A single acting actuator (1) for an aircraft landing gear assembly having a piston (3) mounted in a cavity (60) and moveable relative to a housing (2) between a retracted position and an extended position, the piston dividing the cavity into first and second pressure chambers (5a, 5b). At least one of the pressure chambers is associated with first and second outlets (8a, 9a, 8b, 9b), with the actuator being arranged such that, in respect of the relative movement in which the pressure chamber is the decreasing volume pressure chamber, in a first stage of the relative movement the first and second outlets are open thereby allowing actuator fluid to flow out of the pressure chamber through the first and second outlets and in a second stage of the relative movement the second outlet is open but the first outlet is closed, thereby acting to slow the relative movement of the piston with respect to the housing.