Hazards and Mitigation Measures in Aerospace Non-Destructive Testing

<p>As an aircraft component is subjected to tensile/torsional/bending forces and heat cycles during operation, non-destructive inspection programs have been mandated by aviation regulatory authorities and component manufacturers to ensure that cracks and flaws in the aircraft structure, engine and components are detected before reaching catastrophic failure modes. In aerospace settings, eddy current, magnetic particle, dye penetrant and radiography inspection methods are known to affect worker health. Two recent studies have linked dye chemicals to bladder cancer, excessive electromagnetic field exposure has been linked to undue stress on the human body, and excessive exposure to ionizing radiation has been linked to cancer. The electromagnetic field magnitude levels (at respective frequencies) during eddy current and magnetic particle inspection processes must be within the established safety limits. Dye chemicals utilized in magnetic particle and dye penetrant testing must be kept away from contact or isolated through dilution and exhaust ventilation. Wireless imaging and data transfer technology and shielding should be used to minimize ionizing radiation during radiographic inspection. Ultrasonic testing is much less hazardous to human health when compared to radiographic, eddy current, magnetic particle and dye penetrant inspection methods, and passive infrared thermography devices pose no health hazards to workers in aerospace. As such, regulatory authorities and aircraft manufacturers should prescribe ultrasonic testing and passive thermographic inspections as the preferred non-destructive testing methods in the aviation field to mitigate the health hazards.</p>