I'm more surprised the wing rupture didn't cause a fire/explosion because this is where most of the fuel is stored.
Hell even in a crash landing like this you want the plane to stay upright and stable.
They know how much peak load is supposed to be for the airframe, then they go well beyond it to see how the plane fails. Generally you want the wings to break not the fuselage.
You can in a lot of situations land a plane with 1.5 wings. But once the spine cracks you’re just a ballistic object.
I used to work at Boeing on the 757 stabilizer trim system. There's the design group and the stress group. I was in the design group, the stress group double checks the design work.
One day the stress group called me on the carpet, and asked me why my designs consistently just barely exceeded 150%. I said I started with the ultimate load, and worked backwards to size the part. The stress groups said they prefered designs to be 10% over the ultimate load. I replied that I designed to the requirements, as adding 10% makes the airplane overweight. If they didn't like the design requirements, change them.
They grumbled, but I got my way :-/
A few months later, they offered me a position on the stress group. It was a nice compliment, as they normally required a masters' degree and I only had a bachelors. I told them I was honored by the offer, but my heart was in design.
Some time later, my parts were put on the torture rack to see if they passed the ultimate load test. All of them passed on the first try.
I also had the privilege in being mentored by some really fine engineers at Boeing, such as J Burton Berlin and Erwin Schweizer.
Am I proud of that? Yes. I love flying in the 757. Best airplane Boeing ever made. Whenever I fly in them I chat a bit with the flight crew, and they love it, too.
Have you shared your thoughts on MCAS? I feel like there are a lot of potential lessons that got missed for all the noise.
The 737 is an electric drive, with a manual backup. The 757 is a scaled down version of the 747's dual hydraulic drive, no manual backup.
More efficient wings and engines obsoleted the 757.
Thanks for making the D programming language. If it did not insist on a GC and had a robust and stable GC-free stdlib, I believe it could have conquered the world.
BTW, the GC makes the compile time function execution sweet and easy.
If anyone is wondering, this is always the correct answer when there’s a disagreement between reality and the specification and you’re following the spec.
I don't know enough about the details of the CRJ-900 to say for certain, but in general aerospace engineering does include considerations of this sort, where if a component breaks off you want to ensure that it separates in a specific way.
from an Admiral Cloudberg article [0] about El-Al 1862 [1]:
> The Boeing 747 engine pylon is attached to the wing by four fittings: one at the front, one in the back, and two in the middle (or midspar). Each of these fittings consists of a wing-mounted male lug and a pylon-mounted female lug, which are connected by a fuse pin. The four fuse pins are the weakest part of the pylon, but this is by design. Every airplane system and structure contains planned failure sequences which work to minimize damage in the event of an overload. In the case of the 747’s engine pylons, the fuse pins were designed to fail at a lower load threshold than the fittings themselves, ensuring that if the engine is torn off the wing — perhaps due to extreme turbulence, or a gear-up landing — the fuse pins will fail first, causing the engine to separate cleanly without ripping open the fuel tanks located directly above it. In theory, this should allow an engine to break off upon reaching its design load limit without starting a fire or otherwise compromising the plane’s ability to fly.
0: https://admiralcloudberg.medium.com/concrete-and-fire-the-cr...
The integrity of the wings is a function that supersedes just about every other possible thing on a plane. You can safely land without any engines. You can safely land without hydraulics. You can safely land without gear. Without wings, a plane is a brick.
The engines are built to rip off cleanly, because when they don't, they have caused https://en.wikipedia.org/wiki/American_Airlines_Flight_191 and https://en.wikipedia.org/wiki/El_Al_Flight_1862 which were fairly serious and catastrophic accidents at least partially caused by the engines tearing off and damaging the wing in such a serious manner as to cause a stall and crash. The wings stayed on the aircraft in both instances. Interestingly, both accidents were caused by those same sheer pins being damaged in minor and unpredicted ways.
I highly doubt the wing is DESIGNED to cleanly separate. Planes are just very not rigid for something going such a high speed, and so tend to turn into confetti when faced with a harder surface, like a runway or a concrete building. Usually the only parts that survive serious crashes are the landing gear struts.
The fuselage couldn’t take a fraction of the stress the wings are designed to endure.
https://simpleflying.com/minimum-fuel-requirements-definitio...
If an aircraft is anticipated to land with fuel for 30 minutes or less they must make a mayday call, and there's an incident report to fill in.
Yes they want to land with as little fuel as possible, but regulations require them to carry more because we know what happens when you let airlines carry less.
It isn't on any aircraft I've heard of. Only the engines have "fuses" which allow an engine to rip itself off without taking the wing with it.
