What is the term for a magnetic compass error caused by local magnetic fields within the aircraft?

The term that accurately describes the magnetic compass error caused by local magnetic fields within the aircraft is Deviation. This error occurs when the magnetic compass is influenced by magnetic interference generated by electrical equipment, metallic structures, or other magnetic fields within the aircraft itself.

Deviation can vary depending on aircraft orientation, the specific internal equipment layout, and the position of the magnetic compass. Pilots must be aware of this error since it can lead to inaccurate headings if not accounted for, especially during flight maneuvers. Deviation is typically corrected by referencing a compass deviation card, which indicates the error at various headings.

In contrast, Variation refers to the difference between magnetic north and true north, which is a geographic consideration and does not relate to the aircraft's internal magnetic fields. Magnetic drift is not a standard term used to describe compass errors, and resolution usually pertains to the accuracy of instruments or measurement systems rather than compass errors. Understanding deviation is critical for pilots to ensure they navigate accurately using their compasses.