As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT WAS OPERATING UNDER 14 CFR 141 RULES IN IMC CONDITIONS WHEN THE AIRCRAFT EXPERIENCED AN INSTRUMENTATION FAILURE OF THE HORIZONTAL SITUATION INDICATOR. INSTRUMENT WAS OPERATING NORMALLY FOR THE FIRST 30 MINUTES OF IFR FLIGHT AND BECAME DEGRADED AFTER ENTERING TURNS WITH THE AIRCRAFT. INSTRUMENT WAS REMOVED AND SENT TO LOCAL AIRCRAFT INSTRUMENT SHOP FOR REPAIR, UPON INSPECTION IT WAS FOUND THAT INTERNAL BEARINGS WERE WORN TO SERVICEABLE LIMITS.