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#1
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KGARS - Kiting Glider Automatic Relase System
Richard Green of the Wycombe Test Group, High Wycombe, Bucks. UK designed and tested an auto release and offered to sell me one back in 1980. His long hand letter to me said that he was "an old age pensioner" so maybe he and his BGA certified release are something of history.
The engineering blue print of it is 3X2 feet in size, but a side view is on a normal size sheet of paper which I'd be happy to send to anyone. A Schweizer release is attached to the device which essentially operates when the angle up exceeds a certain limit. He said the club made over 1000 tows with it and there were no "spurious releases." Karl Striedieck |
#2
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KGARS - Kiting Glider Automatic Relase System
On Monday, May 18, 2020 at 7:06:34 PM UTC-7, Karl Striedieck wrote:
Richard Green of the Wycombe Test Group, High Wycombe, Bucks. UK designed and tested an auto release and offered to sell me one back in 1980. His long hand letter to me said that he was "an old age pensioner" so maybe he and his BGA certified release are something of history. The engineering blue print of it is 3X2 feet in size, but a side view is on a normal size sheet of paper which I'd be happy to send to anyone. A Schweizer release is attached to the device which essentially operates when the angle up exceeds a certain limit. He said the club made over 1000 tows with it and there were no "spurious releases." Karl Striedieck The question is has it every been tested in an actual towplane upset event? One other poster here thinks that there won't be much of an angle of the towrope to the towplane. |
#3
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KGARS - Kiting Glider Automatic Relase System
On Monday, May 18, 2020 at 7:06:34 PM UTC-7, Karl Striedieck wrote:
Richard Green of the Wycombe Test Group, High Wycombe, Bucks. UK designed and tested an auto release and offered to sell me one back in 1980. His long hand letter to me said that he was "an old age pensioner" so maybe he and his BGA certified release are something of history. The engineering blue print of it is 3X2 feet in size, but a side view is on a normal size sheet of paper which I'd be happy to send to anyone. A Schweizer release is attached to the device which essentially operates when the angle up exceeds a certain limit. He said the club made over 1000 tows with it and there were no "spurious releases." Karl Striedieck This is the 1980 article from Sailplane and Gliding: https://drive.google.com/file/d/0B1O...J6dkIxM0U/edit |
#4
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KGARS - Kiting Glider Automatic Relase System
On Tuesday, May 19, 2020 at 5:41:00 AM UTC-7, wrote:
On Monday, May 18, 2020 at 7:06:34 PM UTC-7, Karl Striedieck wrote: Richard Green of the Wycombe Test Group, High Wycombe, Bucks. UK designed and tested an auto release and offered to sell me one back in 1980. His long hand letter to me said that he was "an old age pensioner" so maybe he and his BGA certified release are something of history. The engineering blue print of it is 3X2 feet in size, but a side view is on a normal size sheet of paper which I'd be happy to send to anyone. A Schweizer release is attached to the device which essentially operates when the angle up exceeds a certain limit. He said the club made over 1000 tows with it and there were no "spurious releases." Karl Striedieck This is the 1980 article from Sailplane and Gliding: https://drive.google.com/file/d/0B1O...J6dkIxM0U/edit But Chris Rollings later said it didn't work: https://groups.google.com/forum/#!to...g%5B151-175%5D |
#5
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KGARS - Kiting Glider Automatic Relase System
On Tuesday, May 19, 2020 at 1:42:38 PM UTC+1, wrote:
On Tuesday, May 19, 2020 at 5:41:00 AM UTC-7, wrote: On Monday, May 18, 2020 at 7:06:34 PM UTC-7, Karl Striedieck wrote: Richard Green of the Wycombe Test Group, High Wycombe, Bucks. UK designed and tested an auto release and offered to sell me one back in 1980. His long hand letter to me said that he was "an old age pensioner" so maybe he and his BGA certified release are something of history. The engineering blue print of it is 3X2 feet in size, but a side view is on a normal size sheet of paper which I'd be happy to send to anyone. A Schweizer release is attached to the device which essentially operates when the angle up exceeds a certain limit. He said the club made over 1000 tows with it and there were no "spurious releases." Karl Striedieck This is the 1980 article from Sailplane and Gliding: https://drive.google.com/file/d/0B1O...J6dkIxM0U/edit But Chris Rollings later said it didn't work: https://groups.google.com/forum/#!to...g%5B151-175%5D Wouldn't it be better to design a automatic release based on the tug flight parameters such as say primarily sudden change of pitch downwards? I thought that what Chris Rollings wrote in his 2014 RAS post about the difficulty of designing an effective system based on relative angle of the tow rope was long generally accepted. |
#6
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KGARS - Kiting Glider Automatic Relase System
Once again, aviation reminds us that simplistic solutions (including my own weak-ass ideas) are rarely as "simple" as they first appear. Which brings us full circle to the original question, "How hard could it be?"
Apparently, quite a bit harder. Maybe better training IS the best option. |
#7
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KGARS - Kiting Glider Automatic Relase System
Look at water skiing. A good slalom skier can slow, and turn a heavy boat. Pro ski boats have a hitch mount on a center pole in the boat instead of the stern, also they have huge rudders and skegs down the center of the boat to resist when the skier pulls over to the side. This is a 200 lb person moving a really heavy boat with a tiny ski in water. Compare this with a 3000 lb towplane pulling a 800 lb glider (with a huge wing) letting an aero tow turn into a winch launch. The glider loads the rope, (2000 lbs) slows, and pitches the towplane down so quickly the tug doesn't have a chance. A glider boxing the wake can pull a towplane all over the place, if he doesn't resist. Towplanes can resist lateral movement by banking the wings. In a kiting situation only the elevator is any good. So, the glider can pitch the towplane down without having an extreme up rope angle. The towplane would need cg hook and a big elevator. The glider pilot must pay attention during tow! If you absolutely have to deal with a problem that takes your attention from the towplane, then release first! Now deal with the canopy or whatever.. Don't fiddle with a cellphone, camera, flight computer, radio, canopy, bug in cockpit, look around, or anything that takes your focus off the tow. Do this before takeoff or before you even move onto the runway. The towplane must be your entire world until 1500 ft at least.
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#8
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KGARS - Kiting Glider Automatic Relase System
I’d suggest we get input from tow pilots who’ve actually experienced an upset. I suspect tow rope angle is not likely to help, but tow plane pitch change and elevator position are likely inputs that can be measured and provide reasonable value. But it’s just a guess. Asking someone who’s been there makes a lot of sense.
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#9
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KGARS - Kiting Glider Automatic Relase System
On Tuesday, May 19, 2020 at 1:14:22 PM UTC-4, wrote:
I’d suggest we get input from tow pilots who’ve actually experienced an upset. I suspect tow rope angle is not likely to help, but tow plane pitch change and elevator position are likely inputs that can be measured and provide reasonable value. But it’s just a guess. Asking someone who’s been there makes a lot of sense. Increased towrope angle and increase in tension precede pitch change. Measuring and controlling from these inputs would seem to me to be better than controlling off pitch change, which is an output, and elevator position which is a following output. FWIW UH |
#10
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KGARS - Kiting Glider Automatic Relase System
Per JPG above... towrope angle has been studied and was determined to not be a viable input, even though it happens first.
Chris Rollings wrote in his 2014 RAS post about the difficulty of designing an effective system based on relative angle of the tow rope was long generally accepted. |
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