In what way do magnetic fields generated by electrical equipment and steel parts in the airplane affect the magnetic compass?

In what way do magnetic fields generated by electrical equipment and steel parts in the airplane affect the magnetic compass?

• A. Stray magnetic fields deflect the compass from correct alignment with the earth's magnetic field
• B. They improve compass accuracy by calibrating alignment
• C. They have no effect on the compass
• D. They cause the compass to spin

Answer: (C)

Magnetic fields from electrical gear and steel parts create local disturbances in the airplane’s magnetic environment. The compass reads the combined field, not Earth’s field alone, so these local fields shift the direction the needle shows. This deflection causes the compass to indicate a direction away from true magnetic north, and the amount can change as equipment is turned on or off or as the airplane’s orientation changes. Pilots account for this with compass deviation corrections and compensators, rather than assuming the readings are perfect. In short, stray fields deflect the compass rather than improving or stabilizing its indication.

Magnetic fields from electrical gear and steel parts create local disturbances in the airplane’s magnetic environment. The compass reads the combined field, not Earth’s field alone, so these local fields shift the direction the needle shows. This deflection causes the compass to indicate a direction away from true magnetic north, and the amount can change as equipment is turned on or off or as the airplane’s orientation changes. Pilots account for this with compass deviation corrections and compensators, rather than assuming the readings are perfect. In short, stray fields deflect the compass rather than improving or stabilizing its indication.