WalterFaber wrote:

Rogers99 wrote:

I think the threats of an a350NEO is over exaggerated. I think airbus first wants to extract as much value from the a350-1000. Which is already a big competition to the 777-9. Then investing in a 10 abreast cabin is to improve the economics against the 777-9. And I think that 777-300er market will be about 50:50 when all is said and done. They’re both extremely efficient aircraft.

Also there’s a lot of 777-300ERs and 330s to replace. When that market is when and truly milked. Then we can talk about NEOs and at that point we are looking at 15 years.

I love the 777-9 too. My favorite airliner

I think it will be fine.

Flight tests will resume January. And TIA is expected to be received in mid 2023.

Re A350NEO: I am a bit surprised that there is a competitive 777x at all. Shouldn't an A350-2000 be better due to lower fuselage weight and similar wing and engine technology? Why did Airbus not immediately compete with the 777x directly?
Another motivation for an A350NEO could be increased competition from an improved 787 with higher gross weight or updated engines. But I agree that an A350NEO isn't going to enter service in the 2020s. However, the 777x has already lost 5 years of its time without an A350NEO, which is significant imho.

ADent wrote:

2. Yes. 777X stopped for awhile, but is scheduled to resume soonish (dates elsewhere in thread IIRC)
3. I think you answered your own question. But by slowing production rate down. The 787 line was down to 2/month during delivery shut down.
4. See 3. Worked so well for the 737 and 787 that Boeing thought the 777 should join in. Originally the delay was not expected to be years instead of months. Now it’s just a calculus on shutting down the line and restarting vs trickling them out.
5 Currently on hold awaiting 737-7 & 737-10 certification. Started off waiting for repercussions of 737MAX crashes and changing certification from an grandfather of 777 to a new cert. EASA wants more redundancy. Engine problems delayed first flight. Now awaiting 737MAX certification.

Thanks!
Re 5), so it is more about certification overload at Boeing and possibly the FAA than about technical problems with the 777x itself (although they certainly exist as well).

swapcv wrote:

LDRA wrote:

77west wrote:

Having a look at the -8F specs I see they have upped the MTOW to 366,000kg - I guess we may see this applied to the -9 PAX model as well. 15,000kg is a not insignificant range/payload bump.

Not an insignificant change. Not just the gears, the wing system needs to carry the flight load as well. Did Boeing find more load carrying capacity in the wing system than predicted from the destructive ultimate load test?

It was already built in the day they announced it'd be equipped with that humongous wing. Won't be surprised if MTOW goes upto 380t or more. That wing can support a lot more than being advertized.

rfarlz wrote:

swapcv wrote:

LDRA wrote:

Not an insignificant change. Not just the gears, the wing system needs to carry the flight load as well. Did Boeing find more load carrying capacity in the wing system than predicted from the destructive ultimate load test?

It was already built in the day they announced it'd be equipped with that humongous wing. Won't be surprised if MTOW goes upto 380t or more. That wing can support a lot more than being advertized.

The B77W already has some of the highest pavement loading of any commercial aircraft, I was quite surprised to see the 779 MTOW increased so much over that with the same sized MLG. The pavement loadings would start to be very restrictive if it went up any more without a whole new main gear.

Rogers99 wrote:

rfarlz wrote:

swapcv wrote:

It was already built in the day they announced it'd be equipped with that humongous wing. Won't be surprised if MTOW goes upto 380t or more. That wing can support a lot more than being advertized.

The B77W already has some of the highest pavement loading of any commercial aircraft, I was quite surprised to see the 779 MTOW increased so much over that with the same sized MLG. The pavement loadings would start to be very restrictive if it went up any more without a whole new main gear.

779 MTOW is flat with 77W. Have the exact same

778F MTOW is what has gone up

77west wrote:

Having a look at the -8F specs I see they have upped the MTOW to 366,000kg - I guess we may see this applied to the -9 PAX model as well. 15,000kg is a not insignificant range/payload bump.

Noshow wrote:

Might partly be a structural modification after the rupture?

Noshow wrote:

Might partly be a structural modification after the rupture?

BoeingVista wrote:

77west wrote:

Having a look at the -8F specs I see they have upped the MTOW to 366,000kg - I guess we may see this applied to the -9 PAX model as well. 15,000kg is a not insignificant range/payload bump.

How do you know its a range / payload bump and not OEW increase + accompanying fuel to meet range spec?

