Algherghez

What is the correct T/O range of speeds and trim? Have you done any testing on that matter? I'm taking off with trim neutral gently pulling the stick around 250kph but it's very wobbly

After engine start i try to taxi, rpm goes up, and the plane starts trembling like something is holding it, but parking brakes are off, brakes also, brake pressure is at 0 and choks are off.