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#1
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Spinning the SZD 50-3
I love to spin. It's exciting. I took aerobatic training with Wayne
Handley and was taught spin recoveries by him. I have direct experience spinning the Puchacz at Minden. This is what I remember from my experience. Your mileage may vary. With friends (usually lighter than me) in the front, I spun it while sitting in the back seat more than a dozen times. The CG was within the published range and I didn't have any trouble with simple recovery- stick centered and forward and rudder away from the direction of rotation. Worked great. I should mention that I used to be 50 lbs heavier than I am now, but still in the published range for the plane. During the training towards my instructors rating, I spun the Puch twice with my instructor. The first 2 or so rotation spin I was able to recover normally, no sweat. The second manuver was quite different. I was asked to let the spin develop a little deeper for the second. After 4 or so rotations, the nose seemed to float up and the rotation *seemed* to slow considerably. I remember thinking that this is cool! Kind of like floating. When it was time for the recovery I applied the control inputs I'd been taught (as specified above) and much to my surprise, nothing different happened.....for a long time. I estimate that we completed another 5+ rotations nose high before it broke, rolled over and recovered. I had the stick centered and against the front stop with the rudder also pegged away from the rotation. We recovered with several (4 or 5) thousand feet under us (we'd been playing at cloudbase at about 15K). Once on the ground, we discussed this incident in the grumpy bar for at least an hour. I (and he) decided to never spin the Puch again. I didn't. I doubt he did either. I had heard of this happening before. I assumed that it was from operation outside of the design envelope. Apparently I was wrong. John Shelton probably said it best: "On my own as a test pilot, I will certainly get killed". I felt like a dumb-ass for quite a while (more than usual) after that. |
#2
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Tim Shea wrote:
I love to spin. It's exciting. I took aerobatic training with Wayne Handley and was taught spin recoveries by him. I have direct experience spinning the Puchacz at Minden. This is what I remember from my experience. Your mileage may vary. With friends (usually lighter than me) in the front, I spun it while sitting in the back seat more than a dozen times. The CG was within the published range and I didn't have any trouble with simple recovery- stick centered and forward and rudder away from the direction of rotation. Worked great. I should mention that I used to be 50 lbs heavier than I am now, but still in the published range for the plane. During the training towards my instructors rating, I spun the Puch twice with my instructor. The first 2 or so rotation spin I was able to recover normally, no sweat. The second manuver was quite different. I was asked to let the spin develop a little deeper for the second. After 4 or so rotations, the nose seemed to float up and the rotation *seemed* to slow considerably. I remember thinking that this is cool! Kind of like floating. When it was time for the recovery I applied the control inputs I'd been taught (as specified above) and much to my surprise, nothing different happened.....for a long time. I estimate that we completed another 5+ rotations nose high before it broke, rolled over and recovered. I had the stick centered and against the front stop with the rudder also pegged away from the rotation. We recovered with several (4 or 5) thousand feet under us (we'd been playing at cloudbase at about 15K). Once on the ground, we discussed this incident in the grumpy bar for at least an hour. I (and he) decided to never spin the Puch again. I didn't. I doubt he did either. I had heard of this happening before. I assumed that it was from operation outside of the design envelope. Apparently I was wrong. John Shelton probably said it best: "On my own as a test pilot, I will certainly get killed". I felt like a dumb-ass for quite a while (more than usual) after that. Anyone else spin the Puch for more than three turns? What happened (obviously you survived)? I've heard that some other aircraft also have a flatter spin mode that after several turns that is hard to recover from. Any knowledge of why this happens? (Now where's my copy of Stick and Rudder?) Shawn |
#3
