As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AFTER TAKEOFF LEFT MLG STAYED DOWN . LEFT GEAR DOOR LIGHT WAS ON. LEFT GEAR UNSAFE LIGHT WAS ON. RETURNED TO FIELD. LANDING UNEVENTFUL. NO PRESENT FAULTS IN PSEU. COULD NOT DUPLICATE PROBLEM WHILE DOING GEAR SWINGS. REPLACED SECONDARY MLG SELECTOR VALVE FILTER FITTINGS. PERFORMED RETRACTION AND EXTENSION OF THE LANDING GEAR NUMEROUS TIMES IAW 32-31-00-867-801. NO DEFECTS NOTED. CHECK FLIGHT PASSED. RETURNED TO SERVICE.