NDI: "Cracking" down on mishaps

  • Published
  • By Airman 1st Class Ned T. Johnston
  • 6th Air Mobility Wing Public Affairs
MACDILL AIR FORCE BASE, Fla. --  When it comes to aircraft, the smallest crack on any part could jeopardize a mission, ground the fleet, or lead to something as catastrophic as a crash landing.

Tasked with finding these blemishes are the nondestructive inspection Airmen of the 6th Maintenance Squadron, whose mission it is to make sure none of these tragedies occur.

"We look for defects on the surface and subsurface of parts often invisible," said Staff Sgt. Dustin Harris, 6th MXS NDI technician.

NDI Airmen perform seven different preventative maintenance inspections on aircraft parts and equipment used on aircraft.

The most common inspection that NDI Airmen use is the wet horizontal magnetic particle inspection unit. The MPI unit magnetizes ferromagnetic materials through direct and indirect magnetization.

For direct magnetization, a part is clamped between two electrical contact pads. Once in place, an NDI Airmen applies a wet magnetic particle solution to the part. The "bath" is then interrupted and a magnetizing current is applied.

For indirect magnetization, a coil is used to establish a longitudinal magnetic field within the part. As with the direct magnetization, the NDI Airmen applies the solution to the part, and then interrupts it with a magnetizing current.

This process of "bathing" the part in a magnetic particle solution and then applying a magnetizing current attracts particles from the solution to the defects in the parts to create indicators.

"To an untrained eye, you wouldn't really know what you're looking at," said Harris, "but to us, we see the smallest of cracks in parts and know the threat they cause."

No matter which of the seven types of inspections that the 6th MXS NDI technicians are performing, we can all rest assured that there will be no cracks within their attention to detail.