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"Shawn Curry" wrote in message link.net... Tim Shea wrote: I love to spin. It's exciting. I took aerobatic training with Wayne Handley and was taught spin recoveries by him. I have direct experience spinning the Puchacz at Minden. This is what I remember from my experience. Your mileage may vary. With friends (usually lighter than me) in the front, I spun it while sitting in the back seat more than a dozen times. The CG was within the published range and I didn't have any trouble with simple recovery- stick centered and forward and rudder away from the direction of rotation. Worked great. I should mention that I used to be 50 lbs heavier than I am now, but still in the published range for the plane. During the training towards my instructors rating, I spun the Puch twice with my instructor. The first 2 or so rotation spin I was able to recover normally, no sweat. The second manuver was quite different. I was asked to let the spin develop a little deeper for the second. After 4 or so rotations, the nose seemed to float up and the rotation *seemed* to slow considerably. I remember thinking that this is cool! Kind of like floating. When it was time for the recovery I applied the control inputs I'd been taught (as specified above) and much to my surprise, nothing different happened.....for a long time. I estimate that we completed another 5+ rotations nose high before it broke, rolled over and recovered. I had the stick centered and against the front stop with the rudder also pegged away from the rotation. We recovered with several (4 or 5) thousand feet under us (we'd been playing at cloudbase at about 15K). Once on the ground, we discussed this incident in the grumpy bar for at least an hour. I (and he) decided to never spin the Puch again. I didn't. I doubt he did either. I had heard of this happening before. I assumed that it was from operation outside of the design envelope. Apparently I was wrong. John Shelton probably said it best: "On my own as a test pilot, I will certainly get killed". I felt like a dumb-ass for quite a while (more than usual) after that. Anyone else spin the Puch for more than three turns? What happened (obviously you survived)? I've heard that some other aircraft also have a flatter spin mode that after several turns that is hard to recover from. Any knowledge of why this happens? (Now where's my copy of Stick and Rudder?) Shawn OK, this is speculation. Remember the old spin-the-hammer trick from freshman physics? It seems solid objects don't like to spin around their long axis - they prefer to spin about their shortest. Imagine a glider with the CG in the middle of the allowed range but the mass distributed far away from the CG in heavy wings and long fuselage with a heavy load in the cockpit balanced with a weight in the tail. Might it tend to flatten and spin about the vertical axis? BTW, any time I feel a glider hesitate to recover from a spin, I'm going to throw full aileron into the spin. (As per the POH of most Eastern European gliders.) Bill Daniels Bill Daniels |
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On Wed, 28 Jan 2004 01:43:36 UTC, "Bill Daniels"
wrote: : Remember the old spin-the-hammer trick from freshman physics? It seems : solid objects don't like to spin around their long axis - they prefer to : spin about their shortest. Actually, the physics says that objects are stable when rotating around the axes corresponding to the greatest and least moments of inertia. For a glider I'd expect yaw to be the highest moment of inertia and pitch to be the lowest. Howver, that ignores aerodynamic effects, which I'd expect to be much more significant. Ian -- |
#5
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Shawn Curry wrote in message hlink.net...
Tim Shea wrote: I love to spin. Anyone else spin the Puch for more than three turns? What happened (obviously you survived)? I've heard that some other aircraft also have a flatter spin mode that after several turns that is hard to recover from. Any knowledge of why this happens? (Now where's my copy of Stick and Rudder?) Shawn The Puke will usually recover quickly within the first 3 or so turns, but it does go int a more stable, nose higher-type rotation after maybe 4 or 5. I've spun both the 55 and the 59 out of wave, maybe 15 turns or so, and experianced what Tandem Tim described. I also got into this mode in the 103 once, believe it or not, spinning it up over 17K. I believe it has most to do with the gyroscopic inertia that builds after a few turns. SInce I was plenty high, ( in each case) my first thought was to loosen the belts & lean forward, but I wanted to try control input first. I held full opposite rudder, and centered & full forward stick. In each case, they dropped through & recovered, but you had to sit through a few rev's just holding those inputs and Believe that it will eventually work. I was ready to try other options & inputs, but I wanted to see if the hold-it & wait method would work. It was a bit unnerving, the 103 went on for maybe 3 turns, the Puch maybe 4, and the 59 maybe 5 or 6. (I don't remember if I had the tips on) and I would never enter that mode again without 2 miles between me and the nearest planet, and a rented plane. If you instruct to fully developed rotation, start recovery in the Puch as soon as it falls through, or within 1 turn, and don't stick yer toes under the back seat pedals. I fully agree with putting the emphasis on incipiant recovery, tho I think there's value in training a pilot to remain calm & methodical in an unexpected emergancy event, when the world is spinning way faster than it should. For those up to it, it does a nice snap at 55~60, nose up a little, & full rudder, elevator & aileron. If you hold it all the way through, it comes around a second time with the nose real high. (Flame suite on for the safety nazis) Remember to live live at your own risk, Choose your level of involvement to be just under your ability, and remember... You've gotta be tough... If you're gonna be stupid. -Dan |
#6
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Shawn Curry writes:
Anyone else spin the Puch for more than three turns? What happened (obviously you survived)? I've heard that some other aircraft also have a flatter spin mode that after several turns that is hard to recover from. Any knowledge of why this happens? (Now where's my copy of Stick and Rudder?) The Pitts S-1S is the one for this. Get it spinnong, then let the controls train and open the throttle. It will go into a FAST flat spin, picking the nose up to above the horizon. If you are not carfull and precise in the recovery you can inadvertantly flick it into a spin in the other direction, or into an outside spin. Not ever heard that it is hard to recover from though. -- Paul Repacholi 1 Crescent Rd., +61 (08) 9257-1001 Kalamunda. West Australia 6076 comp.os.vms,- The Older, Grumpier Slashdot Raw, Cooked or Well-done, it's all half baked. EPIC, The Architecture of the future, always has been, always will be. |
#7
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If you were within the permitted CoG range, and used
the standard recovery method, the spin behaviour you described is definitely non-compliant with JAR 22 certification rules. JAR22.221 states that a sailplane certificated for intentional spinning must be able to recover from a fully developed spin (5 turns) within 1 turn after recovery action is done. This has to be demonstrated in several loading and control conditions. Additionally, this paragraph states that it must be impossible to obtain uncontrollable spins with any use of the controls. The Puchacz may not have been certificated to JAR 22, but possibly to the older OSTIV rules. However, I very much doubt that this type of behaviour would have been acceptable under older certification rules, although the verification/testing requirements might have been less strict in earlier days. Geir At 01:00 28 January 2004, Tim Shea wrote: I love to spin. It's exciting. I took aerobatic training with Wayne Handley and was taught spin recoveries by him. I have direct experience spinning the Puchacz at Minden. This is what I remember from my experience. Your mileage may vary. With friends (usually lighter than me) in the front, I spun it while sitting in the back seat more than a dozen times. The CG was within the published range and I didn't have any trouble with simple recovery- stick centered and forward and rudder away from the direction of rotation. Worked great. I should mention that I used to be 50 lbs heavier than I am now, but still in the published range for the plane. During the training towards my instructors rating, I spun the Puch twice with my instructor. The first 2 or so rotation spin I was able to recover normally, no sweat. The second manuver was quite different. I was asked to let the spin develop a little deeper for the second. After 4 or so rotations, the nose seemed to float up and the rotation *seemed* to slow considerably. I remember thinking that this is cool! Kind of like floating. When it was time for the recovery I applied the control inputs I'd been taught (as specified above) and much to my surprise, nothing different happened.....for a long time. I estimate that we completed another 5+ rotations nose high before it broke, rolled over and recovered. I had the stick centered and against the front stop with the rudder also pegged away from the rotation. We recovered with several (4 or 5) thousand feet under us (we'd been playing at cloudbase at about 15K). Once on the ground, we discussed this incident in the grumpy bar for at least an hour. I (and he) decided to never spin the Puch again. I didn't. I doubt he did either. I had heard of this happening before. I assumed that it was from operation outside of the design envelope. Apparently I was wrong. John Shelton probably said it best: 'On my own as a test pilot, I will certainly get killed'. I felt like a dumb-ass for quite a while (more than usual) after that. |
#8
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In article ,
Geir Raudsandmoen om wrote: If you were within the permitted CoG range, and used the standard recovery method, the spin behaviour you described is definitely non-compliant with JAR 22 certification rules. JAR22.221 states that a sailplane certificated for intentional spinning must be able to recover from a fully developed spin (5 turns) within 1 turn after recovery action is done. This has to be demonstrated in several loading and control conditions. Fine. Additionally, this paragraph states that it must be impossible to obtain uncontrollable spins with any use of the controls. But how on earth can that be demonstrated? No matter *what* you do, you can't get into an uncontrollable spin? But there are an infinite number of possible things you *might* do with the controls. They can't ALL be tested. -- Bruce |
#9
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Independently of the type of certification which did the Puchacz =
undergo, it has been put through a very extensive in-flight testing = program. The SZD used to be a state runned company which in this area = meant that the new glider has to pass a very detailed programme of tests = almost without counting the costs (remember that it was designed in deep = communism era where the economy rules we know didn't exist in practice). It has to be tested thoroughly as it was intended to be full acro = allowed two seater which was mainly designed to be a primary trainer. Nowadays *all* Polish clubs use the Puchacz for spin training (the = Bocians have been prohibited to spin after they reached the age of 25), = as there are no other trainers than few (maybe 5 all) KR-03 Puchateks = (known also as Krosno or Peregrine). For ten years I have been flying = gliders I have never heard of any accident like this one which started = all the recent threads on Puchacz. There were few spin fatalities = indeed, even one in aour club, but all of them happened on the final = leg, or in the moment of the base/final leg turn, most of them caused by = the licensed (but not used to fly from the instructor's cockpit) pilot = in the backseat carrying passenger in the front seat. Regards, --=20 Janusz Kesik visit www.leszno.pl - home of the www.css-leszno.it.pl |
#10
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You shouldn't spin more than 3 turns unless you're practicing for aerobatic
flight. In a case as you describe, application of full PRO-SPIN controls for a few seconds should have been performed prior to a second attempt at recovery. And recovery should be rudder and stick at the same time (as recomended by Dick Johnson after his testing) or with the Rudder leading the recovery by 1 second or so (as recomended by the Puchacz's POH). Commencing recovery with the Stick first is not recomended, and it may in fact retard recovery significantly. Also, chances are that you didn't have the stick and/or rudder against the stops, for simple reasons such as Trim not being Neutral (as recommended by the manual), or the Ailerons might not have been Neutral (as they should), or the CG may have been slightly off-limits. The same things would cause similar behaviour in any other modern training glider. In a regular spin, with 3 or less rotations, some of these things are less of an issue, but they have to be observed anyway. Recovery however has to be the same way in a fully developed spin : -Anti-spin rudder to the stop -After 1 second or less, release back pressure on the stick or even move it forward, all-the-way if you have to. Rotation should stop. If it doesn't, apply full pro-spin controls, verify the ailerons in neutral (stick not in any of the sides) and trim in neutral, then repeat recovery. "Tim Shea" wrote in message m... I love to spin. It's exciting. I took aerobatic training with Wayne Handley and was taught spin recoveries by him. I have direct experience spinning the Puchacz at Minden. This is what I remember from my experience. Your mileage may vary. With friends (usually lighter than me) in the front, I spun it while sitting in the back seat more than a dozen times. The CG was within the published range and I didn't have any trouble with simple recovery- stick centered and forward and rudder away from the direction of rotation. Worked great. I should mention that I used to be 50 lbs heavier than I am now, but still in the published range for the plane. During the training towards my instructors rating, I spun the Puch twice with my instructor. The first 2 or so rotation spin I was able to recover normally, no sweat. The second manuver was quite different. I was asked to let the spin develop a little deeper for the second. After 4 or so rotations, the nose seemed to float up and the rotation *seemed* to slow considerably. I remember thinking that this is cool! Kind of like floating. When it was time for the recovery I applied the control inputs I'd been taught (as specified above) and much to my surprise, nothing different happened.....for a long time. I estimate that we completed another 5+ rotations nose high before it broke, rolled over and recovered. I had the stick centered and against the front stop with the rudder also pegged away from the rotation. We recovered with several (4 or 5) thousand feet under us (we'd been playing at cloudbase at about 15K). Once on the ground, we discussed this incident in the grumpy bar for at least an hour. I (and he) decided to never spin the Puch again. I didn't. I doubt he did either. I had heard of this happening before. I assumed that it was from operation outside of the design envelope. Apparently I was wrong. John Shelton probably said it best: "On my own as a test pilot, I will certainly get killed". I felt like a dumb-ass for quite a while (more than usual) after that. |
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