Airworthiness Directives; Boeing Model 757-200 and -300 Series Airplanes and Model 767 Series Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 757-200 and -300 series airplanes and Model 767 series airplanes. This AD requires replacing the existing operational software of the Pegasus flight management computer (FMC) system with new, improved operational software. This AD results from reports of "old" or expired air traffic control (ATC) clearance messages being displayed on the control display unit (CDU) of the FMC system during subsequent flights. We are issuing this AD to prevent display of "old" or expired ATC clearance messages on the CDU of subsequent flights, which could result in the airplane entering unauthorized airspace or following a flight path that does not provide minimum separation requirements between aircraft, and a consequent near miss or a mid-air collision.