Regarding demagnetization of an aircraft part, which statements are true?

• A. Only No. 1 is true
• B. Only No. 2 is true
• C. Both No. 1 and No. 2 are true
• D. Neither is true

Answer: (C)

Demagnetization removes residual magnetic fields from an aircraft part so it won’t interfere with instruments or attract ferrous debris. The process uses a demagnetizer that applies an alternating magnetic field and gradually reduces the field to zero, which allows magnetic domains to randomize and lose net magnetization. In practice, this is done after operations that could magnetize a part (like machining or handling near magnets) and again before installation to ensure the part won’t affect accuracy or safety in service. After demagnetizing, you’d usually verify the result with a simple magnetic check (such as a compass test or a magnetometer) to confirm minimal residual magnetism. Because both of these points describe standard, compatible steps in proper demagnetization practice, it makes sense that both statements are true.