What was found
(CAN) DURING AN ICE PATROL WITH THE RIGHT FLIGHT DIRECTOR (FD) COUPLED IN `ALT` AND `ASPD`, AS HDG PRESELECT WAS SELECTED TO RESET THE DG AFTER 8 MINUTES OF FLIGHT, THE `FD DECOUPLED AND `AP 2 DEGRADED` CAS WAS DISPLAYED FOR A FEW SECONDS. DURING THE WHOLE FLIGHT, EVERY TIME THE PILOT TRIED TO RESET THEIR `DG` THE `FD` WOULD DECOUPLED EVEN IF THEY SOMETIMES COUPLED IN `FMS` MODE INSTEAD. ON SEVERAL OCCASION DURING THIS FLIGHT THE `ALTN DATA FAIL` AND `DATA BUS` CAS WERE DISPLAYED FOR A FEW SECONDS. (TC# 20190712002)