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Boeing’s 777X Fuselage Was Ripped Apart During Pressure Testing

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New images have surfaced of what really happened during the September pressure testing of Boeing’s new 777X aircraft. September’s pressure test was widely reported to have failed, with a cargo door being blamed for the issue. Now, it seems that the situation was a lot more serious than that. The news that a cargo door had blown off the 777X during its stress test in September was shocking enough. However, it now appears that the situation was far worse than we could ever have imagined. According… (www.seattletimes.com) Altro...

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imtxsmoke
Jeffrey Bue 13
As much as this article "seems" to be "negative", I see this as a "positive" for the design. The negative - the structure failed just below the 1.5X limit load - the positive - this thing was instrumented out the ass so the engineers have plenty of data to make the appropriate design changes to finish off the certification "by analysis".
Lneward
Lance Neward 10
Let us remember that 1.5 is an arbitrary, reasonable number established by humans with experience and education in their respective field. We could make it 2.0 have cost the flying public millions, if not billions, of dollars because of the added weight of the structure, or we could go the other way, and be closer to potential loss of life. Yes, sometimes judgements regarding other factors like $ get in the way of those numbers, but in general those numbers (like 1.5) have proven their worth as a good balance of safety factors, engineering costs, manufacturing costs, and economics.
For example: When the 747 did a qualifying evacuation using an average cross-section of population including elderly, adults, children, physically challenged, etc., one of the requirements was that half of the exits (there were a total of 10 on the -100 model)had to be rendered inoperative, and which ones were inoperative were not known to the flight attendants onboard. The evacuation had to be completed in 90 seconds. As it turned out, one of the "good" doors actually failed, in addition to the planned 5, and the evacuation using 4 doors actually took 107 seconds.
The judgement of the regulators, engineers, airline executives and observing crew members was that the evacuation was successful and the aircraft type met its certification requirements in that area. As far as I know, in all of the actual emergencies requiring evacuation, that 107 seconds was never an issue.
Point is, the difference of 1%, is going to be dealt with by knowledgeable people who also will end up flying some day on the 777X, and I for one will trust their judgement, as I do on things, like the make up of Minimum Equipment List, or Maximum Crosswind Component for landing, etc. Once the issue is addressed, I'm OK with that and will be OK to fly on the 777X,as far as structural integrity is concerned.
Falconus
Falconus 4
Counterpoint: you should never reduce your safety margins reactively.

When you are flying, for example, if your personal self-enforced maximum crosswind component is 10 knots, you shouldn't decide 11 is okay because when you check the forecast before takeoff it looks a bit "marginal". You should sit it out. Then, on a nice calm day with a 3-knot crosswind you can think about whether it's safe to increase your personal maximum given your increased experience and knowledge.

Also, if my maximum allowable takeoff weight is 2000 lbs, I know darn well that my airplane can handle 2001 pounds, but I still limit it to 2000 because that's the threshold and if 2001 pounds is okay, why not 2002? I'm not starting on that slippery slope.
KobeHunte
Kobe Hunte 3
Well said.

It's good to test them to the maximum so that only the very unexpected will make them crash.
wwharris
Bill Harris 8
The source article in the Seattle Times:

https://www.seattletimes.com/business/boeing-aerospace/boeing-777xs-fuselage-split-dramatically-during-september-stress-test/

[This comment has been downvoted. Show anyway.]

TorstenHoff
Torsten Hoff 17
It matters because with modern design and engineering methods, the fuselage is tested virtually long before it is ever constructed as a test article -- physical testing is merely used to validate.

If the test wasn't meant to be destructive, it points to a design or manufacturing defect.
KobeHunte
Kobe Hunte 3
Here you go with your negative comments. Can't you say something positive?
KobeHunte
Kobe Hunte 6
I was not replying to Torsten's comment. It was linbb. I totally agree with Torsten's comment.

[This comment has been downvoted. Show anyway.]

lynx318
lynx318 4
Testing done at 1.5 times any expected situation seems unlikely to be overly threatening in normal flight use. The main need to test above and beyond is to factor in fatigue and degradation over the planes lifespan. Australian Standards for lifting equipment is 2X the rating listed for it, i.e. a trolley jack rated at 1500kg is tested at 3000kg. Over time wear and tear will lessen its capability so a wear test factor has to be used. Also there is the idiot factor on people using them for what they're not designed for, not saying pilots would do this with airliners obviously though.
plausipo
Po Lau 4
Why is that part more prone to rupture than the other parts? Also, if they were doing numerical simulation I hope they have enough real data from this test to fine tune their models.
jedswift
Jared Smith 7
The circular pressure hull that constitutes the fuselage ahead of and behind the wing structural carry-through box is cut-out to allow the box through to connect the wings that must carry bending moments and torques generated by the wings and reacted through the fuselage. The pressure loads on the fuselage have to be supported by flat panel pressure bulkheads ahead of the wing box, the floor over the wing box and down just aft of the main landing gear box. The forward and aft bulkheads are tied together and the fuselage bending loads are carried through a "keel beam" that can be seen running longitudinally, even with the lower surface of the fuselage, between the left and right main gear wells.

