Airworthiness Directives; Boeing Model 737-300, -400, -500, -600, -700, -700C, -800 and -900 Series Airplanes

The FAA is adopting a new airworthiness directive (AD) for certain Boeing Model 737-300, -400, -500, -600, -700, -700C, -800 and - 900 series airplanes. This AD requires installing an updated version of the operational program software (OPS) and certain other software in the flight management computers (FMCs); and doing configuration checks to ensure that certain software is properly installed and doing other specified actions. This AD also requires reinstalling software, if necessary. This AD results from one operator reporting FMC map shifts on several Model 737-400 series airplanes with dual FMCs, using OPS version U10.4A. We are issuing this AD to prevent the FMC from displaying the incorrect actual navigation performance value to the flightcrew, which could prevent adequate alerting of a potential navigation error. This condition could result in a near miss with other airplanes or terrain, or collision if other warning systems also fail.