every model i have owned capable of iverted flight (world models-worldstar 40, GWS mustang, sledge 540 and an old VMAR hotrod) have always rolled to the left when inverted, but when upright they fly fine.
considering the sledge has a fully semetrical wing, its the worst out of them all, no good for inverted harriers. it makes outside loops look untidy and difficult to get them even.
does torque have anything to do with it?
thanks.

Its possible, but to me it sounds like more of a lateral balancing issue and or a thrust line problem. I have never had a plane do that when inverted it usually tracks as straight inverted as it does upright.

I'll bet you dollars to donuts these airplanes are all built with a little bit of right thrust. That helps offset torque when upright, but actually assists torque when inverted. In other words, if the torque wants to pull the airplane left with a value of 1, the right thrust has a value of 1 which cancels it out, resulting in a left pull of zero in upright level flight ... but flip the airplane upside down and you have a left pull value of 2.

The fixes are:

1. Remove the right thrust and re-trim rudder and ailerons,

2. Tape some spare change to the left wingtip and re-trim rudder and ailerons, play with the amount of weight until your inside and outside loops act the same, or

3. Just live with the fact that to do an outside loop that's straight, you will need a shade of left rudder and a shade of right aileron.

Duane Gall
RCPRO

I also will bet on lateral balance. Most engines have the muffler on the right, causing a need for left aileron to correct. When inverted the muffler weight is already on the left and the left aileron adds to the left roll.

Do a static lateral balance.

Paul