EASA SIB NM-11-25: AVOX Systems - Passenger Supplemental Oxygen Masks on Transport Aeroplanes

What to do

Owners and operators of transport category airplanes equipped with the specified AVOX Systems oxygen masks should follow the actions outlined in AVOX Systems Service Bulletin 289-35-16 dated February 11, 2002, and Service Information Letter SIL-35-123 Rev 1 dated November 20, 2009. They should perform retrofit installations of reinforcement clips on in-flow indicators and conduct repetitive inspections for discrepancies. No specific compliance deadline is stated, but timely action is recommended to ensure oxygen system effectiveness.

Summary

The FAA Special Airworthiness Information Bulletin SAIB: NM-11-25 addresses issues with passenger supplemental oxygen masks manufactured by AVOX Systems, specifically those with Scott part numbers 289-601, 289-701, 289-801, 289-601-441-1, 289-1001, 289-1002, 289-1020, and 289-1030, installed on transport category airplanes. This bulletin informs operators about failures in the in-flow indicators of these oxygen masks and provides guidance to maintain their effectiveness during emergencies. The document is informational and does not impose mandatory requirements.

What changed

SAIB NM-11-25 highlights recent findings that some operators may not be performing recommended inspections and maintenance on affected AVOX Systems oxygen masks, potentially compromising their emergency effectiveness. It introduces service information from AVOX Systems for retrofitting clips to reinforce in-flow indicator connections and outlines repetitive inspection procedures, as well as service life and shelf life guidelines for the masks. The bulletin clarifies that these issues do not currently warrant an airworthiness directive under 14 CFR part 39.

Why it matters

This bulletin is important for aviation professionals because it draws attention to potential oxygen system failures that could impact passenger safety during emergencies. Operators and maintenance organizations must ensure compliance with manufacturer-recommended inspections and retrofits to maintain oxygen mask reliability. Awareness and adherence to these guidelines help prevent in-flight oxygen system malfunctions and support regulatory compliance.