Moderators: jsumali2, richierich, ua900, PanAm_DC10, hOMSaR

 
marcelh
Posts: 1011
Joined: Wed Jun 19, 2013 12:43 pm

Re: Boeing 777X Testing/Production Thread - 2020

Sun May 10, 2020 1:51 pm

Opus99 wrote:
TropicalSky wrote:
I heard that.....hope it's a good thing

Opus99 wrote:
Interesting comms today. The pilots point out a similarity between the 777X to the 300er and the 787-10

http://www.paineairport.com/sounds/wh001may9.mp3

I would hope! Seeing as their both doing well in service and the -10 had a seamless certification

After all the “issues” during the certification of the 788 and the experience with the certification of the 789, you might expect no less than a seamless certification of the 7810.
 
User avatar
par13del
Posts: 10263
Joined: Sun Dec 18, 2005 9:14 pm

Re: Boeing 777X Testing/Production Thread - 2020

Sun May 10, 2020 2:04 pm

Opus99 wrote:
TropicalSky wrote:
I heard that.....hope it's a good thing

Opus99 wrote:
Interesting comms today. The pilots point out a similarity between the 777X to the 300er and the 787-10

http://www.paineairport.com/sounds/wh001may9.mp3

I would hope! Seeing as their both doing well in service and the -10 had a seamless certification

...or it might just be that this stretch is acting just like the other stretches...
 
JohanTally
Posts: 131
Joined: Tue Jun 18, 2019 3:44 am

Re: Boeing 777X Testing/Production Thread - 2020

Sun May 10, 2020 2:05 pm

marcelh wrote:
Opus99 wrote:
JohanTally wrote:

Not a leak but the fact that Qantas was being offered a version of the 777-9 for Project Sunrise would allude to it potentially being more capable than the current specs offered to the public. Who knows what the configuration would of been but maybe it's coming in lighter than we are being told or possibly a MTOW bump can be accommodated with the new gear.

https://www.airlineratings.com/news/boe ... t-sunrise/

Good point. And QR also saying they’ll switch the -8 for the -9 if it meets the -8 capabilities

Do you have a source for this claim?


Old news but it does hint that the 777-9 has potential to be better than advertised.

https://www.reuters.com/article/us-boei ... SKBN1WW0E6
 
Opus99
Posts: 848
Joined: Thu May 30, 2019 10:51 pm

Re: Boeing 777X Testing/Production Thread - 2020

Sun May 10, 2020 2:06 pm

par13del wrote:
Opus99 wrote:
TropicalSky wrote:
I heard that.....hope it's a good thing


I would hope! Seeing as their both doing well in service and the -10 had a seamless certification

...or it might just be that this stretch is acting just like the other stretches...

your point being?
 
Opus99
Posts: 848
Joined: Thu May 30, 2019 10:51 pm

Re: Boeing 777X Testing/Production Thread - 2020

Sun May 10, 2020 2:09 pm

marcelh wrote:
Opus99 wrote:
TropicalSky wrote:
I heard that.....hope it's a good thing


I would hope! Seeing as their both doing well in service and the -10 had a seamless certification

After all the “issues” during the certification of the 788 and the experience with the certification of the 789, you might expect no less than a seamless certification of the 7810.

True, fair point!
 
Opus99
Posts: 848
Joined: Thu May 30, 2019 10:51 pm

Re: Boeing 777X Testing/Production Thread - 2020

Sun May 10, 2020 2:11 pm

JohanTally wrote:
marcelh wrote:
Opus99 wrote:
Good point. And QR also saying they’ll switch the -8 for the -9 if it meets the -8 capabilities

Do you have a source for this claim?


Old news but it does hint that the 777-9 has potential to be better than advertised.

https://www.reuters.com/article/us-boei ... SKBN1WW0E6

I guess so, but i think that actually came on from reports the Boeing was planning on offering the -9 as a stop gap for the -8 so Akbar was asked if the -9 is indeed able to meet those parameters as Boeing seems to be suggesting will they make a switch
 
User avatar
par13del
Posts: 10263
Joined: Sun Dec 18, 2005 9:14 pm

Re: Boeing 777X Testing/Production Thread - 2020

Sun May 10, 2020 2:15 pm

Opus99 wrote:
par13del wrote:
Opus99 wrote:
I would hope! Seeing as their both doing well in service and the -10 had a seamless certification

...or it might just be that this stretch is acting just like the other stretches...

your point being?

...that the pilot might just have made a comment on how the a/c handles and that the model's he mentioned are all stretches of original designs.
 
Opus99
Posts: 848
Joined: Thu May 30, 2019 10:51 pm

Re: Boeing 777X Testing/Production Thread - 2020

Sun May 10, 2020 2:20 pm

par13del wrote:
Opus99 wrote:
par13del wrote:
...or it might just be that this stretch is acting just like the other stretches...

your point being?

...that the pilot might just have made a comment on how the a/c handles and that the model's he mentioned are all stretches of original designs.

okay? so are just saying that as additional information or you're trying to argue with something? I was saying i hope what he means is good news with regards to the aircraft seeing as the other aircrafts he refers too had certifications that were pretty uneventful. the fact that it handles like the other stretches mentioned should be good news? I'm not saying it means oh the aircraft will be super i'm just saying its good news. please
 
User avatar
par13del
Posts: 10263
Joined: Sun Dec 18, 2005 9:14 pm

Re: Boeing 777X Testing/Production Thread - 2020

Sun May 10, 2020 2:44 pm

Opus99 wrote:
par13del wrote:
Opus99 wrote:
your point being?

...that the pilot might just have made a comment on how the a/c handles and that the model's he mentioned are all stretches of original designs.

okay? so are just saying that as additional information or you're trying to argue with something?

