Boeing and Airbus use different philosophies when engineering wings.
Boeing typically designs the wing to be as light as possible and the wing will flex a lot more in normal operating conditions.
Airbus designs the wing to be as aerodynamically stable as possible and the wing is stiffer as a result. Especially noticeable when comparing 787 and A350.
Same that Airbus believes that computers should be in the lead to avoid incidents (because computers don’t suffer from human errors like fatigue, stress etc.) while Boeing believes that pilots should be in the lead because humans are creative thinkers (to come up with solutions) while computers are not.
Both have its ups and downs and in both cases it has lead to incidents and accidents.
That's a concern with any system. If the person operating it doesn't know enough about how it works you can end up fighting it or not getting the best results when things go wrong and the operator tries to do something about it.
MCAS was a systems issue as it was a single sensor failure that could cause major control issues.
But the crashes were also training faults. The pilots in question were not trained on the system, as a cost savings measure (keeping the 737 type rating on the Max) but if they were aware, there is a switch to prevent trim runaways (stab trim cutout) which would have helped the situation.
Exactly. My point was that if the operators aren't given adequate training about how the systems work, what inputs they respond to, etc. then it doesn't matter if the systems design is good or bad, you can still end up with an operator fighting the system.
Conversely, airbus just got burnt by computer errors that humans wouldn’t have been impacted by. There is no perfect solution, but a combination of humans and computers is pretty close
Dumb question, would more wing flex generally mean less turbulence felt at the fuselage or is that not how it works? I know mass probably has more of an effect on turbulence felt, or maybe wing loading?
I believe that is the general idea, yes. I remember reading something about the Dreamliner’s wings and the constant tiny movements they are making to mitigate the effects of turbulence and how it’s felt in the cabin
Why the differing philosophies? I get that each manufacturer has their way of construction, but it would be interesting to hear the engineering reasons for this.
I mean, not really.
The only new program at Boeing is the 777x and Airbus is yet to start theirs. It’ll take a generation. And they’ll continue to be tubes. Airports aren’t made for BWBs.
I intentionally phrased the timeline very vague. Coming years can mean basically anything since it's open-ended. I am well aware on how long these development programs take and how the improvements in technology (in this case particularly material science and composite manufacturing) are advancing.
If we will ever see BWBs, no one really knows at this point. It depends on a multitude of factors.
Look up the turbulence forecast, look up your flight path, having information always helps because it takes away some of the unknown. Learn the sounds of the plane, like what it feels like to get clearance up to cruise. Have something that works your mind instead of sitting there -- crossword or something.
I'm also anti-turbulence but what I have found to help is reminding myself that while the movements feel 'large', they generally aren't. I compare it to driving down a gravel road with some washboard in it. There are a few videos out there as well that demonstrate what turbulence looks like from the outside as well.
Of course it is comparable. Loading is loading. The airplane does not care if the reason it has a certain amount of force applied to the wing is because you put a static load on it or because it was hit by a gust of wind that put the same load on it. The equations don't change as far as bending stress and shear stress and so on. You just have a load that comes from somewhere and you have the response.
Here's what you do to figure out what load to put on that wing when you're doing this quasi-static (remember, it's not truly static because they're increasing the load over time, but it's slow so it's quasi-static) ultimate load test, which does in fact account for gusts and other dynamic loading:
you take your maneuvering load limits, which are going to be -1G to +2.5G for almost everything in the transfer category
then you take your gust load limits which are computed based on the physics of the aircraft and how it responds to sudden variations in vertical wind and changes in airspeed
and you make sure to account for any non-linearities or structural effects associated with, say, maneuvering such that you are at +2.5 g (which will distort your structure of course) and getting hit by gusts
And you just add everything together. That gets you your limit load. Then you slap another 50% on that to get to your ultimate load, which is the forces your aircraft has to be able to withstand.
So you get one single number at the end of this which is probably like +8g in the positive direction...and then you do your quasi-static load test. And if it gets to your ultimate load and are.able to stay there for, I think, 5 seconds, you've demonstrated that your aircraft is strong enough.
Why is this guy getting down voted? The test was indeed a static ultimate test, which is way different from the dynamic flexure seen in the video. Dynamic loads can aggravate stresses well before static ultimate, both companies have factors to account for this. Usually, the 2.5g up bend is assumed quasi-static because it will be a stable load, unlike a turbulence which can be an unstable load.
I flew various versions of the 737 through the MAX for several years. I call it the “Memphis Belle” because it’s relatively dirt simple, rugged and quite reliable. Its wing loading sucks during turbulence for passengers though. But it’s a good, tough plane
A lot of people don't realise that the wing isn't flapping around, the fuselage is bouncing up and down between the wings. It appears this way because the camera is located in the fuselage.
