I need some help on trimming my GP Giles 202. On establishing a vertical upline, I will half roll and she pulls to the canopy and to the left destroying the upline in the process. This is at WOT, engine Saito 180, propeller APC 17x6. Of course I can fly it out but it can get really ugly real quick if I botch it. Should I mix some right and down into WOT position or can anybody think of an aerodynamic fix (preferred).

JMW

John, You need differential in the ailerons. There is no way to tell how much without just trying a little at a time. Where in San Antonio do you fly at? There are several guys around that have the know how to help you out.
Jason Danhakl

John,

Jason hit it right on the head, but it also sounds like you might have some thrust line issues as well ( up or down thrust ).

The first thing I would do is enter a up line perfectly vertical and perpendicular to the flight line. Once you are headed straight up, take your hands completely off the transmitter and see how long it takes to pitch to the canopy or pitch to the belly. Also take note if it yaws off to the left or right at the same time. These 2 steps will help you make sure the thrust is set properly. After you have done this, then enter a vertical down line from way up high at idle and put in full aileron (and only aileron) and watch the flight path as it comes down. If it wanders or barrel rolls, the you'll probably need some differential as Jason had mentioned.

Bill Higgins Jr.
San Antonio, TX

John, take a look at the NSRCA website for the pattern guys. There is a good trimming guide that applies to all aircraft. I beleive the url is

http://www.nsrca.org/technical/trimm...mmingChart.pdf

It might be thrust. Fly straght and level at full power and kill the motor. See what happens. Could also be balance/incidence. The trimming guide should be able to help you narrow down your problem.

Howard

Thanks for all of your inputs, I'll give them all a try.

JMW