The pilot intended to conduct a series of night circuits and landings to maintain currency. On the second circuit, the gear was selected down but failed to fully extend. All attempts to lower the gear were unsuccessful. The aircraft subsequently touched down with the partially extended gear, which collapsed as the aircraft slid to a halt. An inspection of the aircraft revealed that the failure of left maingear hydraulic actuator resulted in the loss of hydraulic fluid and prevented completion of the gear extension cycle.
