Airworthiness Directives; Airbus Industrie Model A320 Series Airplanes

This amendment adopts a new airworthiness directive (AD), applicable to certain Airbus Industrie Model A320 series airplanes, that requires replacement of the disc valve and spring in the low pressure non-return valve of the airborne ground check module (AGCM) of the ram air turbine (RAT). This amendment is prompted by issuance of mandatory continuing airworthiness information by a foreign civil airworthiness authority. The actions specified by this AD are intended to prevent malfunction of the low pressure non-return valve in the AGCM. If the RAT is being used due to the loss of other systems, a malfunction of the valve could result in loss of the blue hydraulic system, and consequent loss of certain flight control and electrical systems of the airplane.