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#41
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"Bill Daniels" s comments read:
I was shown a gadget just for this sort of thing made of PVC pipe. It was essentially a tripod with a 2 meter horizontal pipe along which the wing would slide as the glider started its roll. It was intended for airtow but the thing would work with a winch. Surely this situation normally occurs when retrieving as well as days when the operation is normally closed. I've heard a tale about a coke can and good blast of prop wash being used to get the wind up. Sounds like asking for trouble ... -- Tim - ASW20CL "20" |
#42
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In article , Bill Daniels
writes I agree with Frank. I hope it doesn't come to this. Returning to the USA situation with winch launch for a moment, whenever a group tries a once-a-year winch party with 20 or so untrained people, the result looks a lot like a Chinese fire drill. Since this is the usual situation in the US, there is the widespread opinion that winch launching is a confused, labor intensive affair. However, a group of experienced winch people with polished procedures can make it look as easy as air tow. It sure is a lot quieter, cleaner and more pleasant than the noisy, dusty environment in the vicinity of a tug. Bill Daniels It can also be very efficient. The Midland Gliding Club which operates from a hill top site in Shropshire, England, uses a single drum winch to launch and a lower powered winch to retrieve the cable. The launch rate can be phenomenal! -- Mike Lindsay |
#43
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yeee-hah (cable-please-don't-break), yeee-hah
J. "OscarCVox" wrote in message ... Gliders susceptable to this often have features in common. Light weight High mounted wings nose wheel or skid The whole thing made worse by inexpert winch drivers in a powerfull winch used to launching heavy 2 seaters The worst experience I have ever had was in one of those PW5 things. It rotated until the wheel on the tail hit the ground hard then took off like a scalded cat. With full forward stick I was about 200ft before I managed to resume control. Scary. With a nose wheel or skid they rock back on the all out signal presenting the wings at a large angle of attack before the elevator has a chance to become effective. |
#44
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Mike Lindsay wrote:
It can also be very efficient. The Midland Gliding Club which operates from a hill top site in Shropshire, England, uses a single drum winch to launch and a lower powered winch to retrieve the cable. The launch rate can be phenomenal! How does the retrieve work? I.e. is that not a way of moving the problem to how to get back the retrieve cable, or does it remain tied to the main cable? In this case doesn'it slow down and pull back the main cable? |
#45
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OscarCVox wrote:
Gliders susceptable to this often have features in common. Light weight High mounted wings nose wheel or skid The whole thing made worse by inexpert winch drivers in a powerfull winch used to launching heavy 2 seaters The worst experience I have ever had was in one of those PW5 things. It rotated until the wheel on the tail hit the ground hard then took off like a scalded cat. With full forward stick I was about 200ft before I managed to resume control. Scary. With a nose wheel or skid they rock back on the all out signal presenting the wings at a large angle of attack before the elevator has a chance to become effective. I think the most important factors in the cas of the PW5 are the high position of the tail skid, allowing for a high pitchup before leaving the ground, and a to aft position of the CG hook. The ASK23 is also a light weight glider with high mounted wings and a nose wheel, but it doesn't exhibit this behavior. |
#46
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The lighter Spectra doesn't sag nearly as much as steel so the pull vector
is more nearly aligned with the flight path. The potential height gain at release is more due to the angle that Spectra pulls on the glider. The Van Gelder? You bet. That's the reference winch design. Somebody want to link us to some detailed pictures of the Van Gelder? Bill Daniels "Bob Johnson" wrote in message ... Robert -- There's only about a 100 lb reduction in line weight at release, assuming you're currently using 5mm steel, so I wouldn't expect a dramatic height gain. Hoo boy, a 6 drum Diesel Monster Van Gelder -- now THAT'S a winch!! Robert Johnson 8') Robert John wrote: At Dunstable (London Gliding Club - UK) we have 4 tugs (typically 2 operating unless it's really busy) and a 6 drum diesel Munster Van Gelder winch. The launch rates with a slick ground crew can be extremely good. 30 secs to launch, another 30secs to reel in the cable, then hook up the next one and go. It's quick, quiet and cheap (a quarter the cost of a typical tug launch). Our only bugbear is that the field is fairly short so we rarely see more than 1200 feet from a winch launch, sometimes as little as 800 (flat calm on one of the shorter runs). 1500'+ would make winching the preferred method of launch for most XC flights (standard aerotow is 2000ft - we Brits are used to thermalling up from heights most Americans would regard as circuit height!). Perhaps we should experiment with Plasma rope? The winch is slightly less labour-intensive than the tug in that the hook-on and control crew is the same for both but you only need one winch driver and he is utilised as soon as he is needed - you don't need to wait for him to return to earth and taxi into position after a launch. Someone from the launch point goes to the winch with a tractor and 6-hook trailer before the last cable is used so as to be ready to bring the cables back to the launch point. Rob John At 08:24 14 August 2003, Mike Lindsay wrote: In article , Bill Daniels writes I agree with Frank. I hope it doesn't come to this. Returning to the USA situation with winch launch for a moment, whenever a group tries a once-a-year winch party with 20 or so untrained people, the result looks a lot like a Chinese fire drill. Since this is the usual situation in the US, there is the widespread opinion that winch launching is a confused, labor intensive affair. However, a group of experienced winch people with polished procedures can make it look as easy as air tow. It sure is a lot quieter, cleaner and more pleasant than the noisy, dusty environment in the vicinity of a tug. Bill Daniels It can also be very efficient. The Midland Gliding Club which operates from a hill top site in Shropshire, England, uses a single drum winch to launch and a lower powered winch to retrieve the cable. The launch rate can be phenomenal! -- Mike Lindsay |
#47
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The main cable and the retrieve cable are both shackled to a "triangle", the
rope trace to the glider is attached to the third corner. No parachute is used, the whole thing drops straight down when released. This system can only be used when it is safe and operationally convenient for the cable, triangle and retrieve cable to drop straight down when released, without risk of damage to people or property, and without damaging itself. If you go to the on-line "Gliding Magazine" photo section, page 4, 4/3/2003 http://www.glidingmagazine.com/PhotoGallery.asp?Page=4 you will see 3 photos I posted of a K21 being launched at the Mynd. In the first photo the triangle is about to leave the ground, the retrieve cable is on the ground in the right foreground. In the second photo the triangle is the black object at the end of the rope trace, the wire cable and retrieve cable cannot be seen. The winch is just below the skyline right center well clear of the trees. The third photo was in fact taken first, it shows the glider ready to launch. The first part of the trace is the weak link unit, a short wire trace in coloured (black) hose, you can see a blue link unit (used for most single seaters) under the wing tip. Since we never launch without the retrieve wire attached, it is difficult to know if we are losing height. However, we are saving the drag of the chute used in most other systems. We are well pleased with the height we get. W.J. (Bill) Dean (U.K.) - member of Midland G.C. Remove "ic" to reply. "Robert Ehrlich" wrote in message ... Mike Lindsay wrote: It can also be very efficient. The Midland Gliding Club which operates from a hill top site in Shropshire, England, uses a single drum winch to launch and a lower powered winch to retrieve the cable. The launch rate can be phenomenal! How does the retrieve work? I.e. is that not a way of moving the problem to how to get back the retrieve cable, or does it remain tied to the main cable? In this case doesn'it slow down and pull back the main cable? |
#48
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!doctype html public "-//w3c//dtd html 4.0 transitional//en"
html I don't know about detailed -- pA HREF="http://www.621vgs.co.uk/works.htm"http://www.621vgs.co.uk/works.htm/A pBill Daniels wrote: blockquote TYPE=CITEThe lighter Spectra doesn't sag nearly as much as steel so the pull vector bris more nearly aligned with the flight path. The potential height gain at brrelease is more due to the angle that Spectra pulls on the glider. pThe Van Gelder? You bet. That's the reference winch design. Somebody want brto link us to some detailed pictures of the Van Gelder? pBill Daniels p"Bob Johnson" wrote in message bra "news:3F /a... br Robert -- br br There's only about a 100 lb reduction in line weight at release, br assuming you're currently using 5mm steel, so I wouldn't expect a br dramatic height gain. br br Hoo boy, a 6 drum Diesel Monster Van Gelder -- now THAT'S a winch!! br br Robert Johnson 8') br br br Robert John wrote: br br At Dunstable (London Gliding Club - UK) we have 4 tugs br (typically 2 operating unless it's really busy) and br a 6 drum diesel Munster Van Gelder winch. The launch br rates with a slick ground crew can be extremely good. br 30 secs to launch, another 30secs to reel in the cable, br then hook up the next one and go. br br It's quick, quiet and cheap (a quarter the cost of br a typical tug launch). br br Our only bugbear is that the field is fairly short br so we rarely see more than 1200 feet from a winch launch, br sometimes as little as 800 (flat calm on one of the br shorter runs). 1500'+ would make winching the preferred br method of launch for most XC flights (standard aerotow br is 2000ft - we Brits are used to thermalling up from br heights most Americans would regard as circuit height!). br br br Perhaps we should experiment with Plasma rope? br br The winch is slightly less labour-intensive than the br tug in that the hook-on and control crew is the same br for both but you only need one winch driver and he br is utilised as soon as he is needed - you don't need br to wait for him to return to earth and taxi into position br after a launch. Someone from the launch point goes br to the winch with a tractor and 6-hook trailer before br the last cable is used so as to be ready to bring the br cables back to the launch point. br br Rob John br br At 08:24 14 August 2003, Mike Lindsay wrote: br In article , Bill Daniels br writes br br I agree with Frank. I hope it doesn't come to this. br br Returning to the USA situation with winch launch for br a moment, whenever a br group tries a once-a-year winch party with 20 or so br untrained people, the br result looks a lot like a Chinese fire drill. Since br this is the usual br situation in the US, there is the widespread opinion br that winch launching is br a confused, labor intensive affair. br br However, a group of experienced winch people with polished br procedures can br make it look as easy as air tow. It sure is a lot br quieter, cleaner and more br pleasant than the noisy, dusty environment in the vicinity br of a tug. br br Bill Daniels br It can also be very efficient. The Midland Gliding br Club which operates br from a hill top site in Shropshire, England, uses a br single drum winch br to launch and a lower powered winch to retrieve the br cable. The launch br rate can be phenomenal! br br -- br Mike Lindsay br /blockquote /html |
#50
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![]() "W.J. (Bill) Dean (U.K.)." wrote in message ... The Van Gelder was a superb winch when it first arrived in the U.K., but the reference winch today is the Skylaunch http://www.skylaunchuk.com/ . I have done many launches in solo gliders and in two-seaters by both winches, and I prefer the Skylaunch. I have no commercial interest in that company. The reference you gave is to 621VGS, which is an Air Training Corps squadron, and therefore part of the Royal Air Force. Their equipment is bought and maintained by the taxpayer, and their economics are rather different from the civilian clubs. Note that the Van Gelder needs a substantial vehicle to tow it, the Skylaunch can be towed on the road by any reasonable SUV. The Midland Gliding Club have a Skylaunch which is towed round our rough airfield by a Range Rover. W.J. (Bill) Dean (U.K.). Remove "ic" to reply. Bill, would you expand on the reasons for your preference for the Skylaunch winch? Aren't most of the Van Gelder winches mounted on trucks so the towing issue is moot? Bill Daniels |
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