Avatar2go wrote:

Noshow wrote:

Might partly be a structural modification after the rupture?

Don't think it would have anything to do with the ultimate load test. There may have been some minor structural strengthening afterwards, but it wouldn't affect the MTOW.

The fuselage buckled on the bottom, at 99% ultimate load, which was the expected failure mode. The rupture was the release of pressurization energy, which was unrelated to ultimate load result.

BoeingVista wrote:

The door blowout and destruction of the airframe was not the predicted failure mode, if you have a link attesting that is was please post it.

StTim wrote:

There is an unspecified engine issue that has halted testing. https://aviationweek.com/air-transport/ ... x-incident

TropicalSky wrote:

in article on { https://airwaysmag.com/boeing-777x-tests-halted-ge9x/ } from airways mag they quoted Emirates CEO stating that they will know the extent of damage/delay on DEC 6 & BOE has plans to restart testing in JAN 23.....hopefully its nothing to serious

FluidFlow wrote:

TropicalSky wrote:

in article on { https://airwaysmag.com/boeing-777x-tests-halted-ge9x/ } from airways mag they quoted Emirates CEO stating that they will know the extent of damage/delay on DEC 6 & BOE has plans to restart testing in JAN 23.....hopefully its nothing to serious

In general, according to the article, it comes down to design flaw vs manufacturing problems. The latter will not be a big problem, as the affected parts can be replaced with non-affected parts. If its the former, GE and Boeing will have a problem, because going back to the drawing board will take time and cost money.

Avatar2go wrote:

If they have plans to resume testing next month, it doesn't sound too serious. From the description, they were filling out the thermal operation envelope when something happened with one engine.

Those engines have many thousands of hours, both in flight and on the test stand. So it might be that some aspect of the aircraft support services for the engine wasn't adequate for the operational conditions.

Just have to wait and see what they discover the root cause to be.

Rogers99 wrote:

Avatar2go wrote:

If they have plans to resume testing next month, it doesn't sound too serious. From the description, they were filling out the thermal operation envelope when something happened with one engine.

Those engines have many thousands of hours, both in flight and on the test stand. So it might be that some aspect of the aircraft support services for the engine wasn't adequate for the operational conditions.

Just have to wait and see what they discover the root cause to be.

Important to note they have plans to restart in January IF the issue isn’t too serious

HTCone wrote:

https://samchui.com/2022/12/01/boeing-777x-test-program-halted-after-ge9x-engine-issues/#.Y4kOzcqnyf0

According to Sam Chui’s website, flight testing won’t resume until Summer.

Rogers99 wrote:

HTCone wrote:

https://samchui.com/2022/12/01/boeing-777x-test-program-halted-after-ge9x-engine-issues/#.Y4kOzcqnyf0

According to Sam Chui’s website, flight testing won’t resume until Summer.

That is if there’s a design problem

StTim wrote:

Rogers99 wrote:

HTCone wrote:

https://samchui.com/2022/12/01/boeing-777x-test-program-halted-after-ge9x-engine-issues/#.Y4kOzcqnyf0

According to Sam Chui’s website, flight testing won’t resume until Summer.

That is if there’s a design problem

Fixed it for you. There is a problem - it is more a case of how big it is. If it is just a production issue there is still why it was not found, what needs to change etc to make sure it doesn't happen again.

If the basic design has a flaw in an area that will however be a much bigger problem.

I have no idea which one it is but they have been investigating for a few weeks now.

Avatar2go wrote:

We should know in a few days. But we shouldn't jump the gun and presume the worst. I'll be surprised if it's a design flaw serious enough to ground the test program.

Rogers99 wrote:

GE says, they decided with Boeing to ground the test program out of an abundance of caution until they report their findings

Avatar2go wrote:

BoeingVista wrote:

The door blowout and destruction of the airframe was not the predicted failure mode, if you have a link attesting that is was please post it.

Boeing's public statement at the time, was that the expected mode of failure was buckling of the fuselage.

It was an all-airfame ultimate test, with the wings being deflected upward while the nose & tail were deflected downward, and the fuselage also pressurized to near its limit. For that configuration, the greatest stress concentration relative to strength, is just forward and aft of the wing box. The failure ocurred in the aft location. Since the underside of the fuselage was in compression, the failure mode is buckling.

Once the buckle ocurred, the pressurization energy was released in an explosive decompression. The signature of that release is a split or tear in the fuselage, which is characteristic of any pressure vessel ultimate test. In this case the tear ran rearwards until it was interrupted by a door frame. Splitting the frame released the door, which blew out onto the facility floor.

