Summary
This document proposes to adopt a new airworthiness directive (AD) that would apply to Rockwell Collins, Inc. (Rockwell Collins) FMC-4200, FMC-5000, and FMC-6000 flight management computers (FMC) that are installed on airplanes. This proposed AD would require you to have the FMC modified to correct a problem with the flight management system (FMS) accepting new information when an existing procedure or flight plan is changed. This proposed AD is the result of a report that an aircraft proceeded beyond the published altitude constraint on an arrival procedure. The actions specified by this proposed AD are intended to prevent the FMC from retaining and displaying original altitude constraints when an edit or a replacement is made to a procedure or flight plan that shares a waypoint with another procedure or an airway, and there is an altitude constraint on the shared waypoint. Such a condition could cause the pilot to fly the airplane out of the range of the correct altitude constraint. This condition could result in air traffic control or the pilot making flight decisions that put the airplane in unsafe flight conditions.