On last 2 flights, 35 mins from EGKA to LFAT and back, I noticed a strange screeching noise after landing. It was audible only with headset lifted off, only after touchdown, only when the rpm was below about 1300, and it lasted only a minute or two, it was rpm related, and not related to aircraft motion. It sounded like a motor bearing failing… The causes could have been the engine (not...