What was found
AIR TURNBACK, CAPTAIN NOTICED THE PRIMARY TRIM WAS NOT RESPONDING. FIRST OFFICERS PRIMARY TRIM SWITCHES ALSO DID NOT RESPOND. R&R PRIMARY STAB TRIM DRIVE UNIT IAW MM.
As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
AIR TURNBACK, CAPTAIN NOTICED THE PRIMARY TRIM WAS NOT RESPONDING. FIRST OFFICERS PRIMARY TRIM SWITCHES ALSO DID NOT RESPOND. R&R PRIMARY STAB TRIM DRIVE UNIT IAW MM.