As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
WHEN FLAPS WERE SELECTED TO 30 DEGREES ON FINAL APPROACH TO SLC, THE FLAPS WOULD NOT EXTEND PAST 15 DEGREES. THE AIRCRAFT LANDED WITHOUT INCIDENT. MAINTENANCE LUBRICATED ALL FLAP JACKSCREW GIMBALS PER MM 12-22-21. THE FLAPS OPERATIONALLY CHECKED GOOD SEVERAL TIMES IAW MM 27-51-00.