• Contravariant@lemmy.world
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      3 months ago

      Heck if accelerating to Mach 19 in about 2 meters is acceptable you could just disable the rotors and only experience an acceleration of less than Mach 1 in just a few meters.

      • BluesF@lemmy.world
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        3 months ago

        What about that fancy thing that stops table saws when you touch them? Just get one of those and stop the rotors. I’m certain there’s no physical reason this wouldn’t work.

        • dashydash@lemmy.world
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          3 months ago

          The energy will have to go somewhere, so the passengers can stand up with their arms stretched, and when the rotating energy reaches them they can jump out and they will start spinning and their arms will act as rotors keeping them in the air long enough to reach land safely. You just need to make sure there aren’t a lot of people on board because the energy will have to be divided on all of the passengers, if there isn’t enough for everyone, they will fall to their death.

          • Mongostein@lemmy.ca
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            3 months ago

            The energy can go in to ejecting the seat!

            If it requires the energy of the rotors being stopped suddenly to eject, there’s no chance of getting filleted

    • Madison420@lemmy.world
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      3 months ago

      When helicopters lose power they just fall. If the rotor head isn’t decapitated then when you get ejected sideways there’s s no zero chance you’ll be julienned on the way down.

      It’s why the most (only version currently in operation) common method of helicopter ejection severs the head or blades while it’s still rotating so it/they spin off and hopefully away and then the seat rockets away.

      • Summzashi@lemmy.one
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        3 months ago

        Your first sentence is wrong. Stop explaining things you don’t understand yourself.

        • Madison420@lemmy.world
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          3 months ago

          It’s a fact. Helicopters in general do not have the ability to glide to a landing, they can auto rotate if the rotor is still moving and has enough momentum. If the rotor stops or detaches helicopters fall…

          • psud@aussie.zone
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            3 months ago

            “if the rotor stops” luckily in this universe we have conservation of motion so the rotor doesn’t typically stop in flight

            Sure though, were it to detach the helicopter would fly like a brick

            • Madison420@lemmy.world
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              3 months ago

              Hubris isn’t looked on Kindle in the aviation world.

              Not common doesn’t mean not possible, we teach autorotation for a reason and it’s not because everything happens perfectly and every aircraft is perfectly maintained.

              Helicopters crash constantly and just as an fyi auto rotation is falling with style and so is glide.

              Like I said helicopters just fall, an aircraft in the most extreme engine failures tend to be able to glide effectively helicopters can never count on that luxury. So I dunno, since you agree maybe hop off the high horse and apologize.

              • psud@aussie.zone
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                3 months ago

                I’m terribly sorry that I pointed out conservation of momentum in a thread where you want to imagine helicopter rotors can just stop. I know that reality is inconvenient.

                • andrewta@lemmy.world
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                  3 months ago

                  You are failing to ask him a question: how does he know what he’s talking about?

                  His phrase was “we teach” which implies he’s an instructor. You should ask him if he is.

                • Madison420@lemmy.world
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                  3 months ago

                  Being wrong is the issue.

                  Rotors can add have seized, rotor failure is actually one of the more common modes of failure in a helicopter. Also notably I didn’t say it had to stop just that the rotor is no longer effective, like catastrophic blade loss.

                  • Summzashi@lemmy.one
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                    3 months ago

                    You said helicopters “just fall” when they lose power. That’s what spawned this tangent. You didn’t specify anything about the engine being seized, which is an additional issue.

                    You are moving the goalpost, and asked someone to apologize to you for it. You’re a clown mate.

        • Madison420@lemmy.world
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          3 months ago

          Autorotation relies on one main thing, air being forced past a freewheeling rotor… Air that is being forced past because you’re falling.

          https://youtu.be/NLjFQJiJsZc?feature=shared

          Notice the immediate loss of attitude? It’s because they’re falling, unlike planes which can generally glide after an engine failure.

          https://youtu.be/CEMlny_ExuU?

          Specifically we’re speaking about helicopter ejection which in most cases means total loss of power or control or both. The only known helicopter eje tion seat(to me at least) to operate currently in modern combat is the ka 50/52.

          https://youtu.be/W6y_id3xOX0?

          One like this one which happens to eject and notably falls like a stone.

          • SSJMarx@lemm.ee
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            3 months ago

            The KA-50 and -52 destroy their rotors when the ejection seat fires, as shown in this simulation. That’s why the helicopter drops like a rock after the ejection seat fires - the blades can’t autorotate if they’re not attached.

            Assuming the blades are still attached, the helicopter will autorotate down even if it is completely unpowered. It might lose some altitude initially, but like you said once the air is moving over the blades fast enough for them to spin they will do what they were designed to do.

            One thing helicopters and planes have in common is that if they fail too close to the ground autorotation/gliding won’t help. Helis are generally more dangerous than planes for a lot of reasons, the biggest one being that they spend more time in the most dangerous phase of flight - landing.

            • Madison420@lemmy.world
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              3 months ago

              Tell me you didn’t read the root comment without saying you didn’t read the root comment.

              When helicopters lose power they just fall. If the rotor head isn’t decapitated then when you get ejected sideways there’s s no zero chance you’ll be julienned on the way down.

              It’s why the most (only version currently in operation) common method of helicopter ejection severs the head or blades while it’s still rotating so it/they spin off and hopefully away and then the seat rockets away.

              Losing altitude can be described as falling because the fucking thing is unpowered.

              Agreed, though irrelevant.