Airworthiness Directives; The Boeing Company Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain The Boeing Company Model 777-200, -200LR, -300, -300ER, and 777F series airplanes. This AD was prompted by a report indicating that an airplane experienced a glideslope (G/S) beam anomaly during an instrument landing system (ILS) approach, which resulted in a higher- than-expected descent rate during the final segment of an ILS approach. The flightcrew might follow misleading flight director (F/D) guidance after disconnecting the autopilot, without reference to the other available information and flight deck indications. This AD requires installing new autopilot flight director computer (AFDC) operational program software (OPS) and doing a software configuration check. The FAA is issuing this AD to address the unsafe condition on these products.