As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
THE LT MLG DOOR WOULD NOT RETRACT AFTER TAKEOFF FROM SFO. THE AIRCRAFT WAS RETURNED TO SFO WHERE IT LANDED WITHOUT INCIDENT. MAINTENANCE REMOVED AND REPLACED THE LT MLG DOOR ACTUATOR IAW MM 32-32-81. LEAK AND OPERATIONAL CHECKS WERE GOOD.