Which inspection method would be most appropriate for checking a steel landing gear component for stress cracks?

• A. Dye penetrant inspection
• B. Magnetic Particle inspection
• C. Ultrasonic inspection
• D. Eddy current inspection

Answer: (B)

Stress cracks on a steel landing gear are typically surface-breaking defects that occur where high stress concentrates. Magnetic Particle inspection is the most appropriate because steel is ferromagnetic, so when the part is magnetized the crack disrupts the magnetic flux and attracts the magnetic particles, creating a visible indication of the flaw. This method is highly sensitive to small surface and near-surface cracks and works well on the complex, heavy geometry of landing gear components. Dye penetrant inspection can reveal surface cracks but requires thorough cleaning and can be less reliable on intricate shapes or rough/painted surfaces. Ultrasonic inspection excels at detecting internal flaws but is more involved and may miss sharp surface cracks on such a large ferrous part, and eddy current is generally less effective on thick steel and more suited to surface defects on nonferrous materials.