Flight paths of rubber powered models

 15 February 2022

Initial torque of rubber is large and decreases rapidly, except for those very lightweight indoor see-through type of models which has a very long run. 

On power drive, the model flies in left circles. It is possible to fly in right circle during the power phase but that would mean lots of right thrust to overcome the torque.

I think I will have left circling powered flights.

When the power lessens or ceased, should the transition be continuing with left circles? I'd like that but I think my glide will be right circles. This presents a problem. If I trimmed the model to glide right, that also means that anything other than a right glide will be draggy, it will stall when it is flying straight for a short portion. There's always a straight portion in a S-flight path.

So, should I aim for a C flight or a S flight? 

After thinking it through, a S flight for torquey model to minimise power dives and a C flight for longer runs indoor type.

Features of C flight models, flights that yaws to fly left:

• long motor runs, low torque, big propellers
• longer left wing
• more wing incidence
• more right thrust
• Yawing flight: left rudder for left glide, wash-in at left wing, wash-out at right wing to keep wings level.

For my Herr Engineering's Tri Pacer, the instructions call for a S flight. I may have to re-read that. A modeller replied my query and said he had the same model and did left/left, i.e. a C-flight, with minimal adjustments.