Altitude effects?
In 2010 i took my Weston Magnum to the Carolina Speed Rally. The plane was well flown here in southwest Florida and flew great. On the first launch at the rally it rolled to the left (if i remember correctly) and i almost lost it. It took tons of trim to get it flying straight. When i returned to Florida and flew it again i had to reverse the trim i had used in NC. I don't think the field was at any ultra high altitude but something caused the Magnum to roll stupid. I had a Jett 50LX in it. Does a change in altitude cause that much difference in torque or could the control rods have expanded/contracted? I still have not figured out why this thing went totally stupid. Anyway, i have built a new MagnumR with the same Jett 50LX but have installed two identical servos on the elevators and eliminated the dual-control rod setup that is designed in the kit. I also installed Sullivan inner pushrods in the elevator tubes which fit much more snuggly than the ones in the kit. Anyone have ideas about why the plane would roll so dramatically between a field in southwest florida and north carolina?