Airworthiness Directives mandate Primus Epic integrity checks
The FAA has issued a series of ADs aimed at operators of airplanes equipped with the Honeywell Primus Epic avionics system. The directives–which affect EASy-equipped Dassault Falcon 900EXs and 2000EXs, Planeview-equipped Gulfstreams and the Embraer 170–call for integrity checks of the aviation standard communications bus (ASCB) and the installation of avionics software updates.
The FAA issued the ADs after engineers discovered that ASCB faults could lead to a near total system shutdown of the Primus Epic system in flight, causing all the cockpit displays to show invalid information–or simply go blank–and rendering autopilot, autothrottle, radio communications and other cockpit functions useless. The directives also require a change to the aircraft flight manual with instructions on how to recover the cockpit display units in the event of an ASCB failure.