As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
AIRCRAFT OPERATOR REPORTED THAT AFTER TAKEOFF DURING CLIMB THE LEFT MAIN LANDING GEAR FAILED TO RETRACT AND WENT BACK DOWN INTO THE LOCKED POSITION. THE PILOT PERFORMED AND UNSCHEDULED LANDING. MAINTENANCE FOUND THE LEFT MAIN LANDING GEAR ACTUATOR HAD FAILED.