Airworthiness Directives; Bombardier, Inc., Airplanes

The FAA is adopting a new airworthiness directive (AD) for all Bombardier, Inc., Model BD-700-2A12 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 C- Band), and a recent determination that this interference can result in unavailable or misleading radio altimeter information, adversely affecting the performance of the automatic flight control system (AFCS) and fly-by-wire (FBW) systems and resulting in increased flightcrew workload during takeoff, approach, and landing below 400 feet above ground level (AGL). This AD requires revising the existing airplane flight manual (AFM) with new limitations to mitigate identified hazards due to 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.