Airworthiness Directives; Zodiac Aerotechnics (Formerly Intertechnique Aircraft Systems)

We are adopting a new airworthiness directive (AD) for certain Zodiac Aerotechnics (formerly Intertechnique Aircraft Systems) flightcrew oxygen mask regulators as installed on, but not limited to, various transport and small airplanes. This AD was prompted by a report that improper maintenance on oxygen mask regulators was found. This AD requires the identification and replacement of all potentially affected units. This AD also requires installation of a placard and revision of the airplane flight manual to include an operational procedure for use in case of depressurization. We are issuing this AD to detect and correct affected oxygen mask regulators, which could lead to inadequate protection to the affected flightcrew against hypoxia. Hypoxia can start from a headache and drowsiness and lead eventually to unconsciousness with severe consequence in terms of airplane controllability.