The Carrier event fliers typically use throttles and a third wire. Also many of the scale planes have throttles and sometimes even more operational features such as landing flaps, lights, bomb bay doors, retracts, etc.

Still when it comes to throttle in C/L there is not much real need for midrange speeds. Usually you want all the power an engine can deliver and still be reliable. As for low throttle In Carrier the basic goal is to slow down the aircraft to is to the slowest speed possible and still maintain control and also for high end for the maximum speed possible. These are two points on which Carrier is judged

Speed and other racing events obviously demand one thing... RPMs!

Stunt is all about smooth consistant runs with lots of torque.

Just plain old sport flying has been done with throttles as well. This is often where a lot of experimentation takes place

The J Roberts control line system was developed and marketed for the purpose of the three line control for C/L.

For more info on multifunction handles look here:http://website.lineone.net/~triggerfish/handles.htm

The downside of an extra line is extra drag and a little more weight on the inboard wing panel. Lose the extra line and you have more usable horsepower available from the same powerplant. Also with the extra weight and drag on the inside of the circle makes it more difficult to maintain line tension. Ya gotta have that! This means possibly more weight added to the outboard wing tip and also more rudder offset to help keep lines tight. The trade off to this is even more overall drag besides the extra line.

That said, You can if you want to! Its been done by plenty of others!

Quote:
"I haven't flown a CL plane since the mid '70s. I guess I should buid one just for fun."

Yes, you should!

For more info you should check into these guys here:
http://stunthanger.com/ and click on Stunt forum. its free to join there and they have catagories that include Scale and Carrier forums. Anyone there would be glad to enlighten you.

Robert