A thrust reverser assembly comprising: a thrust reverser; a movable component; one or more actuators configured to selectively move the movable component between a stowed position and a deployed position; and a tertiary lock system comprising: a non-rotating lock member translatable between a locked position, in which the lock member prevents deployment of the thrust reverser by blocking the path of the movable component, and an unlocked position, in which the lock member permits deployment of the thrust reverser by moving out of the path of the movable component; a screw shaft and a nut, wherein rotational movement of one of the screw shaft and the nut causes the other of the screw shaft and the nut to translate along the longitudinal axis of the screw shaft and, in turn, the lock member to move between its locked position and its unlocked position; and an electric motor configured to rotate the one of the screw shaft and the nut to cause the lock member to move between its locked position and its unlocked position; wherein the tertiary lock system is configured to selectively prevent movement of the movable component from its stowed position to its deployed position via selective movement of the lock member between its locked position and its unlocked position. a thrust reverser; a movable component; one or more actuators configured to selectively move the movable component between a stowed position and a deployed position; and a tertiary lock system comprising: a non-rotating lock member translatable between a locked position, in which the lock member prevents deployment of the thrust reverser by blocking the path of the movable component, and an unlocked position, in which the lock member permits deployment of the thrust reverser by moving out of the path of the movable component; a screw shaft and a nut, wherein rotational movement of one of the screw shaft and the nut causes the other of the screw shaft and the nut to translate along the longitudinal axis of the screw shaft and, in turn, the lock member to move between its locked position and its unlocked position; and an electric motor configured to rotate the one of the screw shaft and the nut to cause the lock member to move between its locked position and its unlocked position; wherein the tertiary lock system is configured to selectively prevent movement of the movable component from its stowed position to its deployed position via selective movement of the lock member between its locked position and its unlocked position. a non-rotating lock member translatable between a locked position, in which the lock member prevents deployment of the thrust reverser by blocking the path of the movable component, and an unlocked position, in which the lock member permits deployment of the thrust reverser by moving out of the path of the movable component; a screw shaft and a nut, wherein rotational movement of one of the screw shaft and the nut causes the other of the screw shaft and the nut to translate along the longitudinal axis of the screw shaft and, in turn, the lock member to move between its locked position and its unlocked position; and an electric motor configured to rotate the one of the screw shaft and the nut to cause the lock member to move between its locked position and its unlocked position; wherein the tertiary lock system is configured to selectively prevent movement of the movable component from its stowed position to its deployed position via selective movement of the lock member between its locked position and its unlocked position.