As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
FLT 872 - TRI-CLT - EN ROUTE TO CLT, BOTH ILW WERE UNRELIABLE AS WELL AS BOTH VOR NAVS. WEATHER HAD DETERIORATED IN CLT SO CREW DECIDED TO RETURN TO TRI. FLIGHT LANDED AT TRI WITHOUT FURTHER INCIDENT. MAINTENANCE REPLACED NR 2 HSI, LEFT AND RIGHT NAV RECEIVERS, AND LEFT AND RIGHT NAV CONTROL HEADS. REFERENCE USAAF97001