Many years ago I saw a video of Boeing's stress-to-destruction test for the original 747 wing. It was insane how far that thing flexed before breaking.
I just searched and couldn't find that video. But I did find op's video in YouTube: https://youtube.com/shorts/59wPLzyn4O8
froggo921@reddit
Modern technology is just impressive.
We will see some pretty insane improvements in the coming years with composite materials becoming more prevalent in all aircraft.
I think 787s wing flex still takes the cake at this moment but I am not sure how A350 is in that regard.
dek00s@reddit
Boeing and Airbus use different philosophies when engineering wings.
Boeing typically designs the wing to be as light as possible and the wing will flex a lot more in normal operating conditions.
Airbus designs the wing to be as aerodynamically stable as possible and the wing is stiffer as a result. Especially noticeable when comparing 787 and A350.
froggo921@reddit
Oh awesome, thanks for the information. I didn't know that.
DutchBlob@reddit
Same that Airbus believes that computers should be in the lead to avoid incidents (because computers don’t suffer from human errors like fatigue, stress etc.) while Boeing believes that pilots should be in the lead because humans are creative thinkers (to come up with solutions) while computers are not.
Both have its ups and downs and in both cases it has lead to incidents and accidents.
KillerKowalski1@reddit
Ironic given Boeing's recent issues with humans fighting computers to keep the plane in the air.
bouncypete@reddit
Even more ironic.
That computer you're referring to was fitted, to make the aircraft 'feel and handle' the same as the earlier variants of that aircraft to a human.
Had computers been fully in control, like they are in an Airbus, that 'new' computer wouldn't have been required in the first place.
comptiger5000@reddit
That's a concern with any system. If the person operating it doesn't know enough about how it works you can end up fighting it or not getting the best results when things go wrong and the operator tries to do something about it.
SwimmingThroughHoney@reddit
You described a problem with training, not the system design.
etheran123@reddit
MCAS was a systems issue as it was a single sensor failure that could cause major control issues.
But the crashes were also training faults. The pilots in question were not trained on the system, as a cost savings measure (keeping the 737 type rating on the Max) but if they were aware, there is a switch to prevent trim runaways (stab trim cutout) which would have helped the situation.
comptiger5000@reddit
Exactly. My point was that if the operators aren't given adequate training about how the systems work, what inputs they respond to, etc. then it doesn't matter if the systems design is good or bad, you can still end up with an operator fighting the system.
Temporary-Fix9578@reddit
Conversely, airbus just got burnt by computer errors that humans wouldn’t have been impacted by. There is no perfect solution, but a combination of humans and computers is pretty close
estunum@reddit
Dumb question, would more wing flex generally mean less turbulence felt at the fuselage or is that not how it works? I know mass probably has more of an effect on turbulence felt, or maybe wing loading?
Griff1604@reddit
I believe that is the general idea, yes. I remember reading something about the Dreamliner’s wings and the constant tiny movements they are making to mitigate the effects of turbulence and how it’s felt in the cabin
Temporary-Fix9578@reddit
The Dreamliners also actively dampens turbulence with automatic movement of the flight controls
Griff1604@reddit
That’s super cool, thank you for the info!
ProfessorJeebus@reddit
Why the differing philosophies? I get that each manufacturer has their way of construction, but it would be interesting to hear the engineering reasons for this.
DangerousCable1411@reddit
graphene has entered the chat
emezeekiel@reddit
I mean, not really. The only new program at Boeing is the 777x and Airbus is yet to start theirs. It’ll take a generation. And they’ll continue to be tubes. Airports aren’t made for BWBs.
froggo921@reddit
I intentionally phrased the timeline very vague. Coming years can mean basically anything since it's open-ended. I am well aware on how long these development programs take and how the improvements in technology (in this case particularly material science and composite manufacturing) are advancing.
If we will ever see BWBs, no one really knows at this point. It depends on a multitude of factors.
publicposter988@reddit
i know that the wing can take that, but man it gives me the chills.
Other_Cricket_453@reddit
I always try to get window seats by the wing when I fly. Turbulence freaks me out and for some reason seeing the wing flex like that eases me a bit
NatureDry2903@reddit
How do you work through your turbulence fears? Have a flight Thursday and I’m freaking out
DrEarlGreyIII@reddit
turbulence has never been the direct cause of an airline accident
Highball61@reddit
Look up the turbulence forecast, look up your flight path, having information always helps because it takes away some of the unknown. Learn the sounds of the plane, like what it feels like to get clearance up to cruise. Have something that works your mind instead of sitting there -- crossword or something.
