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FriscoHeavy
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Re: Boeing 777X Testing Thread - 2019

Wed Jul 31, 2019 1:54 am

OA940 wrote:
It looks great but it's gonna look pretty weird in the air when they're folded.



:banghead:

Ummm? They won’t be folded during flight, unless it fails, which means it wouldn’t have taken off in the first place.
Whatever
 
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OA940
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Re: Boeing 777X Testing Thread - 2019

Wed Jul 31, 2019 8:48 am

Revelation wrote:
Let us know when you see that happen.

Personally I doubt it ever will, but you can never say never.


9Patch wrote:
They look great folded.


FriscoHeavy wrote:
:banghead:

Ummm? They won’t be folded during flight, unless it fails, which means it wouldn’t have taken off in the first place.


Ya I may or may not have used the wrong word there. I meant when they're, well, not like that, in the position they're supposed to be in the air. My bad there
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art
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Re: Boeing 777X Testing Thread - 2019

Wed Jul 31, 2019 9:39 am

Boeing so far says the FAA certification process scrutiny for the 737 MAX hasn’t affected the 777X, but LNA and industry participants believe that the FAA must be reviewing what it’s done in the past and looking at what processes are to come. The consensus, and LNA’s conclusion, is that the FAA’s revisiting the process (if this thesis is correct) will result in a delay as well.

https://leehamnews.com/2019/07/24/boeing-2q-earnings-down-as-expected-777x-delay-confirmed/

Well I hope that the certification work done so far is revisited and, if found suspect, done again properly. The engine delay fortunately mitigates the delay involved. What value would certification have if done as per MAX?
 
WIederling
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Re: Boeing 777X Testing Thread - 2019

Wed Jul 31, 2019 10:14 am

9Patch wrote:
They look great folded.


Actually the articulation looks "medieval". :-)

So many seams, nooks and crannies remaining in the "fly state".
Definitely no laminar flow in that area.
Murphy is an optimist
 
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Revelation
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Re: Boeing 777X Testing Thread - 2019

Wed Jul 31, 2019 12:50 pm

OA940 wrote:
Ya I may or may not have used the wrong word there. I meant when they're, well, not like that, in the position they're supposed to be in the air. My bad there

Seems you stirred up an old controversy you didn't know about. There seem to be a lot of people who don't understand that the wing tips are using very tried and true mechanisms such as those seen on navy fighters, so there was a lot of initial fear about various failure modes and their impacts, both of which were overstated. Hopefully all of that has been put to rest, but you never know.
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bikerthai
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Re: Boeing 777X Testing Thread - 2019

Wed Jul 31, 2019 1:12 pm

Revelation wrote:
There seem to be a lot of people who don't understand that the wing tips are using very tried and true mechanisms such as those seen on navy fighters, so there was a lot of initial fear about various failure modes and their impacts, both of which were overstated.


Have there ever been a document event where the folding wing of a navy get "accidentally" deployed in flight?

Similarly, there is one incident of the thrust reverser deploying in flight. But after that issue was corrected, there seems to be no more issues. The TR can be deactivated in the closed position, the same procedure would apply to the folding wing if needed.

bt
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FluidFlow
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Re: Boeing 777X Testing Thread - 2019

Wed Jul 31, 2019 1:19 pm

bikerthai wrote:
Revelation wrote:
There seem to be a lot of people who don't understand that the wing tips are using very tried and true mechanisms such as those seen on navy fighters, so there was a lot of initial fear about various failure modes and their impacts, both of which were overstated.


Have there ever been a document event where the folding wing of a navy get "accidentally" deployed in flight?

Similarly, there is one incident of the thrust reverser deploying in flight. But after that issue was corrected, there seems to be no more issues. The TR can be deactivated in the closed position, the same procedure would apply to the folding wing if needed.

bt


As the folding mechanism is really far out on the wing of a 777X even if it would fold up during flight, the aircraft will not be in immediate danger, it will just increase drag a lot. But chances are high that it will be bolted and the bolts can not be moved when in flight or most probably over a certain speed > taxi velocity.

What we might see a few times is that the wing tips will not fold up after landing and they have to bring out crew to manually fold them up to park the aircraft at the gate or deboarding will be somewhere else where there is enough space.
 
