Don't a lot of older small craft—such as seaplanes—have radial engines?
Sure, lots of older aircraft (and lots of modern small aircraft) run on avgas or diesel, whether radial or inline. But Harbour Air's fleet is almost all turbines. I think they have just a single non-turbine aircraft: https://en.wikipedia.org/wiki/De_Havilland_Canada_DHC-2_Beav...
>Viking DHC-2T Turbo Beaver
>Remanufactured Beavers by Viking Air, upgraded with a Pratt & Whitney Canada PT6A-34 680 hp (507 kW) turboprop engine.
The Russian ASH-62 is still in production, and depending on spec can produce as much as 1100hp.
No, it isn't. The "new" 62 are just old stock, or made from old stock parts, or rebuilt frankenstein engines with some new parts, or are Dongan HS-5 restamped as original 62 to pass the type test.
I used to be an aviation fan in my childhood. Tried to build a motoglider, but the process stalled before I moved out of the country.