As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
DURING HGS AIII AUTOLAND APPROACH. ACFT BEGAN SIGNIFICANT LT DRIFT AT 100'. DRIFT CONTINUED BELOW 50 WITH NO CORRECTION. DISCONNECTED AND LANDED MANUALLY. HGS APPEARED TO BE OK. ACFT GROUNDED. DFCS CURRENT STATUS - NO FAULTS AND FAULT HISTORY, NO FAULTS, REF FIM 22-11, TASK 801.