GIS AVIATION NDT is a leading provider of quality Non Destructive Testing and inspection services for America and Europe. GIS Aviation is a Certified 145 Repair Station capable of performing all of your Non-Destructive Inspection needs for aircraft and aircraft components. Our technicians remain on standby 24/7, 365 to serve your in house and mobile needs. ​



Visual Inspection

Liquid Penetrant

Magnetic Particle


Eddy Current


GIS is capable of performing all NDT methods in-house & mobile.


Capabilities List

 (812) 725-9961  
7235 Nova's Landing Drive Sellersburg, IN




Non-destructive testing plays a crucial role vital role in the design, manufacture and maintenance of aircraft.

Garrow Inspection Services use non-destructive testing techniques, equipment and analysis to examine materials and components prior to entering service and also while in service. Non-destructive testing is also capable of detecting flaws and differences in materials that would otherwise be very difficult to detect using destructive methods.

When is NDT used in Aerospace?

Safety is the single most critical aspect of aviation. NDT is used throughout a product’s lifecycle – from the qualification of new materials and the designing of new aircraft to in-service inspections of aircraft structures and engines.

During development, researchers may use NDT to help develop lightweight and more flexible materials and structures for aircraft. Engineers will use NDT tools and processes during aircraft testing and certification to test performance and durability and investigate issues.

Aircraft makers use NDT to ensure the quality of materials and joining process during and after manufacturing. Finally, maintenance engineers and technicians will use NDT to inspect in-service aircraft for damage and cracks at regular intervals to guarantee airworthiness and safety.

How is NDT used in the Aerospace Industry?

The vital aspect of NDT is that the part or the material being tested remains whole and serviceable after the testing.

NDT can generally be split into two areas: surface techniques and sub-surface techniques. Within these two areas is a range of established and trusted tools, such as tap tests conducted with hammers to more recent and advanced technologies, such as 3D computed tomography.

Visual inspections are the oldest and simplest method of non-destructive testing. It’s often said the human eye is the most powerful NDT tool. Visual inspections of aircraft structures and components for damage such as cracks, corrosion and misalignment will often be the first sign of a problem.

Various equipment is used for visual inspections, from magnifying glasses and mirrors to video borescopes for viewing hard to reach places, charge-coupled devices and remote viewing systems.

Performing a visual test with the aid of a borescope (Image: US Navy)

Liquid penetrant testing is another simple and quick method widely used in aviation to detect surface defects and structural damage in non-porous materials.

Test objects are coated with a highly viscous dye. Once the dye has settled into any cracks or flaws, the object is cleaned, leaving just the dye which has penetrated the cracks. Some of this remaining dye will flow back out, revealing an indication of the cracks and flaws.

Liquid penetrant testing is one of the most commonly used NDT techniques

Fluorescent penetrants are often used for sensitive materials and parts. Liquid penetrant testing is a flexible technique and can be carried out in-situ or in a workshop or hangar. It is also often part of cleaning and servicing parts, where the surfaces of objects are inspected after cleaning.

Acoustic emission testing is the application of an abrupt force to the test object, a ‘tap test’ and the analysis of the results. This analysis could be as simple as listening to the sound or using multiple sensors to record the resulting stress waves and small deformations that occur.

Ultrasonic testing is the most common sub-surface technique and uses high-frequency sound waves to locate defects within a component or material. It is commonly used to detect defects in welds, fittings, joints, bolts and adhesive bond quality. The technique is similar to sonar, in that it records and analyzes the reflection of sound waves.

The RollerFORM performs ultrasonic testing on composites (Image: Olympus)

There are several different ultrasonic testing techniques used by aerospace engineers and technicians, including straight beam inspection, immersion testing and phased array inspections. All use an ultrasonic transducer, also called a probe, to send and receive soundwaves and display results as a graph on a screen.

Magnetic particle testing involves inducing a magnetic field in the test object, applying magnetic particles to it either in dry form or suspended in a liquid, which could be colored or fluorescent, and then examining the object using suitable lighting.

The technique is used to detect discontinuities in ferromagnetic materials. Several different pieces of equipment can be used for magnetic particle testing depending on the environment, including yokes, prods, coils and heads.