system
Given the following post, respond as if you're commenting on Reddit:
human
Why don't planes use single blade propellers with a counterweight?

A two blade design creates more drag comparatively as one blade must travel through the wake of the other, so wouldn't the weight of the counterweight be overcompensated by the increased efficiency?
gpt
In order to generate the same amount of thrust as a double-bladed propeller, a single-blade propeller has to turn faster. You're correct that due to the wake, a double-bladed propeller produces slightly less than twice as much thrust as a single-bladed propeller (for a given rotation speed), however a more important factor is efficiency loss due to the tips of the propellers reaching the speed of sound and creating shock waves. Therefore it is desirable to have more blades that can turn more slowly, rather than a single blade that has to be turning very fast (of course there are other reasons, such as the strength of the blade and engine performance at high RPM).