After the plane takes off i cant get contorl of it easily. When i turn it, it works, but when i pull back and try to lift up sometimes it goes up a few feet and then falls back to where i was, sometimes it wont go up at all, sometimes it goes down instead or up, and sometimes if i lean it forward trying to descend it will go straight down to the ground and when i try to pull up it doesnt move at all, it just keeps going straight down. I can never get it above the initial altitude the autopilot gets it to. This is only with the Lancaster III bomber, all the other planes work fine for me but i want to know why this happens and what i can do to overcome it.