An NDI for details

  • Published
  • By Senior Airman Wesley Wright
  • 442nd Fighter Wing Public Affairs
WHITEMAN AFB, Mo. --  Some jobs are not all they are cracked up to be, but in the 442nd Maintenance Squadron Nondestructive Inspection shop, cracks are just part of the job.

Tech. Sgt. Kathy Morrison, 442nd NDI technician, is responsible for checking A-10 Thunderbolt II components for cracks and damages. Morrison and the other NDI technicians accomplish this using a variety of tools and methods for the multitude of parts that comprise the warthog.

"For non-ferrous metal parts, such as aluminum, we use a chemical bath," Morrison said.

First, the component is soaked in a chemical penetrant that glows under a blacklight to show any potential defects. If there are any defects, the chemical glows and indicates the flaw.

"For either non-ferrous or ferrous metal parts, we can use the eddy method to detect the cracks," Morrison said.

The eddy method uses alternating magnetic and electric currents to detect faults. Conveniently, the equipment used in this method is portable and can be taken to the flightline, Morrison said.

For ferrous-metal parts that are able to be moved to the NDI lab, the magnetic particle method can be used.

"Basically we magnetize the part and pour oil with fluorescent metal particles in it over the part," Morrison said. "Cracks make a break in the magnetic field of the part and the metal particles will stick to that."

In addition to chemical and magnetic methods, x-ray imaging and ultrasonic testing can determine if parts have cracks. Morrison said the NDI lab has a vault set aside to x-ray parts.

The ultrasonic method uses sound to detect problems in a part, Morrison said. The part is pinged and the timing of the return signal can indicate faults.

"It should take a certain amount of time for the signal to reach the end of the part and bounce back," Morrison said. "If it bounces back sooner, or doesn't bounce back like it should, then something is wrong."

Regardless of the method used, when a fracture is detected, a few things factor in to whether the part must be replaced.

"Cracks have to be a certain size or in a certain place on the component for it to be replaced, but if any damage is found on landing gear, for example, that part is definitely replaced," Morrison said.

In addition to testing parts for damage, the NDI lab is responsible for testing A-10 engine oil daily to see if the engines are running properly.

To test the engine oil, a sample of the oil is put into an oil analysis machine. The oil is burned and the machine analyzes the vapors. The technician interprets the results and determines if the engine is running as intended. Morrison said this is an important part of the job.

While deployed the NDI team takes a portable oil analysis machine to ensure engines downrange are running smoothly so pilots can accomplish the mission - this is just one of the tasks, however, an NDI technician performs in theater.

"We have two people from our lab deployed now," Morrison said. "It gives me a sense of pride, knowing we are helping to keep the pilots safe," she said.