Nondestructive inspection journeyman: Dyess’ mechanical doctors

U.S. Air Force Staff Sgt. Nicholas Guillory, 489th Maintenance Squadron nondestructive inspection craftsman, inspects a C-130J Super Hercules tailpipe clamp at Dyess Air Force Base, Texas, Oct. 24, 2016. After treating the component with a penetrant solution, any cracks unseen by the naked eye glow under ultraviolet light. (U.S. Air Force photo by Airman 1st Class Rebecca Van Syoc)

U.S. Air Force Staff Sgt. Nicholas Guillory, 489th Maintenance Squadron nondestructive inspection craftsman, inspects a C-130J Super Hercules tailpipe clamp at Dyess Air Force Base, Texas, Oct. 24, 2016. After treating the component with a penetrant solution, any cracks unseen by the naked eye glow under ultraviolet light. (U.S. Air Force photo by Airman 1st Class Rebecca Van Syoc)

U.S. Air Force Senior Airman David Situ, 7th Equipment Maintenance Squadron nondestructive inspection journeyman, uses an eddy current to inspect a metal part at Dyess Air Force Base, Texas, Oct. 24, 2016. An eddy current causes a localized electric current wherever a component is being inspected. Even if there are cracks invisible to the naked eye, the reader can pinpoint them. (U.S. Air Force photo by Airman 1st Class Rebecca Van Syoc)

U.S. Air Force Senior Airman David Situ, 7th Equipment Maintenance Squadron nondestructive inspection journeyman, uses an eddy current to inspect a metal part at Dyess Air Force Base, Texas, Oct. 24, 2016. An eddy current causes a localized electric current wherever a component is being inspected. Even if there are cracks invisible to the naked eye, the reader can pinpoint them. (U.S. Air Force photo by Airman 1st Class Rebecca Van Syoc)

U.S. Air Force Staff Sgt. Nicholas Guillory, 489th Maintenance Squadron nondestructive inspection craftsman, dons his personal protective equipment before starting parts inspection at Dyess Air Force Base, Texas, Oct. 24, 2016. When working with chemicals in some techniques of inspection, Airmen must wear gloves, aprons, goggles and face shields to keep them safe. (U.S. Air Force photo by Airman 1st Class Rebecca Van Syoc)

U.S. Air Force Staff Sgt. Nicholas Guillory, 489th Maintenance Squadron nondestructive inspection craftsman, dons his personal protective equipment before starting parts inspection at Dyess Air Force Base, Texas, Oct. 24, 2016. When working with chemicals in some techniques of inspection, Airmen must wear gloves, aprons, goggles and face shields to keep them safe. (U.S. Air Force photo by Airman 1st Class Rebecca Van Syoc)

DYESS AIR FORCE BASE, Texas -- In the nondestructive inspection shop, an Airman holds a C-130J Super Hercules tailpipe clamp.

 

It’s been sent there because there’s a possibility of damage, but it’s unquestionably too small to detect. The Airman goes through a slow process of dipping the piece in one chemical bath after another, and eventually takes the part into a section of the shop with ultraviolet lights. With the care and precision of a doctor, the Airman looks over the clamp and finds it: a small crack, once unseen to the naked eye, with a bright-green glow under the lights due to the special chemical it was dipped in which filled in the crack and made it visible.


“We help prolong the life of [an aircraft] component by assessing which ones can be repaired instead of being replaced,” said Senior Airman David Situ, 7th Equipment Maintenance Squadron nondestructive inspection journeyman.

Just like the human body, sometimes an aircraft has a part that needs a closer inspection or a checkup. In the same way doctors keep the human body healthy, the Airmen working in nondestructive inspection keep aircraft and their individual parts checked off with a clean bill of health, or refer them to another shop for repair or replacement if required.

Nondestructive inspection is the process of inspecting or evaluating components for discontinuities, such as cracks or internal weak points, without doing any damage to the aircraft part itself.

Keeping both the B-1B Lancer and the C-130J Super Hercules at peak condition is a 24/7 job; though the aircrafts’ checkups are on a schedule, the Airmen are prepared for any urgent task that may arise.

“We do a lot of scheduled maintenance, and it’s done according to the number of hours the aircraft has flown,” said Airman 1st Class Austin Hall, 7th Equipment Maintenance Squadron nondestructive inspection apprentice. “However, we’ll also take components whenever a maintainer notices something may be damaged. Then we inspect it to see if a repair or replacement is required before it causes an issue to the aircraft or its crew.”

In order to inspect micro fractures sometimes smaller than what the naked eye can detect, a variety of tools and techniques are used to find them.

Dye penetrant, one of the most common techniques used in the shop, involves dipping the part in a penetrant solution and letting it sink into whatever cracks may appear. After washing the excess off in a series of baths and letting it dry, the cracks are then bright and visible when the component is exposed to ultraviolet light.

There are two other methods the Airmen use to ensure any damage is found and recorded: magnetic particle and eddy current. Magnetic particle takes advantage of ferromagnetic materials to find cracks and damages using a localized magnetic field, and eddy current imparts a localized electric current to detect damage.

“The most common inspection methods we use are dye penetrant, magnetic particle, and eddy current,” Hall said. “Ultrasonic testing and x-rays are the two methods we perform less frequently, but are still options to use if needed.”

Because they take preventative measures and inspect for the smallest damages to components, the nondestructive inspection Airmen are integral to keep the B-1s and C-130s mission capable.

”We ensure the aircraft are safe for flight at all times,” Situ said. “Aircraft undergo a lot of stress during their flights. Any crack that develops on the aircraft’s structure will hurt its structural integrity and endanger the crew. We make certain those damages, however small, never turn into an injury or loss of life.”

The B-1 and C-130 have hardworking Airmen keeping them ready for the mission, down to the smallest crack or dent that may otherwise go completely unnoticed if inspected by the naked eye alone.

Dyess aircraft are complex machines and require as much care and attention as the crew onboard. And just as the crews have doctors to see and keep them healthy, the Airmen of the nondestructive inspection shop are ready to keep the B-1B and C-130 flying strong for the mission.