Türk Hava Yolları

NDT (Non-Destructive Test )

For over 30 years NDT inspections of the aircraft and engine parts have been performed at THY’s Maintenance Center.
These inspections are carried out by Level 2 personnel who are qualified and certified according to NAS 410 and SNT-TC-1A standards.

The following five major methods are used at the Maintenance Center, which offer a full technical background plus a wide range of equipment and materials.

Eddy-Current

In Eddy-current testing electrical currents are generated in a conductive material by an induced magnetic field. Distortions in the flow of the Eddy-currents caused by imperfections/discontinuities (such as a crack, deep scratch, corrosion, etc.) or changes in materials' conductive properties will cause changes in the induced magnetic field. High-Low frequency-bolt hole inspections, conductivity and coating/paint thickness measurement applications are available at the NDT Shop.

Ultrasonic

Ultrasonic inspection uses high frequency (0.1-20 MHz) sound waves to detect imperfections (such as subsurface cracks, corrosion, delamination, water detection, etc.) or changes in properties of the material. It can also be used to measure thicknesses of a wide range of metallic and non metallic materials in cases where access from one side only is possible.

Radiography

This method uses an X-Ray tube or a Radioactive Isotope as the source of radiation which passes through the material under inspection and is captured on a film. After processing the film an image of varying density is obtained. Possible imperfections are identified through density changes. At the center X-Ray application is carried out by using 40-300kV X-Ray tubes only.

Fluorescent- Penetrant

The fluorescent - penetrant inspection process is a visual inspection aid used for detection of small surface defects that may not be visible under normal white light visual inspection. These defects may be cracks, inclusions, voids or other types of defects which are inherent or which are caused by processing or servicing. Two basic types of penetrants, i.e. post-emulsifiable and water-washable penetrants are avaible in the Engine Shop. Red-penetrant application is also used in the NDT Shop.

Magnetic Particle

The magnetic particle inspection process is a visual inspection aid used for detecting discontinuities open to the surface and those slightly below the surface in materials, which are capable of being magnetized. The method basically consists of subjecting the parts to a magnetic field, which sets up magnetic lines of force in that part. Discontinuities cause the lines of force to be distorted and form new magnetic poles. Ferromagnetic particles are attracted to the new magnetic poles or discontinuities and adhere to the part as long as the magnetic force is maintained.