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sassiciai
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Re: Boeing 777X Testing Thread - 2019

Wed Jul 31, 2019 1:28 pm

This site documents occasions when US Navy aircraft took to the air with their wings "folded"

https://theaviationist.com/2014/02/19/u ... ded-wings/

It would be funny if flight experience shows that the 777X wing tips are more effective in the "up" position than "down"!!
 
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Stitch
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Re: Boeing 777X Testing Thread - 2019

Wed Jul 31, 2019 1:30 pm

bikerthai wrote:
Have there ever been a document event where the folding wing of a navy get "accidentally" deployed in flight?


Not to my knowledge. Considering the much larger surface area of the folded wingspan of carrier aircraft and the (often) more complicated folding mechanism, I imagine it is just not possible due to the aerodynamic forces in effect on the wing when in flight.
 
9Patch
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Re: Boeing 777X Testing Thread - 2019

Wed Jul 31, 2019 2:37 pm

WIederling wrote:
9Patch wrote:
They look great folded.


Actually the articulation looks "medieval". :-)

So many seams, nooks and crannies remaining in the "fly state".
Definitely no laminar flow in that area.

"Not invented here."
 
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OA940
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Re: Boeing 777X Testing Thread - 2019

Wed Jul 31, 2019 6:46 pm

FluidFlow wrote:
bikerthai wrote:
Revelation wrote:
There seem to be a lot of people who don't understand that the wing tips are using very tried and true mechanisms such as those seen on navy fighters, so there was a lot of initial fear about various failure modes and their impacts, both of which were overstated.


Have there ever been a document event where the folding wing of a navy get "accidentally" deployed in flight?

Similarly, there is one incident of the thrust reverser deploying in flight. But after that issue was corrected, there seems to be no more issues. The TR can be deactivated in the closed position, the same procedure would apply to the folding wing if needed.

bt


As the folding mechanism is really far out on the wing of a 777X even if it would fold up during flight, the aircraft will not be in immediate danger, it will just increase drag a lot. But chances are high that it will be bolted and the bolts can not be moved when in flight or most probably over a certain speed > taxi velocity.

What we might see a few times is that the wing tips will not fold up after landing and they have to bring out crew to manually fold them up to park the aircraft at the gate or deboarding will be somewhere else where there is enough space.


I'm pretty sure Boeing actually said at one point that even if they did fold mid-flight it wouldn't be any major threat to the aircraft. I assume they're gonna test how the plane responds to such an event, rare as it may be
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WIederling
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Re: Boeing 777X Testing Thread - 2019

Thu Aug 01, 2019 7:30 am

9Patch wrote:
WIederling wrote:
9Patch wrote:
They look great folded.


Actually the articulation looks "medieval". :-)

So many seams, nooks and crannies remaining in the "fly state".
Definitely no laminar flow in that area.

"Not invented here."

Let me elaborate on the invalidity of your answer after a shorter one went missing:

Quite a large effort goes into creating unbroken surfaces ( be that wing skins, fuselages or engine nacelles..)
the one piece wing skins of a CFRP wing are quite instrumental here.
Longitudinal seams have less impact than the air stream crossing ones.

It is surprising that Boeing "kills" this process via introducing a convoluted articulation design
that nixes all these advantages for that part of the wing.

It is a design that works towards impressing as "visually sturdy".
Murphy is an optimist
 
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bikerthai
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Re: Boeing 777X Testing Thread - 2019

Thu Aug 01, 2019 11:48 am

sassiciai wrote:
This site documents occasions when US Navy aircraft took to the air with their wings "folded"

https://theaviationist.com/2014/02/19/u ... ded-wings/

It would be funny if flight experience shows that the 777X wing tips are more effective in the "up" position than "down"!!


Now we know at least planes can fly with folded wings. If I read it right, all the situation noted are examples of pilots forgetting to unfold the wings and not wings folding themselves during flight.

Hopefully control towers will know enough to remind the pilots if they forget to unfold or the checklist before clearing for take off.

bt
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RickNRoll
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Re: Boeing 777X Testing Thread - 2019

Thu Aug 01, 2019 11:52 am

Pretty sure the safety systems would detect the unfolded wingtips and alert the pilots. Can't see it ever happening.
 
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Stitch
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Re: Boeing 777X Testing Thread - 2019

Thu Aug 01, 2019 12:54 pm

bikerthai wrote:
If I read it right, all the situation noted are examples of pilots forgetting to unfold the wings and not wings folding themselves during flight. Hopefully control towers will know enough to remind the pilots if they forget to unfold or the checklist before clearing for take off.


