Which inspection method is primarily visual?

The selection of visual inspection as the primary visual method is appropriate because this technique relies solely on the examiner's eyesight to detect flaws, surface irregularities, or signs of deterioration in materials and structures. Visual inspection is fundamental in aviation maintenance as it requires minimal equipment and can be performed quickly and efficiently. Inspectors look for issues such as cracks, corrosion, and general wear, which can often be identified without the need for advanced technology or equipment.

In contrast, other inspection methods like ultrasonic, magnetic particle, and x-ray inspections utilize specialized equipment and techniques to detect internal flaws or structural integrity issues that are not visible to the naked eye. These methods are instrumental for specific situations but do not fit the criterion of being purely visual, making visual inspection the correct choice when it comes to primarily visual inspection methods.