The wing root is the strongest part of the airplane (because that is where the maximum forces are).
If the engine loses a fan blade, it will vibrate violently and it's probably better to lose the engine.
I don't know about the other two things you mention. Maybe it's a newer feature than my time :-/
That's the idea with a fan blade loss, they didn't want to just drop an engine in that case so the centering mechanism on the turbine has an intentionally weaker part is designed to snap off to allow the spinning turbine to recenter itself as opposed to vibrating the whole structure off and causing more damage.
The gear thing is to prevent puncturing the fuel tanks in the wings on a hard landing. It's preferable to snap off the gear, otherwise leaking fuel has a good chance of it immediately igniting.
But yes, in a full size passenger aircraft I would expect the specification for wings falling off to say "avoid"
I’m guessing wind, ice, or something else moved the plane off the centerline and into a crab, it hooked a wheel off the pavement, and cartwheeled. 100% conjecture at this point, just seems like a possible chain of events.
Edit: listing to the ATC audio I think they said gusts in the 30s (man do they ever speak fast and mumble! Enunciate damn it! Unique New York), which is markedly slower than what the Apple Weather app reported for Pearson.
33kt/hr * 1.15mi/kt * 1.609km/mi ~= 61km/hr.
The weather app was right. Just different units.
https://people.com/new-video-dc-plane-crash-shows-final-seco... was an airport camera, IIRC.
It looks like the video is taken from https://www.youtube.com/watch?v=VaIL2UOX4ss - it says it's "Kennedy Center Cam", it also wobbles, but that's probably wind. But yeah, it's not an airport camera.
https://www.reddit.com/r/Damnthatsinteresting/comments/1isa8...
Does nobody have a sense for the dramatic?
https://cdn.shopify.com/s/files/1/2604/4866/files/5aedc13c-3...
It's likely not a morbid curiosity here, especially since noone died AFAIK, but genuine technical curiosity so he can see what happened, and perhaps educate us readers.
Back in my 757 days Boeing ran individual wires for everything. I suggested using a bus to save weight and improve reliability. I just got blank looks in response. Modern cars use a bus now, and probably the airliners do, but I have no direct knowledge of it.
The thing about cameras, though, is you can buy an HD dash cam for $100 that records in a loop. Buy it, plug it in, and point it at the runway. It doesn't need anything beyond a wall socket.
If I was an ATC sitting in the tower, I'd probably just install one myself.
This kind of footage of an aviation accident should not be left to chance.
You seem to know a lot about him, which indicates you bravely made a throwaway to write this drivel. Please seek help. In the meantime, I do hope our lone mod IP bans such low effort members.
I recommend using actual quotes when quoting. Otherwise people might think you're just making things up.
I think parent was saying the roll was along the planes' length rather than tail-over-nose, the latter usually result in the aircraft breaking up as the torque will be really high.
- longitudinal axis: roll, controlled by ailerons.
- vertical axis: yaw, controlled by rudder.
- lateral axis (through the wings): pitch, controlled by elevators.
In larger aircraft that do have the ability to dump fuel, the reason is to make the airplane lighter so it does not have do an overweight landing and the subsequent high-cost overweight landing inspection. It is not done to reduce the probability of a post-crash fire.
Unless you're a checked bag.
They are in shock and acting on instinct. I’d like to believe I’d do better but who knows.
It’s probably not that, but is possible.
Perhaps a fanny pack would be a better idea:
People with T1 either have insulin pumps attached, or long-lasting insulin injected. They are not going to keel over from lack of insulin on most days, even if their pack is gone. Except if the pump stopped working hours ago, or they forgot to inject. Then they may be close to collapse already. And being away from sugar can become life-threatening quickly for people who shoot insulin. So overall they have a pretty good reason to always carry their stuff, even in an emergency. And yes, better always attached than in some bag than can get lost easily.
This might not be new or exclusive to Canada - it's just the first I've noticed it.
Not Canada-only:
> So sorry for the disappointment with the carryon requirements. Please know that your fanny pack is considered a personal item and must be stowed properly during taxi, takeoff, and landing. Still, we understand the frustration and have documented your concern.
* https://twitter.com/SouthwestAir/status/1796641027924889819
* https://viewfromthewing.com/stupid-airline-carry-on-rules-if...
It may be a case of people abusing things and instead of a 'small' pack, they have a 'regular' purse and are trying to call it fanny pack. Then actually have a purse / personal item and a carry-on.
It also goes without saying that you should keep in on while showering and sleeping too, you never know when your hotel could catch on fire.
