Ultrasound on an aircraft: Maintainers keep KC-10s ready to fly by checking for cracks in control box

Published Nov. 1, 2013
By Staff Sgt. Patrick Harrower
60th Air Mobility Wing Public Affairs

TRAVIS AIR FORCE BASE, Calif. -- When most people hear the term ultrasound, they may think of the process of taking a peek at the early stages of life to get an idea of its current state of health and development.

For the Airmen of the 60th Maintenance Squadron nondestructive inspections shop, an ultrasound inspection can be surprisingly similar to that.

Inside the tail section of a KC-10 Extender is a control box. The box can be moved up and down, which in turn, causes the elevators on the tail to move in correlation. Not only is the box is difficult to get to, but the area is cramped, dark and gets warm, but, much like any other aircraft component, it still must be inspected regularly.

"Every KC-10 gets this inspection every 90 days," said Staff Sgt. Rebecca Linden de Romero, 60th MXS NDI technician. "We use ultrasound technology to see what is going on inside the panels of the box. The sound reflects through the surface and back to the machine where we can track any cracks or other potential problems the naked eye cannot see."

The measurements must be precise, as the condition of the plane can be based on them. If the NDI technicians find a problem that deems the aircraft bad, it must go to another base for higher-level repair, she said.

To maintain total accuracy, the technicians use standard blocks that are made with the same material and physical dimensions as the parts on the aircraft. These blocks are used to calibrate the ultrasound equipment before the inspection to give the technicians a frame of reference for exactly what they should see, Linden de Romero said.

Accuracy aside, there also is a physical component that presents a unique challenge to the technicians when they perform an ultrasound.

"We can inspect 98 percent of the area just fine," said Tech Sgt. Zach Williams, 349th MXS NDI technician. "But for 100 percent coverage, someone needs to go inside of the box. Our whole shop could be fully qualified to do the inspection, but if nobody can physically get in there, we can't call the job complete."

The 60th MXS NDI shop spends a lot of time ensuring technicians know how to perform an ultrasound inspection, he said.

"We have gotten so proficient at this inspection that we have a lot of engineers come to us to have a set of Travis eyes check their work before they go somewhere else," Williams said. "It's a real confidence booster."