As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RAD ALT READ 0' AT FL290. DURING DESCENT "LG" WARNING AURAL. QRH PROCEDURES PERFORMED.-C/A-REMOVED LOTS OF COFFEE COATING FROM F/O RAD ALT ANTENNAS WHILE CLEANING THEM. CMC SHOWS NO R.A. FAULTS FOR 5 PREVIOUS FLIGHTS TODAY. F/O RAD ALT OPT CHECKS GOOD PER AMM 34-31-00.