Hi!
I would say that all R/C planes are controlled with just ailerons and elevator!!! Certainly my Marutaka DC-3, PBY Catalina, , 33 % Yak-54 and all my sport and pylonracers through 35 years of flying.
Rudder is used when taking off (but not necessary) or when doing certain manuvers.

There are exceptions to this (No rudder flying) and that is large ,slow flying high winged planes like 1/4 scale or larger CUB´s. Then you need rudder in some cases.
Yes I use rudder occationally ,just for fun! But it's not mandatory when flying an R/C model.


The P-20 could benifit from using ailerons, but remember to straighten the wing if you intend to use ailerons. Using just rudder requiers more wing incidence