Airworthiness Directives; The Boeing Company Airplanes

The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 747-8 and -8F series airplanes and Model 777- 200, -200LR, -300, -300ER, and 777F series airplanes. This AD was prompted by the determination that radio altimeters cannot be relied upon to perform their intended function if they experience interference from wireless broadband operations in the 3.7-3.98 GHz frequency band (5G Lower C-Band) while operating in Canadian airspace, and the determination that this interference may affect multiple other airplane systems using radio altimeter data, including the pitch control laws, including those that provide tail strike protection, regardless of the approach type or weather. This AD requires revising the existing airplane flight manual (AFM) to incorporate limitations prohibiting certain operations requiring radio altimeter data when operating in Canadian airspace. The FAA is issuing this AD to address the unsafe condition on these products.