How are external surfaces of aircraft inspected for wear?

The inspection of external surfaces of aircraft for wear primarily involves external visual inspections and non-destructive testing methods. Visual inspections allow inspectors to closely examine the aircraft's surfaces for any visible signs of wear, damage, or deformation, such as cracks, dents, or corrosion. These inspections are often performed during routine maintenance checks and pre-flight inspections, where attention to detail is crucial.

Non-destructive testing (NDT) techniques complement visual inspections by enabling the detection of subsurface defects without causing any damage to the aircraft material. Common NDT methods used include ultrasonic testing, magnetic particle testing, and dye penetrant testing. These techniques are essential for identifying issues that may not be visible with the naked eye, thus ensuring the structural integrity of the aircraft is maintained.

While electrical testing and thermal imaging can be beneficial for certain contexts, they are not typically employed as primary methods for inspecting external surfaces of aircraft. Chemical tests for corrosion detection are useful but do not encompass the broader range of wear inspections necessary for comprehensive aircraft maintenance. Fatigue testing in wind tunnels, while important for understanding aerodynamic and structural characteristics during design phases, does not apply to regular inspections of aircraft already in operation.