Structural discontinuities such as these are both difficult to accurately model and are material intensive and heavy. Adding a lot of structural margin is costly, so failures initiating at these features tend to be more common. Thus the instrumentation and test.
KobeHunte
Kobe Hunte 0
Because the amount of pressure that is pushing against it, and every plane is different size and specifications, so the testing would be different in each one.
sgbelverta
sharon bias 9
I know everyone thinks we're just picking on Boeing, but Damn, that was a big hole. And they don't think a retest is required because the pressure results were so close to the desired specs? Did I mention that there is a big hole in that plane after the first test? No wonder Boeing didn't want those pictures released. The problem is that Boeing doesn't want to start from scratch on a new aircraft. They want to update existing models to keep costs down. Don't think having the 737Max grounded for over a year is saving Boeing much money. And it's been a public relations nightmare.
tomcat1965
Airbus does exactly the same thing.....they keep updating existing aircraft such as the A330 and A320.
Jackx9
Don Quixote 2
It's like Dominoes falling down. Once one bad thing happened, it's seems like it's been all down hill since. But that's also what the media does to you, they love to report everything negative as possible. Which makes things seem a lot worse than it actually is. But this is exactly why they do plenty of tests, just as they always have in the past, to work out the kinks before the plane is fit to fly and in production. Plenty of stuff happens to other aircraft, such as Airbus etc, but you most likely won't hear about it because all eyes are on Boeing right now. But I'm 100% confident they'll get things worked out. Boeing is a fantastic company, with a lot of great people that work for them, and make great aircraft.
gtpalmer
Gary Palmer 2
It is unfortunate when press paints a negative and alarming picture. I always thought the (and still believe) the purpose of a test is to validate. I test the lid is watertight on a container before I trust the container to carry liquid in my car. We test all sorts of things to make sure they operate as expected. And when it fails in a test we should be happy that the situation was not live. If a car will have a steering problem, I prefer that failure in test, not with my family on the road.

But the press seems to turn a failed test into a real problem. What about fixing that car, getting a better container for liquid, or reinforcing the airplane. I applaud Boeing for testing beyond a limit they expect in normal conditions. Using words like "ripped apart" makes it sound so dramatic and dangerous.

DISCLAIMER- That is my personal opinion, while I work for Boeing I have zero knowledge, affect, insight or involvement with airplanes other than what I read publicly.
animal2010
Steve Ortiz 2
If a tested item failed at 149% of it's required limit - I would consider that to be a winner. The point of having a 150% passing grade is to ensure the item's design exceeds requirements of every day use.
claymdavis
Clay Davis 2
This is why we test.
SkyAware123
SkyAware123 4
"It will not have to be retested". I feel much better. Why test in the first place if you're going to go with 'theoretical' proof?
alroba43
Alain Rohrbach 3
Whether the comment is positive or negative, only one thing should make you think, it is the life of thousands of people who are at stake.
mariescreations
Jerry Rader 1
There are comments given here that imply that the structure of the airplane is determined by a budget that is given to the engineers by Boeing management and that safety is a secondary issue because that has an adverse effect on “profits”. I think this is absurd and the farthest from the truth. I am not a Boeing engineer but I have an idea that money does not enter into any equations when it comes down to designing the aircraft structure. It all boils down to building the strength into the structure to meet the airworthiness requirements with the least amount of weight - period.

Look at the photo of the failure. Where did it fail? In the middle of the skin! It did not fail at a seam. Why did it fail at that particular location? What really failed? Did that particular sheet of aluminum have an unseen flaw that caused the failure? Was the test overkill in how it was performed? Would the test have been a success without the “extra” twists and turns? All of these things will go into evaluating the failure by Boeing and FAA engineers and will probably show that the airplane is perfectly safe structurally and will meet the airworthiness regulations. Profits and shareholder concerns will have nothing to do with it!
nasdisco
Chris B 1
Engineers design and build to meet certain specs.
Then test them to meet those specs. But sometimes they get destroyed during the process. If the damage or destruction happens, they figure out the problems, fix them and retest.
Information on the event in question is probably available via a freedom of information request in addition to the way the ST went about it.
MKanzler
Mark Kanzler 1
FOIA wouldn't apply to proprietary information owned by a private company.
KobeHunte
Kobe Hunte 1
I don't like all the problems that this aircraft is having. I hope they can be resolved quickly, and quicker than the MAX.
charlie02vy
Charlie Roberts 15
Keep in mind this is a static test article, not the actual aircraft. Static test aircraft exist are for destructive testing.
AndrewNZ
Andrew Bunker 6
But it was not a destructive test!
KobeHunte
Kobe Hunte -7
Yes I know. But in general it has been having a lot of problems - engines, winglets and now this. Glad they are being resolved.
KicksOnRoute66
Roger Anderson 7
C'mon Kobe, that's what the tests are for. This is what I hate about the media coverage sometimes. Something goes wrong and suddenly Boeing is in disrepute when you stack all that's going on otherwise.
cvs62
F Minook 3
You are correct Roger. I worked for a company that built the flood lights for the Apollo program. I did the stress testing on the components that went into the flood lights. Some components had a high failure rate and our engineers sought replacements. The components were assembled into the final product and the first one was used for the final destructive testing. The final testing passed. The testing proved that our lights would last through the Apollo program. The Boeing stress testing is done for the same purpose. The 1.5X stress testing proves that the 777 will serve the expected life time of the aircraft. It is proven by the life of the 737 minus the 737Max.I so glad that the engineering group now report to the CEO.
whip5209
Ken McIntyre 4
That's why they do these tests, says Captain Obvious.
JMARTINSON
JMARTINSON 5
I hope so, too. Let's stay positive.
jrgargiulo
john Gargiulo -1
Boeing needs new management as they have a verynbad corporate culture, problems with the 737NG, 737MAX and no this.
Quirkyfrog
Robert Cowling -2
Well, damn glad it happened on the ground, rather than a rubber stamped Boeing/FAA flying catastrophe! Good grief!

