How fast do small airplanes fly?

Apparently, as slow as zero mph.

The Concorde was supersonic (2.2 mach), and compared to today’s jumbo jet liners, was relatively small. Of course, it’s no longer flying.

Gulfstream makes several planes, the largest of which can carry up to 18 passengers at speeds approaching 0.90 mach.

Virgin Galactic’s Spaceship Two -class sub-orbital craft reach speeds of 3.0 mach.

The Eclipse 500 Very Light Jet can cruise at 425 mph with 4 occupants. Max mach is .64.

I have a Bonanza and we can usually get to 185 knots with a nice tail wind. If your talking about jets, the Citation X by Cessna is the fastest passenger jet you can buy, it goes mach .92.

We have a Piper Meridian single engine turboprop and it goes 270 Kts (about 300 mph).