Hello all,
I'm new to pattern flying and decided to buy a used plane to see if I liked it. My plane is a Sportsman Aviation Excelleron 90. The engine is a Saito 125. I bought the plane used from a guy on RCU that has owned three of these planes over several years. He says he loves the plane. Seems like a real nice guy. He recently decided to go big and do IMAC stuff. My problem started on my maiden flight. I didn't check the CG on my first flight because the previous owner said it flew just fine. On my first flight right after take off the plane seemed drop the nose. I added seven clicks of up trim on my DX7 radio. No problem until I rolled inverted. Went for the ground. I went home and checked the CG and found it to be on the rear most limit of the CG with empty tank. FYI the CG range is 6 3/4-7 1/4. Thought that was odd given the up needed to fly straight and level. On advise of a experienced pilot I moved the CG back to 7 1/2" by adding 2 1/4 oz of tail weight. Flew the plane and it still needed up trim. I then suspected the stab incidence was off. I checked it and only found the leading edge of the stab to have + .7 degree. Doesn't make sense. I then made a dramatic change and moved the CG back another 1/4" to 7 3/4" by moving my receiver pack 6" rearward. Flew the plane another time. NO CHANGE in trim. Still needed seven clicks of up trim.
I'm at a lost as to what to do to correct the problem. Please HELP. FYI I have been flying model planes since I was 18 years old. I'm 57 now. I have never had this much problem trimming out a plane. Where to go from here? Thanks in advance for any help on this matter.
Frustrated
Bob Nellor