Simply saying that we do not have to go over every single thing about the a/c testing or what pilots say with a microscope as if there is some great conspiracy related to the 777X testing.
Test flying is complicated and detailed, we really expect the pilots to offer up tangible details to the general public during the process? Is it possible for us to just accept the comment as is, that the a/c lateral handling is similar to another a/c in the Boeing fleet?

However, if you are looking for conspiracy and controversy, why is the engine growling comment not getting greater play, why is there not a separate thread about that, one minute the engine is going along fine, then it growls and they just continue on their merry way and that does not raise multiple comments, what is GE hiding? We already went through multiple flights where the fuse failure prevented the a/c from going above 10k, and the landing gear staying down on subsequent flights because it lifted off the runway on the initial flight before the pilots were ready.
 
User avatar
Revelation
Posts: 23962
Joined: Wed Feb 09, 2005 9:37 pm

Re: Boeing 777X Testing/Production Thread - 2020

Sun May 10, 2020 3:22 pm

par13del wrote:
Opus99 wrote:
par13del wrote:
...that the pilot might just have made a comment on how the a/c handles and that the model's he mentioned are all stretches of original designs.

okay? so are just saying that as additional information or you're trying to argue with something?

Simply saying that we do not have to go over every single thing about the a/c testing or what pilots say with a microscope as if there is some great conspiracy related to the 777X testing.
Test flying is complicated and detailed, we really expect the pilots to offer up tangible details to the general public during the process? Is it possible for us to just accept the comment as is, that the a/c lateral handling is similar to another a/c in the Boeing fleet?

However, if you are looking for conspiracy and controversy, why is the engine growling comment not getting greater play, why is there not a separate thread about that, one minute the engine is going along fine, then it growls and they just continue on their merry way and that does not raise multiple comments, what is GE hiding? We already went through multiple flights where the fuse failure prevented the a/c from going above 10k, and the landing gear staying down on subsequent flights because it lifted off the runway on the initial flight before the pilots were ready.

All of the above is "situation normal" for flight testing.

This thread is "colorful" because we have people with axes to grind, some ready to suggest 77X is better than expected, others ready to shoot down such an idea. Clearly the little tidbits we get as distant observers of the test program can't tell us enough to know either way. Ideally people would calm down till we see the airplane flying on actual airline routes and some data from that gets released/leaked.
Wake up to find out that you are the eyes of the world
The heart has its beaches, its homeland and thoughts of its own
Wake now, discover that you are the song that the morning brings
The heart has its seasons, its evenings and songs of its own
 
Opus99
Posts: 848
Joined: Thu May 30, 2019 10:51 pm

Re: Boeing 777X Testing/Production Thread - 2020

Sun May 10, 2020 3:29 pm

par13del wrote:
Opus99 wrote:
par13del wrote:
...that the pilot might just have made a comment on how the a/c handles and that the model's he mentioned are all stretches of original designs.

okay? so are just saying that as additional information or you're trying to argue with something?

Simply saying that we do not have to go over every single thing about the a/c testing or what pilots say with a microscope as if there is some great conspiracy related to the 777X testing.
Test flying is complicated and detailed, we really expect the pilots to offer up tangible details to the general public during the process? Is it possible for us to just accept the comment as is, that the a/c lateral handling is similar to another a/c in the Boeing fleet?

However, if you are looking for conspiracy and controversy, why is the engine growling comment not getting greater play, why is there not a separate thread about that, one minute the engine is going along fine, then it growls and they just continue on their merry way and that does not raise multiple comments, what is GE hiding? We already went through multiple flights where the fuse failure prevented the a/c from going above 10k, and the landing gear staying down on subsequent flights because it lifted off the runway on the initial flight before the pilots were ready.

I'm not trying to look into it with a microscope or trying to raise up any conspiracy, we are saying the same thing. I am a huge fan of the 777X. I am taking it at face value and just saying that i hope the certification goes well as it did with the other aircrafts, this really not a big deal. I'm not a conspiracy theorists, i'm not looking into engine sounds because its testing they'll hear all sorts, i for one have always said the aircraft not going above 20K is not a big deal and people should get over it, its a new aircraft in testing. The fuse failure assumption is gravely incorrect as previously explained by stich, and i don't think anyone had anyone linked landing gear retracting issues to the first take off. Anyway, this really isn't a big deal. Nobody is trying to dissect pilot comments. I was just saying that i HOPE it means something good, if that bothers you then sorry about that
 
VV
Posts: 1705
Joined: Sat Feb 13, 2016 1:03 pm

Re: Boeing 777X Testing/Production Thread - 2020

Sun May 10, 2020 3:34 pm

So it is confirmed that the aircraft did not fly above 20,000 ft simply because it was absolutely not needed for the initial airworthiness certification.

Once that airworthiness is obtained they can fly all over the places.

It was so obvious since the beginning, but some people kept insisting it had to do with the static test.
I am not sure what they wanted to obtain.

The good thing is that things are now cleared and the silly discussion about the static test is now over.
 
marcelh
Posts: 1011
Joined: Wed Jun 19, 2013 12:43 pm

Re: Boeing 777X Testing/Production Thread - 2020

Sun May 10, 2020 4:15 pm

[photoid][/photoid]
JohanTally wrote:
marcelh wrote:
Opus99 wrote:
Good point. And QR also saying they’ll switch the -8 for the -9 if it meets the -8 capabilities

Do you have a source for this claim?


