Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all Airbus Model A330-200, A330-300, A340-200, and A340-300 series airplanes; and Model A340-541 and A340-642 airplanes. This proposed AD would require an inspection for anti-fretting material contamination of the Halon filters and plumbing parts of the flow metering system (FMS) and flow metering compact unit (FMCU) in the lower deck cargo compartment (LDCC) and bulk crew rest compartment (BCRC), as applicable; other specified actions; and corrective actions if necessary. This proposed AD results from a report that the FMS and FMCU of the fire extinguishing system may be blocked by anti-fretting material contamination. We are proposing this AD to prevent such anti- fretting material contamination, which could reduce the effectiveness of the fire extinguisher system to discharge fire extinguishing agents and to lower the concentration of Halon gas in the LDCC or BCRC in a timely manner. An ineffective fire extinguisher system in the event of a fire could result in an uncontrollable fire in the LDCC or BCRC.