the B-17's tail wheel, it does have a locking tail wheel, like the DC-3/C-47
Thanks, I have no knowledge of B-17's. That said, When I was trained in the DC-3, I was told to assure that when I let the tail down after touchdown, I had the plane aligned with the runway, 'cause once the tailwheel was firmly on (presumed locked), that was where the plane was going to go. I never did any single engined work on the runway, so am unfamiliar with the forces involved, but rnzoli's really helpful image makes the forces at work here very hard for me to imagine. If the plane were ground looping, it'd be headed the other way out of [into] the turn! But, for me, most puzzling is the distance covered where the tailwheel path was so parallel to the mainwheel path. To see the tailwheel path veer out, and back in again (or ground loop completely) is not so hard to imagine, but running parallel for that distance is.