That sequence was captured in the data acquisition, and well understood. It's possible that the tear running as far as it did was not expected by Boeing. Explosive events are more difficult to predict. But the initial failure mode of buckling was predicted, and the explosive decompression would be inevitable, by definition.

My point is that these failures were so close to the mandated ultimate load, that they served the purpose of validating the finite element structural models. So may have been some minor tweaking based on those models, but not enough to affect the weight rating of the aircraft.

FluidFlow wrote:

TropicalSky wrote:

in article on { https://airwaysmag.com/boeing-777x-tests-halted-ge9x/ } from airways mag they quoted Emirates CEO stating that they will know the extent of damage/delay on DEC 6 & BOE has plans to restart testing in JAN 23.....hopefully its nothing to serious

In general, according to the article, it comes down to design flaw vs manufacturing problems. The latter will not be a big problem, as the affected parts can be replaced with non-affected parts. If its the former, GE and Boeing will have a problem, because going back to the drawing board will take time and cost money.

BoeingVista wrote:

FluidFlow wrote:

TropicalSky wrote:

in article on { https://airwaysmag.com/boeing-777x-tests-halted-ge9x/ } from airways mag they quoted Emirates CEO stating that they will know the extent of damage/delay on DEC 6 & BOE has plans to restart testing in JAN 23.....hopefully its nothing to serious

In general, according to the article, it comes down to design flaw vs manufacturing problems. The latter will not be a big problem, as the affected parts can be replaced with non-affected parts. If its the former, GE and Boeing will have a problem, because going back to the drawing board will take time and cost money.

There is a 3rd option, it could point to a materials issue as they were playing with thermal margins. That could be a big problem.

Edit: From the Sam Chui article the glitch happened and they dropped the engine in October, Its been stripped at the factory long since, GE already know whats going on and its not good news. We are being softened up for another delay announcement around the 6th.

BoeingVista wrote:

So that's a no then.

FluidFlow wrote:

BoeingVista wrote:

FluidFlow wrote:

In general, according to the article, it comes down to design flaw vs manufacturing problems. The latter will not be a big problem, as the affected parts can be replaced with non-affected parts. If its the former, GE and Boeing will have a problem, because going back to the drawing board will take time and cost money.

There is a 3rd option, it could point to a materials issue as they were playing with thermal margins. That could be a big problem.

Edit: From the Sam Chui article the glitch happened and they dropped the engine in October, Its been stripped at the factory long since, GE already know whats going on and its not good news. We are being softened up for another delay announcement around the 6th.

For me this are just semantics: If you use the wrong material its a design flaw if you designed it with the wrong one or, the supplier delivered bad material and GE didnt cought it and used it, what would be a manufacturing issue. We will see, the former would really be a problem…

pugman211 wrote:

Is this likely to be a coatings issue?? Especially with it being linked to EGT?

Avatar2go wrote:

BoeingVista wrote:

So that's a no then.

I gave you the facts, which were accepted by the FAA, who had staff onsite to observe the test. You are the one making the claim that it's other than the truth. Therefore up to you to provide evidence for your viewpoint.

Anyone can make any claim and then demand it be disproved. That is the basis of all conspiracy theories. But that's not how rational discussion works. It's up to you to show that the facts you are provided, are not correct.

BoeingVista wrote:

No, you gave me your opinion. I asked for a link to somebody, anybody that agrees with it. You haven't provided a link because there is nobody who does. You were the one making the original claim and are of course unable to back it up.

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.

But as Boeing personnel along with six FAA observers watched from the windows of a control room, at 1.48 times limit load — 99% of ultimate load — the structure gave way. Under the center fuselage, just aft of the wing and the well where the landing gear wheels are stowed, the extreme compression load caused the plane’s aluminum skin to buckle and rupture, according to the person familiar with the details.

That then caused secondary damage: The photos show that the fuselage skin split part of the way up the side of the airplane, along with areas of bent and twisted structure that extended through the area around a passenger door.

These secondary damage sites — the rip up the side of the fuselage, the door blown out — alarming as they might seem, are not a concern to air safety engineers. “The doors were not a precipitating factor,” said the person familiar with the details.

It’s the initiating failure, the weakness in that localized area of the keel, that Boeing must now fix.

Yet the fix is very unlikely to require a retest.

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.