Old news but it does hint that the 777-9 has potential to be better than advertised.

https://www.reuters.com/article/us-boei ... SKBN1WW0E6

Thanks!
IMHO Qatar will use the beefed up A35K for the routes originally destined for the 778 and use those additional 779 as a replacement for the A380. Maybe convert some 77W into a 77W Freigher and they have a nice line up of toys
 
User avatar
par13del
Posts: 10263
Joined: Sun Dec 18, 2005 9:14 pm

Re: Boeing 777X Testing/Production Thread - 2020

Sun May 10, 2020 7:44 pm

VV wrote:
So it is confirmed that the aircraft did not fly above 20,000 ft simply because it was absolutely not needed for the initial airworthiness certification.

Once that airworthiness is obtained they can fly all over the places.

It was so obvious since the beginning, but some people kept insisting it had to do with the static test.
I am not sure what they wanted to obtain.

The good thing is that things are now cleared and the silly discussion about the static test is now over.

Ever the optimist.....this is A.Net, wait till they do not reach 41,650 feet.
 
VV
Posts: 1705
Joined: Sat Feb 13, 2016 1:03 pm

Re: Boeing 777X Testing/Production Thread - 2020

Sun May 10, 2020 8:14 pm

par13del wrote:
VV wrote:
So it is confirmed that the aircraft did not fly above 20,000 ft simply because it was absolutely not needed for the initial airworthiness certification.

Once that airworthiness is obtained they can fly all over the places.

It was so obvious since the beginning, but some people kept insisting it had to do with the static test.
I am not sure what they wanted to obtain.

The good thing is that things are now cleared and the silly discussion about the static test is now over.

Ever the optimist.....this is A.Net, wait till they do not reach 41,650 feet.


Wait, why cannot it go to 43,000 ft? Is it because of the static test?
 
Opus99
Posts: 848
Joined: Thu May 30, 2019 10:51 pm

Re: Boeing 777X Testing/Production Thread - 2020

Sun May 10, 2020 9:15 pm

VV wrote:
par13del wrote:
VV wrote:
So it is confirmed that the aircraft did not fly above 20,000 ft simply because it was absolutely not needed for the initial airworthiness certification.

Once that airworthiness is obtained they can fly all over the places.

It was so obvious since the beginning, but some people kept insisting it had to do with the static test.
I am not sure what they wanted to obtain.

The good thing is that things are now cleared and the silly discussion about the static test is now over.

Ever the optimist.....this is A.Net, wait till they do not reach 41,650 feet.


Wait, why cannot it go to 43,000 ft? Is it because of the static test?

I think he means, people won’t stop complaining about that static test till the plane is certified. If they don’t climb up to an even higher level People will start complaining that Boeing is hiding something and the plane can’t go higher due to the static test or some other outrageous reason
 
VV
Posts: 1705
Joined: Sat Feb 13, 2016 1:03 pm

Re: Boeing 777X Testing/Production Thread - 2020

Sun May 10, 2020 9:35 pm

Opus99 wrote:
VV wrote:
par13del wrote:
Ever the optimist.....this is A.Net, wait till they do not reach 41,650 feet.

Wait, why cannot it go to 43,000 ft? Is it because of the static test?

I think he means, people won’t stop complaining about that static test till the plane is certified. If they don’t climb up to an even higher level People will start complaining that Boeing is hiding something and the plane can’t go higher due to the static test or some other outrageous reason


I am so sorry.
I should have put a wink smiley to underline it was sarcasm.
 
morrisond
Posts: 2664
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 777X Testing/Production Thread - 2020

Sun May 10, 2020 10:14 pm

Forgive me if I have this wrong - but aren't the dynamic loads lower at higher altitude due to the thinner air?

Isn't that why the Tornado is so beefy so it can fly at really high speeds low to the ground?
 
virage
Posts: 50
Joined: Wed Dec 29, 2010 11:59 am

Re: Boeing 777X Testing/Production Thread - 2020

Mon May 11, 2020 1:04 pm

morrisond wrote:
Forgive me if I have this wrong - but aren't the dynamic loads lower at higher altitude due to the thinner air?

Isn't that why the Tornado is so beefy so it can fly at really high speeds low to the ground?


Yes, absolutely. There is also a documented story of Tupolev's Tu-16 "Badger" first prototype coming up significantly above the target weight. The solution was to limit its Vmax speed ceiling to altitudes 6250m and above, which allowed to lighten the airframe by 11% (from 41.05 to 36.49 tons).
 
User avatar
bikerthai
Posts: 3344
Joined: Wed Apr 28, 2010 1:45 pm

Re: Boeing 777X Testing/Production Thread - 2020

Mon May 11, 2020 1:16 pm

morrisond wrote:
Forgive me if I have this wrong - but aren't the dynamic loads lower at higher altitude due to the thinner air?

Isn't that why the Tornado is so beefy so it can fly at really high speeds low to the ground?


At the micro level you are right. But for an airline, where you are not doing a lot of maneuvering, the dynamic load most affecting structural integrity is turbulence. At altitude, specially at cruise, you don't get as much turbulence and you try to avoid them when you can.



bt
Intelligent seeks knowledge. Enlightened seeks wisdom.
 
User avatar
Revelation
Posts: 23962
Joined: Wed Feb 09, 2005 9:37 pm

Re: Boeing 777X Testing/Production Thread - 2020

Mon May 11, 2020 1:43 pm

bikerthai wrote:
morrisond wrote:
Forgive me if I have this wrong - but aren't the dynamic loads lower at higher altitude due to the thinner air?

Isn't that why the Tornado is so beefy so it can fly at really high speeds low to the ground?

