Summary
The FAA proposes to supersede Airworthiness Directive (AD) 2023-07-09, which applies to certain The Boeing Company Model 747-400 and -8 series airplanes. AD 2023-07-09 requires inspecting for wear of the transfer pump housing inlet check valves and transfer pump motor impeller inlet adapters for the horizontal stabilizer fuel tank and doing corrective actions, if necessary, and limits the installation of affected parts. Since the FAA issued AD 2023-07-09, the manufacturer has developed further action to address the unsafe condition. This proposed AD would require repetitive inspections for damage of the transfer pump housing inlet check valves and transfer pump motor impeller inlet adapters for the horizontal stabilizer fuel tank and applicable on-condition actions. This proposed AD would also limit the installation of affected parts under certain conditions. The FAA is proposing this AD to address the unsafe condition on these products.