So, how much money was saved for Boeing shareholders if that design has worked? 1 million? 2 million? 5 million?

Yes, the drive for 'profit above all' is counted in 'Monte Carlo simulations' of how many accidents to be expected. How many human lives to be 'lost'. Yeah, sometimes they are off. By a little...
Quirkyfrog
Robert Cowling 0
Down vote this if you want, but if you don't know that somewhere int he bowels of Boeing, conversations were going on over the Max 'fix', and what if it didn't, and how many lives they could end before it became a 'PR problem', then you live in a strange world. Sure, *some* risk is expected, but corporations gaming the chances and making decisions on 'how bad could it get' has gotten out of hand.

To me, what Boeing did was indefensible. They have gamed their advantage with the FAA to 'squeak in' a design that had some rather large flaws that could take it our of the air. Rather than provide a through education on the fix, and delay the plane for a year while they really fixed the physics of the plane, they 'rolled the dice', and quietly fixed it without telling anyone. They abused their relationship with the FAA, and betrayed their fiduciary duty to protect the customers of their customers, as well as betraying their long history of reliability and quality. End of story. They chose the money over their reputation.

Did this 777 failure also come from the same drive for profit over safety?

I think that's a very valid question, and the answer should concern their shareholders, and anyone that flies their planes.
lynx318
lynx318 1
It's not an overall failure, it's a testing destruction fail, this happens with most aircraft tested. All this is a slow media day and looking for an angle on a story.
klcdenver
kenneth cox 0
They should have to fix it in the weak point then retest because it may have another weak point that would rupture if this area didn't fail first.
mutrock
Mark Kortum 0
Boeing needs to be innovative to compete. The biggest innovators always face the biggest obstacles and outright failures. The obstacle itself is not an issue here. It is how Boeing will respond to it. If Boeing sees this as a learning experience and not just an obstacle to go around they will succeed. "You have to crack a few eggs to make an omelet."
akebonolove
bob elmar 0
Cant read if not subscriber, please post.
md69
Martin Dennett 3
I read it without being a subscriber. I have an ad-blocker on my browser so I just opened a "private browsing" window and pasted the link in.
KobeHunte
Kobe Hunte 0
How many of these planes have already started being made for airlines?
TorstenHoff
Torsten Hoff 2
None. The 777X hasn't even flown yet, let alone received a type certificate.
JMARTINSON
JMARTINSON -4
Now, it seems that the situation was a lot more serious than that? It now appears that the situation was far worse than we could ever have imagined?

You have a real flair for the dramatic, bud.


"the test failed so explosively at just 1% shy of meeting federal requirements, it will almost certainly not have to do 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."
TorstenHoff
Torsten Hoff 12
Except it didn't meet the requirements, and given the scrutiny that the FAA and Boeing are under, nobody is going to sign off on this test as having passed.

"Barely counts as a failure" sounds pretty hollow when the fuselage has ruptured. If that happened during a flight, the aircraft will be coming down as confetti-sized pieces.
KobeHunte
Kobe Hunte 5
And that "1% shy" could happen during a flight.
lynx318
lynx318 2
That's 1% shy of 150% of real load expectations.
JMARTINSON
JMARTINSON 4
Yeah, airliners pull 3.75g’s all the time.
serdyfsx12
JOE SERDYNSKI 4
Yes, they exceed 3.75g's in heavy turbulence and hard landings . . . Not like a fighter jet, but still there . . .
JMARTINSON
JMARTINSON 3
No, they don't. Not without falling apart, anyway. 3.75g is not the limit load, it's the ultimate load, and has been for airliners since the 1950's.
serdyfsx12
JOE SERDYNSKI 1
Ask the Flight Attendant/un-belted passenger that hits the roof (-g), then hits the floor/seat/other passengers (+g) . . . Instantaneous G-forces can and do exceed Load limits . . .
JMARTINSON
JMARTINSON 1
And suddenly Joe gets very quiet, with only the faint sound of a downvote click.
JMARTINSON
JMARTINSON -1
Unless they also happen to be aerospace engineers, I could care less what flight attendants or unbelted passengers have to say.

You seem confident, so tell me... if the load limit of an airliner is 3.75g, what is the ultimate load?

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