Boeing will have so much data gathered on the way to the 99% stage that it can now compare with its computer models to analyze the failure precisely, the FAA engineer said. It can then reinforce the weak area, and prove by analysis that that’s sufficient to cover the extra 1%.

The engineer said it’s not that unusual to find a vulnerability when taking an airplane structure to the edge of destruction.

FrenchPotatoEye wrote:

The peoples forgets this only ONE G9X engine under inspections


How many thousands of test flights hours since since the firstings flight all with no accident or event?

Wear tear is best guess as test fighting resume in just a few the weeks. Sheesh

RJMAZ wrote:

A PIP package on the GE90 might have been enough to keep it going.

xwb777 wrote:

I see Tim Clark ordering the A350-1000 if there would be a further in certification/ delivery. Boeing will be updating him with the latest test results on December 6.

accentra wrote:

FrenchPotatoEye wrote:

The peoples forgets this only ONE G9X engine under inspections


How many thousands of test flights hours since since the firstings flight all with no accident or event?

Wear tear is best guess as test fighting resume in just a few the weeks. Sheesh

I think people are just anxious because a previous issue with GE9X led to a significant delay to the 777X programme (when the stator redesign was required). Everyone is just hoping it won't be the same thing again and that there won't be another big delay. Hopefully more definitive news in the coming days.

FrenchPotatoEye wrote:

accentra wrote:

FrenchPotatoEye wrote:

The peoples forgets this only ONE G9X engine under inspections


How many thousands of test flights hours since since the firstings flight all with no accident or event?

Wear tear is best guess as test fighting resume in just a few the weeks. Sheesh

I think people are just anxious because a previous issue with GE9X led to a significant delay to the 777X programme (when the stator redesign was required). Everyone is just hoping it won't be the same thing again and that there won't be another big delay. Hopefully more definitive news in the coming days.

There no redesigning impact because the flight tests have been going for 2 the year since 2020

And only one engine is the affected piece, not all g9X engines

reidar76 wrote:

RJMAZ wrote:

A PIP package on the GE90 might have been enough to keep it going.

The GE90 violates the noise emissions standards. I think that is difficult to address without a significant redesign.

An 777X EIS in 2025 would mean more than 12 years since programme launch. Now Boeing might be facing further delays, due to the recent engine issues. This must be the longest development time for any civilian aircraft ever, and it's not even a clean-sheet. Due to the many years of delays, this aircraft design and its engine will not exactly be state of art at EIS.

Is there any chance the 777X programme might be outright cancelled? Even though a lot of resources have already been spent, there is significant cost in ramping up and manufacturing these aircraft. After so many years of delays, and with all the compensation required, and that combined with the usual low launch price (2013), I can't imagine that Boeing can even cover even production cost per frame.

I can't even imagine that there will be any significant further orders for the 777X. There will probably be cancellations. Total production might end at anything between 250 and 350 frames, is my guess. That is dependent on when this aircraft accually will EIS (still 2025 or will it be 2027?), and when Airbus launches the A350neo (with Ultrafan) and Boeing proceeds with a 787 MAX (and 787-10ER / 787-11).

Is the 777X DOA (?), or just a new 747-8 (?).

Avatar2go wrote:

Every time an issue surfaces with an aircraft, or with a manufacturer, we get the cancel theories. It's not going to happen.

The 12 years includes 2 years of pandemic and 2 years of extraordinary circumstances, which continue in the new rigor applied by the FAA. There is no comparison with earlier development models.

It speaks volumes that customers, despite complaining about the circumstances, have not cancelled their orders and moved on to other aircraft. There are reasons for that.

FrenchPotatoEye wrote:

accentra wrote:

FrenchPotatoEye wrote:

The peoples forgets this only ONE G9X engine under inspections


How many thousands of test flights hours since since the firstings flight all with no accident or event?

Wear tear is best guess as test fighting resume in just a few the weeks. Sheesh

I think people are just anxious because a previous issue with GE9X led to a significant delay to the 777X programme (when the stator redesign was required). Everyone is just hoping it won't be the same thing again and that there won't be another big delay. Hopefully more definitive news in the coming days.

There no redesigning impact because the flight tests have been going for 2 the year since 2020

And only one engine is the affected piece, not all g9X engines

reidar76 wrote:

The GE90 violates the noise emissions standards. I think that is difficult to address without a significant redesign.

reidar76 wrote:

Is the 777X DOA (?), or just a new 747-8 (?).