of work to be done, but they are still pushin
43 tdscanuck : Relatively little hydraulics run inside the pressure vessel. The reservoirs and pumps are usually tucked away in the pylons, wheel wells, wing body f
44 abba : I would also imagine that it will help verify that all the systems fit together as planed at an early stage. I think I remember that Airbus once had a
45 Post contains images r2rho : Indeed, and the trade that Airbus has made is that MSN1 will have no cabin and so most of those systems won't be installed or only partially (you do
46 N14AZ : Any news about the Trent XWB testbed alias A 380 MSN 001 F-WWOW. It was part of those airframes, for which they had to make the immediate checks of th
47 Post contains images ferpe : No news yet but Bregier said they would start the TXWB test flights in Feb so it might be time for it now. Finally something happening, bin a bit qui
48 knoxibus : I believe she did some ground engine runs this morning in the "Bikini" pit.
49 Post contains links N14AZ : Haa, I saw her rolling into exactly that area on http://www.radar-toulouse.fr . So thanks for your feedback.
50 Post contains links ferpe : Aspire aviation is reporting of a misalignment on the one-piece barell section 19 tail cone from Airbus Spain in Illescas in this article about the 77
51 r2rho : First flight should be imminent, TLS spotters be alert!
52 AngMoh : Not sure that production issues of the first prototype of the A350 are relevant to the success of the 777X. Aspire has often pink coloured sunglasses
53 ferpe : I agree with your analysis, I think it depends on who is writing, Mr Aspire him-selves seems to have pink glasses, when I read what his analysis guy
54 Stitch : Boeing had "out of round" issues with mating the fuselage barrels on LN001, so if Section 19 is having some issues, they're hardly unique and I imagin
55 N14AZ : Hmm, I didn't see any sign of F-WWOW for the last days. Any news? That's exactly what came to my mind as well. I remember one of Boeing's engineers s
56 scouseflyer : An CFRP is a lot more "floppy" that Al when it's not been put together as a whole structrure so everything can lean out of shape when you're trying t
57 nomadd22 : Boeing's issue was just a tweak in the assembly process. The barrels didn't keep a perfect shape without everything being assembeld and shipped in a
58 ferpe : I don't think this means they do no patch work, what they have said is "we do no patchwork without at the same time defining the definite fix and doc
59 CM : Without Aspire giving some better information, it's not possible to know the nature of the issues. However, this comment from the article is not enco
60 Post contains links and images ferpe : Here a picture of the tail being wound in one piece on the mandrel, now for you to tell us what type of mandrel this is: And here the piece ready to
61 CM : Wow, great pictures, and you gotta just love the way these new structures are manufactured! I know similar methods are already in use on the A380 and
62 Post contains images ferpe : IIRC the stringers are cocured with the skin so the stringers are actually placed in recesses on the mandrel in the first picture. So any shape chang
63 Post contains links N14AZ : F-WWOW, the engine test bed of the Trent XWB, is currently taxiing in TLS: http://www.radar-toulouse.fr/
64 flipdewaf : Doesnt seem to be on there now. Fred
65 N14AZ : Nope, it looked almost like someone who made a cigarette break. She turned up in that area where usually all the prodcution A 330s are standing, roll
66 knoxibus : She's supposed to do the first flight today it seems as they are getting ready around it as I speak.
67 Post contains images bikerthai : For the reason above and a variety of other reasons (the most important would be the mandrel have to withstand the rigor of mass production without h
68 Post contains images ferpe : Thanks for sharing your insights, we will get to the bottom of this somehow .
69 Post contains links and images ferpe : So then the TXWB is finally flying, look up F-WWOW or 383E7D at http://www.radar-toulouse.fr/. They have been flying at about 20,000ft since 09.45 thi
70 Post contains images EPA001 : That is good news I guess. It will be the first of many flights I guess. I am anxious to hear some of the preliminary test results. .
71 bjorn14 : I little bit OT, but did Airbus ever launch the 332HGW or 333HGW?
72 Daysleeper : if your on about the 240T MTOW and shark-lets update then I don't think they are expected to make a decision until the summer.
