Wait-No Need to upgrade. I have a jr 421ex(5 channel). I have quad flaps set up. You can't do crow or couple flaps to ailerons or all the other cool stuff, but I hooked flaps up to my gear switch, flip it and boom,flaps are down. It almost essential for flaps to keep landing speeds good. With flaps it lands slower than my trainer, without them you would almost certainly shear the gear off with the speed you would need to land. Hopefully this helps-remember, a 5 channel radio with yharness is all thats needed for flaps, but no crow, flaps to ailerons, ect.