The 777X ACAP notes that as part of the takeoff clearance procedure, the crew will inform the tower that the wings are in the proper configuration for takeoff. I also expect that a configuration EICAS and/or Master Caution warning will sound if a takeoff is attempted with the wingtips folded (like when the slats and/or flaps are not properly configured).
 
mxaxai
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Re: Boeing 777X Testing Thread - 2019

Thu Aug 01, 2019 12:56 pm

WIederling wrote:
9Patch wrote:
WIederling wrote:
Definitely no laminar flow in that area.
"Not invented here."
Quite a large effort goes into creating unbroken surfaces ( be that wing skins, fuselages or engine nacelles..)
the one piece wing skins of a CFRP wing are quite instrumental here.
Longitudinal seams have less impact than the air stream crossing ones.

At the high Reynolds numbers of commercial jets, singificant laminar flow is not to be expected anyway. If the -9's wing is aerodynamically derived from the original 777 wing - which I expect it to be - there won't be much to worry about laminar flow in the first place.
The first airliners to incorporate significant areas of laminar flow are (AFAIK) the 787 and A350. Even there, it's only on select parts, mostly vertical stabilizer and engine nacelles.
 
WIederling
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Re: Boeing 777X Testing Thread - 2019

Thu Aug 01, 2019 1:15 pm

mxaxai wrote:
At the high Reynolds numbers of commercial jets, singificant laminar flow is not to be expected anyway. If the -9's wing is aerodynamically derived from the original 777 wing - which I expect it to be - there won't be much to worry about laminar flow in the first place.
The first airliners to incorporate significant areas of laminar flow are (AFAIK) the 787 and A350. Even there, it's only on select parts, mostly vertical stabilizer and engine nacelles.


IMU and afair all talk was about the 777 CFRP wing being a (more or less, scaling rules apply ) upsized 787 derivation!?
Murphy is an optimist
 
9Patch
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Re: Boeing 777X Testing Thread - 2019

Thu Aug 01, 2019 2:07 pm

WIederling wrote:
9Patch wrote:
WIederling wrote:

Actually the articulation looks "medieval". :-)

So many seams, nooks and crannies remaining in the "fly state".
Definitely no laminar flow in that area.

"Not invented here."

Let me elaborate on the invalidity of your answer after a shorter one went missing:

Quite a large effort goes into creating unbroken surfaces ( be that wing skins, fuselages or engine nacelles..)
the one piece wing skins of a CFRP wing are quite instrumental here.
Longitudinal seams have less impact than the air stream crossing ones.

It is surprising that Boeing "kills" this process via introducing a convoluted articulation design
that nixes all these advantages for that part of the wing.

It is a design that works towards impressing as "visually sturdy".

But the benefits of the increased wing span on fuel efficiency must more than compensate for any of your contrived caviling, or Boeing wouldn't have done them in the first place.
 
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seabosdca
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Re: Boeing 777X Testing Thread - 2019

Thu Aug 01, 2019 6:10 pm

WIederling wrote:
IMU and afair all talk was about the 777 CFRP wing being a (more or less, scaling rules apply ) upsized 787 derivation!?


:checkmark: By all appearances it has more in common with the 787 wing than the 777 Classic/LR wing.

In any event it seems rather unlikely that they didn't take into account the effect of the folding mechanism when they evaluated the design of the wing as a whole.
 
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Re: Boeing 777X Testing Thread - 2019

Thu Aug 01, 2019 7:20 pm

seabosdca wrote:
In any event it seems rather unlikely that they didn't take into account the effect of the folding mechanism when they evaluated the design of the wing as a whole.

I know that Boeing is in the doghouse these days, but it's amazing that people think Boeing went through all the time and expense of developing the folding wingtip itself and the procedures and the software to use it, and yes, satisfying aviation regulations, without having a solid understanding of what benefits it provides versus any hits in efficiency it may suffer due to not presenting a flat surface when unfolded for a small number of inches/centimeters.
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bikerthai
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Re: Boeing 777X Testing Thread - 2019

Thu Aug 01, 2019 9:39 pm

seabosdca wrote:
By all appearances it has more in common with the 787 wing than the 777 Classic/LR wing.