You'll need to first avoid succumbing to smoke inhalation or flames if you don't get out in time (or cause someone else to not get out because your fumbling).
The take-offs and landings (and perhaps add approach) phases of flight constitute ~5% of flight time, but the vast majority of the fatalities:
* https://flightsafety.org/asw-article/loc-i-accidents-led-oth...
But the whole point of all those procedures about turning stuff off and putting things is away is situations like this: you may or may not have time to think, and you may or may not have to deal with smoke or flames. And just because there weren't smoke/flames right at that moment, you can't tell if they would arrive "soon": planes have been completely engulfed in fire with-in 90 seconds in the past.
The idea behind suggesting a fanny pack, and perhaps having all your cards and papers (and medicine) on your person, is so that if such a thing should happen you do not have to think to make sure you have what you need. So that in a panic you already have it with you if you get out just by the fact you got out and it was physically attached to you.
Your points are well reasoned—and I believe well-intentioned—and I should’ve done better. I apologise.
People die in hospital waiting rooms. Why risk it when you know you have everything you need right on hand? At this time in the video the situation looked to already be fairly under control. Worrying about recording a video on your phone to post to social media before you’re even out seems worse.
Because people also die in incomplete airplane evacuations. In the Aeroflot Flight 1492 crash, 41 of 78 occupants died while folks were seen evacuating with their bags. Some of them would have died no matter what, but somebody slowing down an evacuation from a serious airplane crash for even just seconds to quickly grab their insulin kit out from under the seat in front of them (let alone to film for social media or whatever else) could cost someone else their life.
The situation might look "fairly under control", but the plane is upside down, leaking flammable jetfuel, and surrounded by firefighting foam that no one wants to spend more time around than they have to. Leaving behind medical supplies in a crash has a real impact on a diabetic or similar, but any slowdown to the evacuation also has a real impact on all of the other passengers.
A "pancreas kit" can fit in a bag small enough to be carried in one hand, so it shouldn't be necessary to hold up an evacuation by carrying something large. As others have mentioned, this is also likely an instinctive reaction, and it's hard to criticize someone for reacting that way in such a stressful situation.
In Hawaii we were robbed with my girlfriend and went to a pharmacy and to doctor with no papers and we weren't able to refill our contraception pill (pharmacy told us to go to doctor, doctors said we need a lot of tests even though she was already taking the medication and we had police reports). Generally it's not advised to skip a day, and skipping 2 is not allowed, but doctors didn't care.
(after a lot of search we found out that Amazon online clinic is much better and even cheaper with prescriptions).
In latin america or Thailand or anywhere else in the world we could just go to a pharmacy and get what we want.
You may not survive a day without insulin, but the people behind you might not survive the next few seconds if they can't get out in time because you were fumbling with a bag
You don't know what's in that luggage. Maybe it's hard to source medication. Maybe it's very important legal documents. It's clearly not big enough to be typical low value personal belongings. The plane isn't even full of smoke yet.
>The plane isn't even full of smoke yet
The plane previously had some pretty impressive flames in the process of landing, and depending one what sort of fire gets going there might not be time for everyone to get out. That being said, insulin isn't actually a valid excuse nor are very important legal documents. Every second counts, and could be the difference between life and death for passengers and crew not yet evacuated. There's a reason that air traffic controllers ask pilots in emergencies for the number of "souls on board" referring to living humans and not important legal documents or medicine.
In the case of this aircraft not only were the maximum number of lives saved but the some people also got their luggage reducing the sum total of BS and PITA the passengers involved had to endure. This is a superior overall solution than following the "rules" because that solution would have saved the same number of lives and increased the overall PITA because a greater number of passengers would have been without their luggage.
Basically the people involved rightly judged they could allocate some resources away from GTFOing and allocate them toward PITA reducing and we're all screeching about it like idiots because had the situation been different they would not have been able to make such a tradeoff and get the same results.
This entire topic of comments is in the same category as complaining about people ignoring the speed limit on empty highways or hopping some queue control ropes to skip a bunch of zig zagging when the queue is short enough they're not cutting anyone by doing so.
Of course the solution would be to make airlines liable to replace passengers' luggage in the event of a crash and inform the passengers that they will do so, but that's not how the world works currently.
Aren’t they? AFAIK it’s standard (if not required?) for airlines to have insurance which includes passenger legal liability.
Were there any recent crashes where passengers weren’t compensated? e.g. after US Airways 1549 everyone received at minimum $5k (or higher depending on damages) for lost luggage.
Airline customer service standards are very low; I can see how a person making the decision based on just their experience with airlines would conclude it was better to grab their carry-on if it was safe to do so.
