Airworthiness Directives; Boeing Model 747-400, 747-400D, and 747-400F Series Airplanes
The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 747-400, 747-400D, and 747-400F series airplanes. This AD requires replacement of an electronic flight instrument system/ engine indicating and crew alerting system (EFIS/EICAS) interface unit (EIU) located on the E2-6 shelf of the main equipment center with a new or modified EIU. This AD results from two instances where all six integrated display units (IDUs) on the flight deck panels went blank in flight. We are issuing this AD to prevent loss of the IDUs due to failure of all three EIUs, which could result in the inability of the flightcrew to maintain safe flight and landing of the airplane.