Re: [Sursound] So long CIPIC HRTF?
Fons Adriaensen A 'spiral', very different from any spin, was mentioned, > and Sampo seemed to think that recovery from that would > require regaining speed. The opposite is true, as in a > spiral your airspeed will increase [1]. Unless you recover, > there are two ways in which it can end: by smashing into > the ground, by or structural breakdown as the result of > excessive speed. > > So as part of spiral recovery, you need to reduce speed. I am never been a pilot, but my understanding is that a fighter jet can also deploy a parachute from the tail. This reduces the airspeed, and so helps the pilot escape from a spiral. Sigmund Gudvangen wrote: > Subject: Re: [Sursound] Death Spiral > > What has this aviation stuff to do with surround sound? Well, nothing; boy, is my face red. Please ignore this post. Regards, Martin -- Martin J Leese E-mail: martin.leese stanfordalumni.org Web: http://members.tripod.com/martin_leese/ ___ 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] Death Spiral
What has this aviation stuff to do with surround sound? Sigmund G. --- Original Message --- Le mercredi 22 février 2023 à 14:27, Rudy Chalupa a écrit : > Hi Stefan, > The layperson's explanation: If you are flying by visual flight rules > (typically a small plane with no instruments)(or you ignore your instruments) > and you cannot see the horizon (clouds, night), you can get into a situation > where the plane begins to bank (turn) but you don't know it (due to gravity > plus centrifugal force still pulling you toward the floor). In this case the > plane will spiral ever tighter and lower until it reaches the ground while > you are all the while convinced you are flying straight and level. > Hope this helps! > Rudy ChalupaPleiades Audio + Electronics > > > -Original Message- > From: Stefan Schreiber st...@mail.telepac.pt > > To: Surround Sound discussion group sursound@music.vt.edu > > Sent: Tue, Feb 21, 2023 7:50 pm > Subject: Re: [Sursound] So long CIPIC HRTF? > > Maybe it is me who now really would need some crash course in aviation, but: > > Is flying in a spiral not something you would do in some intentional way? > > (Opposite to the spin situation, because this is kind of uncontrolled. > Or you "have to do something".) > > So in which sense would you have to "recover" from the spiral? > > I read this before, btw: > > "But whoever cares, really? We all know what we're talking about. > Especially when you have to use the instrument in order to deliver > yourself and your passengers from a death spiral." > > So what is this spiral? A situation when the plane is spinning, even a > stall (interruption of air flow), or what else? > > (Please enlighten me, and then I will ask Anders H. "what to do". ;-) > > Best, > > Stefan > > - Mensagem de Fons Adriaensen f...@linuxaudio.org - > > > Data: Tue, 21 Feb 2023 21:45:38 +0100 > > De: Fons Adriaensen f...@linuxaudio.org > > > Assunto: Re: [Sursound] So long CIPIC HRTF? > > Para: sursound@music.vt.edu > > > On Tue, Feb 21, 2023 at 07:08:51PM +, Stefan Schreiber wrote: > > > > > I am just “sharing” what a Swedish pilot and aviation engineer wrote to > > > me, > > > > > > discussing and clarifying your problem(s)... ;-) > > > > We were not discussing spins, either upright or inverted. > > > > A 'spiral', very different from any spin, was mentioned, > > > > and Sampo seemed to think that recovery from that would > > > > require regaining speed. The opposite is true, as in a > > > > spiral your airspeed will increase [1]. Unless you recover, > > > > there are two ways in which it can end: by smashing into > > > > the ground, by or structural breakdown as the result of > > > > excessive speed. > > > > So as part of spiral recovery, you need to reduce speed. > > > > [1] As it will during any turn, unless you compensate > > > > by pulling the stick to maintain altitude. > > > > Ciao, > > > > -- > > > > FA > > > > ___ > > > > Sursound mailing list > > > > surso...@music.vt.eduhttps://mail.music.vt.edu/mailman/listinfo/sursound - > > unsubscribe here, edit account or options, view archives and so on. > > > - Fim da mensagem de Fons Adriaensen f...@linuxaudio.org - > > -- next part -- > An HTML attachment was scrubbed... > URL: > https://mail.music.vt.edu/mailman/private/sursound/attachments/20230222/99f1f079/attachment.htm > > ___ > 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. > -- next part -- > An HTML attachment was scrubbed... > URL: > https://mail.music.vt.edu/mailman/private/sursound/attachments/20230222/f00da670/attachment.htm > > ___ > 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 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] Death Spiral