The thing most in common with the 787 would be how it was constructed (skin, stringer, frame configuration). The new wing necessitate a different airfoil profile than the original wing because of how the wing flex during flight. However, the 777X has a different wing sweep than the 787, so direct scaling is not necessarily accurate.

bt
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qf789
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Re: Boeing 777X Testing Thread - 2019

Fri Aug 02, 2019 5:27 am

Another close up view of that EK folding wingtip now on the flightline

Image

https://twitter.com/mattcawby/status/11 ... 25248?s=20
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steman
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Re: Boeing 777X Testing Thread - 2019

Fri Aug 02, 2019 7:03 am

qf789 wrote:
Another close up view of that EK folding wingtip now on the flightline

Image

https://twitter.com/mattcawby/status/11 ... 25248?s=20



There´s something I don´t understand.
The plane hasn´t even had its first flight, probably not even started the certification process and they are already building examples for customer airlines?
LH first and EK now?
Is it because it is not a completely new model and they don´t expect to have to change anything on the production line following flight tests?
Or is this standard for all modern airliners? I don´t recall the 787 or A350 having started production of customer examples before the prototype
made its first flight.

Thank you
 
StTim
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Re: Boeing 777X Testing Thread - 2019

Fri Aug 02, 2019 7:05 am

How many will they have produced before certification completes?

A lot of inventory with potential rework required.
 
StTim
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Re: Boeing 777X Testing Thread - 2019

Fri Aug 02, 2019 7:17 am

How long and how costly was the rework on the terrible teens?
 
CX Flyboy
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Re: Boeing 777X Testing Thread - 2019

Fri Aug 02, 2019 8:52 am

StTim wrote:
How long and how costly was the rework on the terrible teens?


But that was an unusual event and not the standard to which normal and future certification programs should be scheduled to.
 
StTim
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Re: Boeing 777X Testing Thread - 2019

Fri Aug 02, 2019 9:17 am

CX Flyboy wrote:
StTim wrote:
How long and how costly was the rework on the terrible teens?


But that was an unusual event and not the standard to which normal and future certification programs should be scheduled to.


Agree - unusual and I doubt this will be anywhere near as bad. But we do not know what testing will show.
 
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FrenchPotatoEye
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Re: Boeing 777X Testing Thread - 2019

Fri Aug 02, 2019 9:38 am

steman wrote:
qf789 wrote:
Another close up view of that EK folding wingtip now on the flightline

Image

https://twitter.com/mattcawby/status/11 ... 25248?s=20



There´s something I don´t understand.
The plane hasn´t even had its first flight, probably not even started the certification process and they are already building examples for customer airlines?
LH first and EK now?
Is it because it is not a completely new model and they don´t expect to have to change anything on the production line following flight tests?
Or is this standard for all modern airliners? I don´t recall the 787 or A350 having started production of customer examples before the prototype
made its first flight.

Thank you


Certainly there were many pictures of the 787 line with ex-northwest 787s with red tails on the assembly line.

All before the furst flights.
 
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RobK
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Re: Boeing 777X Testing Thread - 2019

Fri Aug 02, 2019 11:01 am

FrenchPotatoEye wrote:
Certainly there were many pictures of the 787 line with ex-northwest 787s with red tails on the assembly line.

All before the furst flights.


There were no ex-northwest 787s with red tails. The red tails were all Air India with some Hainan.
 
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Revelation
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Re: Boeing 777X Testing Thread - 2019

Fri Aug 02, 2019 11:39 am

StTim wrote:
CX Flyboy wrote:
StTim wrote:
How long and how costly was the rework on the terrible teens?


But that was an unusual event and not the standard to which normal and future certification programs should be scheduled to.


Agree - unusual and I doubt this will be anywhere near as bad. But we do not know what testing will show.

Surely there are GE9X engines already needing rework.

Good thing they are detachable.
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steman
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Re: Boeing 777X Testing Thread - 2019

Fri Aug 02, 2019 11:40 am

RobK wrote:
FrenchPotatoEye wrote:
Certainly there were many pictures of the 787 line with ex-northwest 787s with red tails on the assembly line.

All before the furst flights.


There were no ex-northwest 787s with red tails. The red tails were all Air India with some Hainan.


So it is standard practice for Boeing to start building airplanes destined to customers even before the prototype makes its first flight?
 
UAEflyer
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Re: Boeing 777X Testing Thread - 2019

Fri Aug 02, 2019 11:42 am

Is there a 1% chance that 777X can make it to Dubai Airshow ? Display only..
 
