Hi Sandor: I'll respond to this in my typical fashion. type in rcfaq.com, Click on flying faqs, scroll to trimming your plane, and click on that, explore the whole site, it has a wealth of info. on it. To trim a plane proper with out any instructions to go by, you have to fly the plane in different attitudes, and observe how the plane reacts. I won't go into it because this site explains it better then I could on my best day, in fewer words, that even I can understand. I know this is not much immediate help, but it is the best I can do, sorry. Always glad to help if I can. Garry