After two crashes, one a week ago Friday in the trunk of my car when my flight box turned over on the tail of my trainer, and the second this last Friday, I am forced to spend a bit of time in the shop, not at the field. While I'm putting things back to gethere, again, I want to address some bad habbits my plane has.

I think I know the cause of the last crash, a nose high stance on a trike gear. Just at the point of rotation for take off, the tail would lift just a bit and one wing would drop. I figure I was pushing on the nose wheel and it just fell over. It does bring up the question though of just how to set up the plane.

I've read Dean Pappas's Triming from the ground up series in Model Aviation and he has cleared up a bunch of my questions. One lingers though and he breifly touches on it. My trainer is an ARF, and is sadly lacking in useful information on just about all aspects of setting the plane up. There is no reference to a Datum line and what the incidents of the wing and stablizer should be and what the down and right thrust of the engine should be. My first couple weeks were spent trying to figure out what was screwy with the way it handles. First, the CG was set with a slight nose heavy, but we had to trim in quite a bit of down elevator to get it to fly level at cruise speed. Having just read Dean's first installment, I got out my old machinest protractor and tried to get a set of angles that I could relate to the values in Dean's article. What I discovered was that the wing was about 8 degrees away from the stablizer. Dean shows a 4 degree difference in his example. So, I shimmed the trailing edge up about 3/16" and that did eliminate the down elevator trim issue.

Now, two problems show up. First was very agressive climbing at full throtle and nose over steep glide at idle. I believe this is due to insufficient down thrust on the motor. The second issue was lack of elevator response near touch down on landing. We dialed in all the additional up elevator possible and while it helped some, it didn't resolve the problem.

Along came the crash in the trunk and I had to rebuild the stabilizer and elevator. While I was at it, I gave the elevator an additional 1/4" of cord. That seemed to answer the lack of response, but the additued on landing is still a problem. I cut the throtle back on approach and the plane wants to nose down. I'm fighting to keep it level with the elevator and then it starts getting soft. I've had a couple really hard landings as a result. After Fridays crash took out the firewall, I decided to start from scratch on getting the incidents and down thrust where they belong before going back to the field mid week.

My questions, 1. is there a rule of thumb for incidence angles and down thrust. 2. Is my approach of developing the angles and working on the relationships vs worrying about the datum line the right approach. Last, 3. The wing is flat bottomed, but only from about 1/3 the way back. If I draw a line from the trailing edge to the leading edge, the leading edge is 3/4" higher than the extended flat bottom. I expect I have a semi symetrical airfoil vs the flat bottom trainer wing. Am I correct in using the cord line as my reference for wing incidence vs using the flat bottom ?

Sorry for the long winded question, but I'm kind of grouping in the dark for a light swithc here.

Don