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FrenchPotatoEye
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Re: Boeing 777X Testing Thread - 2019

Fri Aug 02, 2019 11:45 am

RobK wrote:
FrenchPotatoEye wrote:
Certainly there were many pictures of the 787 line with ex-northwest 787s with red tails on the assembly line.

All before the furst flights.


There were no ex-northwest 787s with red tails. The red tails were all Air India with some Hainan.


Sigh:

https://advancelocal-adapter-image-uplo ... -large.jpg

Randy"s Journal in 2007 showed three 787s in assembly. Two of which had red painted ruddeers that were due to go to northwest, prior to being taken over by Delta.

Google is your friend.

Image
Last edited by FrenchPotatoEye on Fri Aug 02, 2019 11:52 am, edited 2 times in total.
 
BlatantEcho
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Re: Boeing 777X Testing Thread - 2019

Fri Aug 02, 2019 11:46 am

FrenchPotatoEye wrote:

So it is standard practice for Boeing to start building airplanes destined to customers even before the prototype makes its first flight?



of course.
Same for Airbus too.
They don't just wait for certification to be complete and say 'ok, now let's build some of these'
 
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FrenchPotatoEye
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Re: Boeing 777X Testing Thread - 2019

Fri Aug 02, 2019 11:58 am

UAEflyer wrote:
Is there a 1% chance that 777X can make it to Dubai Airshow ? Display only..


Denis mullenburg said first flight was now in 2020, so I guess the 1% chance is more like 100% no chances!
 
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RobK
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Re: Boeing 777X Testing Thread - 2019

Fri Aug 02, 2019 12:12 pm

FrenchPotatoEye wrote:
Randy"s Journal in 2007 showed three 787s in assembly. Two of which had red painted ruddeers that were due to go to northwest, prior to being taken over by Delta.


I stand corrected. It's so long ago now I'd completely forgotten about those and they were only very short-lived if I recall before getting painted in Boeing house livery.
 
StTim
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Re: Boeing 777X Testing Thread - 2019

Fri Aug 02, 2019 12:12 pm

BlatantEcho wrote:
FrenchPotatoEye wrote:

So it is standard practice for Boeing to start building airplanes destined to customers even before the prototype makes its first flight?



of course.
Same for Airbus too.
They don't just wait for certification to be complete and say 'ok, now let's build some of these'


Of course they do but I cannot recall production versions off the line before a first flight of the variant has happened.
 
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FrenchPotatoEye
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Re: Boeing 777X Testing Thread - 2019

Fri Aug 02, 2019 12:36 pm

RobK wrote:
FrenchPotatoEye wrote:
Randy"s Journal in 2007 showed three 787s in assembly. Two of which had red painted ruddeers that were due to go to northwest, prior to being taken over by Delta.


I stand corrected. It's so long ago now I'd completely forgotten about those and they were only very short-lived if I recall before getting painted in Boeing house livery.


Not a problem robk, easily done.

Still, would have been nice to see them in NW colors! Ah well!
 
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bikerthai
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Re: Boeing 777X Testing Thread - 2019

Fri Aug 02, 2019 1:04 pm

StTim wrote:
Of course they do but I cannot recall production versions off the line before a first flight of the variant has happened.


First flight and production output is really not dependent on each other. The reason why they need to keep pumping out planes during testing and certification is they can not afford to keep a large work force idle waiting for certification to be complete. Long lead parts forces them to continue with the fabrication. It is a risk that they must take to enable a sufficient number of frames available for the first customer as soon as FAA approves the certificate.

As we saw with the 787, if some issue is discovered during flight test, then the ramification can be significant. However, the delay of getting frames to the customer also have a financial impact as well.

bt
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Polot
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Re: Boeing 777X Testing Thread - 2019

Fri Aug 02, 2019 1:09 pm

StTim wrote:
BlatantEcho wrote:
FrenchPotatoEye wrote:

So it is standard practice for Boeing to start building airplanes destined to customers even before the prototype makes its first flight?



of course.
Same for Airbus too.
They don't just wait for certification to be complete and say 'ok, now let's build some of these'


Of course they do but I cannot recall production versions off the line before a first flight of the variant has happened.

