"Kev" wrote ...

Of course, LIGHT does not mean "light aircraft". Some 152s are
vortex HEAVY in the case of big instructors and students ;-)

I see your point ;-)

However, I've never seen a condensation trail behind a C152 wingtip. Not
that it necessarily means anything.

But you made me think about air viscosity, i.e. friction that dissipates
turbulence. One might argue that a C152 flies in relatively "thicker" air
than a B757 and thus a vortex or downwash might not propagate away from the
flightpath as easily. How far from a bumblebee can its downwash be felt?

Just rambling ... ;-)