Re: [Sursound] about aviation [ot]
Sampo, to still answer this "personal posting" below (and then taking the discussion offline...): The (also) Swedish pilot I know has been both a military pilot and some (civilian) pilot. I know that he has worked in a very professional sense on air traffic safety. (Means: He has been on security "boards"/committees.) So I don't care if I am an aviation layman or not, but compared to him we are probably all laymen. Regarding avoid death spirals, you might "learn" about how to avoid these, via YT channels and other means. ;-) Do you really think that any modern passenger airplane should come even close to any such a state? (I mean, there are potent autopilots nowadays.) This is why you have sensors, automatic plane stabilization, etc. In this sense I also don't quite know why we are discussing these issues here. It seems to be a special air safety "issue", and of course this should not happen. Regarding military airplanes, these are aerodynamically relatively unstable - which actually is a feature. Even in this case the main safety issue is certainly not some death spiral. (Rather: to crush into a tree or mountain, because you were flying just "a few meters" too low? But this is more for the military aviation case, I guess...) We can happilty discuss ALL these issues between us, and I will happikly add Anders to the discussion. (Who might know the "young Swedish pilot discussing security stuff on YT for laymen", probably.) ""But whoever cares, really?" "We should. Because none of us wants to drive an aircraft into the ground, or a mountain." Frankly, I trust in Airbus and "my pilot". (Because I am not better than them...) Best, Stefan - Mensagem de Sampo Syreeni ----- Data: Wed, 1 Mar 2023 05:04:53 +0200 (EET) De: Sampo Syreeni Assunto: [Sursound] about aviation [ot] Para: Surround Sound discussion group On 2023-02-22, Stefan Schreiber wrote: Maybe it is me who now really would need some crash course in aviation, Yes. Is flying in a spiral not something you would do in some intentional way? Sometimes you might do it purposely, yes, but no, you typically would not do that sort of thing willingly. Because it's *highly* dangerous. Most likely if you go there, you will dive, and then die, with no means of recovery. You'd crash yourself and all of your passengers. https://en.wikipedia.org/wiki/Graveyard_spiral Stefan, lately I've been minding the Mentour Pilot channel on Youtube. The guy doing that is a Swedish pilot, used to piloting the Boeing 737, and not so much anything AirBus. He then also takes down *all* of the disasters which have happened in the recent decades, talking down and analysing what happened in talk and instrumentation. I'd thoroughly recommend that Swedish Chef. He's stupendously good, physically minded, all of it. He knows what he does. In fact, just now, within weeks, he took upon himself to spin a 737 in a simulator, upside down, going into an upset and something which could go into a lateral spin. "Yes, you can do it, but..." https://www.youtube.com/watch?v=JhzaogGQNFU Then on the other hand... https://www.youtube.com/watch?v=AaA7kPfC5Hk Everybody thinks this sort manoeuvre is hazardous. Whereas it isn't: a barrel roll is just a 1G monoeuvre with pretty much no risk at all. An aileron roll carries much more risk, and is much more difficult to execute properly. Flipping a helicopter is harder, but not *much* harder; these aerodynamics go to superavionics and high control, of the kind leading to such movements as the infamous Pugachev Cobra ( https://www.youtube.com/watch?v=kcLavSl58yQ ). Of course, there will be more. One of the things here is active parametric arrays. To order twenty or more, in military radars, such as there are in the F-36. Those AESA's work interferometrically just as would a high order coherent ambisonic rig. They only do so at VHF/UHF/Ka-band fŕequencies, in radio, at about 2000-6000 closely spaced "speakers"/transmitters, all of them spaced about a quarter of a wavelength apart. Each of them doing gigabits per second, and maybe a 50W max. In toto, some continuous 100kW in software defined radio, in intermittent, fully superfast transmittance and receivership. Opposite to the spin situation, because this is kind of uncontrolled. Or you "have to do something".) I've never flown a plane. Yet I think I could recover a plane from such a spiral. What you do there is: 1) you push down on the yoke to recover airspeed, 2) you use ailerons to level off, and 3) if you then have to go to too much airspeed while descending, you'll spoil your airfoil, and then apply lift and drag via flaps, while not approching aerodynamic stall. So in which sense wo
Re: [Sursound] about aviation [ot]
On 2023-03-01, Fons Adriaensen wrote: What you do there is: 1) you push down on the yoke to recover airspeed, Do that if you want to crash even sooner. You also do that in order to avert an impending stall. 2) you use ailerons to level off, You need to use ailerons, but certainly not to level off. To level off from the spiral or as the case may be, from an excessive roll. The fall is an another matter, to be dealt with separately. 3) apply lift and drag via flaps Your flaps may be ripped off if you do that. That's why you don't apply them in full, or willy-nilly. This is all *so completely wrong* that I don't know where to start to correct it. Is it, though? I kind of think I know what you are talking about in pilot training. However what I'm talking about is the optimized control law of a modern fly-by-wire fighter jet, or say something like an Airbus jumbo. Especially the former *will* know it's aerodynamically "unstable" (so as to say it's more "general" in its solution), so that in general the optimum path back from a death spiral will almost necessarily go through things like intermittent stalls on all flight control surfaces. Sure, human pilots typically haven't been trained to do anything of the like. Commercial pilots probably shouldn't, at all. But if you think about how to control an aircraft in full, how to control its full state space while observing the same, control theory wise, you'll fast see the easy and safe manoeuvre taught to pilots is *not* the optimum one. And in fact it's not what highly automated fighter jets such as the F22 or the F35 really do; nor does any one of the modern Airbus jets. They in fact employ spoilers and sometimes even flaps, by automation, they do pull down even in a heavy spin in order to preserve planform stressess, and so on. Fons, surely it shows I've not flown an aeroplane in my life. But at the same time, it surely also shows you've never written a line of code which would automatically and optimally take an airplane optimally out of . (Neither have I. But at least I've thought about it all, rather systematically and seriously. I even see immediate solutions which the pilot academy does not; say, spoiling your energy from the death spiral by putting your craft into maximum structurally permitted overall stall. You *can* do that and recover from it, you know.) I posted the essentials of getting out of a spiral a week ago. Please then post a link into the archives. Apparently I could benefit from them. -- Sampo Syreeni, aka decoy - de...@iki.fi, http://decoy.iki.fi/front +358-40-3751464, 025E D175 ABE5 027C 9494 EEB0 E090 8BA9 0509 85C2 ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit account or options, view archives and so on.