At the micro level you are right. But for an airline, where you are not doing a lot of maneuvering, the dynamic load most affecting structural integrity is turbulence. At altitude, specially at cruise, you don't get as much turbulence and you try to avoid them when you can.

bt

Right, so you're agreeing with the premise that Boeing put an altitude restriction on 777x due to structural issues doesn't make sense, since at higher altitudes you have less turbulence and thinner air. If there was a true concern about structural issues it would have stayed on the ground.
Wake up to find out that you are the eyes of the world
The heart has its beaches, its homeland and thoughts of its own
Wake now, discover that you are the song that the morning brings
The heart has its seasons, its evenings and songs of its own
 
User avatar
bikerthai
Posts: 3344
Joined: Wed Apr 28, 2010 1:45 pm

Re: Boeing 777X Testing/Production Thread - 2020

Mon May 11, 2020 7:26 pm

My response of higher altitude and thinner air is only relavent to dynamics load as per the quote.

The static test failure in my opinion would impact the higher altitude testing with respect to the pressure differential in the fuselage. Even if the difference is within 1 percent of ultimate, I believe the test group are operating at hightened sensitivity, and will not dismiss any risk, however small.

That being said, they will probably test at higher altitude but not at max altitude until they have the door fix implemented.

bt
Intelligent seeks knowledge. Enlightened seeks wisdom.
 
morrisond
Posts: 2664
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 777X Testing/Production Thread - 2020

Mon May 11, 2020 8:11 pm

bikerthai wrote:
My response of higher altitude and thinner air is only relavent to dynamics load as per the quote.

The static test failure in my opinion would impact the higher altitude testing with respect to the pressure differential in the fuselage. Even if the difference is within 1 percent of ultimate, I believe the test group are operating at hightened sensitivity, and will not dismiss any risk, however small.

That being said, they will probably test at higher altitude but not at max altitude until they have the door fix implemented.

bt


Yes - if they decide to pull 4G's at altitude they could be in trouble. It's not the door that needs to be fixed - it's in the Keel beam. If they fly at 98% of MTOW and not pretend they are dogfighting with Maverick at Top Gun they should be fine.

Stop throwing shade on something that really isn't an issue.


From Seattle Times https://www.seattletimes.com/business/b ... ress-test/


"The test conducted that day was the final test of this airplane, which was fixed in a test rig inside the Everett factory specifically to be stressed close to destruction. The jet was surrounded by scaffolding and multiple orange weights hung from the airframe. Wires were hooked to instrumentation that studded the surface to measure every stress and deflection, the data monitored in real time by engineers sitting at control room computers.

As the test neared its climax, weighted pulleys had bent the jet’s giant carbon composite wings upward more than 28 feet from their resting position. That’s far beyond the expected maximum deflection in normal flight of about 9 feet, according to a person familiar with the details.

At the same time, the fuselage was bent downward at the extreme front and aft ends with millions of pounds of force. And the interior of the plane was pressurized beyond normal levels to about 10 pounds per square inch — not typically a requirement for this test, but something Boeing chose to do.

All this simulated the loads in a flight maneuver where a pilot would experience a force of 3.75 G, compared to the maximum of 1.3 G in normal flight.

The combination of the bending forces on the wing and fuselage created a high compression load on the bottom centerline of the fuselage — the keel — according to the person, who asked for anonymity because the details are sensitive.

Federal certification regulations require engineers to ratchet up the forces until they reach “ultimate load” — defined as 1.5 times the “limit load,” which is the maximum that would ever be experienced in normal flight — and hold it there for at least three seconds."

"A safety engineer at the Federal Aviation Administration (FAA), speaking anonymously without permission from the agency, said that because the blowout happened so close to the target load, it barely counts as a failure."
 
User avatar
qf789
Moderator
Topic Author
Posts: 11105
Joined: Thu Feb 05, 2015 3:42 pm

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 2:11 am

Could we please just discuss the topic and keep all off topic comments out of the discussion. This includes not trying to provoke one another, flamebait, discussing other users etc
Forum Moderator
 
travaz
Posts: 896
Joined: Wed Jun 13, 2001 1:03 am

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 2:54 am

qf789 wrote:
Could we please just discuss the topic and keep all off topic comments out of the discussion. This includes not trying to provoke one another, flamebait, discussing other users etc


Thank you I have been here since the start and I miss the tech info without the AB baloney.
 
User avatar
bikerthai
Posts: 3344
Joined: Wed Apr 28, 2010 1:45 pm

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 1:33 pm

morrisond wrote:
Yes - if they decide to pull 4G's at altitude they could be in trouble. It's not the door that needs to be fixed - it's in the Keel beam. If they fly at 98% of MTOW and not pretend they are dogfighting with Maverick at Top Gun they should be fine.


:box: :spin:

We are caught in a perception loop with the static test result. The Seattle Times article is too general in its characterization to truly understand the mind of the testing group and their protocol.

Yes the load is something that the plane does not see in regular flight. But the requirement must be met in order to operate at max design condition.

Agreed that during this flight test block, that max condition will not be approached, so for now, the static test failure does not come in to play.

The quoted regulators may not think the static failure would impact the certification. This may be true, but we are not talking about final certification, we are talking about a test phase.

Unlike an typical experimental test program where you are pushing into an unknown envelope, this is a test program to verify known parameters, so the test group may be sensitive to any condition that deviate from their prediction. That is why my opinion is that they will be extra careful. It doesn't mean that they wont eventually get to where they want to go, max condition at max altitude.

bt
Intelligent seeks knowledge. Enlightened seeks wisdom.
 
User avatar
keesje
Posts: 13843
Joined: Thu Apr 12, 2001 2:08 am

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 2:38 pm

If I remember correctly 787 and A350 reached 40k ft early in their initial test flight programs. I do not know why the 777x did not cruise level early on in the program. .
An update on the root cause analyses of the 777X ground test fuselage rupture could make clear it is totally unrelated.

The 777X is undergoing a new certification process. Quoting Calhoun:

"The certification process is a new one and it's going to get applied to every next airplane, so we have a lot of planning to do around the 777X, etc., to make sure that we can accommodate a really thorough review and investigation," he told reporters. "It's just the way it's going to be."

Overseas regulators, including the European Union Aviation Safety Agency, have indicated they will conduct a parallel review of the 777X, a departure from established practice in which they have usually deferred to the decisions of the Federal Aviation Administration.

https://uk.advfn.com/stock-market/NYSE/ ... t/81599409

I expect there is an extensive EASA / Lufthansa representation in Seattle to smooth out the process. What is currently the 777-9 estimated entry into service?
Based on Emirates comments mid 2021. But I haven't heard FAA or EASA on this.
"Never mistake motion for action." Ernest Hemingway
 
User avatar
Stitch
Posts: 27093
Joined: Wed Jul 06, 2005 4:26 am

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 2:56 pm

keesje wrote:
If I remember correctly 787 and A350 reached 40k ft early in their initial test flight programs. I do not know why the 777x did not cruise level early on in the program.


I looked up the 787 and posted it up-thread, but as I recall it the first two frames had a fair number of flights under them before they started high-altitude testing so the 777X is not incongruent with this.

And since the 777-9 is a derivative of an existing type, the testing protocol may be different than for an all-new type like the 787 (or A350). Boeing is going to be required to clearly identify any differential training that 777-300ER pilots will need when transitioning to the 777X so I would not be surprised if they are spending more time on these tests to have a very clear view of how the 777-9's handling characteristics compare to the 777-300ER's across the entire flight-regime.
 
morrisond
Posts: 2664
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 2:57 pm

keesje wrote:
If I remember correctly 787 and A350 reached 40k ft early in their initial test flight programs. I do not know why the 777x did not cruise level early on in the program. .
An update on the root cause analyses of the 777X ground test fuselage rupture could make clear it is totally unrelated.

The 777X is undergoing a new certification process. Quoting Calhoun:

"The certification process is a new one and it's going to get applied to every next airplane, so we have a lot of planning to do around the 777X, etc., to make sure that we can accommodate a really thorough review and investigation," he told reporters. "It's just the way it's going to be."

Overseas regulators, including the European Union Aviation Safety Agency, have indicated they will conduct a parallel review of the 777X, a departure from established practice in which they have usually deferred to the decisions of the Federal Aviation Administration.

https://uk.advfn.com/stock-market/NYSE/ ... t/81599409

I expect there is an extensive EASA / Lufthansa representation in Seattle to smooth out the process. What is currently the 777-9 estimated entry into service?
Based on Emirates comments mid 2021. But I haven't heard FAA or EASA on this.


You said it yourself - it's an entirely new process. This may be the new method of testing.

Doing stalls and whatever other manoeuvers they were doing at 20,000' which could have resulted in spins would have put far more load on the airframe.

Yet somehow the Boeing test pilots found the bravery to go ahead and perform those tests even with the failure in the wing bending test only 1-2% below there target.

Why would they act any differently than with the original 777 test program where the wings failed at 154%?

The air is so thin up at 40,000' that is really hard to put much load on the airframe.
 
User avatar
keesje
Posts: 13843
Joined: Thu Apr 12, 2001 2:08 am

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 3:26 pm

morrisond wrote:
keesje wrote:
If I remember correctly 787 and A350 reached 40k ft early in their initial test flight programs. I do not know why the 777x did not cruise level early on in the program. .
An update on the root cause analyses of the 777X ground test fuselage rupture could make clear it is totally unrelated.

The 777X is undergoing a new certification process. Quoting Calhoun:

"The certification process is a new one and it's going to get applied to every next airplane, so we have a lot of planning to do around the 777X, etc., to make sure that we can accommodate a really thorough review and investigation," he told reporters. "It's just the way it's going to be."

Overseas regulators, including the European Union Aviation Safety Agency, have indicated they will conduct a parallel review of the 777X, a departure from established practice in which they have usually deferred to the decisions of the Federal Aviation Administration.

https://uk.advfn.com/stock-market/NYSE/ ... t/81599409

I expect there is an extensive EASA / Lufthansa representation in Seattle to smooth out the process. What is currently the 777-9 estimated entry into service?
Based on Emirates comments mid 2021. But I haven't heard FAA or EASA on this.


You said it yourself - it's an entirely new process. This may be the new method of testing.

Doing stalls and whatever other manoeuvers they were doing at 20,000' which could have resulted in spins would have put far more load on the airframe.

Yet somehow the Boeing test pilots found the bravery to go ahead and perform those tests even with the failure in the wing bending test only 1-2% below there target.

Why would they act any differently than with the original 777 test program where the wings failed at 154%?

The air is so thin up at 40,000' that is really hard to put much load on the airframe.


I guess it might have to do with unexpected failure mode.

If you are doing a maximum speed test on a new car, and while you reach 99% of the maximum speed, the right rear wheel seperates, you need to do extra research to determine why that suddenly happened.

Despite you nearly reached the required maximum speed.
"Never mistake motion for action." Ernest Hemingway
 
User avatar
bikerthai
Posts: 3344
Joined: Wed Apr 28, 2010 1:45 pm

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 3:36 pm

morrisond wrote:
Doing stalls and whatever other manoeuvers they were doing at 20,000' which could have resulted in spins would have put far more load on the airframe.


Curios though, did they really stall the aircraft this early in the program? I mean i can see them approach the stall and do the stick shaker test, but full blown stall?

