Airworthiness Directives; Airbus Model A319, A320, and A321 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Model A319, A320, and A321 series airplanes, that requires replacement of the low-pressure solenoid valve for the crew oxygen supply with a modified valve. This action is necessary to prevent faulty operation of the low-pressure solenoid valve for the crew oxygen supply, which could prevent oxygen from being supplied to the airplane crew when needed, such as in the event of smoke in the cabin or rapid depressurization of the airplane. This action is intended to address the identified unsafe condition.