Boeing 777 Wing Test
Why Hacker News recommends it
HN links it constantly as vivid evidence of how much margin aircraft structures have and that destructive testing is real.
What it is
A short video of a Boeing 777 wing being tested to destruction, finally breaking at 154 percent of its designed limit load. The wing is flexed upward until it fails.
Recommended by 2 HN commenters across 2 different months, 2013 to 2023.
What Hacker News said
Recommends vanderZwan · 2015-02 · on “The Last of the Typewriter Men”
Planes come to mind. Basically, back in the age of the slide ruler, engineers "overcompensated" in durability. This is why older planes are much heavier (so more inefficient and costly to run) but also last forever. PS: Not to crap on the structural engineering of more modern planes, don't get me wrong! Check out this video: [this video]
Recommends sjm-lbm · 2018-07 · on “Ask HN: How to overcome fear of flying?”
Since you are posting on HN and I'm guessing you are technically minded, you might find this really interesting: [this video] - it's a video from a documentary about the development of the Boeing 777. Specifically, the video shows a test where they bend/stress the 777 wings to the point where they actually snap. Spoiler alert: they snap at orders of magnitude more flex than you've ever seen. Even for very severe turbulence (like you experienced), it's very comforting for me to know (via that video evidence) that even if I haven't seen turbulence this bad, the people that made the airplane definitely thought about it.
Cites beachstartup · 2013-07 · on “Video shows plane's moment of impact at SFO”
[this video] video of boeing stress-testing 777 wings by deflecting them up with cables, against a stationary fuselage first thing that came to mind after seeing the video of the crashed plane do a cartwheel on its wing.
Cites toomuchtodo · 2014-10 · on “Aboard a Cargo Colossus: Maersk’s New Container Ships”
One of the wing tests: [this video] "This Boeing 777 wing was tested to destruction, finally breaking at one fifty four percent (154%) of the designed limit load."
Cites cesarb · 2019-05 · on “Boeing’s Own Test Pilots Lacked Key Details of 737 Max Flight-Control System”
> There is no such thing as 'destructive aircraft testing' Actually, there is: [this video] "This Boeing 777 wing was tested to destruction, finally breaking at one fifty four percent of the designed limit load."
Cites cyberferret · 2019-09 · on “Door blows off Boeing 777X during stress test”
It's a stress test. You would expect things to break during a stress test. > "They loaded it up well beyond capacity and bent its wings in an extreme manner, in a way almost certain to never happen in the real world." Here is another video of a 777 wing test where it broke at 154% of the [s/normal/maximum theoretical/] load - a bit beyond what was expected by the engineering team. [this video]
Cites mkl · 2019-09 · on “Door blows off Boeing 777X during stress test”
It's not a matter of interpretation or tricky language. The video says "of" [1] so it's 1.54 times the design limit. [1] [this video]
Cites jvanderbot · 2019-11 · on “Boeing 777X’s fuselage split dramatically during September stress test”
This sounds fine. It's a catastrophic failure test. They push until it breaks, then it broke, and they were very close to their designed target (within 1%). If they had gone 1% past their designed target, they would have been upset, as they could have made the plane lighter. They were 1% short of design limit, they are upset because they'll have to add reinforcement. Have you seen the wing failure test? I worked for the company that did these tests (they did them before I worked there), and they still talk about how upset the engineers were that it went over spec in strength. [this video]