MalayaJinny@reddit
I'm also anti-turbulence but what I have found to help is reminding myself that while the movements feel 'large', they generally aren't. I compare it to driving down a gravel road with some washboard in it. There are a few videos out there as well that demonstrate what turbulence looks like from the outside as well.
Maldivesblue@reddit
That’s a rough ride.
A-Waxxx656@reddit
Nope
iamthenev@reddit
That is mild-low flex during turbulence. The wings can go way wilder than this!
Key-Monk6159@reddit
I know it’s fine but it’s still unsettling to see from the novice perspective
5043090@reddit
It's amazing g how those things are engineered to withstand A LOT of pressure changes and flexing.
Impossible_Most_4518@reddit
Flew over a cyclone once, that shit was scary especially in a tiny 737. I think the wing flexed more than in this video.
truth-telling-troll@reddit
Yeah wings can flex alright
haebigou@reddit
Obligatory 154!
changyang1230@reddit
After the video, my first response was to Ctrl-F "154" and upvote.
950771dd@reddit
It's a different (static) load scenario, not comparable.
Typical reddit armchair knowledge.
Coomb@reddit
Of course it is comparable. Loading is loading. The airplane does not care if the reason it has a certain amount of force applied to the wing is because you put a static load on it or because it was hit by a gust of wind that put the same load on it. The equations don't change as far as bending stress and shear stress and so on. You just have a load that comes from somewhere and you have the response.
Here's what you do to figure out what load to put on that wing when you're doing this quasi-static (remember, it's not truly static because they're increasing the load over time, but it's slow so it's quasi-static) ultimate load test, which does in fact account for gusts and other dynamic loading:
you take your maneuvering load limits, which are going to be -1G to +2.5G for almost everything in the transfer category
then you take your gust load limits which are computed based on the physics of the aircraft and how it responds to sudden variations in vertical wind and changes in airspeed
and you make sure to account for any non-linearities or structural effects associated with, say, maneuvering such that you are at +2.5 g (which will distort your structure of course) and getting hit by gusts
And you just add everything together. That gets you your limit load. Then you slap another 50% on that to get to your ultimate load, which is the forces your aircraft has to be able to withstand.
So you get one single number at the end of this which is probably like +8g in the positive direction...and then you do your quasi-static load test. And if it gets to your ultimate load and are.able to stay there for, I think, 5 seconds, you've demonstrated that your aircraft is strong enough.
TheJohn_Doe69@reddit
Pretty sure thousands of Engineers know more than you do
950771dd@reddit
Lol you're the typical redditor that knows layer 1 of the aviation ice berg and can't help not to post his secrets below each video.
The good news, however: no engineering degree needed!:
Just
If you still think that inertia and sudden load changes don't play a role, you can come back here posting.
TheJohn_Doe69@reddit
Strawman argument. Not even going to nibble on that bait
950771dd@reddit
Hahaha well okay. I hope they don't let you close to designing any system, because real world physics won't be impressed with "strawman" words.
PeaStatus2109@reddit
Why is this guy getting down voted? The test was indeed a static ultimate test, which is way different from the dynamic flexure seen in the video. Dynamic loads can aggravate stresses well before static ultimate, both companies have factors to account for this. Usually, the 2.5g up bend is assumed quasi-static because it will be a stable load, unlike a turbulence which can be an unstable load.
EmotionalBrontosaur@reddit
…that’s a lot of stain!
hatlad43@reddit
That's some turbulence, innit?
Ok-Mud3439@reddit
One Fifty-Four
Mihnea2002@reddit
You should see the 787 wing flex
oktsi@reddit
This is what made me an Avgeek. First time seeing the wing of A320 flexing like crazy when I was 10-yr-old and it made me fall in love with aviation.
Which_Material_3100@reddit
I flew various versions of the 737 through the MAX for several years. I call it the “Memphis Belle” because it’s relatively dirt simple, rugged and quite reliable. Its wing loading sucks during turbulence for passengers though. But it’s a good, tough plane
HarryFuzz@reddit
A lot of people don't realise that the wing isn't flapping around, the fuselage is bouncing up and down between the wings. It appears this way because the camera is located in the fuselage.
allez2015@reddit
Mmmm sorry, no, that's not entire true.
dpdxguy@reddit
Many years ago I saw a video of Boeing's stress-to-destruction test for the original 747 wing. It was insane how far that thing flexed before breaking.
I just searched and couldn't find that video. But I did find op's video in YouTube: https://youtube.com/shorts/59wPLzyn4O8
_Yellow_13@reddit
One of my fav things is looking back and seeing them flex when flying 🖤 737 is a dog but always a soft spot.