ORIGINAL: Stratman
Thanks for the replys.
What is excessive decalage? is it the area over the canopy and turtle deck?
It has a tall fuz.
I was sure I had the cg quite far back on the second try because it was twichy at the back and the wings got tippy, cg was 4 1\4 in back on a 15 in root cord but still needed lots of up.
You mention thrust line... Yes this could be wrong, I built it with the engine thrust line, the wing and the horizontal stab on the same line but I did not put any left or down thrust on the engine.
Coming in to land was hairy beacuse the back end is hard to control, too sensitive on the sticks.
I've had a somthin' extra for about a year and I have always found this to need up elevator to fly level apart from when I open the throttle wide. The cg is about 3\4 in after the spar on the SE.
"decalage" refers to the difference in incidend angles between the upper and lower wing of a biplane.
Inappropriatley used here.
The correct term for a difference in wing and horizontal tail incidences is "longitudinal dihedral".. Think on it, it makes more sense.
Since you have a constant chord, the usual SE problem of a too far forward c.g. should be considered.
The c.g. on the SE plans is at 23% mac.
Most acitive SE's find a 35% c.g. better by far... for your chord, that would be 5-1/4".
And pitch sensitivity is as Montague says, due to excessive elevator throw, especially with your forward c.g..