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FAASTeam Notice
Type: Airworthiness
Notice Date: Monday, November 24, 2014
Notice Number: NOTC5736
Maintenance Safety Tip
This notice expired on

                    "Heading Off” Aircraft Heading Errors

How often do you think about the sensitive nature of the heading reference systems installed in that aircraft you are working on? Maybe you should. Check out the new Special Airworthiness Information Bulletin (SAIB CE-15-01) issued by the FAA on 11/4/2014. There continues to be a growing number of reported heading errors and anomalies in heading reference systems due to standard maintenance practices and the use of standard tools while maintaining these systems. The problem stems from the sensitive nature of these heading sensors which can be substantially affected by ferrous materials, including the improper use of magnetic tools (like magnetic screwdrivers) in close proximity. What can you do to help?
            The FAA recommends that you follow all manufacturer installation/maintenance instructions, warnings, and troubleshooting procedures per their instructions for continued airworthiness or maintenance manuals. A simple test for possible magnetic interference is to use a magnetic compass and slowly move around the area of the sensor looking for any deflections of the compass needle. Excessive needle movement can be evidence of ferrous material or sources of magnetic interference like flap motors or flight control system components.
          For more information on how to identify sources of magnetic interference that might affect heading sensor operations, see this SAIB at:

Are interested in learning about other safety information and recommendations from the FAA? Go to this website: