JOINT BASE PEARL HARBOR-HICKAM, Hawaii -- Non-destructive inspections (NDI) flight is responsible for diagnosing aircraft structures and maintenance equipment to ensure they are operationally safe and ready for continuous use.
“We’re here to verify the structural integrity of the aircraft,” said Staff Sgt. Kyle Pajarillo, 15th Maintenance Squadron NDI journeyman
The 15 MXS NDI flight supports and provides inspections for the C-17 Globemaster III, F-22 Raptor and, at times, the Coast Guard’s HC-130J Super Hercules.
When surface and subsurface cracks are suspected in one of these aircraft, the unit is responsible for identifying and describing the location and measurements of the damage.
“A lot of the cracks we look for are fatigue cracks or in-service cracks,” said Staff Sgt. John McCurry, 15th MXS NDI noncommissioned officer in-charge. “[We expect] to catch it before it gets catastrophic on the plane, and then something breaks during flight.”
One of many essential inspections that occur is of the wheel and tire shop’s C-17 wheels.
“Every C-17’s nose, main landing gear, and seat 37 wheel that comes in here — we get hands-on and [we] go out and inspect it.”
Since wheels are used during takeoff and landing, these Airmen probe the wheels to test their structural integrity. The probe allows them to spot any subsurface cracks that may not be visible to the naked eye.
In order to prevent and test for damage, NDI provides 24-hour service by utilizing five different inspections to test metals for damage when needed, including the eddy current, magnetic particle, penetrant, radiographic and ultrasonic methods.
Of the five methods, the eddy current and ultrasound methods can be conducted through portable machines, giving NDI Airmen the ability to test for damage on site. The eddy current method uses a probe to send an electric current into a part being tested and damage is identified when distortion to the current is displayed. The ultrasound is used along with a gel just as a mother undergoes an ultrasound to see an image of their unborn child. If needed, a part can be removed from the aircraft and taken to be tested by other means, including magnetic particle, penetrant, radiographic methods.
The magnetic particle involves magnetizing the part needing to be tested and implementing particles to disturb the magnetic field to depict damage. A penetrant is used to detect unwanted deformities in metal by entering the part’s surface. Lastly, damaged parts can be tested with radiation by x-ray to expose defects within the metal’s interior.
NDI utilizes these testing methods to provide scheduled inspections as a preventative measure and to report damage specifications and measurements for correction. Their purpose is to be able to pinpoint structural issues, giving aircrew the confidence that the aircraft can be safely flown and support the mission to ensure a free and open Indo-Pacific.