Airworthiness Directives; The Boeing Company Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 777 airplanes. This AD was prompted by reports of discrepancies between the center wing tank (CWT) fuel quantity, as indicated by the fuel quantity indicating system (FQIS), and the refueling truck uploaded fuel amount, followed by certain engine-indicating and crew-alerting system (EICAS) messages. This AD requires installing new software in the fuel quantity processor unit (FQPU), or replacing the FQPU with one that includes new software, depending on airplane configuration; doing a software version check; and doing a FQPU operational check, depending on airplane configuration. This AD also prohibits the installation of certain FQPUs on certain airplanes. The FAA is issuing this AD to address the unsafe condition on these products.