FAA Aviation Mechanic Airframe (AMA)Airframe InspectionMedium
A technician needs to inspect a steel landing gear component for surface cracks. Which NDT method relies on magnetizing the part and applying iron particles that cluster at flux leakage points?
- AEddy current inspection
- BDye penetrant inspection
- CUltrasonic inspection
- DMagnetic particle inspection
Show answer & explanationAnswer & explanation
Correct answer: D. Magnetic particle inspection
Magnetic particle inspection magnetizes a ferromagnetic part; cracks disrupt the magnetic field, causing flux leakage that attracts iron particles and reveals the flaw location.
Why the other options are wrong
- A. Eddy current uses induced currents and works on conductive metals but doesn't require magnetizing
- B. Dye penetrant uses capillary action of liquid dye, not magnetism
- C. Ultrasonic uses sound waves for subsurface flaws, not magnetic flux
Magnetic Particle Inspection
An NDT method for ferromagnetic materials that magnetizes the part and applies iron particles to reveal surface and near-surface cracks via magnetic flux leakage.
- Only works on ferromagnetic materials like steel
- Cracks perpendicular to the magnetic field are most visible
- Part must be demagnetized after inspection to prevent residual magnetism issues
Memory trick: Magnets only love iron, and cracks leak the field like a broken dam