system
Given the following post, respond as if you're commenting on Reddit:
human
helicopters have rear rotors to control spin, why don't single prop planes need to control roll?

I get that the rotational torque of a helicopter's main rotor needs to be offset to prevent it the body from spinning in place--and that is what the rear rotor is for, makes sense. But in the case of a single propeller plane, why doesn't it need some smaller prop/rotor at the wingtips to help with the rotational force that would make it roll?
gpt
Small single engine aircraft DO in fact have torque-based roll and thus turning tendencies.  However the wings and flight control trim counter roll and rudder trim counteracts turn tendencies.  The mass and surface area of the prop compared to the mass and area of the aircraft is a much smaller ratio.