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	Christer Jun 17^th, 2013 at 1:32am where have you been, Mr. Christer? I missed you for a few days. Vacation?
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Christer

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	Re: Christer Reply #1 - Jun 17^th, 2013 at 4:33am I've been away from home for a few days. We had to go to Germany to a company called Schleicher with an engine for our self launching glider. A three day trip which also includes a visit to Kreuzberg for a few beers.
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	Re: Christer Reply #2 - Jun 17^th, 2013 at 10:51am is it your opinion that germany, on average, makes the best beer? a self-launching glider? seems like something of an oxymoron, no? when i lived on the north shore of oahu (hawaii) we lived walking distance from a glider park there. beautiful, silent, scenic.
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Re: Christer
Reply #3 - Jun 17^th, 2013 at 12:26pm

I like German beer but other breweries in Central Europe (Poland, Czech Republic) also make good stuff. Which is the best is a matter of taste and there are nice Swedish beers as well.

There are Touring Motor Gliders and they look like normal airplanes, work like normal airplanes and are used more or less like normal airplanes. A Self Launching Glider is different. When the engine/propellor has been retracted there is no difference compared to a normal glider.

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	Re: Christer Reply #4 - Jun 18^th, 2013 at 12:46am Christer wrote on Jun 17^th, 2013 at 12:26pm: When the engine/propellor has been retracted when do you retract? up in the sky? what about the weight of the engine?
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Re: Christer
Reply #5 - Jun 18^th, 2013 at 1:51am

We use the engine to get airborne and at some 500-1000 meters altitude the engine is shut down, cooled a bit and finally retracted.

The weight of the engine is an issue. It is fitted in the rear fuselage and that makes the glider tail heavy. That has to be trimmed out by fitting lead weights in the nose. When the engine is removed, the trimming weights are also removed.

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	Re: Christer Reply #6 - Jun 20^th, 2013 at 2:25am with the extra weight, the glider drops more quickly, no? less time in air = less fun ? seems that lightness is a big part of what makes a glider so special. i sound like a purist.
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Re: Christer
Reply #7 - Jun 20^th, 2013 at 10:49am

Well, it's not that simple. You need light weight to climb well but you need weight multiplied by altitude to convert into speed. The more you weigh, the less altitude you lose while gliding. Sounds wrong but that's the way it is. If the weather is strong with good lift, we put water ballast in to get up to maximum weight. If the weather gets weaker, we get rid of the ballast.

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Re: Christer
Reply #8 - Jun 28^th, 2013 at 2:39am

You can have a look in the sales brochure for the ASH 31 Mi. On the first page in the center, there is a drawing with a polar, plotting speed (km/h) versus sink rate (m/s). At full load (53,2 kg/m2), it doesn't even fly at the lowest speeds (75 km/h) and the minimum sink rate is higher. At higher speeds (over 125 km/h) the higher wing loading (kg/m2) results in better performance.

A way to explain it or at least try to: You have to convert potential energy to dynamical energy. Potential energy is the product of weight and altitude. The more you weigh, the less altitude you have to sacrifice. The higher minimum sink rate is explained by higher drag of the wing to carry the extra weight.

Old chinese proverb:
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