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Old Sep 15, 2012, 03:20 AM
Joe W is offline
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launch low, fly high
New Zealand, Hawke's Bay, Havelock North
Joined Dec 2004
2,132 Posts
Quote:
Originally Posted by kdt View Post
...I think Joe likes the tow hook area... Another question Joe
Yes, I hold at the towhook.


Quote:
Originally Posted by kdt View Post
Technique seems to be a very big factor. In France you did very fast zoom launches in reflex with a two man tow that resulted in over 100 meters. Are you using a similar technique with the mega bungee? Some pilots I've seen are getting a lower but faster launch by doing a quick deliberate pop off. This would not be very efficient use of the bungee stretch. Very often you hear the chute pop with the left over tension not utilized by the model on launch. It seems a bit daunting to measure this with so many variables.

What are your ideas on technique in various wind conditions to maximize the height time relationship? How do you measure this? How much does your technique differ with a 2 man tow over a mega bungee for a short tow?
Technique matters... Even with the same start tension, the launch tension/height will definitely show who is throwing with more energy. I've seen this demonstrated many times.

Yes, I got pretty well trained for the quick tow via practice with my bungee. I tend to get about 100m of launch height with a quick tow, whether from a f3j hand tow or from my bungee.

The time/height optimization is not an easy one to sort out. So much of the answer is dependent on what the pilot thinks is the best choice given the conditions (good thermals?, wind?, length of contest?). With the advent of the 1 pt/ 20 cm landing tape, there is a bit less emphasis on the absolute shortest tow. That said, in some conditions a short tow is very much desired (for example, the cup event prelim rounds held prior to the South Africa WC). With the bungee, you have to factor in the energy in the bungee so as to sort out when it is the best time to zoom. With light to no wind, the best time to zoom is only a couple of seconds after the throw if you are going for maximum height. BTW, it does not take much wind to change this. Just a couple m/s of wind and the highest launch results from a zoom at around 50-60 deg up as measured from from the stake location.

BTW, I'll have my bungee with me in Muncie next week. If DW brings his bungee, he and I can do some death-match bungee style competition while practicing for the comp...
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