Chapter 17

Pitch and Roll Trim

The trim system allows the pilot to trim the aircraft for certain attitudes of flight and not have to apply as much pressure on the stick to keep it in that attitude. The Roll trim, while shown in the plans, will not be installed since I am installing an autopilot that controls the roll axis. While not using the autopilot, roll trim is rarely used and I'll most likely do without it. However, if I find that I do need some sort of roll trim, I will probably add a small servo driven trim tab to one of the outboard wings.

The pitch trim will also not be used as the plans call for. I have decided instead to install an electric pitch trim system by Alex Strong. The motor is attached to a spring loaded rod that connects it to the control stick on the co-pilot's side of the aircraft. The spring load is available to override the system should the motor fail. The trim will be controlled using a hat switch on my stick grip. The electronics involved are a couple of relays mounted under the pilot seat. Here is a photo of the trim motor as installed.