A glowing inspection

U.S. Air Force Airman Matthew Walker and Airman 1st Class Devin Betancourt, 18th Equipment Maintenance Squadron nondestructive inspection technicians, don their personal protective equipment prior to performing wheel penetrant inspections at Kadena Air Base, Japan, June 28, 2021. Penetrant inspections allow technicians to detect surface breaking flaws such as cracks that may be invisible to the human eye. Penetrant is a very thin liquid designed to seep into even the smallest of cracks. (U.S. Air Force photo by Airman 1st Class Yosselin Perla)

U.S. Air Force Airman Matthew Walker, 18th Equipment Maintenance Squadron nondestructive inspection technician, submerges a KC-135 Stratotanker wheel in fluorescent penetrant at Kadena Air Base, Japan, June 28, 2021. The fluorescent penetrant must coat the wheel for 30 minutes before moving on to the next step of the inspection. There are six steps to the penetrant inspection: pre-cleaning the part, applying the penetrant, removing the penetrant, applying developer, evaluating indications and post inspection cleaning. (U.S. Air Force photo by Airman 1st Class Yosselin Perla)

Airman 1st Class Devin Betancourt, 18th Equipment Maintenance Squadron nondestructive inspection technician, coats an MC-130J wheel with fluorescent penetrant at Kadena Air Base, Japan, June 28, 2021. The fluorescent penetrant may be applied to equipment by submerging, spraying or coating the equipment by hand. The method of applying fluorescent penetrants depends on the size of the equipment that needs inspection. (U.S. Air Force photo by Airman 1st Class Yosselin Perla)

Airman 1st Class Devin Betancourt, 18th Equipment Maintenance Squadron nondestructive inspection technician, sprays water on a KC-135 Stratotanker wheel coated with fluorescent penetrant at Kadena Air Base, Japan, June 28, 2021. This is the first rinse the wheels go through after being coated with the fluorescent penetrant. The wheels will be rinsed again after being submerged in a hydrophilic emulsifier. (U.S. Air Force photo by Airman 1st Class Yosselin Perla)

Airman 1st Class Devin Betancourt, 18th Equipment Maintenance Squadron nondestructive inspection technician, pulls a KC-135 Stratotanker wheel out of a tub filled with a hydrophilic emulsifier at Kadena Air Base, Japan, June 28, 2021. After the initial rinsing of the fluorescent penetrant, the wheel was submerged into a bath of hydrophilic emulsifier. The hydrophilic emulsifier is used to remove excess penetrant from the test surface. (U.S. Air Force photo by Airman 1st Class Yosselin Perla)

Airman 1st Class Devin Betancourt, 18th Equipment Maintenance Squadron nondestructive inspection technician, sprays water on a KC-135 Stratotanker wheel at Kadena Air Base, Japan, June 28, 2021. Air Force NDI technicians identify possible defects in systems and equipment before they can become a dangerous problem. They utilize X-ray, eddy current, dye penetrant and ultrasonic scanners to find the smallest imperfections and take the corrective measures needed to keep equipment and aircraft working safely. (U.S. Air Force photo by Airman 1st Class Yosselin Perla)

U.S. Air Force Airman Joshua Bailey, 18th Equipment Maintenance Squadron nondestructive inspection technician, rolls an MC-130J wheel into a dryer at Kadena Air Base, Japan, June 28, 2021. After a piece of equipment has been rinsed off completely, it must go into a dryer before being inspected. The hot air dryer has a temperature of up to 135 degrees Fahrenheit for 20 minutes or until it’s completely dry. (U.S. Air Force photo by Airman 1st Class Yosselin Perla)

U.S. Air Force Airman Matthew Walker, 18th Equipment Maintenance Squadron nondestructive inspection technician, sprays penetrant developer on a KC-135 Stratotanker wheel at Kadena Air Base, Japan, June 28, 2021. After a piece of equipment is completely dried, a penetrant developer is applied to the equipment. The developer pulls the trapped penetrant material out of defects and spreads it out on the surface of the part so it can be seen. (U.S. Air Force photo by Airman 1st Class Yosselin Perla)

Senior Airman Jasmyn Yoder-Jefferson, 18th Equipment Maintenance Squadron nondestructive inspection technician, inspects a KC-135 Stratotanker wheel under fluorescent lighting at Kadena Air Base, Japan, June 28, 2021. Fluorescent penetrants are used under an ultraviolet light that makes the penetrant shine brightly. The penetrant contrasts with the surface of the part so cracks can be more easily identified. (U.S. Air Force photo by Airman 1st Class Yosselin Perla)

U.S. Air Force Airman Matthew Walker, 18th Equipment Maintenance Squadron nondestructive inspection technician, wipes down a fully inspected KC-135 Stratotanker wheel at Kadena Air Base, Japan, June 28, 2021. The wheel will be sent back to the tire and wheel shop and then out to the flightline to be reinstalled. The NDI shop inspects more than 3,500 pieces of equipment and aircraft each year, and also provides support to other U.S. services on Okinawa, Japan. (U.S. Air Force photo by Airman 1st Class Yosselin Perla)