And no, airplane at stall may put more load on the wing locally because of high lift, but the fuselage do not see the same increase in load. The weight of the aircraft is the same whether at stall or cruise. Fuselage stresses occurs more during severe turbulence and hard landing. But I doubt they flew in much turbulence during the flight test.

Any pilot out there who experienced a stall? Does the stall recovery cause significant higher g load?

bt
Intelligent seeks knowledge. Enlightened seeks wisdom.
 
User avatar
VCVSpotter
Posts: 957
Joined: Mon May 04, 2020 6:10 am

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 3:57 pm

777-9 N779XW (BOE1) filed a flight plan BFI-BFI 10AM - 12:43PM

https://flightaware.com/live/flight/BOE1
https://docs.google.com/spreadsheets/d/ ... edit#gid=0

Just a normal teenager juggling AP classes and airplanes. No biggie • Love the 747 & 777-9 • Farewell BA/KL 744s
 
morrisond
Posts: 2664
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 3:57 pm

bikerthai wrote:
morrisond wrote:
Doing stalls and whatever other manoeuvers they were doing at 20,000' which could have resulted in spins would have put far more load on the airframe.


Curios though, did they really stall the aircraft this early in the program? I mean i can see them approach the stall and do the stick shaker test, but full blown stall?

And no, airplane at stall may put more load on the wing locally because of high lift, but the fuselage do not see the same increase in load. The weight of the aircraft is the same whether at stall or cruise. Fuselage stresses occurs more during severe turbulence and hard landing. But I doubt they flew in much turbulence during the flight test.

Any pilot out there who experienced a stall? Does the stall recovery cause significant higher g load?

bt


I have albeit only in 172's - but in Canada we do full stall and spin training. Other than landings it was the funnest part of the experience for me.

Normal Stalls (stick shaker type events) don't do a lot - but when testing for stall with a new Wing you would be aware that it could develop into a full Spin which could put very high loads on the frame, especially during the recovery (which would happen with Stall recovery as well if you let it fully develop and had to recover from a dive).

You would not even want to think about getting close to stick shaker if you had any concerns with the airframe as it could put huge loads on the keel as the tail tried to rip itself off as you pulled up in a deep stall or spin recovery.

That would be the only time you got anywhere close to 3.75G sustained on the keel. Turbulence wouldn't do the same (or not nearly for the same duration).
 
OldAeroGuy
Posts: 3921
Joined: Sun Dec 05, 2004 6:50 am

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 4:07 pm

Based on past Cert Program experience, I suspect the airplane has been stalled several times at all flap settings and at forward and aft CG's. The saw tooth altitude traces along with speed changes seen for some flight tests appear to indicate stall testing.

Wing loads are not particularly high during stall entry and recovery. From a structural standpoint, the usual concern during stall tests are the dynamic loads on the horizontal tail due to operating in the separated wing wake.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
User avatar
keesje
Posts: 13843
Joined: Thu Apr 12, 2001 2:08 am

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 4:36 pm

bikerthai wrote:
morrisond wrote:
Doing stalls and whatever other manoeuvers they were doing at 20,000' which could have resulted in spins would have put far more load on the airframe.


Curios though, did they really stall the aircraft this early in the program? I mean i can see them approach the stall and do the stick shaker test, but full blown stall?

And no, airplane at stall may put more load on the wing locally because of high lift, but the fuselage do not see the same increase in load. The weight of the aircraft is the same whether at stall or cruise. Fuselage stresses occurs more during severe turbulence and hard landing. But I doubt they flew in much turbulence during the flight test.

Any pilot out there who experienced a stall? Does the stall recovery cause significant higher g load?

bt


The wing load distribution at high AOA's is different, in combination with control surfaces creating concentrated loads.
https://lh3.googleusercontent.com/proxy ... 0VIihJv_js

Stitch wrote:
keesje wrote:
If I remember correctly 787 and A350 reached 40k ft early in their initial test flight programs. I do not know why the 777x did not cruise level early on in the program.


I looked up the 787 and posted it up-thread, but as I recall it the first two frames had a fair number of flights under them before they started high-altitude testing so the 777X is not incongruent with this.

And since the 777-9 is a derivative of an existing type, the testing protocol may be different than for an all-new type like the 787 (or A350). Boeing is going to be required to clearly identify any differential training that 777-300ER pilots will need when transitioning to the 777X so I would not be surprised if they are spending more time on these tests to have a very clear view of how the 777-9's handling characteristics compare to the 777-300ER's across the entire flight-regime.


Stitch, you probably found out (but didn't mention) the 787 in 3 months and 10 days after first flight completed testing for flutter and ground effects, clearing the aircraft to fly its entire flight envelope. On a similar schedule the 777X would have reached that in April, which did not happen. A derivative aircraft should be easier to certify than a new aircraft.
Last edited by keesje on Tue May 12, 2020 4:49 pm, edited 3 times in total.
"Never mistake motion for action." Ernest Hemingway
 
morrisond
Posts: 2664
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 4:42 pm

OldAeroGuy wrote:
Based on past Cert Program experience, I suspect the airplane has been stalled several times at all flap settings and at forward and aft CG's. The saw tooth altitude traces along with speed changes seen for some flight tests appear to indicate stall testing.

Wing loads are not particularly high during stall entry and recovery. From a structural standpoint, the usual concern during stall tests are the dynamic loads on the horizontal tail due to operating in the separated wing wake.


Which in turn put's a high load on the keel? - so if you had any concerns with Keel not having sufficient strength (it's what failed in the 777X wing test) then you would not run the tests?
 
User avatar
Stitch
Posts: 27093
Joined: Wed Jul 06, 2005 4:26 am

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 4:51 pm

keesje wrote:
Stitch, you probably found out (but didn't mention) the 787 in 3 months and 10 days after first flight completed testing for flutter and ground effects, clearing the aircraft to fly its entire flight envelope. On a similar schedule the 777X would have reached that in April, which did not happen.


