I flew a Viking that had a habit of dropping a wing at the stall (to the left), if you flew it slow it would always drop that wing, despite reporting it several times nothing could be found including after a geometry check. Still reported as No Fault Found !!!
Even odder was if it got chilly and we got condensation on the parked aircraft, that particular Viking would always have the port wing with condensation on it well before any of the others !! (cant remember the tail number).
I never enjoyed flying that one when I appeared on the rota for it..............
Arc