Airworthiness Directives; The Boeing Company Airplanes

Issuing agencies

Abstract

The FAA is adopting a new airworthiness directive (AD) for all The Boeing Company Model 747-8F and 747-8 series airplanes and Model 777 airplanes. This AD was prompted by a 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 C-Band), and a recent determination that this interference may affect multiple 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 limitations section of the existing airplane flight manual (AFM) to incorporate limitations prohibiting dispatching or releasing to airports, and approaches or landings on runways, when in the presence of 5G C-Band interference as identified by Notices to Air Missions (NOTAMs). The FAA is issuing this AD to address the unsafe condition on these products.