As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER DEPARTURE, CREW WAS UNABLE TO RETRACT THE LANDING GEAR. LT MAIN GEAR INITIALLY RETRACTED THEN RETURNED TO A DOWN AND LOCKED POSITION. RT AND NLG OPERATED NORMALLY. AFTER COMPLETING THE GEAR MALFUNCTION CHECKLIST CREW RETURNED TO DEPARTURE FOR A NORMAL APPROACH AND LANDING. UPON INSP, LT MLG UPLOCK SWITCH FOUND TO BE FAILED. REPLACED SWITCH.