Document ID: chunk:federal_register_of_legislation:F2005L00574:body:0:p2
Version: federal_register_of_legislation:F2005L00574
Segment Type: other
Provision Reference: 
Character Range: 2859–3888

have shown that the Flow Metering System (FMS) of the fire extinguishing system may be blocked by anti-fretting material contamination.  The origin of this anti-fretting material inside the piping, filters and pressure reducers may come from manufacturing of the parts as well as installation on aircraft during production or maintenance.  After the first activation of the fire extinguishing system, it has been assumed that the FMS is contaminated and it cannot be guaranteed that the system is fully operable for the next fire extinguishing process if requested.  An uncontrollable fire in the affected compartment may lead to a catastrophic event.  To avoid this hidden failure of the Lower Deck Cargo Compartment (LDCC) fire extinguishing system due to contamination, this Airworthiness Directive requires a one time inspection to clean the FMS and mandates new procedures for the restoration of the fire extinguishing system after any activation.

James Coyne
Delegate of the Civil Aviation Safety Authority

2 March 2005