73 Post contains links and images ferpe : Here is a filtered view of this spotter site, I played around with the options (it's my first time as a spotter thanks N14AZ ) and found in "show opti
74 Post contains images BoeingVista : They are having fun up there, they did one westbound Pyrenes transit at 10,000 164 knots and came back eastbound at even slower speeds down to 134 kno
75 Post contains links and images ferpe : Well this is the almost complete test today, they are approaching the TLS final around 4PM. Seems like a full day at the (flying) office, on the north
76 Post contains links and images ferpe : Airbus were quick with the pressrelease: http://www.airbus.com/newsevents/new...ight-on-airbus-a380-test-aircraft/ "The aircraft took off from Airbus
77 Post contains links and images ferpe : And here the engine flying earlier today:
78 Post contains links BoeingVista : Can't tell you when she will sorte next but the RR press release gives more details abut the flight test program http://rollsroyce.com/civil/news/201
79 abba : It even looks as if it were made for the A380....
80 Post contains images CM : It looks right at home on the A380! Maybe there is a Trent XWB pip in the A380's future
81 Post contains links and images ferpe : Yes, there is now a separate thread on the test flight, guess it will cover the engines use on the A380, I am convinced it will end up there some day
82 Post contains images EPA001 : No doubt imho the Trent-900 will see many improvements coming off the XWB-engine, or the Trent-900 will be phased out in favor of this latest technol
83 Post contains links ferpe : A rather comprehensive update on the TXWB from Aviation Week. Seems the TSFC will be enchanced some 0.35% due to the better then expected compressor:
84 Post contains links and images ferpe : A Spanish tier one, Alestis have started deliveries of the belly fairing for section 15 to Airbus St Nazaire. It seems it should not be a to complicat
85 Post contains images N14AZ : Thanks like always for this comprehensive information. What is no. 15? The MLG hinge? I remember Airbus saying something like they adopted the VC 10 a
86 Post contains images ferpe : It is called the MLG grounding point (picture from ACAP), I would assume you put the jack there to work on the MLG strut. What I can see the 787 uses
87 kanban : if it were a jack point it would be called such, a grounding point would be for a/c grounding especially during fueling.
88 Post contains images CM : The saga of A350 and 787 MLG designs is a comical tit-for-tat spat between two landing gear suppliers... Early in the 787 program, Boeing abandoned t
89 abba : What a drama in the sky!
90 Post contains images ferpe : Thanks CM, insights like this makes this forum . Here a principle picture of the A350 MLG: And here the real thing in it's test rig at Airbus Filton:
91 Daysleeper : Could Airbus certify the A380 with the TXB I could be wrong as I can't confirm with google, but I was sure the A380 had Goodrich gear also...
92 Post contains links and images ferpe : You are asking as if I would know , no idea, but there is a separate thread which is speculating in that. Correct according to this directory over A3
93 CM : Looks like carbon braces, similar to the 787. Is that right? You could be correct. Word on the street when Boeing selected Messier-Dowty for the 787
94 Post contains links ferpe : Here the supplier list for the A350: http://www.airframer.com/aircraft_de...ml?model=A350#Landing%20Assemblies Seems to be the Goodrich carbon brakes,
95 Post contains images Daysleeper : Sorry, I't was a half cooked responce that had been left on my clip-board. I didn't intend to post it
96 Post contains links ferpe : Airbus have released more info on the TXWB test flight, they seem quite satisfied: http://www.flightglobal.com/news/art...f-first-a350-engine-flight-3
97 Post contains links aircellist : As per Aviation Week, Aer Lingus expects another delay in the delivery of its A359... http://www.aviationweek.com/aw/gener...0More%20A350%20Delays&
98 frigatebird : The A359 is the wrong airplane for EI. It's too big. They've already said that earlier, and confirm it in this article, saying (quote) "the A321NEO w
99 ferpe : To me it seems his delay comment on the 350 was not a central part of the interview, the more present planning was. Then his passing comment on the 35
100 Post contains images ghifty : I don't know/have the source for the image. But here's a picture of the forward section.
101 76er : Looks like quite a narrow cockpit to me.
102 EPA001 : ^^ I think the type of lens with which the picture was made contributes to that impression. I do not think the cockpit to be small at all.
103 CM : Is it an optical illusion, or do the pad-ups around the wiper shafts protrude a bit from the skin mold line? It seems odd, as this is an area which is
104 Post contains links and images ferpe : It is the nose section 11 being built at Aerolia in Meaulte, France, it should then go to Airbus St. Nazaire for integration with the forward fuselag
105 nomadd22 : It looks like a whole layer of skin is missing on Ghifty's picture.
