Summary
The FAA proposes to adopt a new airworthiness directive (AD) for all Airbus SAS Model A350-941 and -1041 airplanes. This proposed AD was prompted by reports of potential foreign object debris (FOD) contamination of the thermal relief valve (TRV). This proposed AD would require replacement of affected auxiliary power unit (APU) low pressure (LP) shut-off valves (SOVs), an inspection to detect fuel leaks of affected engine LP SOVs and APU isolation shut-off valves (ISOVs), and applicable corrective actions, and would prohibit installation of affected parts, as specified in a European Union Aviation Safety Agency (EASA) AD, which is proposed for incorporation by reference (IBR). The FAA is proposing this AD to address the unsafe condition on these products.