Incident Overview
Upon arriving at the destination, the pilot was unable to extend the landing gear. The aircraft was subsequently flown back to its base, where a gear-up landing was performed. No injuries or other complications were reported during the flight.
Examination Findings
Post-landing examination of the airplane revealed that the left gear door had not unlocked. The emergency extension system failed to operate properly. The cause was determined to be either the failure of the clutch actuator to reset after the last retraction or slippage of the clutch mechanism.
Maintenance Report
According to the pilot's report, the director of maintenance indicated that more frequent lubrication of the clutch could have prevented the incident. No further details on maintenance procedures or schedules were provided.