Slack line crash.

I've been having trouble with my foam wing ringmaster, it's scratch built from old plans. It flew great as long as the plane was upright. Inverted loops gave me trouble. I hit the ground several times at the bottom of the loop. Three times in one session. Today I came real close to doing it again but missed somehow. I went higher and tried again but the lines went slack and it lawn darted into the ground. The wing didn't have a scratch though. I cleaned the engine off when I got home and ran it. The ground is soft now. I did a first flight on a new design called the Ringmaster 307. It's a .15 size plane with 307 square inches in the wing. It flew real nice. This was before crashing the other plane. My Twister gave me fits the other day. I forgot to add the spinner and muffler so the c/g was way aft. It jumped all over the place and almost crashed but I saved it. I had it in the car today but didn't want to push my luck. I added all the heavy things and added heavier landing gear to boot. It should fly good like before.Now I have a wing with out a fuselage. But I think the wing was the cause of my problems so I'll let it sit for a while. Maybe make a trainer out of it. I'm planning on visiting the contest at Brodaks in June. It's a big one, 6 days. It's in southwestern PA. and you can't get there from here.