True, but this is due to a relatively last minute delay involving a bolt on exterior component built elsewhere. Any manufacturer would be in the same situation. Nothing about the first flight is going to change anything about the production aircraft (obviously things that crop up during flight testing might).
 
WIederling
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Re: Boeing 777X Testing Thread - 2019

Sat Aug 03, 2019 7:17 am

Polot wrote:
.................last minute delay involving a bolt on exterior component built elsewhere. ................


as in "jet engine, 2 of " ? :-))))))
Murphy is an optimist
 
musman9853
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Re: Boeing 777X Testing Thread - 2019

Sat Aug 03, 2019 11:13 am

WIederling wrote:
Polot wrote:
.................last minute delay involving a bolt on exterior component built elsewhere. ................


as in "jet engine, 2 of " ? :-))))))


Yeah, a fairly minor part lol
Welcome to the City Beautiful.
 
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qf789
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Re: Boeing 777X Testing Thread - 2019

Sun Aug 04, 2019 6:23 am

777-9 N779XW is scheduled to have more taxi and brake system testing at 12pm today

https://twitter.com/mattcawby/status/11 ... 99265?s=20
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Spetsnaz55
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Re: Boeing 777X Testing Thread - 2019

Sun Aug 04, 2019 10:10 am

qf789 wrote:
777-9 N779XW is scheduled to have more taxi and brake system testing at 12pm today

https://twitter.com/mattcawby/status/11 ... 99265?s=20

I get off at 12. Perfect will head straight there
 
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Re: Boeing 777X Testing Thread - 2019

Sun Aug 04, 2019 7:58 pm

qf789 wrote:
777-9 N779XW is scheduled to have more taxi and brake system testing at 12pm today

https://twitter.com/mattcawby/status/11 ... 99265?s=20



Dont think it's still happening. 1 PM and no movement yet
 
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Revelation
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Re: Boeing 777X Testing Thread - 2019

Thu Aug 08, 2019 7:23 pm

Watch the wingtips unfold as 777-9 N779XW taxis to the runway at https://twitter.com/JenSchuld/status/11 ... 6404265984 ...
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777222LR
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Re: Boeing 777X Testing Thread - 2019

Thu Aug 08, 2019 7:45 pm

It's definitely a good looking aircraft. Can we expect the wing flex to more along the lines of the 787 now since the wings are carbon fiber? (Correct me if I'm wrong on that).
 
Sooner787
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Re: Boeing 777X Testing Thread - 2019

Thu Aug 08, 2019 8:09 pm

777222LR wrote:
It's definitely a good looking aircraft. Can we expect the wing flex to more along the lines of the 787 now since the wings are carbon fiber? (Correct me if I'm wrong on that).


I just received my new 1/200 B779x in house colors and the wings are curved up just like the 787 wings.

Also..... that model shows the 777X title on the belly of the beast.

Btw.... bought the model at boeingstore.com :)
Last edited by Sooner787 on Thu Aug 08, 2019 8:10 pm, edited 1 time in total.
 
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Re: Boeing 777X Testing Thread - 2019

Thu Aug 08, 2019 8:09 pm

777222LR wrote:
It's definitely a good looking aircraft. Can we expect the wing flex to more along the lines of the 787 now since the wings are carbon fiber? (Correct me if I'm wrong on that).


I hope so - love the flex on the 747-8 (which I know is aluminum) and 787.
 
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Re: Boeing 777X Testing Thread - 2019

Fri Aug 09, 2019 12:06 am

777222LR wrote:
It's definitely a good looking aircraft. Can we expect the wing flex to more along the lines of the 787 now since the wings are carbon fiber? (Correct me if I'm wrong on that).

The amount of wing flex is tied to several factors. But the most important ones are the strength to stiffness ratio of the structural material, and its ability to withstand flexing without fatigue. CFRP is far superior to aluminum in these regards; it is very strong without being stiff, and is pretty much immune to fatigue, whereas aluminum is very susceptible to it. In fact, what drives the life limits that the FAA has required that airframe manufacturers put on all airliners is primarily aluminum fatigue. Steel has a fatigue floor; you can stress it less than the floor value basically indefinitely, and it will not fatigue. Aluminum does not. If you stress it repeatedly, no matter how slightly, and repeat it enough times it will crack. So aluminum wings, if they are allowed to flex a significant amount, will have much shorter lives than is desirable. CFRP wings, on the other hand, can happily flex to the designer’s heart’s content.
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