Re: [Sursound] about aviation [ot]
On Wed, Mar 01, 2023 at 05:04:53AM +0200, Sampo Syreeni wrote: > I've never flown a plane It shows... > What you do there is: > 1) you push down on the yoke to recover airspeed, Do that if you want to crash even sooner. > 2) you use ailerons to level off, You need to use ailerons, but certainly not to level off. > 3) apply lift and drag via flaps Your flaps may be ripped off if you do that. This is all *so completely wrong* that I don't know where to start to correct it. I posted the essentials of getting out of a spiral a week ago. Ciao, -- FA ___ Sursound mailing list Sursound@music.vt.edu https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit account or options, view archives and so on.
[Sursound] about aviation [ot]
On 2023-02-22, Stefan Schreiber wrote: Maybe it is me who now really would need some crash course in aviation, Yes. Is flying in a spiral not something you would do in some intentional way? Sometimes you might do it purposely, yes, but no, you typically would not do that sort of thing willingly. Because it's *highly* dangerous. Most likely if you go there, you will dive, and then die, with no means of recovery. You'd crash yourself and all of your passengers. https://en.wikipedia.org/wiki/Graveyard_spiral Stefan, lately I've been minding the Mentour Pilot channel on Youtube. The guy doing that is a Swedish pilot, used to piloting the Boeing 737, and not so much anything AirBus. He then also takes down *all* of the disasters which have happened in the recent decades, talking down and analysing what happened in talk and instrumentation. I'd thoroughly recommend that Swedish Chef. He's stupendously good, physically minded, all of it. He knows what he does. In fact, just now, within weeks, he took upon himself to spin a 737 in a simulator, upside down, going into an upset and something which could go into a lateral spin. "Yes, you can do it, but..." https://www.youtube.com/watch?v=JhzaogGQNFU Then on the other hand... https://www.youtube.com/watch?v=AaA7kPfC5Hk Everybody thinks this sort manoeuvre is hazardous. Whereas it isn't: a barrel roll is just a 1G monoeuvre with pretty much no risk at all. An aileron roll carries much more risk, and is much more difficult to execute properly. Flipping a helicopter is harder, but not *much* harder; these aerodynamics go to superavionics and high control, of the kind leading to such movements as the infamous Pugachev Cobra ( https://www.youtube.com/watch?v=kcLavSl58yQ ). Of course, there will be more. One of the things here is active parametric arrays. To order twenty or more, in military radars, such as there are in the F-36. Those AESA's work interferometrically just as would a high order coherent ambisonic rig. They only do so at VHF/UHF/Ka-band fŕequencies, in radio, at about 2000-6000 closely spaced "speakers"/transmitters, all of them spaced about a quarter of a wavelength apart. Each of them doing gigabits per second, and maybe a 50W max. In toto, some continuous 100kW in software defined radio, in intermittent, fully superfast transmittance and receivership. Opposite to the spin situation, because this is kind of uncontrolled. Or you "have to do something".) I've never flown a plane. Yet I think I could recover a plane from such a spiral. What you do there is: 1) you push down on the yoke to recover airspeed, 2) you use ailerons to level off, and 3) if you then have to go to too much airspeed while descending, you'll spoil your airfoil, and then apply lift and drag via flaps, while not approching aerodynamic stall. So in which sense would you have to "recover" from the spiral? You need to see which attitude you're at. You will need to put slight ailerons in the opposite diretion. You'd be falling and you'd need to follow your airspeed. If too much, you'd have to even spoil. If not, you'd need to increase thrust in order to gain kinetic energy. In any case, you'd want to keep yourself at about 160-200 knots of equivalent speed and so kinetic energy, in order to stabilize the aircraft, and then level off. I read this before, btw: "But whoever cares, really? We should. Because none of us wants to drive an aircraft into the ground, or a mountain. We all know what we're talking about. I know. Do we all? Especially when you have to use the instrument in order to deliver yourself and your passengers from a death spiral." One of these things really is the death spiral. The thing here is that you don't *feel* at *all* that you're in it. It's kind of like the barrel roll, at one G. It's just a manoeuvre or a mistake, which feels like nothing bad is happening. Yet if you don't follow your instrumentation, you might be going into a death spiral. (This is why the synthetic horizon in an airplane *is*. You're supposed, as a pilot, to follow it, precisely *because* when it isn't level while you feel level, *then* you're off in your feelings. You might be going into a dive or spiral, and you're supposed to fly by meters/instrumentation, not by your seat. So what is this spiral? A situation when the plane is spinning, even a stall (interruption of air flow), or what else? The typical death spiral isn't a stall at first at all. Rather it's a continuously advancing bank to either side of the airplane. As a pilot, you won't feel it happening, because the airplane is intrinsically stable by design. Even if you go into that bank, you'll just feel 1G of acceleration towards the floor. However, now the floor might be at 15, 30, 45, 60, 90, and eventually even 180 degrees from upright. Before you even know it. And when you go even half there, think about the lift your wings give you:
