Inspection, Testing, and Troubleshooting
Core concepts
Inspection methods include visual, borescope, eddy current, ultrasonic, radiographic, dye penetrant, and magnetic particle techniques. Candidates should know what each method detects and its limitations: penetrant finds surface-breaking defects in non-porous materials; magnetic particle works only on ferromagnetic materials; ultrasonic detects internal flaws and requires couplant; radiography reveals internal density differences but poses safety considerations. Understand calibration and functional check requirements for test equipment, and the logic of fault isolation: gather symptoms, consult approved data, form a hypothesis, test, and confirm. Know the difference between an operational check, a functional check, and a bench test.
Traps in questions
A common trap is selecting a method that cannot detect the defect described, such as magnetic particle inspection on an aluminum part. Another is skipping verification after a repair or component replacement; the correct sequence usually includes an operational or functional check per approved data. Questions may confuse a system test with a leak check, or assume a fault code identifies the failed component rather than the circuit. Watch for the temptation to substitute a general visual inspection where a detailed or special inspection is specified.
Worked example / rule of thumb
Rule of thumb: Match the method to the material and the defect location. Worked example: a suspected crack at a steel landing-gear attachment is reported. Magnetic particle inspection is suitable because the material is ferromagnetic and the defect is at or near the surface; ultrasonic would be considered if internal flaws are suspected. After any corrective action, perform the required functional check and document results before release.