LITTLE ROCK AIR FORCE BASE, Ark. -- Chemical tanks, conveyer belts and intricate machines line
the walls of the 19th Maintenance Squadron nondestructive inspections shop here.
The lights are turned off as one ultraviolet light shines a
new spectrum of colors to an NDI technician.
Shades of purple, blue and neon-green light up the dark as the
Airman searches for what the naked eye can’t see.
Just as a special investigator uses black lights searching
for clues, NDI Airmen use them to identify potential cracks in a variety of aircraft
parts.
“We specialize in preventative maintenance,” said Staff Sgt. Derik Shannon, 19th MXS NDI craftsman. “We use noninvasive ways to
inspect aircraft for defects.”
NDI Airmen at Little Rock Air Force Base,
Arkansas, use five methods to detect discrepancies: magnetic particle,
fluorescent penetrant, X-ray, ultrasonic and eddy current.
Each method uses a distinct technique to safeguard a
C-130J’s structural integrity.
Two procedures unique to the NDI shop are magnetic particle
and fluorescent penetrant which use fluorescent liquid, and ultraviolet lighting
to illuminate small structural flaws.
X-ray and ultrasonic are two other methods that enable NDI
Airmen to inspect the structural inside of any part without disassembling it
completely, using radiation and sound energy.
Eddy current, the most common method, consists of infusing electricity
into an object creating an opposing magnetic field. Interruptions found within the
field are identified as cracks and marked.
This enables the NDI team to perform inspections in their
shop and on the flight line.
“Last week, we inspected the entire exterior of a C-130J for
hail damage,” Shannon said. “Using an eddy current probe, we combed over it in
what was expected to be a 48-hour inspection that we finished in eight hours.”
The NDI team has five methods at their disposal. Every
technique is a sure-fire way to identify even the smallest crack before it
becomes a major problem.
“We do the small stuff to keep the big aircraft flying,
making sure every little piece is intact,” said Airman 1st Class
James Schwein, 19th MXS NDI journeyman.
The NDI shop inspects approximately 3,000 parts annually. Even
down to an aircraft’s smallest bolt, the shop’s ultimate goal is to keep the aircrew
safe and the C-130J in flight to provide combat capabilities across the globe.