Do we know how many actual flights that was and how many 787 were operational in the flight test program at the time? The 777-9 testing has been impacted by the COVID-19 situation.


keesje wrote:
A derivative aircraft should be easier to certify than a new aircraft.


Well as you like to point out at every opportunity, the 777-9 incorporates a significant number of changes for a derivative.
 
User avatar
Revelation
Posts: 23962
Joined: Wed Feb 09, 2005 9:37 pm

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 5:53 pm

Stitch wrote:
Well as you like to point out at every opportunity, the 777-9 incorporates a significant number of changes for a derivative.

And as he just pointed out it's an all new certification process, one presumably more rigorous, yet suggests it's strange that milestones are happening at different times. I guess Boeing is expected to deliver milestones quicker with a more rigorous process while its own employees and the regulators are all dealing with the impacts of a global pandemic.
Wake up to find out that you are the eyes of the world
The heart has its beaches, its homeland and thoughts of its own
Wake now, discover that you are the song that the morning brings
The heart has its seasons, its evenings and songs of its own
 
User avatar
ikolkyo
Posts: 2984
Joined: Tue Nov 05, 2013 8:43 pm

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 6:05 pm

keesje wrote:
Stitch wrote:
keesje wrote:
If I remember correctly 787 and A350 reached 40k ft early in their initial test flight programs. I do not know why the 777x did not cruise level early on in the program.


I looked up the 787 and posted it up-thread, but as I recall it the first two frames had a fair number of flights under them before they started high-altitude testing so the 777X is not incongruent with this.

And since the 777-9 is a derivative of an existing type, the testing protocol may be different than for an all-new type like the 787 (or A350). Boeing is going to be required to clearly identify any differential training that 777-300ER pilots will need when transitioning to the 777X so I would not be surprised if they are spending more time on these tests to have a very clear view of how the 777-9's handling characteristics compare to the 777-300ER's across the entire flight-regime.


Stitch, you probably found out (but didn't mention) the 787 in 3 months and 10 days after first flight completed testing for flutter and ground effects, clearing the aircraft to fly its entire flight envelope. On a similar schedule the 777X would have reached that in April, which did not happen. A derivative aircraft should be easier to certify than a new aircraft.


If I recall there also wasn't a complete halt in flight testing for weeks due to a pandemic during the initial flights of the 787.
 
OldAeroGuy
Posts: 3921
Joined: Sun Dec 05, 2004 6:50 am

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 6:37 pm

morrisond wrote:
OldAeroGuy wrote:
Based on past Cert Program experience, I suspect the airplane has been stalled several times at all flap settings and at forward and aft CG's. The saw tooth altitude traces along with speed changes seen for some flight tests appear to indicate stall testing.

Wing loads are not particularly high during stall entry and recovery. From a structural standpoint, the usual concern during stall tests are the dynamic loads on the horizontal tail due to operating in the separated wing wake.


Which in turn put's a high load on the keel? - so if you had any concerns with Keel not having sufficient strength (it's what failed in the 777X wing test) then you would not run the tests?


The tail loads during a stall are dynamic, ie the tail bounces around a lot in the wing wake and the concern is structural fatigue. Flight test airplanes do numerous stalls as part of a flight test program. Production airplanes will probably never encounter a stall in their service life so h. tail stall fatigue issues are a minor design condition.

If the keel beam has a strength issue, I doubt that it would be impacted by the h. tail fatigue condition.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
User avatar
Stitch
Posts: 27093
Joined: Wed Jul 06, 2005 4:26 am

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 7:57 pm

So you comment that the 777X certification process is taking longer than you feel it should be to hit certain arbitrary milestones, keesje, and then you comment that said 777X certification process is inherently flawed and should be slower to ensure the mistakes that were allowed in the MAX certification do not occur again.

And you wonder then why some people ignore or downplay said contradictory comments. :scratchchin:
 
morrisond
Posts: 2664
Joined: Thu Jan 07, 2010 12:22 am

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 8:13 pm

OldAeroGuy wrote:
morrisond wrote:
OldAeroGuy wrote:
Based on past Cert Program experience, I suspect the airplane has been stalled several times at all flap settings and at forward and aft CG's. The saw tooth altitude traces along with speed changes seen for some flight tests appear to indicate stall testing.

Wing loads are not particularly high during stall entry and recovery. From a structural standpoint, the usual concern during stall tests are the dynamic loads on the horizontal tail due to operating in the separated wing wake.


Which in turn put's a high load on the keel? - so if you had any concerns with Keel not having sufficient strength (it's what failed in the 777X wing test) then you would not run the tests?


The tail loads during a stall are dynamic, ie the tail bounces around a lot in the wing wake and the concern is structural fatigue. Flight test airplanes do numerous stalls as part of a flight test program. Production airplanes will probably never encounter a stall in their service life so h. tail stall fatigue issues are a minor design condition.

If the keel beam has a strength issue, I doubt that it would be impacted by the h. tail fatigue condition.


What about when you are in a full stall (or spin) though and pointed at the ground and have to pull significant G's once you get the wing flying again to pull out of it?
 
minister
Posts: 20
Joined: Tue Jul 18, 2006 10:22 pm

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 8:26 pm

VCVSpotter wrote:
777-9 N779XW (BOE1) filed a flight plan BFI-BFI 10AM - 12:43PM

https://flightaware.com/live/flight/BOE1


Currently flying at 25,000 feet, up from an extended time at 20,000 feet.
 
