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#11
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Where to get Winched?
If you're only getting 33% of the rope length, yours is a low
performance winch operation. If you optimize it, 45% or so is achievable in no-wind conditions. A 10 knot wind can boost that over 50%. Again, I'm saying this is for gliders with better than 30:1 and rope tensions equal to the weight of the glider. Below 30:1, achieved height falls off a lot. On Jun 7, 7:51*am, GC wrote: On 7/06/2012 02:45, Chris wrote: We in europe do winch launching as the standard procedure. Our airfield has 1200m (~4000 feet) paid out cable and we get release height of about 400m (~1300 feet). With strong headwind we even get 600m, sometimes more. Our club charges 4,- ? for a launch. Yes. *Bill Daniels seems optimistic to me. *1 for 3 is about what I'd expect with a nil to light wind. It depends on lots of factors: engine power, pilot skills, wind direction and strength, cable (steel or dyneema), lenght of cable, glider type... and certainly more. The above numbers are for a double seater like ASK21, steel cable and moderate headwind. There have been launches with dyneema cable of 3000m length and release heights of 1200m. This is a really cost effective way to do aerobatics. To answer your question: I would think 3000 feet is the minimun for a reasonable winch operation. However, I have seen fields with only 2000 feet. The length you need is wire length - not runway length. *The ground run for a launch is barely 100 yards. *Any more is for landing, launch emergencies, etc. *Winches are also commonly sited well beyond the upwind runway threshold. *It's a very flexible launching system. GC Chris |
#12
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Where to get Winched?
On Jun 7, 7:51*am, GC wrote:
On 7/06/2012 02:45, Chris wrote: We in europe do winch launching as the standard procedure. Our airfield has 1200m (~4000 feet) paid out cable and we get release height of about 400m (~1300 feet). With strong headwind we even get 600m, sometimes more. Our club charges 4,- ? for a launch. Yes. *Bill Daniels seems optimistic to me. *1 for 3 is about what I'd expect with a nil to light wind. It depends on lots of factors: engine power, pilot skills, wind direction and strength, cable (steel or dyneema), lenght of cable, glider type... and certainly more. The above numbers are for a double seater like ASK21, steel cable and moderate headwind. There have been launches with dyneema cable of 3000m length and release heights of 1200m. This is a really cost effective way to do aerobatics. To answer your question: I would think 3000 feet is the minimun for a reasonable winch operation. However, I have seen fields with only 2000 feet. The length you need is wire length - not runway length. *The ground run for a launch is barely 100 yards. *Any more is for landing, launch emergencies, etc. *Winches are also commonly sited well beyond the upwind runway threshold. *It's a very flexible launching system. GC Chris 100 yards for acceleration is way too long. A 1G acceleration will get a glider to 40 knots liftoff speed in 71 feet. |
#13
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Where to get Winched?
On Jun 7, 5:05*am, toad wrote:
The only place that I have ever found advertising an endorsement training was a soaring club in Houston. *If there are any other operations that will train a new pilot to winch launch, I have not yet found them. *They may exist, but they don't advertise. AGCSC down in southern California runs periodic weekend winch launch training sessions: http://www.agcsc.org/ We're putting the finishing touches on a winch that will be used for training at Crazy Creek in northern California... Marc |
#14
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Where to get Winched?
I have read that the insurance is much higher for winch operations.
Anyone have a comment or tips on reducing this? |
#15
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Where to get Winched?
On Thursday, June 7, 2012 12:26:55 PM UTC-4, soartech wrote:
I have read that the insurance is much higher for winch operations. Anyone have a comment or tips on reducing this? We have not experienced this at PGC, however, we do not have SSA insurance. I suspect that the carrier's knowledge--or should I say lack of knowledge--may have a lot to do with this. Skip |
#16
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Where to get Winched?
GC wrote:
The length you need is wire length - not runway length. The ground run for a launch is barely 100 yards. Any more is for landing, launch emergencies, etc. Winches are also commonly sited well beyond the upwind runway threshold. It's a very flexible launching system. While this is true, there is another reason for a 3000 feet runway: safety. You need to be prepared for a cable break at any time. Up to 300 feet you can land straight ahead, if there is enough runway left. If the cable breaks at a higher altitude, you can do a full circle or a short pattern. If the runway is too short, you can get in a situation where both options do not apply. I guess that you refer to this scenario when you talk about launch emergency. My opinion is that a cable break is no emergency, but is part of the procedure. It must be trained well, but if the pilot is prepared for a break, this is no emergency. You can expect a cable break in one of 100 launches. BTW, my last break on the winch was in 120m. Too high to land straight, so I initiated a 180 for a short pattern. After that turn, my altimeter showed 150m. I decided to do a full circle and got 200m. Now I continued and got 1300m in the end. This was fun while the guys below had to fix the cable :-) Chris |
#17
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Where to get Winched?
On Jun 6, 6:38*am, Walt Connelly
wrote: Where in the South East US of A might one go to get a winch launch endorsement? *ALSO, in general how much runway is needed for an adequate winch launch? *What might the minimum runway length be? Walt -- Walt Connelly Come over to San Antonio Soaring Society, our club located at Boerne Stage airport (5C1). We winched last weekend and plan to do it once a month this summer. You can get an endorsement with our CFIG. Tom |
#18
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Where to get Winched?
At 02:42 08 June 2012, Tom Nau wrote:
On Jun 6, 6:38=A0am, Walt Connelly wrote: Where in the South East US of A might one go to get a winch launch endorsement? =A0ALSO, in general how much runway is needed for an adequat= e winch launch? =A0What might the minimum runway length be? Walt -- Walt Connelly Come over to San Antonio Soaring Society, our club located at Boerne Stage airport (5C1). We winched last weekend and plan to do it once a month this summer. You can get an endorsement with our CFIG. Tom I applaud your efforts to promote winching, coming from a UK club with no current aerotow option, winching is my usual (and cost effective) way into the sky. This BGA leaflet is essential reading: http://www.gliding.co.uk/bgainfo/saf...ts/safewinchbr ochure-0210.pdf If you ask them nicely, I expect they'd have no objections to clubs on your side of the pond printing them off for circulation. |
#19
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Where to get Winched?
On Thursday, June 7, 2012 10:26:55 AM UTC-6, soartech wrote:
I have read that the insurance is much higher for winch operations. Anyone have a comment or tips on reducing this? Winch liability insurance was split off from premises liability under the SSA plan. Winch hull insurance is also a separate product. The advantage is that the 3rd party liability now allows operation away from home base. So yes, it did increase the fixed cost of operating a winch and included a restriction against using steel wire or steel wire rope. |
#20
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Where to get Winched?
On 8/06/2012 03:50, Chris wrote:
GC wrote: The length you need is wire length - not runway length. The ground run for a launch is barely 100 yards. Any more is for landing, launch emergencies, etc. Winches are also commonly sited well beyond the upwind runway threshold. It's a very flexible launching system. While this is true, there is another reason for a 3000 feet runway: safety. You need to be prepared for a cable break at any time. Up to 300 feet you can land straight ahead, if there is enough runway left. If the cable breaks at a higher altitude, you can do a full circle or a short pattern. If the runway is too short, you can get in a situation where both options do not apply. I guess that you refer to this scenario when you talk about launch emergency. Well, yes I do. My opinion is that a cable break is no emergency, but is part of the procedure. It must be trained well, but if the pilot is prepared for a break, this is no emergency. You can expect a cable break in one of 100 launches. Ok, call it 'launch failures'. Whatever floats your boat. My actual point was that winching is very flexible. On Long Mynd, a launch emergency (or failure) high enough for a circuit sometimes means landing at right angles to the takeoff direction. The actual length requirement is ONLY for ground over which the wire can be laid out. A winch operation - unlike aerotow - doesn't necessarily require a single continuous runway. GC BTW, my last break on the winch was in 120m. Too high to land straight, so I initiated a 180 for a short pattern. After that turn, my altimeter showed 150m. I decided to do a full circle and got 200m. Now I continued and got 1300m in the end. This was fun while the guys below had to fix the cable :-) Chris |
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