What inspection method would be most appropriate for checking the internal structure of an airplane wing for corrosion?

• A. X-Ray Inspection.
• B. Visual Inspection.
• C. Dye Penetrant.
• D. Ultrasonic Inspection.

Answer: (A)

Internal corrosion inside a wing is hidden behind skin, ribs, spars, and fasteners, so you need a method that can image the interior rather than just surface conditions. X-ray inspection uses radiation to penetrate the metal and produce an image of the internal structure. Changes in material density, voids, or corrosion products show up on the radiograph, allowing you to see corrosion that isn’t visible from the outside. This makes radiography the most reliable way to assess the integrity of internal wing structures.

Visual inspection can only reveal surface corrosion and surface defects, not what lies inside the members. Dye penetrant reveals only surface-breaking defects, not internal corrosion hidden within hollow sections. Ultrasonic inspection can detect some internal flaws and measure thickness, but it’s more challenging to apply over complex wing geometries and may not readily reveal all hidden internal corrosion, especially in areas with difficult access. Radiographic inspection provides a direct view of the interior, making it the best choice for this scenario.