If it does apply only to turbines, maybe they could clear up all ambiguity by simply amending the rule to:
-All turbine powered aircraft (not all RC aircraft) must have a rudder.
Seems a simple enough thing to do. Even being in that particular section, it has raised some eyebrows localy due to the wording.
Other items in the turbine rules specify turbines, and do not use the blanket statement "all RC aircraft" such as:
21. "Turbine engine RC models shall not be flown during any period of darkness...."
....so why not this one??
Is this like Washington law makers piggy-backing bills onto others being passed, with intent being hidden with-in other "higher-profile" items? I'm optimistic that this is not the case.

Brian

PS- Any of you waiver holders out there have a CL turbine?? I see some rules for CL in the turbine section too, and was wondering if these too applied only to turbine engines.
CL turbine....too crazy!! hehe