NDT in Aviation: Non-Destructive Testing

NDT = Non-Destructive Testing (also NDI – Inspection, NDE – Evaluation).

Purpose

Inspect aircraft materials, components, structures for defects (cracks, corrosion, delamination, voids) without impairing future usefulness.

Common Methods (Aviation)

• Visual (VT): Enhanced (borescopes, magnifiers).
• Eddy Current (ET): Surface/near-surface cracks in conductive materials (aluminum, titanium).
• Ultrasonic (UT): Internal flaws, thickness (corrosion mapping), bond testing.
• Radiographic (RT): X-ray/gamma for internal structure (welds, composites).
• Magnetic Particle (MT): Surface cracks in ferromagnetic parts (steel landing gear).
• Dye Penetrant (PT): Surface-breaking flaws on non-porous materials.
• Thermography (IRT): Delamination, water ingress in composites.
• Shearography: Full-field strain mapping for composites.

Regulatory Framework

• FAA/EASA: Mandate NDT programs in maintenance manuals (CAMP, MSG-3).
• Standards: ASTM, ASNT, AMS, NAS 410 (personnel qualification).
• Levels: I (perform), II (set up/interpret), III (develop procedures, certify).

NDT is the backbone of airworthiness—detecting fatigue, corrosion, manufacturing flaws before they become catastrophic.