106 Post contains links and images ferpe : For the benefit of all, here the A350 fuselage and wing production flow once again (both corrected vs. the ones in part 1 of the thread): [Edited 2012
107 Post contains images N14AZ : Waow! He is back! Can't wait until he starts to speak with a French-German accent!
108 Ruscoe : I think the most likely explanation is that the windscreen wiper units have not been installed yet, in the units already sent to Airbus. Once again s
109 Post contains images CM : I don't think so. The A380 has a very different wiper design, with the posts tucked very high up against the lower window frame.
110 bikerthai : Which lead me to agree with nomadd22. If the design is similar, then once they install the wipers, they will cover the area with an aerodynamic cover
111 ghifty : Again, I have no official source for the image, I found just the image along with a caption "A350 cockpit." It's unscientific, but if you observe the
112 Post contains images ferpe : Here a concluding post on the Air cond installation and the belly fairings that I posted over at the TXWB thread where we dicussed the global fuel eff
113 CM : The 787 cabin air compressors actually work fine without ram pressure. The reason the inlets stand off from the fuselage is to ensure no contaminants
114 tdscanuck : In addition to what CM said, the pack inlets are under suction due to the compressor draw (which is not the same as the passive ram inlets)...there's
115 Post contains images ferpe : First, thanks to CM and Tom for explaining the function of the blocker doors (has puzzeled me quite a bit ) and also the reason the compressor inlet i
116 sweair : The bleed less air/electric system, will 787 be one of a kind or do you guys think there is merit to this change for future designs? Is it maintenance
117 Post contains links and images ferpe : As the B guys would speak in their own thing here is my (amateur) judgement, I think it is something that will come more and more, first on the ULH f
118 tdscanuck : I think it's here to stay on widebodies; narrowbodies is a tougher one because of space constraints. There's a constant debate (that will go unresolv
119 ferpe : I know that the system required some adjustments among other things on the humidity side (air cond it is one of the systems that are reworked on the
120 CM : The humidity issue and solution were not related to the packs or really any part of the environmental system. The 787 operates at higher humidity lev
121 tomcat : Not to be picky but the A350 slats and slat tracks are designed and manufactured in Belgium (Sonaca and Asco), just like all the Airbus slats and tra
122 Post contains images EPA001 : As does the A380, which also as the higher cabin pressure the B787 now also has. These issues are often forgotten here on A-net. . Of course also the
123 Ruscoe : The ability of both manufacturers to offer higher humidity, is a direct result of the carbon fibre fuselage. Above a certain low humidity Al and proba
124 Post contains links zeke : That is what Boeing would like you to think, the technology has been in service now for the best part of 7 years. http://www.cisionwire.com/ctt-syste
125 Post contains images ferpe : @CM, Thanks for an excellent response, the thing about the TXWB bleed strategy is intriguing, will be watched very carefully . Reports say there was r
126 Post contains images ferpe : Thanks for the link Zeke. Actually the whole thing is quite interesting, one can follow the evaluation of the use of the system through the companies
127 Post contains images CM : I doubt we'll see it on the 777X, as the basic reason for not offering higher humidity on today's 777 will not have changed; the aluminum fuselage wo
128 Post contains links and images ferpe : Airbus just announced that the Filton landing gear test facility is ready to torture the stuff now: http://www.airbus.com/presscentre/pr...gear-test-b
129 zeke : Again, this is not a 787 first, it was introduced on the A340-500/600. The pax count is an input on the INIT page on the Airbus MCDU.
130 CM : You keep implying Boeing has claimed something untrue. Did Boeing claim this was pioneered on the 787?
131 Post contains links zeke : Have a look at what they were saying to the newspapers back n 2005/2006.....e.g. "Dreamliner designed so fliers can breathe easy - USATODAY.com" from
132 CM : Did you want to point out what was incorrect, untrue or misleading in the article? I couldn't find it. A result of a higher cabin differential A resu
133 Post contains images EPA001 : Maybe not specifically, the they certainly gave the impression, as part of the hype around the B787 that was unstoppable at that time, that it was a
134 CXB77L : If anything, that goes to show how well Boeing's marketing worked. As far as I know, Boeing never specifically claimed that the 787 was the first wit
135 abba : And many still do!
