Thread: Build Log Piper Cub Sailplane
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Old Oct 13, 2012, 07:54 PM
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United States, CT, Fairfield
Joined Mar 2012
728 Posts
I agree, a nice slope would be ideal for test flights however where I live here in Connecticut, all the hills are either covered with trees or urban sprawl. The closest slope soaring spots are hours away.

Paul you're not alone in suggesting she may have been tail heavy. I'm not convinced she was though, as I'm pretty meticulous when it comes to balancing my planes but I can't ignore the possibility. We'll never know for sure as I've re-balanced her now that she's been modified. This time airing on the side of caution I've set the CG further ahead of the neutral point, at 15% static margin (last time was around 8%).


After Further Analysis...
Well I goofed up. I've no clue why I chose to just eye-ball the location for the high-start hook, especially as I'm well aware of the 30 ahead of the CG rule for tow-hooks. Look how far back I had my tow-hook positioned!..



Its no wonder she behaved like she did, I had the tow-hook WAY TO FAR BACK...



Aerotowing
So lets simplify things. I lobbed off the nose-skid & "tundra sized" wheel & now we have a nice smooth fuselage to work with. The wing struts are history too...



After re-balancing here's how she sits...



Unfortunately due to the Guppy shaped fuselage the tail is still up in the air & it looks like she'll probably rock forward on her nose again during aerotow. Still though I think its an improvement. At the very least she looks cleaner...



I'm going to concentrate on aerotowing for now. I'll worry about adding a new high-start hook later on.

So anyway, weather permitting, we'll give her another try tomorrow.
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