Production. Aircraft. Here's one good reason why refrigerator freezing trays and other aluminum gadgets are out for the duration. On trays in the background are hundreds of aluminum castings going into Lockheed bombers and fighters. Every prime casting is "explored" in a huge X-ray camera like the one seen here. On X-ray film, flaws that might cause failure of these vital parts show up plainly to the expert eye, and the part is discarded