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#41
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At 17:34 08 October 2013, Bill D wrote:
On Monday, October 7, 2013 2:24:08 AM UTC-6, Don Johnstone wrote: OK, try sitting in a Schemp Hirth or even and ASW 17/19/20 with the stick full to the left and try finding the release knob if you do not actually have your hand on it. The time you have to realise you have a problem and react is very short, trying to find the release will take longer than the time you have. If reaching the release is difficult, it gets an extension installed ASAP. = (That a minor modification not requiring paperwork.) The really bonehead a= ction is to continue flying a glider where the pilot can't reach the releas= e. does that idea actually occur to anyone in the UK? I wish it were that simple. A change of this nature, to a critical control, requires approval from EASA which in turn requires the TC Holder to approve. In all the gliders I fly I use a paracord loop which I loop round my wrist and the release knob. As it is a modification to my hand it does not require EASA approval. I am not going to bother answering the rest of your points, I feel you have proved your ignorance sufficiently. As far as the UK is concerned starting a winch launch with the hand on the release is not optional. As I have said before doing it can save your life, it is a complete no brainer. |
#42
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At 16:52 08 October 2013, Bill D wrote:
On Sunday, October 6, 2013 4:05:57 PM UTC-6, Don Johnstone wrote: All John says is absolutely correct. The sad fact is that this type of Which is? Come on, lets hear it Bill! BTW it is not always possible to launch straight into wind due to the layout of some glider sites. Wing drops are usually caused by gusts, which are usually not predictable. The only safe way of dealing with them is to release as soon as the wing starts to drop and before it touches the ground. Releasing under tension often requires a good firm pull, so a good firm grip on the release knob (or an extension cable if necessary) is essential. Derek Copeland accident occurs on a fairly regular basis and as yet no one has come up with a plausible cause. What is clear that the wing drop is a symptom and requires that the glider is released very early which is why the hand should be on the release. A similar accident happened at my club a month back involving a Discus, in that case the pilot was unhurt but the glider was written off. What is clear is that once the glider starts to yaw nothing on this earth is going to stop it except contact with the ground so early release, to mitigate the inevitable accident, is essential. The sad fact is the UK hasn't figured out the cause - everyone else has. |
#43
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Bill,
I have watched this tread with some interest. Just for the record, what authority are you on the subject? I find it very interesting that you are so dismissive of the hours of research done by trained professionals who have considerable amount of date and past cases to work with. If this is your humble opinion, look after yourself, but keep your opinions to yourself. If how ever you are some sort of authority in the subject, I will bow to your superior judgement. Regards, Justin At 16:52 08 October 2013, Bill D wrote: On Sunday, October 6, 2013 4:05:57 PM UTC-6, Don Johnstone wrote: All John says is absolutely correct. The sad fact is that this type of accident occurs on a fairly regular basis and as yet no one has come up with a plausible cause. What is clear that the wing drop is a symptom and requires that the glider is released very early which is why the hand should be on the release. A similar accident happened at my club a month back involving a Discus, in that case the pilot was unhurt but the glider was written off. What is clear is that once the glider starts to yaw nothing on this earth is going to stop it except contact with the ground so early release, to mitigate the inevitable accident, is essential. The sad fact is the UK hasn't figured out the cause - everyone else has. |
#44
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Time for pogo sticks.
The idea of launching a glider by having someone run the wing originated with wooden gliders and quite low speeds for stall and aileron effectiveness. Those speeds have gradually crept up through the years, to the point that really nobody can run the wing of a modern glider, with waterballast, and anything less than 10 mph straight down the runway, to the point of aileron effectiveness. Mostly we hope that the wing runner lets go, with the aircraft in balanced position, and it picks up speed faster than one wing drops. That often isn't true. For airtows the results are usually just some scraped gel coat; sometimes a collision with a runway light, and occasionally a ground loop. There have been accidents where wing down gliders hurt bystanders, the Tonopah 15 m nationals being the one I remember best. Clearly, for winching, wing-down events are much more serious. The answer: either retractable or disposable pogo sticks on the wingtips, or mid-wing. Something that keeps the wings level to 25 mph and then either drops off or retracts into the wing. Reading the UK Nimbus 3 report, it would seem that a video link between winch driver and launch point would be a good idea, and quite cheap with current technology. It would cut a crucial second or so out of the abort-the-launch loop John Cochrane |
#45
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Hi Justin,
I suspect that this is Bill Daniels, a Google search for Bill Daniels gliding shows that IN the USA in any case he is considered to perhaps be an expert. I suspect that by such comments as "imperial arrogance" he is most certainly not an Anglophile and to be honest find the arrogance part somewhat ironic. Terry Walsh At 12:56 09 October 2013, Justin Craig wrote: Bill, I have watched this tread with some interest. Just for the record, what authority are you on the subject? I find it very interesting that you are so dismissive of the hours of research done by trained professionals who have considerable amount of date and past cases to work with. If this is your humble opinion, look after yourself, but keep your opinions to yourself. If how ever you are some sort of authority in the subject, I will bow to your superior judgement. Regards, Justin At 16:52 08 October 2013, Bill D wrote: On Sunday, October 6, 2013 4:05:57 PM UTC-6, Don Johnstone wrote: All John says is absolutely correct. The sad fact is that this type of accident occurs on a fairly regular basis and as yet no one has come up with a plausible cause. What is clear that the wing drop is a symptom and requires that the glider is released very early which is why the hand should be on the release. A similar accident happened at my club a month back involving a Discus, in that case the pilot was unhurt but the glider was written off. What is clear is that once the glider starts to yaw nothing on this earth is going to stop it except contact with the ground so early release, to mitigate the inevitable accident, is essential. The sad fact is the UK hasn't figured out the cause - everyone else has. |
#46
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#47
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JC wrote:
The answer: either retractable or disposable pogo sticks on the wingtips, or mid-wing. Something that keeps the wings level to 25 mph and then either drops off or retracts into the wing. Along this line, many self-launchers have small in-line skate wheels on the wingtips so they can start with the wing already touching the runway. Perhaps a simple retrofit could save your gel-coat (or your life). As for dropable pogo sticks, hang gliders that aerotow often use a 3 wheeled launch cart(with a wide stance)to keep the wing level until it flies away from the cart. No one wants to lift their sailplane into a cart so this won't work for us. :-) |
#48
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Well said. Just another big-mouthed Ugly American.
On 10/9/2013 11:45 AM, Terry Walsh wrote: Hi Justin, I suspect that this is Bill Daniels, a Google search for Bill Daniels gliding shows that IN the USA in any case he is considered to perhaps be an expert. I suspect that by such comments as "imperial arrogance" he is most certainly not an Anglophile and to be honest find the arrogance part somewhat ironic. Terry Walsh At 12:56 09 October 2013, Justin Craig wrote: Bill, I have watched this tread with some interest. Just for the record, what authority are you on the subject? I find it very interesting that you are so dismissive of the hours of research done by trained professionals who have considerable amount of date and past cases to work with. If this is your humble opinion, look after yourself, but keep your opinions to yourself. If how ever you are some sort of authority in the subject, I will bow to your superior judgement. Regards, Justin At 16:52 08 October 2013, Bill D wrote: On Sunday, October 6, 2013 4:05:57 PM UTC-6, Don Johnstone wrote: All John says is absolutely correct. The sad fact is that this type of accident occurs on a fairly regular basis and as yet no one has come up with a plausible cause. What is clear that the wing drop is a symptom and requires that the glider is released very early which is why the hand should be on the release. A similar accident happened at my club a month back involving a Discus, in that case the pilot was unhurt but the glider was written off. What is clear is that once the glider starts to yaw nothing on this earth is going to stop it except contact with the ground so early release, to mitigate the inevitable accident, is essential. The sad fact is the UK hasn't figured out the cause - everyone else has. |
#49
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On Wednesday, October 9, 2013 8:44:52 AM UTC-6, wrote:
Time for pogo sticks. The idea of launching a glider by having someone run the wing originated with wooden gliders and quite low speeds for stall and aileron effectiveness. Those speeds have gradually crept up through the years, to the point that really nobody can run the wing of a modern glider, with waterballast, and anything less than 10 mph straight down the runway, to the point of aileron effectiveness. Mostly we hope that the wing runner lets go, with the aircraft in balanced position, and it picks up speed faster than one wing drops.. That often isn't true. For airtows the results are usually just some scraped gel coat; sometimes a collision with a runway light, and occasionally a ground loop. There have been accidents where wing down gliders hurt bystanders, the Tonopah 15 m nationals being the one I remember best. Clearly, for winching, wing-down events are much more serious. The answer: either retractable or disposable pogo sticks on the wingtips, or mid-wing. Something that keeps the wings level to 25 mph and then either drops off or retracts into the wing. Reading the UK Nimbus 3 report, it would seem that a video link between winch driver and launch point would be a good idea, and quite cheap with current technology. It would cut a crucial second or so out of the abort-the-launch loop John Cochrane John, wing-down events are indeed more serious for winch launch simply because of the CG hook and the large amount of energy being delivered to the glider by the winch. The best solution is one where wing drops don't happen at all - or are least extremely unlikely. It's true that modern, heavy gliders have minimum aileron control speeds much higher than a wing runner can reach. Just as with aero tow, slow acceleration leaves a glider vulnerable to a wing drop. As with aero tow, reaching minimum control speed quickly is a very good thing. The time for a glider on winch launch to reach aileron control speed from a standstill (Anywhere except the UK) is a second or less so how can a wing drop in that interval? Even in a crosswind, a glider can be balanced laterally so if the wing tip is simply released it will take two or three seconds for it to drop. Something has to cause it to drop or it won't happen. A rare problem is a pilot unintentionally holding aileron input at the start of the roll. Control authority comes on fast that a wing may go down before a pilot realizes his error and backs off the aileron input. The solution is being careful to neutralize the ailerons before the roll starts. Also rare (Again, outside the UK) is mis-aligned staging which results in the rope pulling the glider slightly sideways. This can start a wing down before aileron control speed is reached. The solution is to be careful to stage the glider so it points at the winch. Strong gusts can be problem but the longer a glider wobbles along with minimal control authority, the greater the vulnerability to them. Wing runners should be re-trained from what they learned with aero tow. Any attempt to hold on will be disastrous so they need to do a very "clean" release. They must also learn the art of balancing the wing rather than just holding it sort of level. They won't so much "run" the wing as take a very quick step or two. Video is under serious consideration. As you say, a CCTV link is very cheap as are all sorts of data-links. I think one of the best uses is a simple data-link to send a "STOP" message to the winch operator. That message could be displayed in .2 seconds from when an observer at the launch point first sees a launch starting to go wrong and the rope cut with the guillotine in another .2 seconds stopping the launch. |
#50
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On Wednesday, October 9, 2013 10:59:50 AM UTC-6, Fred Bear wrote:
Well said. Just another big-mouthed Ugly American. On 10/9/2013 11:45 AM, Terry Walsh wrote: Hi Justin, I suspect that this is Bill Daniels, a Google search for Bill Daniels gliding shows that IN the USA in any case he is considered to perhaps be an expert. I suspect that by such comments as "imperial arrogance" he is most certainly not an Anglophile and to be honest find the arrogance part somewhat ironic. Terry Walsh At 12:56 09 October 2013, Justin Craig wrote: Bill, I have watched this tread with some interest. Just for the record, what authority are you on the subject? I find it very interesting that you are so dismissive of the hours of research done by trained professionals who have considerable amount of date and past cases to work with. If this is your humble opinion, look after yourself, but keep your opinions to yourself. If how ever you are some sort of authority in the subject, I will bow to your superior judgement. Regards, Justin At 16:52 08 October 2013, Bill D wrote: On Sunday, October 6, 2013 4:05:57 PM UTC-6, Don Johnstone wrote: All John says is absolutely correct. The sad fact is that this type of accident occurs on a fairly regular basis and as yet no one has come up with a plausible cause. What is clear that the wing drop is a symptom and requires that the glider is released very early which is why the hand should be on the release. A similar accident happened at my club a month back involving a Discus, in that case the pilot was unhurt but the glider was written off. What is clear is that once the glider starts to yaw nothing on this earth is going to stop it except contact with the ground so early release, to mitigate the inevitable accident, is essential. The sad fact is the UK hasn't figured out the cause - everyone else has. What's ugly is death caused by incompetence. |
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