Before you go trying any expensive stuff, check your rubber bands. If they are loose in front you can get a jump when the front of the wing picks up, then yanks the fuselage behind it. It'll scare the **** out of you.

Rubber bands should be installed from front to back. When you stretch them out and put the end on the dowel, that end has less stretch than the starting end. I'll bet you are installing yours from back to front, a common, but incorrect, way to do it.

For climbing under power, you need 2 popsicle sticks under the trailing edge of your wing. You'll know when you need them because on the ground, your elevator will be trimmed down. This is a sure fire indication of too much power for the incidence or too much incidence for the power. You may also notice you have to hold a lot of up elevator on final approach before landing.

Start with 2 popsicle sticks, and increase if you need them. You can glue them in after you find the correct amount.

By the way, I teach an aerobatic maneuver every month in my column. Some are advanced maneuvers, but many are able to be done by trainers. I have recently started over with the simple maneuvers like aileron roll, loop, etc.