A Mechanic reports that a B767-300 passenger oxygen generator he had replaced two years earlier was recently found with the oxygen release pin in the safety pin hole instead of the lanyard pin hole. As a result; the release pin could not be disconnected from the firing pin when the lanyard was pulled. No oxygen would have been available to the passenger.

Narrative

A representative from our carrier's FAA Liaison office notified me of a non-compliance issue concerning a non-routine card for a B767-300 that I signed. This card dealt with an oxygen generator that was out of date in the mid forward lavatory. Evidently upon installation; it was incorrectly installed with the lanyard pin installed in the safety pin hole instead of the lanyard pin hole. These pins became an issue in July 2000; when a B-757 operator reported that some oxygen generators did not release oxygen during a decompression event. A subsequent review found the oxygen release pins were installed in the safety pin holes during maintenance. As a result; the release pins could not be disconnected from the firing pins when the release cables were pulled. This condition caused a reduction in the number of serviceable oxygen masks available in an emergency. I was not aware of this issue and became aware when the representative notified me about this (non-routine) card. He has been assigned to do research after a Line Mechanic who was aware of this issue; discovered some oxygen generators pinned incorrectly. It was subsequently discovered that several of our aircraft had multiple oxygen generators were incorrectly pinned; requiring the issuance of an Engineering Order (EA); which is a requirement for our carrier to inspect these oxygen generators. It was during this Inspection that the generator in question was discovered. The representative investigated and discovered that I was the last person to sign for this generator and advised me to submit this disclosure. As stated earlier; I was unaware of this issue at the time of installation. As a professional aircraft Mechanic integrity means everything to me and to say I regret this inadvertent mistake would be an understatement.