SeamusG,

I too have built the HB from a kit, and have about 10 flights on it. Must say, it was/is a learning experience. When building I reallly took my time in the wing build and mounting to make sure the incidence's the plans were calling out were right on. This is my first bi-plane and I still get the pucker factor when I fly it. However on my last flight, when I took off the plane was real sluggish in a climb, and very slow in response to get the plane higher and turn. I thought I maybe didn't let it get enough ground speed to lift off. It was so sluggish/waggly I was lucky I got it back on the ground in one piece. I checked the controls to make sure nothing was sticking. Everything looked good on the elevator/aileron/rudder inputs. So I took off again, but letting the plane get more ground speed before lifting off. Again the same symptoms. Got it back on the ground safely, and took the wings off and guesss what I found. My servo tray rails had come loose. Can't say if this could apply to your case, but I did have a few landings that ended up nosing the plane over on it's back a few times, which explained why my rails came loose. Didn't notice it during pre-flight, but it's part of my pre-flight now, to check the rails. I have a OS 75 on mine. Does your's have any issues on take off? Mine wants to track to the left. And I dont' think the plans showed any down thrust or right thrust numbers like most of the other SIG kits I've built.