Summary
We propose to adopt a new airworthiness directive (AD) for certain Rockwell Collins, Inc. (Rockwell Collins) flight management systems (FMS) installed on airplanes. This proposed AD was prompted by reports of the flight management computer (FMC) software issuing incorrect turn commands when the altitude climb field is edited or the temperature compensation is activated on the FMS control display unit. This proposed AD would require disabling the automatic temperature compensation feature of the FMS through the configuration strapping units (CSU) and revising the airplane flight manual (AFM) Limitations section. We are proposing this AD to address the unsafe condition on these products.