User avatar
Revelation
Posts: 23962
Joined: Wed Feb 09, 2005 9:37 pm

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 9:01 pm

Stitch wrote:
And you wonder then why some people ignore or downplay said contradictory comments. :scratchchin:

Be fair, there is one constant throughout all the comments.
Wake up to find out that you are the eyes of the world
The heart has its beaches, its homeland and thoughts of its own
Wake now, discover that you are the song that the morning brings
The heart has its seasons, its evenings and songs of its own
 
OldAeroGuy
Posts: 3921
Joined: Sun Dec 05, 2004 6:50 am

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 10:49 pm

morrisond wrote:
OldAeroGuy wrote:
morrisond wrote:

Which in turn put's a high load on the keel? - so if you had any concerns with Keel not having sufficient strength (it's what failed in the 777X wing test) then you would not run the tests?


The tail loads during a stall are dynamic, ie the tail bounces around a lot in the wing wake and the concern is structural fatigue. Flight test airplanes do numerous stalls as part of a flight test program. Production airplanes will probably never encounter a stall in their service life so h. tail stall fatigue issues are a minor design condition.

If the keel beam has a strength issue, I doubt that it would be impacted by the h. tail fatigue condition.



What about when you are in a full stall (or spin) though and pointed at the ground and have to pull significant G's once you get the wing flying again to pull out of it?


You're being a bit dramatic. I was on the airplane or analyzed/reviewed data for 100's of stalls on the 737 Classic, 737NG, 747, 757 and 777 during configuration development and certification. Pulling more than 1.5 G's during recovery was a rare event with the norm being 1.05 - 1.20.

Spins on Part 25 airplanes during stall testing is very unlikely. About the most exciting thing that does happen during Part 25 stall tests are high bank angles due to asymmetric wing stalling. A sudden, uncommanded 60 deg bank can be pretty eye opening but they don't entail high recovery loads.

Remember at stall, the load factor is less than 1.0. During recovery, high load factors are not needed unless you're near the ground. The solution is to initiate all stall tests above 10,000 ft AGL.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
User avatar
VirginFlyer
Posts: 5571
Joined: Sun Sep 10, 2000 12:27 pm

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 11:00 pm

OldAeroGuy wrote:
morrisond wrote:
OldAeroGuy wrote:

The tail loads during a stall are dynamic, ie the tail bounces around a lot in the wing wake and the concern is structural fatigue. Flight test airplanes do numerous stalls as part of a flight test program. Production airplanes will probably never encounter a stall in their service life so h. tail stall fatigue issues are a minor design condition.

If the keel beam has a strength issue, I doubt that it would be impacted by the h. tail fatigue condition.



What about when you are in a full stall (or spin) though and pointed at the ground and have to pull significant G's once you get the wing flying again to pull out of it?


You're being a bit dramatic. I was on the airplane or analyzed/reviewed data for 100's of stalls on the 737 Classic, 737NG, 747, 757 and 777 during configuration development and certification. Pulling more than 1.5 G's during recovery was a rare event with the norm being 1.05 - 1.20.

Spins on Part 25 airplanes during stall testing is very unlikely. About the most exciting thing that does happen during Part 25 stall tests are high bank angles due to asymmetric wing stalling. A sudden, uncommanded 60 deg bank can be pretty eye opening but they don't entail high recovery loads.

Remember at stall, the load factor is less than 1.0. During recovery, high load factors are not needed unless you're near the ground. The solution is to initiate all stall tests above 10,000 ft AGL.

Thinking specifically about spins, my understanding is that a transport category aircraft would not be recoverable if it entered a fully developed spin, owing to the distribution of the weight of the engines.

V/F
It is not for him to pride himself who loveth his own country, but rather for him who loveth the whole world. The earth is but one country, and mankind its citizens. —Bahá'u'lláh
 
Opus99
Posts: 848
Joined: Thu May 30, 2019 10:51 pm

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 11:21 pm

https://twitter.com/mattcawby/status/12 ... 54049?s=21

The first Lufthansa 777X D-ABTA has rolled out
 
User avatar
ikolkyo
Posts: 2984
Joined: Tue Nov 05, 2013 8:43 pm

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 11:26 pm

Opus99 wrote:
https://twitter.com/mattcawby/status/1260341576682754049?s=21

The first Lufthansa 777X D-ABTA has rolled out


Technically one of the prototypes is an LH frame.
 
Opus99
Posts: 848
Joined: Thu May 30, 2019 10:51 pm

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 11:30 pm

ikolkyo wrote:
Opus99 wrote:
https://twitter.com/mattcawby/status/1260341576682754049?s=21

The first Lufthansa 777X D-ABTA has rolled out


Technically one of the prototypes is an LH frame.

I think this one might be going into storage. WH003 and 004 are also LH frames but will be delivered later on after they are refurbished for delivery
 
User avatar
VCVSpotter
Posts: 957
Joined: Mon May 04, 2020 6:10 am

Re: Boeing 777X Testing/Production Thread - 2020

Tue May 12, 2020 11:30 pm

777-9 N779XW today performed the longest flight for a 777-9, clocking in at 6 hours and 18 minutes. (The 2nd longest was back in February 24, 2020 at 6:17, it was the first stall test for the 777-9). Also, toward the tail end of the flight, it was cruising at roughly 30,000ft at roughly 500kts. That seems to be testing for a regular cruise, hopefully out of state flights will be soon (looking at my username you can probably tell why :D )

https://www.flightradar24.com/data/aircraft/n779xw
https://docs.google.com/spreadsheets/d/ ... edit#gid=0

Just a normal teenager juggling AP classes and airplanes. No biggie • Love the 747 & 777-9 • Farewell BA/KL 744s

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos