As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
RIGHT PACK TRIM AIR PRSOV STATUS MSG 21-24202 APPEARED WHILE TESTING RT PACK PROBLEM. WHILE TROUBLE SHOOTING RT PACK FAILED 21-51T816 WITH MSG 21-24202,WITH MANY HIS AT TAXI. REPLACED R TRIM AIR PRSOV. GRD TEST AGAIN PASS, NO EXISTING FAULT.