Hi there - I'm tossing this thread into the Beginner's Formum because I believe that there's some good trimming basics that I'm missing that will be helpful for the newbies.

I have a Hog Bipe (HB)with a Saito 100 under the hood. I set its static CG using a Vanessa Rig. Being a biplane it's somewhat problematic knowing where the actual CGis. I thought things were somewhat nose heavy. The static lateral CGwas established using a wire-over-the-celing-joist rig. The control surface throws were set up to SIGspecs.

I've got 4 "good ending" flights on it. Definitely puts a smile on my face big time. But I noticed a couple of things. The HBis a bit twitchy in the back end. Rudder input moved the backend back and forth pretty aggressively. Most noticeable when I did a stall turn - the down line was really twitchy - kind of a tank slapper on the way down. My exponential is at 30%(DX7). Ditto observation on the elevator but less noticeable.

The 5th flight didn't have such a good ending to it. I was doing fly bys straight-n-level at 10 - 15 feet. Not trying to do a touch-n-go just checking out my visual reference points for getting the plane comfortably centered over the runway. Speed (I think)was about 1/3 throttle. The plane then started an aggressive glide path towards the concrete runway. I applied (what Ithought was)full throttle (smoothly but quickly) and applied back (up) elevator. The plane sped up but didn't climb. Seemed to do an aggressive flare at 5 feet (yuk). Nice 3-point landing with the throttle nearly full bore. The nylon landing gear bolts (31/4x20) sheared off and the plane veered a bit to the right into nice soft dirt and did 2 very nice cartwheels.

All things considered this will be a pretty simple repair. As a buddy used to say about the first scratch on a motorcycle - "ain't a virgin any more, just get back on and ride!".

Back to the thread. What are the basic steps in trimming a biplane. Please identify those things that are similar to a high wing/low wing trainer and those things that a biplane flying fool has got to tell you that come from real life experience (preferrably good experiences ).

TIAfor your input.