as a kid in the 1950’s, my dad would take me to our small town airport and watch the planes come and go. There was a regional airline that flew DC-3’s. When it came it, they would turn parallel to the fence (literally 20 yards away) and leave the outboard engine running while passengers boarded and debarked. I can still hear that ka-thumpa ka-thumpa ka-thumpa.... of the radial running. Now, burned into my mind!
When I go to air shows today, I always tell my family that it's mostly to listen. They think I'm a bit "off"