AD NUMBER: 2008-06-25
MANUFACTURER: Airbus
SUBJECT: Airworthiness Directive 2008-06-25
SUMMARY: We are adopting a new airworthiness directive (AD) for the products listed above. This AD results from mandatory continuing airworthiness information (MCAI) originated by an aviation authority of another country to identify and correct an unsafe condition on an aviation product. The MCAI describes the unsafe condition as: Two A330 operators have reported that the guide shaft of the Refuel Isolation Valve has been broken away from the main casting and entered the fuel tank.The Supplier Investigation evidenced that water builds-up in the cavity of the Refuel Isolation Valve and freezes during flight. When refuel pressure is applied to the piston, the ice restricts the piston travel on one side leading to an asymmetric movement of the piston resulting in breakage of the guide shaft. A non-bonded metallic object within the fuel tank can result [in] a potential ignition source, which in combination with a lightning strike constitutes an unsafe condition. We are issuing this AD to require actions to correct the unsafe condition on these products.

FMI: www.faa.gov/regulations_policies/airworthiness_directives/