Commercial Fixed Wing
Maintenance Powerplant; Maintenance Airframe
Situational Awareness
Aircraft Equipment Problem Less Severe
General Maintenance Action
Aircraft; Equipment / Tooling; Procedure
I chose [aircraft] however this effects multiple aircraft across fleet types. There appears to be a growing concern for the potential of an EMERGENCY EQUIPMENT FAILURE on the flight decks of many aircraft; that if not addressed could lead to the lack of oxygen equipment for our flight crews. The fleets affected are any aircraft flying the Zodiac (EROS) Crew Oxygen Mask; with hose assembly MPN: DTS4058; DTS4032; and DTS4069. For [company] that includes the 737; 757; 767; 777; 787 and all Airbus Aircraft. There was an FAA AD (Airworthiness Directive) 2015-08-07 that applied to the inflation harness for the masks that had a comfort harness. My point in bringing that up is because the supply line that supplies 80 PSIG (Pounds per Square Inch Gauge) to the regulator of the mask has the same issue of separation that the comfort harness had; yet the supply line was not addressed in the FAA AD. Since the first quarter of 2017 the oxygen mask shop in ZZZ that performs maintenance on these masks has been collecting data and is seeing a rise in separation failures. Some of these supply hoses are coming apart with less than a year in service; with a few lasting 90 days. The shop has collected approximately 230 either separated hoses or hoses that were caught by the flight crew before separation.
Talked with Maintenance Technician who filed the report and he said that the issue is the Oxygen Line casing which is a fabric mesh over the rubber line which will get frayed due to frequent use by Flight Crews due to the requirement for pilots to don the mask if a crew member has to leave the cockpit in flight. He mentioned that the manufacturer is working on a solution to this problem. He didn't know how long it would be before it is available to the customers to procure. He did say that this is a bigger problem for domestic air carriers due to the requirement for one pilot to don the mask when the other pilot leaves the cockpit as opposed to foreign carriers which may not be required to do this by their regulatory authorities.
Maintenance Technician reports that the EROS Flight Crew Oxygen Mask has a defective supply line.