A nacelle for a gas turbine engine, comprising a thrust reverser movable between a stowed position and a deployed position, and a locking system configured to selectively prevent movement of the thrust reverser from the stowed position, the locking system comprising a locking mechanism and an actuator configured to actuate the locking mechanism, wherein the locking mechanism is positioned aft of a blade-off zone defined across the nacelle and the actuator is positioned fore of, or at least partially within, the blade-off zone.