I give zero shits if you think you’re going to lose your stuff. And you should give zero shits if I’m going to lose mine.
Don’t act like this is a class / means thing. It isn’t. This is just Americanism.
Yeah, last time an airline lost my bag they said pretty much the same thing.
The way I see it, there are two types of idiot:
You're an idiot if you delay the evacuation of a crashed plane. Shit's on fire, yo.
And you're an idiot if you expect an airline will make you whole. Airlines are in the business of delivering the worst customer service they can get away with - they don't even guarantee that a person who has booked a seat on a flight will have a seat on the flight.
The DMV is pure customer service.
Airlines are "applied" customer service since they actually deliver a service there is demand for.
Customers have been trained to stop and think twice when someone tells them what to do. That's just the reality of the world we live in.
If you think this is bad, I guarantee you could play out this scenario in roughly 3/4 of the world and it would be worse.
On international flights, an airline is liable for up to $1700 per the Montreal Convention. This might cover say half of one's laptop, which no matter how stupid it sounds, makes taking your luggage with you the only financially sensible choice in a crash (unless you have insurance). Now obviously such an event has other priorities than just financial ones, but it's no surprise if people choose to take their luggage with them.
On US domestic flights the amount is somewhat higher, $4700. However even this might not be enough for some. On EU domestic flights it's 1800€.
Airlines however are free to pay any amount they want, but they are not legally required to pay more than the limits set by law. So it is possible you will be reimbursed in full, but you wouldn't know that beforehand.
If there's no smoke, no visible flames, and you can do so safely without obstructing other passengers' egress? I can see the argument, sure.
Obviously if the cabin is filling with smoke or there are visible flames or other obvious dangers, the financially sensible choice is to evacuate ASAP as funerals often cost more than laptops.
I guess my argument mainly is that people who take their luggage are not stupid, instead their behavior may be highly rational, however we have the means to change it with by making such choice irrational and I wish we will.
I agree with your parent’s post explaining its a sensible financial choice. However as you noted there’s other things One could consider like other’s passagers survival chances or firefighter taking dangerous steps during their work.
Taking your language is financially sensible but socially dumb and selfish. It seems an acceptable choices in the countries that values individual liberties and financial independence, but the other half of the world look very bad at that behavior.
The best anyone here can do is screech about not following the default suggested practice of leaving the luggage but the person who took the bag was actually there. Perhaps they had to pick it up because it was on the floor (ceiling) in their way. Not much harm in carrying it if it's something that small anyway.
I’ve realized that fires are a way bigger issue than you might imagine after a crash — things can go south really quickly. Multiple stories of planes going from “fire outside” to “people suffocating and burning to death in their seats” in minutes. Here’s one of a 737 in Manchester, taxied of the runway intact, 55 people died: https://admiralcloudberg.medium.com/fire-on-the-runway-the-m...
I might have taken my laptop bag in such a case out of habit before reading these stories, not so much now.
While there are no smoke/flames now or initially, that doesn't mean they won't appear "soon": planes have been completely engulfed with-in 90 seconds.
$3400 is a pretty pricey laptop for someone short on cash.
Also, am I correct in understanding that these requirements are the base requirement for any crash and don't actually absolve the airline of the full liability in case they are found to be responsible for the crash?
One person's means are not more important than the lives of the people on board. Stuff can be replaced; get everyone to safety first, then worry about stuff.
And yeah airlines are liable to replace stuff in the event of a crash and pay for damages if it's their fault. If it's the fault of the airplane manufacturer, they will have to; Boeing paid out billions to all parties involved in accidents and groundings of the 737 max:
> On January 7, 2021, Boeing settled to pay over $2.5 billion after being charged with fraud over the company's hiding of information from safety regulators: a criminal monetary penalty of $243.6 million, $1.77 billion of damages to airline customers, and a $500 million crash-victim beneficiaries fund.
https://en.wikipedia.org/wiki/Financial_impact_of_the_Boeing...
People like to imagine how they would act in an extreme situation that is unique and beyond anything they have ever experienced before. But the reality is people do very poorly most of the time without regular training. In a crash, the adrenaline is flooding your body, and most people are not “thinking” much at all. You know you need to get out but your brain is barely processing, so what do you do when you exit a plane? You grab your luggage and head for the door.
Flight attendants giving simple, clear, easy to follow instructions is partly because people are not thinking and processing properly and need help doing things that would be easy in a non-emergency situation.
Also, there was an emergency a few years ago where a jet lost cabin pressure, and people were getting dragged on social media afterwards for not putting the oxygen masks over their noses.