I hate to dissappoint you guys but you are not correct with regards to right thrust. Contrary to popular opinions around the RC forums right thrust is not required for engine torque or even P-factor.....which most folks do not fully understand. The only reason you need right thrust is due to the spiralling slipstream caused by the rotating propeller. Becuase most a/c have the vertical stab and rudder above the fuselage versus below, right thrust is required to compensate for more air pressure on the left side of the vertical than the right side. Many factors do come into play like airspeed and prop rpm, as well as angle of attack. Upright or inverted makes no difference whatsoever. There is no perfect solution other than to learn to compensate with the rudder yourself at different speeds and attitudes. 2 1/2 degrees of right thrust is a very good compromise for most prop job planes.