Welcome to the Tools and Equipment Supplement to the September issue of AMT Magazine. Four times each year, AMT includes a Tools & Equipment Supplement to the issue. Each supplement highlights tools, equipment, and products that you may find useful in accomplishing aircraft maintenance, relating to a specific area of aircraft maintenance. This issue’s supplement has a focus on nondestructive testing (NDT) equipment and highlights items such as ultrasonic testing equipment, borescope and videoscope equipment, lamps for ultraviolet inspections, and much more.
NDT or nondestructive inspection (NDI) as it is referred to by some, is one of the many specialized disciplines within aircraft maintenance and inspection. There are several methods of NDT depending on what the outcome is you are attempting to achieve, or what type of flaw it is that you may be attempting to verify or confirm. The methods range from simple to complex and all require the use of special tools and equipment. A quick review of the common methods used in aircraft maintenance and inspection are:
Visual examination is the simplest method and can range from looking for a flaw with the help of a flashlight and a magnifying glass, to using modern day videoscope or borescope equipment. In all cases good eyesight is a requirement.
Liquid penetrant is used to detect surface flaws. The local area is coated with a visible dye solution and after a specific period of time has past, the excess penetrant is removed exposing the flaw. A developer is generally used to draw out the penetrant making the flaw more visible. An ultraviolet lamp is used with fluorescent dye which increases the visibility of a potential flaw.
Ultrasonic testing (UT) uses ultra-high frequency sound waves that are transmitted into a material in order to detect changes in the material indicating a possible flaw. UT is generally used to detect subsurface defects or defects originating from the surface.
Eddy current uses electrical currents that are generated into a conductive material by a type of magnetic field. Changes in a material’s conductive property will cause interruptions in the flow of electrical currents indicating a possible flaw. The eddy current method is used extensively to inspect aircraft skin.
Magnetic particle inspection is used on ferrous material and induces a magnetic field into the part. The surface of the part is then coated with iron particles and a flaw will distort the magnetic field causing the particles to accumulate near the flaw.
Radiography uses an X-ray machine to direct radiation through the part and the image is recorded on a media or film. Once the film is developed you can view the internal condition of a part.
If you are interested in becoming certified to accomplish NDT/NDI, you’ll want to read the feature article in this supplement. Greg Linkert, chief inspector for an FAA approved repair station which provides NDT/NDI services and training, explains the details of what it takes for the AMT to become qualified and certified for accomplishing NDT/NDI.
Enjoy the supplement, Ron
"The Big Five" By Joseph Stump Nondestructive inspection (NDI) in the field of aviation came into its own in the 1940s. While still in its infancy, it represented a major innovation in...
Another Look at Visual Inspection By Fred Workley November 1999 Fred Workley is the president of Workley Aircraft and Maintenance Inc. in Manassas, VA. He is on the technical...
One of the most diverse nondestructive testing (NDT) methods.