Definition
Metal components within the aircraft that have acquired their own magnetic field, causing them to influence the magnetic compass and produce a compass error known as deviation. The magnetism may come from ferrous metals near the compass, electrical currents flowing through wiring, or steel parts that have become magnetized over time through exposure to other magnetic fields or vibration.
Plain English
Pieces of metal in the aircraft that have become slightly magnetic themselves and pull the compass needle off true magnetic north.
Context Anchor
Seen in compass system discussions, especially when explaining why a magnetic compass may read differently in different aircraft or after equipment changes.
Derivation
‘Magnetized’ comes from ‘magnet,’ originally from the Greek region Magnesia, where naturally magnetic stones (lodestones) were found. A magnetized part is a piece of metal that has taken on some of that magnet-like behavior — it now has its own small magnetic pull.
Why Pilots Care
Uncorrected magnetized parts produce heading errors that compromise navigation accuracy and flight safety.
Intuition Check
Do not assume magnetized parts means parts of the compass itself. In this context, it means nearby aircraft parts or equipment that have become magnetic enough to influence the compass.
Example Sentence 1
Because magnetized parts in the panel pull the compass slightly off, the pilot reads the correction card and adjusts the heading by two degrees.
Example Sentence 2
Before reinstalling equipment, the technician verified that no magnetized parts remained near the compass to preserve accurate headings.