Summary
The FAA is revising an earlier NPRM for an airworthiness directive (AD) that applies to certain Airbus Model A318-111 airplanes; A319-100 series airplanes; A320-111 airplanes; A320-200 series airplanes; and A321-100 and -200 series airplanes. The original NPRM would have required inspecting to determine the part number of the twin motor actuators, and related investigative and corrective actions if necessary. The original NPRM resulted from a report of a low pressure valve of the twin motor actuator found partially open, although the valve detection system indicated that the valve was closed. Investigation revealed that the locating pin in the actuator was too short to engage with the valve slot, resulting in incorrect alignment of the actuator and the drive assembly, causing the valve to remain partially open. This action revises the original NPRM by expanding the applicability. We are proposing this supplemental NPRM to ensure that, in the event of an engine fire, the valveactuator functions properly to block the fuel flow to the engine and prevent an uncontrollable fire.