As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
LEFT LANDING GEAR DID NOT RETRACT WITH GEAR HANDLE UP ON TAKEOFF UNTIL 1300FT WITH A LOUD THUD. GEAR UNSAFE LIGHT ON. TROUBLE SHOT- FOUND L/H MLG ACTUATOR BYPASSING DURING GEAR SWING. REMOVED LH MLG RETRACT CYLINDER PER AMM 32-33-01-000-801. INSTALLED LH MLG RETRACT ACTUATOR CYLINDER PER AMM 32-33-01OPS AND LEAK CHECK GOOD. GEAR SWING CHECK GOOD.