What was found
STL - CREW REPORTED STANDBY ATTITUDE INDICATOR FAILED. FLIGHT RETURNED STL LANDED WITHOUT INCIDENT. REPLACED THE STANDBY HORIZON INDICATOR AND INVERTER. SYSTEM GROUND CHECKED NORMAL OPERATION.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
STL - CREW REPORTED STANDBY ATTITUDE INDICATOR FAILED. FLIGHT RETURNED STL LANDED WITHOUT INCIDENT. REPLACED THE STANDBY HORIZON INDICATOR AND INVERTER. SYSTEM GROUND CHECKED NORMAL OPERATION.