Nondestructive Inspection: highlighting the cracks

  • Published
  • By Tech. Sgt. Aaron Oelrich
  • 15th Wing Public Affairs
3/6/2015 - JOINT BASE PEARL HARBOR-HICKAM, Hawaii --  The 15th Maintenance Squadron's Nondestructive Inspection Lab plays a critical role in aircraft safety.

NDI specialists conduct inspections of aircraft parts much like a doctor would inspect someone with a broken bone. They use x-ray and ultrasound equipment to identify and diagnose defects and cracks without damaging the aircraft components.

"When you think NDI think aircraft doctor," said Tech. Sgt. Samuel Djonorh, non-commissioned officer in charge of the NDI Lab for the 15th MXS. "If you go to the doctor he uses equipment to diagnose what is wrong. NDI is similar, a part comes into the lab and we don't know what is wrong, we use our equipment to determent if there is a crack or damage to the part and if it needs to be replaced or repaired."

In addition to the x-ray and ultrasound, NDI technicians use magnetic particles, dye penetrant and eddy current to test aircraft parts for damage and structural integrity.

According to Airmen 1st Class Jose Herrera-Valtierra, nondestructive inspection specialist for the 15th MXS, the magnetic particles inspection uses magnetic fields and a magnetic particle compound to detect flaws in components. The magnet particle compound contains a neon green dye that glows under a black light, and iron particles that attach to the components when magnified.

Senior Airman Emily Morrissey, nondestructive inspection specialist from the 15th MXS, explained dye penetrant inspection is used to identify surface defects in metals and plastics. Dye penetrant uses a fluorescent dye that sinks into any defect and highlighting the defect on the component.

Djonorh said, eddy current is used to examine large areas very quickly, unlike magnetic particle inspection or dye penetrant, eddy current doesn't require the use of any liquids. In addition to finding cracks, eddy current can be used to check metal hardness in components and parts.

However, not all of the NDI technician's work happens in the lab.

"I enjoy when we are up on the wing of the aircraft inspecting a spar or a panel and you look up to see the entire airfield," said Morrissey.

Additionally, the NDI technicians work with aircraft crew chief, structural engineer and aircraft metals technology to ensure aircraft parts are structurally sound.

"I like when we make a big call on a critical part being cracked and we keep a part that could fail off the aircraft, that is when I really like my job," said Herraera-Valtierra.