Hi Stefan, The layperson's explanation: If you are flying by visual flight rules (typically a small plane with no instruments)(or you ignore your instruments) and you cannot see the horizon (clouds, night), you can get into a situation where the plane begins to bank (turn) but you don't know it (due to gravity plus centrifugal force still pulling you toward the floor). In this case the plane will spiral ever tighter and lower until it reaches the ground while you are all the while convinced you are flying straight and level. Hope this helps! Rudy ChalupaPleiades Audio + Electronics -Original Message- From: Stefan Schreiber To: Surround Sound discussion group Sent: Tue, Feb 21, 2023 7:50 pm Subject: Re: [Sursound] So long CIPIC HRTF? Maybe it is me who now really would need some crash course in aviation, but: Is flying in a spiral not something you would do in some intentional way? (Opposite to the spin situation, because this is kind of uncontrolled. Or you "have to do something".) So in which sense would you have to "recover" from the spiral? I read this before, btw: "But whoever cares, really? We all know what we're talking about. Especially when you have to use the instrument in order to deliver yourself and your passengers from a death spiral." So what is this spiral? A situation when the plane is spinning, even a stall (interruption of air flow), or what else? (Please enlighten me, and then I will ask Anders H. "what to do". ;-) Best, Stefan - Mensagem de Fons Adriaensen - Data: Tue, 21 Feb 2023 21:45:38 +0100 De: Fons Adriaensen Assunto: Re: [Sursound] So long CIPIC HRTF? Para: sursound@music.vt.edu > On Tue, Feb 21, 2023 at 07:08:51PM +, Stefan Schreiber wrote: > >> I am just “sharing” what a Swedish pilot and aviation engineer wrote to me, >> >> discussing and clarifying your problem(s)... ;-) > > We were not discussing spins, either upright or inverted. > > > > A 'spiral', very different from any spin, was mentioned, > > and Sampo seemed to think that recovery from that would > > require regaining speed. The opposite is true, as in a > > spiral your airspeed will increase [1]. Unless you recover, > > there are two ways in which it can end: by smashing into > > the ground, by or structural breakdown as the result of > > excessive speed. > > > > So as part of spiral recovery, you need to reduce speed. > > > > [1] As it will during any turn, unless you compensate > > by pulling the stick to maintain altitude. > > > > Ciao, > > > > -- > > FA > > > > ___ > > Sursound mailing list > > > surso...@music.vt.eduhttps://mail.music.vt.edu/mailman/listinfo/sursound - > unsubscribe here, edit account or options, view archives and so on. - Fim da mensagem de Fons Adriaensen - -- next part -- An HTML attachment was scrubbed... URL: <https://mail.music.vt.edu/mailman/private/sursound/attachments/20230222/99f1f079/attachment.htm> ___ 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. -- next part -- An HTML attachment was scrubbed... URL: <https://mail.music.vt.edu/mailman/private/sursound/attachments/20230222/f00da670/attachment.htm> ___ 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] [off-topic] Spirals
On Wed, Feb 22, 2023 at 12:50:31AM +, Stefan Schreiber wrote: > Is flying in a spiral not something you would do in some intentional way? Yes and no... There is no essential difference between a spiral and a normal turn, except that a spiral is usually not intentional and in that case it can become so extreme that it puts the aircraft in danger. Both spins and spirals are done intentionally as part of pilot training. All (normal) aircraft have pitch stability, but few have roll stability. That means that if the wings are not level, there is nothing that would make them return to level. And in many cases the aircraft may very well be unstable in that axis: if left alone, the roll angle will slowly increase. A non-zero roll angle means that part of the lift force generated by the wings is now sideways. That - and not the rudder - is what makes the aircraft make a turn. The vertical component of lift is reduced, and a pitch-stable aircraft will just by itself increase its airspeed to restore it. It can do that only by going down at that same time. Unless you watch the horizon or the attitude indicator, you will not be aware that this is happening. As the roll angle increases, the g-force will apparently remain vertical (relative to the aircraft) but increase as well. And at some point you will notice that you are pinned down in your seat and unable to move - you are effectively in a centrifuge, way too fast, going down, and the g-forces will be so high that they can break up the aircraft. To recover: 1. Reduce power to idle. 2. Bring the wings level. This has to be done gently, to avoid even more mechanical stress. 3. As the wings return to level, the excessive speed will put the aircraft into a steep climb. Let it happen but keep the pitch angle under control. You will regain some of the lost altitude, and airspeed will decrease. 4. As you approach normal airspeed, bring back power and level off. 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.