136 zeke : What was untrue is their claims that this was not on current jetliners, when in fact it was. Similar to their claims of 20% reduction in fuel burn ag
137 76er : On the MD11 it was standard procedure during preflight to enter the amount of pax on the air panel to optimize bleed air demand...
138 BoeingVista : It shows that people who don't know the truth can be persuaded to believe things that are not true but I guess that's that is the whole point of mark
139 aircellist : To give the impression and to market to their advantage, they are kings. I remember, it may have been on the 50th anniversary of the 707's first flig
140 Post contains images ferpe : Somewhat in aftermath I have finally found evidence of the production of section 16-18, here a picture of a proud Premium Aerotec Augsburg team delive
141 tdscanuck : Curious that they abandoned it...the CFM56-7 has had multi-port bleed for 10+ years. I always assumed the -5 did to, although I don't know for sure.
142 CM : I can't say for certain this is the case. Here's why I asked: I spoke at a pilot symposium last summer, where an Airbus pilot spoke on "flying the A3
143 CM : I should also add; the same A350 air system schematic shown at the symposium had a precooler in the system, something which was initially not going to
144 Post contains links BoeingVista : Looks like the TXWB is doing another tour of southern france on F-WWOW today. http://www.radar-toulouse.fr/ Currently climbing through 27575 feet at 4
145 zeke : What exactly is well documented ? That I actually learn and understand the technology and capabilities used by both sides ? I am often the only perso
146 tdscanuck : That's the ram air heat exchanger...it's not bigger on the 787 than on any conventional ECS system. Air cycle machines (whether powered by bleed air
147 Post contains links and images zeke : That is not the one I was thinking of, it is the radiator that is part of the ACM, and used to dump the heat overboard. The packs on the 787 are larg
148 Post contains links and images ferpe : It seems we will not see much deliveries to FAL during March: http://www.flightglobal.com/news/art...-assembly-slips-into-april-369261/ That is a furt
149 Post contains images bikerthai : From a integration standpoint, it is easier to get a bigger generator than trying to route titanium/inconel ducts from both the low pressure and high
150 tdscanuck : I've had my head up in a 787 pack bay...there's no radiator on the ACM itself. There are several in the ram air duct but that's true of both bleedles
151 Post contains links Revelation : Wouldn't it make more sense to just sample the humidity so the system can get to the desired humidity automatically? Maybe I'm a victim of advertisin
152 Post contains images ferpe : Spot on, having lived in the area I had to take another route to work one day as they found one of those unexploded buggers when making a new stretch
153 Post contains images r2rho : Nice to have started a discussion on systems, which is more my thing than structures Correct. Same architecture as previous Airbus designs in that asp
154 bikerthai : Perhaps as fan aspect ratio is getting high, it is more efficient to mount to where the "mass" is. bt
155 Post contains links zeke : It is smaller, the 787 needs a higher ram air mass flow to achieve the cooling required. As far as I am aware, the 787 ECS is larger in size than the
156 Ruscoe : This does not answer the question re humidity and corrosion in Al aircraft v CFRP. I do know that corrosion in al aircraft even with low humidity can
157 tdscanuck : I haven't had my head up in the A350 system so I take your word for it; I still don't really understand why that would be the case though. The actual
158 XT6Wagon : Much easier to keep a wire from leaking than a duct too. The electronics will continue to get smaller, lighter, more efficent much faster too.
159 astuteman : That's ok, Tom. But in order to generate that "nearly 100% efficient" power takeoff, the engines had to generate that power by compressing air with c
160 Post contains links and images ferpe : While we get to the bottom of the one area where the two new generation frames really differ I have listened to one of the always interesting telephon
161 Post contains images ferpe : Re bleed vs non bleed architectures, here is the 365-420 Pax AC cooling inlet of the 1000th 77W for EK: Compare this to a 220-250 pax 788: I am surpri
162 tdscanuck : The problem is that it *is* a double hit; when you pull the bleed air out of the compressor you extract all the work the engine did to compress that
163 nomadd22 : You lost me there. Why would generated power be at 40% efficiency? Generators are more like 90% efficient and the mechanical power you extract form t
164 zeke : The system does not increase the humidity level for the whole aircraft, it is mainly in the passenger space. The system includes zonal dryers which r
165 nomadd22 : I pretty obviously was referring to generator efficiency and not engine efficiency. Shaft horsepower is the same if you're using it to turn a compres
166 abba : Well - what do you believe will drive the generators? They certainly don't drive themselves! It could not be the engines that runs at only 40%..... I
167 PITingres : What "isn't true"? that the extract power requirement is 10% of the engine output, or that it takes more power to produce power at 40% efficiency tha
168 Post contains links and images astuteman : But as we're talking about the efficiency of the system, then the engine efficiency can't be ignored. If the engine efficiency is only 40%, then in o
169 zeke : That all the energy taken from an engine on a conventional aircraft is in the form of bleed air, it is a combination of bleed, hydraulic, and electri
170 CM : I'm guessing you believe CFM then, when they say the Leap-1B is as efficient as the Leap-1A? Not even Boeing is claiming that, yet CFM says they are
171 abba : I am no engineer. I did, however, do physics in High School so.... I think that it will be helpful if we break the system down to its components (cor
172 Post contains images sweair : I think Airbus will do bleed-less IF the system works out in 787, I guess we have a lot of eyes watching, it is a big departure from the known and hav
173 moderators : This thread was started in order to discuss the A350 prototype production. It is inevitable that some references may be made, but it is important to n
174 sweair : How extensive certification will the 350 have? Faster or about the same as their rival? Lots of new stuff in this frame too.
175 Post contains links aircellist : I'll repost... At EADS' annual conference, Louis Gallois announced that the A350's final assembly "would start at the beginning of april", and not at
176 RayChuang : aircellist, Based on that Flight Global article, has Airbus given any rough estimates of the rollout of the A350-900 prototype? Sounds like a first qu
177 CM : The A350 will be the most efficient example of a bleed system ever designed. However, because of its nature, a bleed system must incorporate certain
178 Post contains links CM : AvWeek offers a less optimistic take on things. It's not encouraging. Relevant excerpts: Airbus will be forced to postpone its entry-into-service dat
179 nomadd22 : Abba echoed my thinking on efficiency, although I assumed I was missing something. Thanks to CM for a very clear explanation of the matter. I'd guesse
180 abba : Thank's. It did help a lot. It also helped put to rest some of the more ridiculous ideas put forward here - e.g. that the electric system by design i
181 CM : Indeed. We are talking about efforts to achieve gains in the low single digits. Someday the history will be written how this airplane derivative did
182 tdscanuck : It's not "obviously nonsense", it's the *same* issue that CM (and I) were talking about. Electric energy conversion is extremely efficient (high 90%'
183 zeke : Trent 1700 - original A350, a more bleed less electric version of the 787 engine Trent XWB - A350 XWB engine, not related to the 787 engine. No confu
184 tdscanuck : It's related to the Trent 1000 in about the same way that the GE90-115B is related to the earlier GE90's...the Trent XWB is a scaled up (more thrust)
185 Post contains images ferpe : The delay article in AW is worrying, however one needs to see behind quotes to try and understand what is happening: "There have been changes to aircr
186 sweair : I saw figures of 4-5 tons overweight on the 1000 and even more on the 800 and less on the 900. We see the 787 problems again and my take is that it is
187 PW100 : Off course the minor detail Astuteman refers to is that before you can convert the electric energy (at high 90%'s), you first have to generate that e
188 Revelation : It's not good to debate what "mess" means, but comments in the article point out that the DMU is a critical bottleneck and that its state is such tha
189 ferpe : If i was an interior company that had signed a contract to supply a defined workpackage, having done progress on my workstatement accordingly and the
190 Stitch : There must be some level of pre-assembly integration because Airbus have stated they will not start serial production until their suppliers can relia
191 Post contains images ferpe : I think this will now happen, Airbus was taken napping by the 787 program (by their own admission), the incredible technology jump and timeplan press
192 Post contains images r2rho : The thread was going really well until we started talking about bleed architecture... a very interesting debate, but let's open a tech-ops thread for
193 CM : If the underlying structure is experiencing late change, this will certainly cause havoc with the interior. This item caught my attention in the AvWe
194 CM : Agreed. And for anyone who is wondering what a DMU is or why maturity matters, here's a quick explanation. A DMU was originally conceived as a "Digit
195 tdscanuck : True, but it's equally true of the energy going into the compressor so it's a wash between electric and bleed. Don't confuse the ~40% thermodynamic e
196 Post contains images ferpe : Airbus is building the MSN001 sections first as they have the have longer flow through time. They are now all complete and are being equipped, the fo
197 ferpe : What can they gain and how quick? As I understand the A350 is now on a 1 per month production rate. If the start of the layup of major parts (wingbox
198 Post contains images scouseflyer : I'd definitely agree with you there, there will not be an issue with versions of software this time! That's properly facisnating and makes me really,
199 metalinyoni : I found it really interesting as well but it had the opposite effect on me - made me glad I didn't work in this area of aviation. The pressure the en
200 Revelation : I'm interested to know if the tools actually 'lock down' the interfaces, or if it's more of a 'free for all'. Suppose Engineer X needs to change some
201 CM : Yes and no. It is certainly not a free for all, as there are maturity gates which include audits to help guide the maturing of the DMU. When an attri
202 Revelation : Very interesting post. Do these "maturity gates" freeze parts of the DMU? Meaning the tool will not allow changes to something frozen? I'm asking beca
203 PW100 : OK. Got it. I see what you mean. I can understand that the bleed air has a lot of temperature and pressure energy that needs to be "bled off". Pressu
204 Post contains images ferpe : Here a snapshot of the deliverables from a Tier 1 subsupplier, Spirit. The had an Investor conference yesterday and here the slide which was about the
205 CM : In some integration process wonk's mind, perhaps, but the reality is when better data becomes available, engineers and performance-minded people will
206 Post contains images EPA001 : ferpe & CM: Thank you both for such highly interesting posts. So far the road ahead for the A350 remains challenging, but most probably they can k
207 astuteman : In the days before these tools became widespread, the engineers actually HAD to talk to each other and HAD to understand the other parts of the busin
208 ferpe : That is why one collects the rippling into block points I gather. Then it is possible to tell the guys "yes we will put it in but we will wait until
209 Post contains links and images ferpe : I found production schedule data which is interesting given the challenges seen by the interior guys (keep in mind parts drumbeat is one shipset per m
210 aircellist : Part 1 and 2 included, this has been and goes on being one of, if not the, the best ever threads I've seen, from my layman's point of view. Many thank
211 Post contains images CM : This is so true. The loss of true creative engineering collaboration is a distressing byproduct of the "new and better way". However, we need to be c
212 tdscanuck : Pressure energy does get lost in lowering the pressure, normally, because regulators usually work by running the flow through very lossy valves (inte
213 CM : It used to work that way, didn't it? Sadly, the last two static tests in this industry (A380 and 787) both found deficiencies rather than excess; neg
214 Revelation : Yes, there seems to be a built-in bias towards accepting change, and presuming ripples are minimal or don't happen at all. Sounds like a very interes
215 zeke : When OEMs delegate work packages for different components, the specification details the requirements, loads, and target weight. Each section has a t
216 Post contains links and images ferpe : So finally the first rear section is complete at Airbus Hamburg, here the Airbus press release: "" Structural assembly of the first A350 XWB aft fusel
217 CM : In light of the previously discussed issues with the aft barrel, the fact these sections are now joined is encouraging - While the defect likely drov
218 flipdewaf : +1 for that, very grateful for your contributions. Fred
219 Post contains images ferpe : So Airbus writes: "The rear fuselage barrel is used as a guide and support for assembling the four aft fuselage panels (two lateral, one upper, one lo
220 Revelation : Yet we read it needs to "undergo its secondary interior structural assembly and system installation". Any idea what "secondary interior structure" is
221 CM : In normal industry parlance, "secondary structure" would refer to other than principal structural elements, which would infer the remaining work does
222 Post contains links WingedMigrator : Could this be because the stringers are co-cured to the panels? What you see in the photo that looks like stringer fasteners in the 4th bay forward i
223 Post contains links and images zeke : it is not flat, not far off either
224 Post contains links and images ferpe : And this is how the bulkhead looked before shipping from Augsburg (found it in their News flyer): with the text: " For the first time ever, the paten
225 CM : The A350 has both fastened and co-cured stringers in the fuselage. I was thinking these would be fastened, but based on the gap in frame fasteners at
226 Post contains images WingedMigrator : I'm having trouble reconciling Zeke's photo of the bulkhead with Ferpe's. The latter looks like a more realistic, detailed structure. ??? Somwhere in
227 ferpe : Both are from the same source, Premium Aerotec in Augsburg and labeled as the bulkhead for the A350 made with this resin infusion technique they devel
228 CM : I expect that dimensionally they are the same. Zeke's photo, however, looks like some kind of demo or proof-of-concept part. There are clearly some l
229 Post contains images india1 : One thread with 200+ posts that still on topic, and wihtout any sniping! Congrats, FERPE! For us on the outside, it's fascinating seeing this baby bei
230 Post contains links and images zeke : My guess is they have attached it something like this ... I think the triangulat clips shownin reply 219 tgat connect t the bulkhead are also composi
231 CM : Yes, there is no mystery why Vought went to EADS as a subcontractor for the 787 pressure dome; nobody in the world had more experience with making th
232 Post contains links and images zeke : I agree with you that it is a demo, it was made before the work package was awarded, much the same time the demo barrels were made. I as just saying
