The Helicopter with Radioactive Blades

Sometimes you find gold in unexpected places. In this case, it’s from a video about the CH-53 helicopter . The CH-53 Sea Stallion first entered service in 1966. It’s a huge helicopter, capable of lifting immense amounts of weight. All that weight hangs from 6 (or 7 on some models) rotor blades. The problem was detecting problems with the blades before they grew into a catastrophic failure.

Much like a fixed-wing aircraft wing, the CH-53 rotor blades are designed with a spar as the main structural member. On early designs, the spar was extruded aluminum. The CH-53D and other variants moved to cold-formed titanium.