EASA AD US-2020-10-05: ROCKWELL COLLINS INC. - Flight Management Computing Hardware System / Airplane Flight Manual - Revision

What to do

Affected operators must disable the automatic temperature compensation feature on the flight management systems through the configuration strapping units and revise the airplane flight manual Limitations section as specified in Rockwell Collins Service Information Letter FMC-XX00-18-1, Revision 1. These actions must be completed by June 24, 2021, which is 12 months after the AD's effective date. Operators should coordinate with Rockwell Collins and FAA guidance to implement these changes promptly.

Summary

ROCKWELL COLLINS INC. - Flight Management Computing Hardware System / Airplane Flight Manual - Revision is a Federal Aviation Administration (FAA) airworthiness directive addressing certain Rockwell Collins Pro Line 4 and Pro Line 21 flight management systems installed on various airplanes. The directive responds to a software design error causing incorrect turn commands during altitude climb edits or when temperature compensation is activated. This issue affects flight safety by potentially leading to collisions or controlled flight into terrain.

What changed

This new FAA airworthiness directive requires disabling the automatic temperature compensation feature of the affected flight management systems via configuration strapping units and mandates revising the airplane flight manual's Limitations section. It introduces operational limitations on editing altitudes during departure and missed approach procedures but removes the previous prohibition on altitude edits during approach procedures. The directive also establishes a compliance timeline for these changes.

Why it matters

This directive is critical for aviation professionals because it addresses a latent unsafe condition in widely used Rockwell Collins flight management systems that could cause incorrect turn commands, risking flight safety. Operators, maintenance organizations, and compliance teams must ensure the FMS software configuration is updated and the flight manual limitations are incorporated to prevent navigation errors during critical flight phases. Compliance reduces the risk of accidents related to erroneous flight path commands.