An airliner's external doors are designed such that they're held closed by internal pressure. Thus opening a door on the ground is pretty easy, which is convenient because that's the only place you should open them. But opening at cruise is extremely difficult.
Now - a strong person can do it when the plane is far enough up that it's very scary, after all some normal passenger airports are a few thousand feet above sea level and we want the doors to work there. But you won't open them at cruise.
All the normal doors on an aeroplane are fire doors so they can't be locked from the inside.
> after all some normal passenger airports are a few thousand feet above sea level and we want the doors to work there
That doesn't make sense.
Regardless of airport altitude, when the pilot shuts off the cabin pressurization and opens the cabin vent[s] there will be zero pressure across the door.
The cabin doesn't "remember" the pressure at the last airport, because it's not a sealed volume. The air is constantly being replaced from outside, and the pressure is constantly being regulated.
> Now - a strong person can do it when the plane is far enough up that it's very scary
Is this true? Some back of the napkin math: An airliner crusing at 30,000 feet is in air at about 0.3 ATM. Cabins are pressurized to about 0.8 ATM, so net air perssure is about 0.5 ATM. That's around 7 lbs/in^2. An airliner door is about 72"x42" for a total of around 3,000 in^2. So you need to be able to lift about 10 tons to open it. That would be a very strong person indeed.
> after all some normal passenger airports are a few thousand feet above sea level
The parent commenter is referring to airports at high elevations. They mean to say that opening the doors is almost impossible at cruising altitude, which is far above any airports. Hence, the doors can only be opened when not on the ground during early ascent and late descent.
You are agreeing with him, he says you can't do it at cruising altitude.
He says you can do it high enough to be scary, but opening the door 100ft before landing would probably cause panic even if it isn't all that dangerous.
Didn't that happen in a plane recently? There have been so many random issues in the air lately, especially with the Boeing planes... so I may be misremembering, but I thought some guy opened the emergency hatch and the plane was up there pretty high at the time.
Paused my reply and took a moment to search. Looks like I was right and wrong. The plane wasn't very high in the air, only about 700 feet. A man did open the emergency hatch, though. [1]
"He allegedly opened the door of the Asiana Airlines plane when it was 700 feet (213 metres) above the ground."
That's a key point - at cruising altitude you'd need to push an equivalent of 2 tonnes of weight to open it - it's just not happening. Obviously even at 200 metres up in the air I bet it was incredibly scary.
Most planes have doors designed in a way that make it impossible to open them while there is significant overpressure in the cabin. Some do have interlocks.
The main risk is the door or the passenger opening it hitting something critical. Otherwise, you can primarily expect some injuries from stuff flying around, barotrauma to the ear, and an emergency descent, but not an "everybody dies" scenario.
Unlike the hatch on the space shuttle, airplane doors open in, and cabins are pressurized at ~10psi, so it's not likely that a person would succeed at doing it before getting tackled by crew and passengers.
That such incidents don't happen more often in commercial aviation may give us some comfort, but in reality, there have been many attempts by passengers to open an emergency exit door in flight. (Fortunately, it's almost impossible at cruising altitudes).
For added context those doors open inward and the pressure differential between the cabin and cruising altitude is such that you would literally have to be superman to do it. When it does happen it's always at relatively low altitudes.
Russia made the best move to get Finland and Sweden to join NATO. Did NATO hire Putin?
It almost seems like some sort of reverse psychology thing… Russia saying "We forbid you to join NATO" is one of few things that would get these countries to join NATO. "Don't tell us what to do!"
He's been very clear: before the second Ukraine invasion he criticised Lenin for allowing the SSRs to exist and for accepting the loss of Imperial Russia by e.g. accepting Finnish independence. His ambition is to restore Russia to (at least) its pre World War I borders, which would involve the obliteration of nations such as Ukraine and Finland.
Up until now he has zero push back on the butcheries in Chechnya, little pushback on previous atrocities in Ukraine or Syria or shooting down civilian airliners, and he no doubt expected the same this time around.
Why it has to be Putin's play? A lot of people seem to take for granted that Putin knows what he is doing and has a long play with an eventual win.
History is full of leaders making terrible mistakes that eventually put the last nail in their coffins, I don't understand why some think that the only possible option is that there must be something that we are missing because Putin is so smart and has so much control that this can't simply be a huge fail on his part
The boring database favored by engineering managers is Postgresql.
React + MobX provides, I think, a good answer to the problem of "how do i update the user interface to reflect changes to the application state?" on the front end.
Commercially I have seen Java used almost exclusively for web back ends, really because it handles the kind of concurrency that matter for servers well. .NET is about the same but less popular.
It is easy to write small servers in Python and you can do really fun things with async/await (e.g. bridge message queues) but because Python is fundamentally single threaded the concurrency story is worse than Java. With node.JS you could write both your front-end and back-end in the same language, which sounds appealing, but hardly anybody does it.
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