Boeing 777X

Moose said:
Sounds like someone messed up the metallurgy...badly.
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Yeah, but that is what flight testing is for... Unexpected loads, undersized parts, installation issues/processes, you name it....
 
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Thrust link (2 per engine);

ge9x_thrust_link_highlighted_photo_source_ge_aerospace.jpg


Boeing Halts 777-9 Certification Tests For Engine Mount Checks | Aviation Week Network

Boeing is halting 777-9 certification flight tests following the failure of a thrust link mounting component on one of the GE9X engines powering a test aircraft
aviationweek.com aviationweek.com
 
I wonder what the thrust linkage is made of, I would imagine Ti or Steel. It would be interesting if this could be linked to the Ti material authentication issues that have been noted recently.
 
Helicoprion said:
I wonder what the thrust linkage is made of, I would imagine Ti or Steel. It would be interesting if this could be linked to the Ti material authentication issues that have been noted recently.
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Looks more like steel, it's polished in the pictures. Titanium doesn't stay polished but quickly gets some gray uniform surface corrosion.
 
Cracks have now been found in the thrust links of the fourth test plane meaning all four aircraft have the issue. This is despite the fourth aircraft not having flown for nearly three years (Only flown between its completion in September 2020 and Nov 2021) and having very limited flight hours.
 
WatcherZero said:
Cracks have now been found in the thrust links of the fourth test plane meaning all four aircraft have the issue. This is despite the fourth aircraft not having flown for nearly three years (Only flown between its completion in September 2020 and Nov 2021) and having very limited flight hours.
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Crud, that is sounding more like "inadequate/incorrect heat treat" than "inadequate design"
 
Yeah does sound like a manufacturing rather than unexpected wear issue. I would be interested to know if the parts were x-rayed during production and certification.
 
@Helicoprion : they are listed as Boeing parts.

The fact that one of the airframe that hasn´t flown for a while is impacted would point toward something not resulting from an exacerbated fatigue failure but a damage resulting from a recurring dynamic incident that overstressed the part.
 

Boeing Confirms No 777-9 Deliveries Until At Least 2027 | Aviation Week Network

Boeing confirms it will need all of 2026 to complete the 777-9’s FAA type certification program, pushing projected first deliveries of the widebody into 2027.
aviationweek.com aviationweek.com

TLDR: Certification running late because Boeing underestimated the work involved, company to take a $4.9Bn charge.

Article is free to read until the 6th. There's also some interesting 737 Max stuff buried at the end.
 
It's amazing that the original 777 program almost 30 years ago was the last time that Boeing got a major aircraft program across the finish line on time. Everything since then has been downhill. The only consolation is that it gives the A380 a couple more years of useful service before they are withdrawn.
 
alberchico said:
It's amazing that the original 777 program almost 30 years ago was the last time that Boeing got a major aircraft program across the finish line on time. Everything since then has been downhill. The only consolation is that it gives the A380 a couple more years of useful service before they are withdrawn.
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When was the last time Boeing designed a new plane from scratch that needed full certification paperwork? 787? And that was doing a whole bunch of new-at-the-time technologies, so of course that one is going to run long.
 
Electroimpact provides automation solutions and robotics for aerospace manufacturing. They have been working with Boeing for a long time. These are a couple of white papers relevant for the 777x.
 

Attachments

  • Electroimpact A Phased Approach to Optimized Robotic Assembly for the 777X.pdf
    1.5 MB · Views: 4
  • Electroimpact case study of a fuselage join automation.pdf
    1.5 MB · Views: 2
Scott Kenny said:
When was the last time Boeing designed a new plane from scratch that needed full certification paperwork? 787?
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Possibly never. Boeing's been in a position of trust for signing off large amounts of its own work for a long time. Even with 777 (the original certification process in 1990-1994, not 777-X), with FBW a whole new technology risk area, FAA had to (IIRC) ask DGAC what they did with Airbus, so would be feeling its way towards what it wanted from a certification process, and when it implemented that, Boeing was the side who knew what the answers should be, not just the organisation whose homework needed checking.

And then suddenly it isn't trusted anymore. It's potentially as much a learning experience for FAA as for Boeing.
 
DWG said:
Possibly never.
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Your response is *CLEARLY* fundamentally logically incorrect. There quite obviously *HAS* to be a last time that Boeing designed a new plane from scratch that needed full certification paperwork. I do honestly neither know or care what that point in time was, but I'll leave it to you or any other interested party to suss it out. I *DO* however trust the FAA to carry out their mandate, even under the current anti regulation regime.
 
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martinbayer said:
Your response is *CLEARLY* fundamentally logically incorrect. There quite obviously *HAS* to be a last time that Boeing designed a new plane from scratch that needed full certification paperwork
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My point was FAA's reliance on Boeing as a trusted authority, or whatever the term is, clearly predates current certification standards. As does allowance for grandfathered-in aspects of multi-generational designs. We're certainly going back to pre-737 days, possibly significantly earlier - it's not clear when Boeing's regulatory capture of the certification process began and I'd be genuinely interested to get informed opinion on that.
 
DWG said:
My point was FAA's reliance on Boeing as a trusted authority, or whatever the term is, clearly predates current certification standards. As does allowance for grandfathered-in aspects of multi-generational designs. We're certainly going back to pre-737 days, possibly significantly earlier - it's not clear when Boeing's regulatory capture of the certification process began and I'd be genuinely interested to get informed opinion on that.
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I'd guess 707/727 design, but that is just a guess.
 
Helicoprion said:
You mean the MD-95?
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The 717 referred specifically to the KC-135 but after Boeing bought MDD (And became McBoeing) the lazy sods renamed the MD-95 the 717.

Helicoprion said:
I thought the KC-135 was based on the 720 airframe.
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No, Both the 707 and 717 were developed from Boeing's 367-80 or Dash 80 for short, the Boeing 720 was a 707 derivative.
 
TomcatViP said:
@Helicoprion : they are listed as Boeing parts.

The fact that one of the airframe that hasn´t flown for a while is impacted would point toward something not resulting from an exacerbated fatigue failure but a damage resulting from a recurring dynamic incident that overstressed the part.
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AW winner 2026:

Boeing 777-9 Thrust Link Fix Team​

A Boeing engineering team employed out-of-the-box thinking – including use of a powerful leaf blower – to investigate and resolve a resonance that caused the premature fatigue failure of a load transferring component attached to the 777-9’s GE Aerospace GE9X engines. Investigation of the puzzling failure and subsequent redesign of the thrust link enabled Boeing to resume flight tests after a five-month hiatus.
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2026 Winners

2026 Winners
laureates.aviationweek.com
 
Here’s a short update from the Dubai Airshow.
AviationWeek said:
AviationWeek - Onboard The First 777-9 Development Aircraft At The Dubai Airshow
With its entry-into-service again delayed, the 777-9 program is advancing to Phase 3 of FAA certification flight testing. Aviation Week editors Guy Norris and Christine Boynton explain what's next, onboard the first 777-9 development aircraft WH001 at the Dubai Airshow.
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Video:
View: https://www.youtube.com/watch?v=-7CmsoImRJ0

Link:
Code: 
https://www.youtube.com/watch?v=-7CmsoImRJ0
 

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