233 CM : Beautiful!
234 Post contains images ferpe : Could be exhibited on a Museum for Modern Arts .
235 Post contains links and images ferpe : I agree, I think they might be very similar to the beautiful A380 webs we see in your photo on the A380. Most likely they use the same principle to g
236 Post contains links and images ferpe : Caveats are always good, especially when ones analysis is not that sharp . Having looked at the pictures again I think there is another interpretatio
237 maxter : Thanks ferpe for all your hard work and wonderful information in this thread. It is very much appreciated. Like many others, I am waiting to see the m
238 Post contains images zkojq : Especially considering the value of what is inside, that doesn't look to be tied down very well.
239 sweair : What are the ramp up goal with A350? Will they see the same problems?
240 Post contains images ferpe : Normally Stitch or Rheinbote are the guys for such info, I don't know of hand. Airbus claims their tactic of stop and fix delays the start of the ram
241 nomadd22 : Good philosophy except for all the issues that don't come to light until after the start of the ramp. I've been a Boeing fan since Joe Sutter was a c
242 Stitch : The original production goal, as announced in July 2008 by Francois Caudron, vice-president A350 customer and business development, was 13 per month
243 ferpe : I think we can come close to the present plan if we just add a year to this schedule, right now everything is shifted 1 year forward compared to orig
244 teme82 : What's the current status of MSN 5000?? I'm currently waiting for the AY's shareholder meeting to start. Would like to know the status before I drop t
245 ferpe : For MSN5000 (second structure through PreFAL (need no equipping). MSN001 has already been PreFALed structure wise and its structures are now in equip
246 teme82 : Ok. Did Airbus stated that they have the MSN 5000 ready in Q1 in this year? Now it seems to bee ready at Q3....
247 ferpe : They stated "early 2012" IIRC now it is more like "MSN5000 FAL begins April". When it is ready is not said by Airbus, the May stuff is my speculation
248 Post contains links and images ferpe : Figuring out the correct build order PreFAL and FAL is a bit tricky. In post 129 I tried to picture what Airbus has told us about frames coming of FAL
249 Post contains links N14AZ : Hello Ferpe, I just checked the latest pictures from Hamburg Finkenwerder and in the background of some of the pictures in this link you can see a lar
250 Post contains images ferpe : Thanks, I find it quite amusing us rallying to puzzle the A350 situation, more sport then if they told us everything . The box is very tall and rathe
251 Post contains images Semaex : Might be a bigger engine prototype for the A380 Thank you very much Ferpe for your continuous updates on this program. Your input is heavily valued !
252 r2rho : Just a little correction there, MSN4 will not have a cabin, if that's what you mean by full interior. The two cabin equipped flight test aircraft are
253 ferpe : Thanks, could you give us the test purpose for MSN4?[Edited 2012-03-29 15:09:19]
254 kmz : talking of interiors: are there official news about the progress of interior suppliers? have galleys, seats lavatories been installed in the cabin0 te
255 ferpe : I have no info on the progress on cabin test other then reading a specialized magazine article some month ago that basically quoted what you are sayin
256 CM : The 787 program permits almost no airline customization, in the cabin or elsewhere. This was a significant strategy shift for Boeing compared to the
257 Post contains links LipeGIG : As this thread become too long (> 250 posts) and that's not so comfortable for some of our members using low speed internet connections, we are clo
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