What was found
DURING SCHEDULED PHASE CHECK, NOTED NON-STANDARD CREW OXYGEN MASKS INSTALLED. PN PILOTS MASK DID NOT SHOW ON EQUIPMENT LIST OR BE 200 IPC. CONTACTED MFG TECH SUPPORT, INSTALLED MASK ASSY NOT LISTED AS A VALID CROSS REFERENCE FOR APPROVED MASK ASSY. NO TSO MARKINGS NOTED ON MASK ASSEMBLY. NO VERIFIABLE RECORDS TO INDICATE WHEN INSTALLED IN AIRCRAFT OR SUPPORTING DOCUMENTATION. TECH AND REPAIR STATIONS NEED TO VERIFY INSTALLED OXYGEN MASKS ARE VALID FOR THAT AIRCRAFT, AS WELL AS IN SERVICEABLE CONDITION. OPERATORS ASSUME ONE MASK IS THE SAME AS ANOTHER, WHEN FLOW RATES, AIRFRAME COMPATABILITY, MAY RENDER IT UNSUITABLE FOR THAT INSTALLATION. REPLACED MASK ASSEMBLY.