As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIR TURNBACK: FLT NR 8202 JNU-SIT. ENROUTE TO SIT FROM JNU THE CAPT'S EFIS (ELECTRONIC FLIGHT INSTRUMENTS SYSTEM) COMP HEADING, PITCH, AND ATTITUDE FAILED. SINCE COPILOT'S SYSTEM WAS OPERATING NORMALLY. A DECISION TO RETURN TO JNU WAS MADE SINCE PARTS WERE NOT AVAILABLE IN SIT AND MX COULD BE ACCOMPLISHED. R&R NR 1 AHRU (ATTITUDE HEADING REFERENCE UNIT).