Hi folks. I have a Great Planes turbo raven arf with a swept wing. The manual calls for 5 5/8 at the root. This is also just behind the wing tube. At this point, I'm extremely nose heavy which I wouldn't think I should be having the bigger of the engine size that they recommend. Does this look about right? I put the battery over the wing tube so you could see where it is.

Steve, that looks about right to me. To be safe you can calculate out to see where 30% of MAC is. Another good thing to do would be to compare it to a G-202 of the same size. The Turbo Raven was just a modded G-202.

try this website. Dan.

http://adamone.rchomepage.com/index5.htm

Thanks guys. I consider myself to be a descent builder. I usually build what I fly, so I definitely understand CG, but its the first time I encounter this much sweep. Figuring it from the root, at the widest part of the chord, it works out to be somewhere around 45% MAC. just wanted to be sure. thanks again.

MAC is not measured at the root chord. Mean Aerodynamic Chord is the AVERAGE chord length. Your MAC will be somewhere mid span, find the CG at that point, then transfer it to the root. That being said, behind the tube seems roughly the right spot. Just want to be clear to hopefully save you from a crash.

Red

Thank you. I did some more research, and spoke with a few people who have experience with this actual airframe, and I'm glad I did. They all say the same thing. "DO NOT MAIDEN AT MANUFACTURERS SUGGESTED CG" appearantly where they say is extremely tail heavy and I should be balancing at 1/2 inch forward of what Seagull recommends.