gismo
Touchdown! Greaser!
Given that there about as many definitions of "middle class" as there are families it seems likely that the majority of private piston singles fit into at least one of them.Maybe my memory is faulty, but I remember seeing some statistic someplace that the vast majority of pilots flying single engine pistons are in the middle class economically.
One of the simplest definitions is "people who actually work for a living or did before reaching retirement age". If you are living off accumulated wealth you're too rich for the middle and if you're living off government handouts you're too poor. Everything else is "in the middle".